CN107005838B

CN107005838B - Method and device for data transmission

Info

Publication number: CN107005838B
Application number: CN201580030158.6A
Authority: CN
Inventors: 黄正磊; 张万强
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2015-07-08
Filing date: 2015-07-08
Publication date: 2020-06-02
Anticipated expiration: 2035-07-08
Also published as: WO2017004805A1; CN107005838A

Abstract

The embodiment of the invention provides a method and equipment for data transmission, wherein the method comprises the steps that a mobility management entity sends a first indication message to a service gateway when downlink data of user equipment sent by a data sending end is unreachable, and the first indication message is used for indicating the service gateway to cache the downlink data; the mobile management entity determines that a second indication message needs to be sent to the data sending end; the mobility management entity sends the second indication message to the data sending end so that the data sending end can send the downlink data of the user equipment according to the second indication message.

Description

Method and device for data transmission

Technical Field

The present invention relates to the field of communications, and more particularly, to a method and apparatus for data transmission.

Background

To support The Evolution of The wireless side (e.g., LTE), The 3rd generation partnership Project (3 GPP) started to study The System Architecture Evolution (SAE) of The network side in 2004 at 12 months. LTE and SAE together constitute an Evolved Packet System (EPS). The EPS network architecture adopts an end-to-end full Internet Protocol (IP) networking and a flat network structure, and fully considers the compatibility with the existing 2G/3G network.

In the EPS network architecture, the main network functional entities are:

1) evolved Universal Terrestrial Radio access network ("EUTRAN") for short: the network consists of a plurality of eNodeBs and is used for realizing the functions of a wireless physical layer, a resource scheduling function, a wireless resource management function, a wireless access control function and a mobility management function. The eNodeB is connected with a Serving Gateway (S-GW) through a user plane interface S1-U and is used for transmitting user data; the eNodeB is connected with the MME through a control plane interface S1-MME, and functions such as wireless access bearer control and the like are realized by adopting an S1-AP protocol.

2) Mobility Management Entity (Mobility Management Entity, abbreviated as "MME"): all control plane functions mainly responsible for user session management include Non Access Stratum (NAS) signaling and security, management of tracking area, selection of PDN Gateway (P-GW), S-GW, and the like.

3) S-GW: the mobility anchor point is mainly responsible for data transmission, forwarding, route switching and the like of User Equipment (User, Equipment, abbreviated as "UE"), and serves as a local mobility anchor point when the UE switches between enodebs, and only one S-GW serves each UE at one time.

4) P-GW: as an anchor point of Packet Data Network (PDN) connection, it is responsible for allocation of an Internet Protocol (IP) address of the UE, filtering of Data packets of the UE, rate control, generation of charging information, and the like.

In the EPS network architecture, an EPS Connection Management (abbreviated as "ECM") status of a UE includes: ECM-IDLE (i.e., IDLE state) and ECM-CONNECTED (i.e., CONNECTED state), which reflects the signaling connection characteristics of the UE.

In an IDLE state (ECM-IDLE), no NAS signaling connection exists between the UE and the network, for example, Radio Resource Control (RRC) connection and S1-MME connection are not included; in the CONNECTED state (ECM-CONNECTED), there is an NAS signaling connection between the UE and the network, including an RRC connection and an S1-MME connection.

If there is no data transmission for a long time, i.e. there is no NAS signaling connection between the UE and the network, the UE enters an idle state. In the idle state, the UE mainly monitors the paging channel and the broadcast channel, and if the UE wants to monitor the user data channel, the UE must transition from the idle state to the connected state. For example, assuming that the UE is in an idle state, when the EPS network side receives a downlink data packet or signaling of the UE, the EPS network may initiate a network side triggered service request procedure, in which the MME initiates paging (paging) in a tracking area where the current UE is located, and the UE may switch to a connected state in response to the paging of the MME, and may monitor a user data channel, thereby receiving data or signaling. The network side triggers the business request process as follows:

step 1: after receiving a downlink data message of the UE, the S-GW sends a downlink data notification message to the MME;

step 2: after receiving the downlink data notification message, the MME searches for a corresponding UE context and returns a confirmation message to the S-GW;

and step 3: MME initiates paging to all eNodeBs in a tracking area where the UE is located, and UE identification (IMSI or P-TMSI, etc.) of the UE, paging priority, etc. are carried in paging messages sent to the eNodeBs;

and 4, step 4: the eNodeB pages the UE according to the received paging message;

and 5: the UE responds to the paging, initiates a service request process, establishes a user plane, and starts to prepare for receiving downlink data.

To reduce power consumption of the user equipment, the user equipment may enable a Power Saving Mode (PSM). The ue requests an Active Time (Active Time) from the network side, and starts a timer (the Time value of the timer is the Active Time) each Time the ue transitions from the connected state to the idle state. When the timer is overtime, the UE enters the power saving mode from an idle state. In the power saving mode, the ue does not monitor the paging message of the network, i.e. the ue does not respond to the paging of the network.

Discontinuous Reception (DRX) is an operation mode that saves power consumption of the UE. If the UE adopts DRX, the UE only turns on the receiver in a specific time period to enter an active period so as to receive downlink data and signaling, and turns off the receiver in other time periods to enter a dormant period so as to stop receiving the downlink data and the signaling.

DRX includes both IDLE state DRX (abbreviated as "I-DRX") which, as the name implies, refers to Discontinuous Reception (DRX) when the UE is in an IDLE (IDLE) state, and connected state DRX (abbreviated as "C-DRX") which is Discontinuous Reception (DRX) when the UE is in a connected state.

The DRX cycle is referred to as a DRX cycle, and one DRX cycle is divided into an active period and a sleep period. The DRX cycle is further divided into a long cycle and a short cycle, wherein the sleep period of the long cycle is longer, and the sleep period of the short cycle is shorter, and the duration of the active period of the long cycle is the same as that of the short cycle. Further, the long period is an integral multiple of the short period.

When User Equipment (UE) in an idle state has downlink data to arrive, a network initiates paging to the UE. However, temporary interruption of radio signals or power saving functions such as PSM, long-cycle DRX, etc. are enabled by the UE, the UE cannot respond to paging of the network. The service application continuously retransmits the data, thereby increasing the load and paging overhead of the core network element.

To avoid this problem, the MME may instruct the S-GW to cache the downlink data of the delay tolerant service, and send the cached data to the UE when the UE is reachable. The MME may provide the S-GW with a cache time T and/or a cache data packet number N, where the cache time T is related to a power saving mechanism employed by the UE and a delay requirement of the application, and N may be determined based on subscription data (user priority, packet loss rate, etc.), and the like. The S-GW determines the number of packets M that can be cached based on N provided by the MME and its own configuration. And the S-GW caches the UE downlink data according to the MME instruction, and can discard the cached data packet when the timer T is overtime or the number of the received data packets exceeds M.

When the timer T times out or the number of received packets exceeds M, the S-GW will discard the buffered packets. At this time, the data sending end, such AS an Application Server (AS) or a Service Capability Server (SCS), does not know whether the UE is reachable, and continues to retransmit or send a new downlink data packet. Since the S-GW does not buffer the received downlink data packet, it is unnecessary to transmit or retransmit the downlink data of the data transmitting end at this time, thereby increasing the load of the core network node and causing a waste of network resources.

Disclosure of Invention

Embodiments of the present invention provide a method and an apparatus for data transmission, where the method can flexibly transmit downlink data, avoid unnecessary data transmission, and improve network efficiency.

In a first aspect, a method for data transmission is provided, including: when downlink data of user equipment sent by a data sending end is not reachable, a mobility management entity sends a first indication message to a service gateway, wherein the first indication message is used for indicating the service gateway to cache the downlink data;

the mobility management entity determines that a second indication message needs to be sent to the data sending end;

the mobility management entity sends the second indication message to the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message.

With reference to the first aspect, in a first possible implementation manner, the first indication message carries indication information indicating that the serving gateway buffers the downlink data, where the indication information includes a duration and/or a number of data packets,

the second indication message carries the indication information.

With reference to the first aspect or the first possible implementation manner, in a second possible implementation manner, before the sending, by the mobility management entity, the first indication message to the serving gateway when downlink data of the user equipment sent by the data sending end is not reachable, the method further includes:

the mobility management entity obtains a first request message sent by the data sending end, the first request message is used for requesting a network to feed back the second indication message when downlink data of the user equipment is not reachable, the first request message carries address information of the data sending end and an identifier of the user equipment,

wherein, the determining, by the mobility management entity, that the second indication message needs to be sent to the data sending end includes:

if the mobility management entity determines that the identifier of the user equipment is the same as the identifier of the user equipment carried in the first request message, the mobility management entity determines that the second indication message needs to be sent to the data sending end.

With reference to the first aspect, and any one possible implementation manner of the first to the second possible implementation manners, in a third possible implementation manner, before the sending, by the mobility management entity, the second indication information to the data sending end, the method further includes:

the mobility management entity generates the second indication message.

With reference to the first aspect and any one of the first to the second possible implementation manners, in a fourth possible implementation manner, the first indication message is further used to instruct the service gateway to generate the second indication message,

before the mobility management entity sends the second indication information to the data sending end, the method further includes:

the mobility management entity receives the second indication message sent by the serving gateway.

With reference to the first aspect or the first possible implementation manner, in a fifth possible implementation manner, the determining, by the mobility management entity, that the second indication message needs to be sent to the data sending end includes:

if the mobility management entity determines that the identifier identical to the identifier of the user equipment exists in a preset feedback identifier list, the mobility management entity determines that the second indication message needs to be sent to the data sending end, wherein the preset feedback identifier list comprises the identifier of the user equipment which needs to feed back the second indication message.

With reference to the fifth possible implementation manner, in a sixth possible implementation manner, the first indication message is further used to indicate that the serving gateway sends address information of the data sending end to the mobility management entity, and before the mobility management entity sends the second indication information to the data sending end, the method further includes:

the mobility management entity receives the address information of the data sending end sent by the service gateway;

the mobility management entity generates the second indication message, where the second indication message carries address information of the data sending end.

With reference to the fifth possible implementation manner, in a seventh possible implementation manner, the first indication message is further used to instruct the service gateway to generate the second indication message,

before the mobility management entity sends the second indication message to the data sender, the method further includes:

With reference to the first aspect, any possible implementation manner of the first to the seventh possible implementation manners, in an eighth possible implementation manner, the method further includes:

and the mobility management entity receives an acknowledgement message sent by the data sending end, wherein the acknowledgement message is used for indicating that the data sending end has received the second indication message.

In a second aspect, a method for data transmission is provided, including: a data sending end acquires a second indication message, wherein the second indication message is generated after a service gateway receives a first indication message, and the first indication message is used for indicating the service gateway to cache downlink data of user equipment with unreachable downlink data;

and the data sending end sends the downlink data of the user equipment according to the second indication message.

With reference to the second aspect, in a first possible implementation manner, the first indication message carries indication information indicating that the serving gateway buffers the downlink data, where the indication information includes a duration and/or a number of data packets,

the second indication message carries the indication information,

wherein,

when the indication information includes the duration, the data sending end sends downlink data of the user equipment according to the second indication message, including:

the data transmitting end determines to transmit the downlink data of the user equipment within the duration according to the second indication message,

when the indication information includes the number of the data packets, the data sending end sends downlink data of the user equipment according to the second indication message, including:

the data sending end sends the downlink data of the user equipment according to the second indication message, and the number of the data packets of the downlink data of the user equipment sent by the data sending end is less than or equal to the number of the data packets,

when the indication information includes the duration and the number of the data packets, the data sending end sends downlink data of the user equipment according to the second indication message, including:

and the data sending end determines to send the downlink data of the user equipment within the duration according to the second indication message, and the number of data packets of the downlink data of the user equipment sent by the data sending end within the duration is less than or equal to the number of the data packets.

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner, when the indication information includes the duration, or the indication information includes the duration and the number of data packets, the method further includes:

and the data sending end determines not to send the downlink data of the user equipment at the time except the duration according to the second indication message.

With reference to the second aspect and any one possible implementation manner of the first to second possible implementation manners of the second aspect, in a third possible implementation manner, before the data sending end acquires the second indication message, the method further includes:

the data sending end sends a first request message, where the first request message is used to request a network to feed back the second indication message when downlink data of the user equipment is not reachable, and the first request message carries address information of the data sending end and an identifier of the user equipment.

With reference to the second aspect and any one possible implementation manner of the first to third possible implementation manners of the second aspect, in a fourth possible implementation manner, the method further includes:

and the data sending end sends a confirmation message to the mobility management entity, wherein the confirmation message is used for indicating that the data sending end has received the second indication message.

In a third aspect, a method for data transmission is provided, including: the method comprises the steps that a service gateway receives a first indication message sent by a mobility management entity, wherein the first indication message is used for indicating that the service gateway caches downlink data of user equipment with unreachable downlink data sent by a data sending end, and generates a second indication message;

the service gateway acquires the address information of the data sending end;

the service gateway generates and sends a second indication message according to the indication of the first indication message and the address information of the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message.

With reference to the third aspect, in a first possible implementation manner, the first indication message carries indication information indicating that the serving gateway buffers the downlink data, where the indication information includes a duration and/or a number of data packets,

the second indication message carries the indication information.

With reference to the third aspect or the first possible implementation manner of the third aspect, in a second possible implementation manner, the first indication message carries address information of the data sending end,

wherein, the service gateway obtains the address information of the data sending end, including:

and the service gateway acquires the address information of the data sending end according to the first indication message.

With reference to the third aspect or the first possible implementation manner of the third aspect, in a third possible implementation manner, the first indication message is further used to instruct the service gateway to obtain address information of the data sending end,

the service gateway detects the downlink data according to the indication of the first indication message, and acquires the address information of the data sending end.

In a fourth aspect, a method for data transmission is provided, including: a service gateway receives a first indication message sent by a mobility management entity, wherein the first indication message is used for indicating that the service gateway caches downlink data of user equipment with unreachable downlink data sent by a data sending end and acquiring address information of the data sending end;

the service gateway detects the downlink data according to the indication of the first indication message, and acquires the address information of the data sending end;

the service gateway sends the address information of the data sending end to the mobility management entity, so that the mobility management entity generates and sends a second indication message to the data sending end according to the address information of the data sending end, and the data sending end sends downlink data of the user equipment according to the second indication message.

With reference to the fourth aspect, in a first possible implementation manner, the first indication message carries indication information indicating that the serving gateway buffers the downlink data, where the indication information includes a duration and/or a number of data packets,

the second indication message carries the indication information.

In a fifth aspect, a mobility management entity is provided, including:

a first determining unit, configured to send a first indication message to a serving gateway when downlink data of a user equipment sent by a data sending end is not reachable, where the first indication message is used to indicate the serving gateway to cache the downlink data;

a second determining unit, configured to determine that a second indication message needs to be sent to the data sending end;

a sending unit, configured to send the second indication message to the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message.

With reference to the fifth aspect, in a first possible implementation manner, the first indication message carries indication information indicating that the serving gateway buffers the downlink data, where the indication information includes a duration and/or a number of data packets,

the second indication message carries the indication information.

With reference to the fifth aspect or the first possible implementation manner of the fifth aspect, in a second possible implementation manner, the method further includes:

an obtaining unit, configured to obtain a first request message sent by a data sending end before sending a first indication message to a serving gateway when downlink data of a user equipment sent by the data sending end is unreachable by a first determining unit, where the first request message is used to request a network to feed back a second indication message when the user equipment is unreachable, and the first request message carries address information of the data sending end and an identifier of the user equipment,

if the second determining unit determines that the identifier of the user equipment is the same as the identifier of the user equipment carried in the first request message, it determines that the second indication message needs to be sent to the data sending end.

With reference to the fifth aspect and any possible implementation manner of the first to second possible implementation manners of the fifth aspect, in a third possible implementation manner, the method further includes:

a first generating unit, configured to generate the second indication message before the sending unit sends the second indication message to the data sending end.

With reference to the fifth aspect and any possible implementation manner of the first to second possible implementation manners of the fifth aspect, in a fourth possible implementation manner, the first indication message is further used to instruct the serving gateway to generate the second indication message, and the mobility management entity further includes:

a receiving unit, configured to receive the second indication message sent by the service gateway before the sending unit sends the second indication message sent by the downlink data to the data sending end.

With reference to the fifth aspect or the first possible implementation manner of the fifth aspect, in a fifth possible implementation manner, if it is determined that the identifier that is the same as the identifier of the user equipment exists in a preset feedback identifier list, the first determining unit determines that the second indication message needs to be sent to the data sending end, where the preset feedback identifier list includes an identifier of the user equipment that needs to feed back the second indication message.

With reference to the fifth possible implementation manner of the fifth aspect, in a sixth possible implementation manner, the first indication message is further used to indicate that the serving gateway sends address information of the data sending end to the mobility management entity, and the mobility management entity further includes:

a first receiving unit, configured to receive, before the sending unit sends the downlink data sending indication information to the data sending end, address information of the data sending end sent by the service gateway;

a second generating unit, configured to generate the second indication message before the sending unit sends the downlink data sending indication information to the data sending end, where the second indication message carries address information of the data sending end.

With reference to the fifth possible implementation manner of the fifth aspect, in a seventh possible implementation manner, the first indication message is further used to instruct the serving gateway to generate the second indication message, and the mobility management entity further includes:

a second receiving unit, configured to receive the second indication message sent by the service gateway before the sending unit sends the second indication message to the data sending end.

With reference to the fifth aspect and any possible implementation manner of the first to seventh possible implementation manners of the fifth aspect, in an eighth possible implementation manner, the method further includes:

a third receiving unit, configured to receive an acknowledgement message sent by the data sending end, where the acknowledgement message is used to indicate that the data sending end has received the second indication message.

In a sixth aspect, a data transmitting end is provided, including:

an obtaining unit, configured to obtain a second indication message, where the second indication message is generated after a service gateway receives a first indication message, and the first indication message is used to indicate that the service gateway buffers downlink data of a user equipment whose downlink data is unreachable;

and a first sending unit, configured to send downlink data of the user equipment according to the second indication message.

With reference to the sixth aspect, in a first possible implementation manner, the second indication message carries indication information that the serving gateway buffers the downlink data, where the indication information includes a duration and/or a number of data packets,

wherein,

when the indication information includes the duration, the first sending unit determines to send the downlink data of the user equipment within the duration according to the second indication message,

when the indication information includes the number of data packets, the first sending unit sends the downlink data of the user equipment according to the second indication message, and the number of data packets of the downlink data of the user equipment sent by the data sending end is less than or equal to the number of data packets,

when the indication information includes the duration and the number of data packets, the first sending unit determines to send the downlink data of the ue within the duration according to the second indication message, and the number of data packets of the downlink data of the ue sent by the data sending end within the duration is less than or equal to the number of data packets.

With reference to the first possible implementation manner of the sixth aspect, in a second possible implementation manner, when the indication information includes the duration, or the indication information includes the duration and the number of data packets, the data sending end further includes:

a determining unit, configured to determine not to send downlink data of the user equipment at a time other than the duration according to the second indication message.

With reference to the sixth aspect and any one possible implementation manner of the first to the second possible implementation manners of the sixth aspect, in a third possible implementation manner, the method further includes:

a second sending unit, configured to send a first request message before the obtaining unit obtains a second indication message, where the first request message is used to request a network to feed back the second indication message when downlink data of the user equipment is not reachable, and the first request message carries address information of the data sending end and an identifier of the user equipment.

With reference to the sixth aspect and any one possible implementation manner of the first to third possible implementation manners of the sixth aspect, in a fourth possible implementation manner, the method further includes:

a third sending unit, configured to send a downlink data sending confirmation message to the mobility management entity, where the confirmation message is used to indicate that the data sending end has received the second indication message.

In a seventh aspect, a service gateway is provided, including:

a receiving unit, configured to receive a first indication message sent by a mobility management entity, where the first indication message is used to indicate that a serving gateway buffers downlink data of a user equipment whose downlink data sent by a data sending end is unreachable, and generate a second indication message;

an obtaining unit, configured to obtain address information of the data sending end;

a sending unit, configured to generate and send a second indication message according to the indication of the first indication message and the address information of the data sending end, so that the data sending end sends downlink data of the user equipment according to the second indication message.

With reference to the seventh aspect, in a first possible implementation manner, the first indication message carries indication information indicating that the serving gateway buffers the downlink data, where the indication information includes a duration and/or a number of data packets,

the second indication message carries the indication information.

With reference to the seventh aspect or the first possible implementation manner of the seventh aspect, in a second possible implementation manner, the first indication message carries address information of the data sending end,

the obtaining unit obtains the address information of the data sending end according to the first indication message.

With reference to the seventh aspect or the first possible implementation manner of the seventh aspect, in a third possible implementation manner, the first indication message is further used to indicate the service gateway to obtain address information of the data sending end,

the obtaining unit detects the downlink data according to the indication of the first indication message, and obtains the address information of the data sending end.

In an eighth aspect, a service gateway is provided, which includes:

a receiving unit, configured to receive a first indication message sent by a mobility management entity, where the first indication message is used to indicate that a serving gateway buffers downlink data of a user equipment whose downlink data sent by a data sending end is unreachable, and obtains address information of the data sending end;

an obtaining unit, configured to perform detection on the downlink data according to the indication of the first indication message, and obtain address information of the data sending end;

a sending unit, configured to send the address information of the data sending end to the mobility management entity, so that the mobility management entity generates and sends the second indication message to the data sending end according to the address information of the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message.

With reference to the eighth aspect, in a first possible implementation manner, the first indication message carries indication information indicating that the serving gateway buffers the downlink data, where the indication information includes a duration and/or a number of data packets,

the second indication message carries the indication information.

Based on the technical scheme, the embodiment of the invention can send the first indication message to the service gateway by the mobile management entity when the downlink data of the user equipment sent by the data sending end is unreachable, and indicate the service gateway to cache the downlink data; and the mobility management entity sends the second indication message to the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message, for example, the downlink data of the user equipment is sent within a certain duration, and the downlink data of the user equipment is not sent in a time except for the duration. Therefore, the downlink data can be flexibly transmitted, unnecessary data transmission is avoided, and the network efficiency is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic diagram of a communication network scenario applicable to an embodiment of the present invention.

Fig. 2 is a schematic flow diagram of a communication method according to one embodiment of the invention.

Fig. 3 is a schematic flow chart of a method of data transmission according to one embodiment of the present invention.

Fig. 4 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention.

Fig. 5 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention.

Fig. 6 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention.

Fig. 7 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention.

Fig. 8 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention.

Fig. 9 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention.

Fig. 10 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention.

Fig. 11 is a schematic block diagram of a mobility management entity according to one embodiment of the present invention.

Fig. 12 is a schematic block diagram of a data transmitting end according to an embodiment of the present invention.

Figure 13 is a schematic block diagram of a service gateway according to one embodiment of the present invention.

Figure 14 is a schematic block diagram of a serving gateway according to another embodiment of the present invention.

Fig. 15 is a schematic block diagram of a mobility management entity according to another embodiment of the present invention.

Fig. 16 is a schematic block diagram of a data transmitting end according to another embodiment of the present invention.

Figure 17 is a schematic block diagram of a serving gateway according to another embodiment of the present invention.

Figure 18 is a schematic block diagram of a serving gateway according to another embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

It should be understood that the technical solution of the present invention may be applied to an Evolved Packet System (EPS), and may also be applied to other various communication systems, for example: a Global System for Mobile communications (GSM) System, a Code Division Multiple Access (CDMA) System, a Wideband Code Division Multiple Access (WCDMA) System, a General Packet Radio Service (GPRS), a Long Term Evolution (LTE), a Frequency Division Duplex (FDD) System, a Time Division Duplex (TDD), a Universal Mobile Telecommunications System (UMTS), etc.

It should also be understood that, in the embodiment of the present invention, a User Equipment (User Equipment, abbreviated as "UE") may also be referred to as a Terminal, a Mobile Terminal (Mobile Terminal), a Mobile Station (Mobile Station, abbreviated as "MS"), and the like. The UE may communicate with one or more core networks via a Radio Access Network (RAN). In particular, the user equipment UE may be, for example, a mobile telephone (or so-called "cellular" telephone), a computer with a mobile terminal, but also a portable, pocket, hand-held, computer-included or vehicle-mounted mobile device, which exchanges language and/or data with the radio access network RAN. In addition, the user equipment UE may also be an MTC device such as a sensor. Or, in this embodiment of the present invention, the mobile device UE may also be a mobile relay device, such as a mobile Access Point (Access Point, abbreviated as "AP"), which is not limited in this embodiment of the present invention.

It should also be understood that, in the embodiment of the present invention, the RAN Node may specifically be a Base Station, which may be an evolved Node B (eNB or e-NodeB) in LTE, a Base Station in GSM (Base Transceiver Station, BTS) or a Base Station in WCDMA (NodeB, NB), and the following embodiments are not limited in the embodiments of the present invention, but for convenience of description, the eNB is taken as an example for the following embodiments.

Fig. 1 is a schematic diagram of a communication network scenario applicable to an embodiment of the present invention. The logical architecture of the mobile communication network as shown in fig. 1 comprises: terminal 110, access network 120, mobility management network element 130, serving gateway 140, data gateway 150, and messaging data network 160. The terminal 110 is connected to the access network 120 through a local wireless network or a limited network, the mobility management network element 130 is responsible for functions of location management, connection management, security authentication, gateway selection, and the like of the terminal 110, the service gateway 140 is a local access gateway of the terminal 110 and is responsible for connection management and data forwarding related to an access technology, and the data gateway 150 is a gateway for the user equipment to access the external message data network 160.

The above-mentioned logic architecture diagram corresponds to an actual Network, and may be an Evolved Packet System (EPS) Network, the Access Network may be UTRAN (Universal Terrestrial Radio Access Network), GERAN (GSM EDGE Radio Access Network, GSM/EDGE Radio Access Network) or E-UTRAN (Evolved Universal Terrestrial Radio Access Network), the mobile Management Network element may be a mobile Management Entity (Mobility Management Entity, MME) or a GPRS service Support Node (SGSN), the service Gateway may be a Serving Gateway (S-GW), and the Data Gateway may be a Packet Data Network Gateway (Data Gateway, PDN-GW).

The following describes, by way of example, network element devices to which embodiments of the present invention mainly relate:

mobility management entity MME: and supporting functions related to the processing of the downlink data sending indication, including requesting, generating and feeding back a downlink data sending indication message and a related local configuration strategy.

Serving gateway S-GW: functions related to the processing of the downlink data sending indication can be supported, including generation and feedback of a downlink data sending indication message, providing information related to the downlink data packet (such as a source/destination IP address and the like) to the MME, and a related local configuration policy.

In order To enhance the network capability of supporting new services such as Machine-To-Machine (M2M), 3GPP is developing an Architecture Enhancement for Service Exposure (AESE) research project. A new network entity is defined in the AESE: the Service Capability Exposure Function (SCEF) may provide multiple Service capabilities through one or more standard Application Programming Interfaces (APIs). The network may interact with external service applications to obtain information such as communication modes of the User Equipment (UE), such as data volume size, location, and mobility patterns. The external service application may also obtain information such as connection attributes, reachability, and network status of the UE from the network through the API.

The following describes how the AESE provides various service capabilities through the SCEF with reference to fig. 2, which is a process of informing a third party Application Server (AS) of the UE connection attributes by the network. Specifically, the flow shown in fig. 2 includes:

201, P-GW finds that UE establishes a new PDN connection;

202, P-GW reports PDN connection establishment message to SCEF, the message includes UE identification, APN and UE IP address;

203, the SCEF saves the received information and returns a confirmation message to the P-GW;

204, the AS sends a message request to the SCEF to inform the UE of the connection attribute, wherein the message comprises the UE identification and IP packet filter information related to the specific service;

205, the SCEF authorizes the UE connection attribute request message of the AS;

the SCEF checks if PDN connection establishment indication information for the UE is received from the P-GW 206, and the IP address of the UE matches the IP filter information received from the AS. If the indication is received, continuing to perform the subsequent information flow;

207, the SCEF sends a UE connection attribute request message to the P-GW, where the message includes a UE identity and UE IP address information;

and 208, the P-GW returns PDN connection information related to the IP address of the UE to the SCEF, such as parameters of an IP-CAN type, a RAT type, APN-AMBR and the like. The SCEF generates a corresponding UE connection attribute according to the received PDN connection information;

the SCEF informs 209 the third party AS about the UE connection attribute information.

It should be understood that the mobility management entity in the embodiment of the present invention may be an MME or may also be an SGSN; the service gateway can be S-GW or SGSN; the user equipment can be MS or UE; the data sending end may be an AS of a third party, or may be a Service Capability Server (SCS), which is not limited in this embodiment of the present invention.

It should also be understood that, in the embodiment of the present invention, the first indication message may also be referred to as a downlink data notification acknowledgement DDNA message, the second indication message may also be referred to as a downlink data transmission indication message, and the first request message may be a downlink data transmission indication request message, which is not limited in the embodiment of the present invention.

For example, the following description will be given by taking a mobility management entity as MME, a serving gateway as S-GW, and a user equipment as UE, where a first indication message is a downlink data notification acknowledgement DDNA message, a second indication message is a downlink data transmission indication message, and a first request message is a downlink data transmission indication request message.

It should be noted that the names of the first indication message, the second indication message, and the first request message in the embodiment of the present invention may all be messages with other names as long as the corresponding functions of these messages can be implemented, and the embodiment of the present invention is not limited thereto.

Fig. 3 is a schematic flow chart of a method of data transmission according to one embodiment of the present invention. The method shown in fig. 3 may be performed by a mobility management entity, and specifically, the method shown in fig. 3 includes:

310, when downlink data of the user equipment sent by the data sending end is not reachable, the mobility management entity sends a first indication message to the serving gateway, where the first indication message is used to indicate the serving gateway to cache the downlink data;

for example, when it is determined that the UE enables power saving functions such as PSM or long cycle DRX, or radio signal interruption, the MME determines that downlink data of the UE is not reachable.

320, the mobility management entity determines that a second indication message needs to be sent to the data sending end;

330, the mobility management entity sends the second indication message to the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message.

It should be understood that the MME sending the downlink data transmission indication message to the server may be the MME sending the downlink data transmission indication message to the server via the SCEF.

For example, after receiving the Downlink Data, the Data gateway P-GW forwards the Downlink Data to the S-GW, and the S-GW sends a Downlink Data Notification (DDN) message to the MME after receiving the Downlink Data. The DDN message carries the UE identification. The MME detects that the UE is temporarily unreachable (e.g., PSM or eDRX enabled by the UE), and decides to buffer the downlink data. The MME sends a Downlink Data Notification Acknowledgement (DDNA) message to a serving gateway S-GW, wherein the DDNA message is used for indicating the S-GW to cache Downlink Data; for example, downlink data is cached within the duration, and the MME determines that the downlink data transmission indication message needs to be sent to the server according to the identity of the UE, where the downlink data transmission indication message may include information of the duration; and the S-GW determines the number M of the cache data packets according to the MME indication, the cache use condition, the local configuration strategy and other information, and starts a timer T to cache the downlink data. When the timer T times out or the number of received packets exceeds M, the S-GW will no longer buffer the packets. The MME sends a downlink data sending indication message to the server, the server determines to send the downlink data of the UE within the duration according to the downlink data sending indication message, and does not send the downlink data of the UE at the time except the duration.

Therefore, in the embodiment of the present invention, when the downlink data of the user equipment sent by the data sending end is not reachable, the mobility management entity sends the first indication message to the serving gateway to indicate the serving gateway to cache the downlink data; and the mobility management entity sends the second indication message to the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message, for example, the downlink data of the user equipment is sent within a certain duration, and the downlink data of the user equipment is not sent in a time except for the duration. Therefore, the downlink data can be flexibly transmitted, unnecessary data transmission is avoided, and the network efficiency is improved.

Optionally, according to the embodiment of the present invention, the first indication message carries indication information indicating that the serving gateway buffers the downlink data, where the indication information includes a duration and/or a number of data packets,

the second indication message carries indication information.

It should be understood that the number of buffered packets refers to the number of packets that can be buffered by the S-GW configured by the MME for the S-GW at most.

It should be noted that, in the embodiment of the present invention, whether to feed back the second indication message may be determined based on a request of the server (AS/SCS), or may be determined based on local configuration information of the MME. The second indication message may be generated by the MME or the S-GW. The following describes these cases in detail, respectively.

In one case, when the embodiment of the present invention performs the feedback of the second indication message based on the request of the AS/SCS, before 310, the method further includes:

the mobility management entity obtains a first request message sent by a data sending end, the first request message is used for requesting a network to feed back a second indication message when downlink data of user equipment is unreachable, the first request message carries address information of the data sending end and an identifier of the user equipment,

it should be understood that the address information of the sending end may be IP, or location geographic information, and the like, and the identifier of the user equipment may be an ID, IP, IMEI code, and the like of the user equipment, and the embodiment of the present invention is not limited thereto.

For example, the AS/SCS sends a downlink data sending indication request message to the SCEF, requesting the network to feed back the indication information when the UE is not reachable. The request message carries the IP address of the AS/SCS, the UE identification and the request validity period. The validity period of the request message may be valid only for the current downlink data transmission of the UE, or may be valid for all downlink data transmissions of the UE within a certain time. The SCEF forwards the request message of the AS/SCS to the MME. The MME stores the request message after receiving the request message and deletes the message after the request message is expired.

In 320, if the mobility management entity determines that the identifier of the user equipment is the same as the identifier of the user equipment carried in the first request message, the mobility management entity determines that a second indication message needs to be sent to the data sending end.

Further, when the second indication message may be generated by the MME, before 330, the method further comprises:

the mobility management entity generates a second indication message.

For example, the MME detects that the UE is temporarily unreachable (e.g., PSM, eDRX enabled by the UE), and decides to buffer the downlink data. The MME sends a Downlink Data Notification Acknowledgement (DDNA) message to the S-GW, indicating that the S-GW needs to cache downlink data and cache duration T, and optionally further including the number N of cache data packets. And the MEE determines whether downlink data transmission indication information needs to be fed back or not according to the UE identification, if the UE identification in the DDN message is the same AS the UE identification in the AS/SCS request message, the MME generates a downlink data transmission indication message and transmits the downlink data transmission indication message to the AS/SCS through the SCEF.

Alternatively, when the second indication message may be generated by the S-GW, the first indication message is further used for instructing the serving gateway to generate the second indication message, wherein, before 330, the method further comprises:

and the mobility management entity receives a second indication message sent by the service gateway.

For example, when the MME detects that the UE is temporarily unreachable (e.g., PSM, eDRX enabled by the UE), it decides to buffer downlink data. And simultaneously, the MEE determines that the downlink data transmission indication message needs to be fed back according to the UE identification. The MME sends a Downlink Data Notification Acknowledgement (DDNA) message to the S-GW, indicating that the S-GW needs to cache downlink data, the cache duration T and the cache data packet number N (optional). And meanwhile, the MME informs the S-GW that downlink data transmission indication information needs to be fed back and provides the IP address of the AS/SCS. And the S-GW determines the number M of the cache data packets according to the MME indication, the cache use condition, the local configuration strategy and other information, generates a downlink data transmission indication message and transmits the downlink data transmission indication message to the MME. S-GW starts timer T to buffer down data, when timer T is overtime or number of received data packets exceeds M, S-GW will not buffer data packets any more. And the MME forwards the downlink data transmission indication message and transmits the downlink data transmission indication message to the AS/SCS through the SCEF.

In another case, when the embodiment of the present invention determines whether to feed back the downlink data transmission indication message based on the local configuration information of the MME, that is, in this case, a list (a preset feedback identifier list) that needs to feed back the downlink data transmission indication message is configured in advance in the MME, where the list includes the UE identifier, that is, all downlink data of the UE in the list need to provide the feedback message when the UE is not reachable.

Optionally, in 320, if the mobility management entity determines that the identifier that is the same as the identifier of the user equipment exists in a preset feedback identifier list, the mobility management entity determines that a second indication message needs to be sent to the data sending end, where the preset feedback identifier list includes the identifier of the user equipment that needs to feed back the second indication message.

Further, when the second indication message may be generated by the MME, the first indication message is further used for instructing the serving gateway to send address information of the data sender to the mobility management entity, and before 330, the method further includes:

a mobile management entity receives address information of a data sending end sent by a service gateway;

and the mobility management entity generates a second indication message, wherein the second indication message carries the address information of the data sending end.

For example, the MME detects that the UE is temporarily unreachable (e.g., PSM or eDRX enabled by the UE), and decides to buffer the downlink data. And the MEE inquires a local configuration list according to the UE identification and determines whether downlink data transmission indication information needs to be fed back or not. If feedback is needed, the MME also needs to request the S-GW to provide the IP address of the AS/SCS. That is, the MME sends a Downlink Data Notification Acknowledgement (DDNA) message to the S-GW, indicating that the S-GW needs to cache downlink data and cache duration T, optionally further including number N of cached data packets. At the same time, the MME also requests the S-GW to provide the IP address of the AS/SCS. And the S-GW starts a data packet detection function according to the MME instruction, acquires the IP address of the AS/SCS corresponding to the downlink data packet and feeds back the IP address to the MME. And the MME generates a downlink data transmission indicating message according to the AS/SCS IP address provided by the S-GW and transmits the downlink data transmission indicating message to the AS/SCS through the SCEF.

Alternatively, when the second indication message may be generated by the S-GW, the first indication message is further used for instructing the serving gateway to generate the second indication message, before 330, the method further comprises: and the mobility management entity receives a second indication message sent by the service gateway.

For example, the MME detects that the UE is temporarily unreachable (e.g., PSM, eDRX enabled by the UE), and decides to buffer the downlink data. And the MEE inquires a local configuration list according to the UE identification and determines whether downlink data transmission indication information needs to be fed back or not. The MME sends a Downlink Data Notification Acknowledgement (DDNA) message to the S-GW, indicating that the S-GW needs to cache downlink data and cache duration T, and optionally further including the number N of cache data packets. And meanwhile, the MME informs the S-GW that downlink data transmission indication information needs to be fed back, and the S-GW determines the number M of the cache data packets according to the MME indication, the cache use condition, the local configuration strategy and other information. And the S-GW starts a data packet detection function according to the MME instruction, acquires the IP address of the AS/SCS corresponding to the downlink data packet, generates a downlink data transmission instruction message and transmits the downlink data transmission instruction message to the MME. And the MME forwards the downlink data transmission indication message and transmits the downlink data transmission indication message to the AS/SCS through the SCEF.

Optionally, the embodiment of the present invention further includes: and the mobile management entity receives a confirmation message sent by the data sending end, wherein the confirmation message is used for indicating that the data sending end has received the second indication message.

It should be understood that the acknowledgement message in the embodiment of the present invention may also be referred to as an indication acknowledgement message or an acknowledgement indication message, and the embodiment of the present invention does not limit this.

For example, the MME (via the SCEF) sends a downlink data transmission indication message to the AS, after the AS receives the downlink data transmission indication message, (via the SCEF) sends a downlink data transmission indication confirmation message to the MME, and the MME learns, according to the downlink data transmission indication confirmation message, that the AS has correctly transmitted the downlink data transmission indication message, and thus does not need to resend (retransmit) the downlink data transmission indication message, thereby improving network efficiency.

In the above, the method for data transmission according to the embodiment of the present invention is described from the mobility management entity side in conjunction with fig. 3, and the method for data transmission according to the embodiment of the present invention is described from the data sending end side in conjunction with fig. 4.

Fig. 4 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention. The method shown in fig. 5 may be performed by a data transmitting end, and specifically, the method shown in fig. 5 includes:

410, the data sending end obtains a second indication message, where the second indication message is generated after the service gateway receives the first indication message, and the first indication message is used to indicate the service gateway to cache downlink data of the user equipment whose downlink data is unreachable;

specifically, the second indication message may be generated by the mobility management entity or the serving gateway, which is not limited in this embodiment of the present invention.

And 420, the data sending end sends the downlink data of the user equipment according to the second indication message.

For example, after receiving the downlink data, the data gateway P-GW forwards the downlink data to the S-GW, and the S-GW sends a Downlink Data Notification (DDN) message to the MME after receiving the downlink data. The DDN message carries the UE identification. The MME detects that the UE is temporarily unreachable (e.g., PSM or eDRX enabled by the UE), and decides to buffer the downlink data. The MME sends a Downlink Data Notification Acknowledgement (DDNA) message to a serving gateway (S-GW), wherein the DDNA message is used for indicating the S-GW to cache downlink data, for example, to cache the downlink data within a duration, for example, to cache the downlink data within the duration; the MME determines that downlink data sending indication information needs to be sent to a data sending end according to the identity of the UE, wherein the downlink data sending indication information comprises duration information; and the S-GW determines the number M of the cache data packets according to the MME indication, the cache use condition, the local configuration strategy and other information, and starts a timer T to cache the downlink data. When the timer T times out or the number of received packets exceeds M, the S-GW will no longer buffer the packets. And the MME sends a downlink data sending indication message to the data sending end, the data sending end determines to send the downlink data of the UE within the duration according to the downlink data sending indication message, and does not send the downlink data of the UE in the time except the duration.

Therefore, in the embodiment of the present invention, a second indication message may be obtained at the data sending end, where the second indication message is generated after the service gateway receives the first indication message, and the first indication message is used to indicate that the service gateway buffers downlink data of the user equipment for which the downlink data is unreachable; and the data sending end sends the downlink data of the user equipment according to the second indication message. For example, downlink data of the user equipment is transmitted for a certain duration, and the downlink data of the user equipment is not transmitted for a time other than the duration. Therefore, the downlink data can be flexibly transmitted, unnecessary data transmission is avoided, and the network efficiency is improved.

Optionally, as another embodiment, the first indication message carries indication information indicating that the serving gateway buffers the downlink data, where the indication information includes a duration and/or a number of data packets,

the second indication message carries indication information.

Wherein,

when the indication information includes the duration, the data transmitting end determines to transmit the downlink data of the user equipment for the duration according to the second indication message at 420,

when the indication information includes the number of data packets, the data transmitting end transmits the downlink data of the user equipment according to the second indication message, and the number of data packets of the downlink data of the user equipment transmitted by the data transmitting end is less than or equal to the number of data packets at 420,

when the indication information includes the duration and the number of data packets, in 420, the data sending end determines to send the downlink data of the user equipment within the duration according to the second sending indication message, and the number of data packets of the downlink data of the user equipment sent by the data sending end within the duration is less than or equal to the number of data packets.

Further, as another embodiment, when the indication information includes duration information, or the indication information includes a duration and a number of packets, the method further includes:

Optionally, as another embodiment, before 410, the method further includes:

the data sending end sends a first request message, the first request message is used for requesting a network to feed back a second indication message when downlink data of the user equipment is not reachable, and the first request message carries address information of the data sending end and an identifier of the user equipment.

For example, a data sending end (e.g., AS or SCS) sends a downlink data sending indication request message to the SCEF, requesting the network to feed back the indication information when the UE is not reachable. The request message carries the IP address of the AS/SCS, the UE identification and the request validity period. The validity period of the request message may be valid only for the current downlink data transmission of the UE, or may be valid for all downlink data transmissions of the UE within a certain time. The SCEF forwards the request message of the AS/SCS to the MME. The MME stores the request message after receiving the request message and deletes the message after the request message is expired.

Optionally, the method in the embodiment of the present invention further includes:

and the data sending end sends a confirmation message to the mobility management entity, wherein the confirmation message is used for indicating that the data sending end receives the second indication message.

For example, the MME sends a downlink data transmission indication message to the data sending end (via the SCEF), after the data sending end receives the downlink data transmission indication message, the data sending end sends a downlink data transmission indication confirmation message to the MME (via the SCEF), and the MME learns that the data sending end has correctly sent the downlink data transmission indication message according to the downlink data transmission indication confirmation message, so that the downlink data transmission indication message does not need to be resent (retransmitted), thereby improving the network efficiency.

In the above, the method for data transmission according to the embodiment of the present invention is described from the mobility management entity side in conjunction with fig. 3, and the method for data transmission according to the embodiment of the present invention is described from the data sending end side in conjunction with fig. 4. The method of data transmission according to the embodiment of the present invention is described below with reference to fig. 5 and 6 from the service gateway side.

Fig. 5 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention. The method of fig. 5 may be performed by a serving gateway, and in particular, the method as shown in fig. 5 includes:

510, the serving gateway receives a first indication message sent by the mobility management entity, where the first indication message is used to indicate that the serving gateway buffers downlink data of the user equipment whose downlink data sent by the data sending end is unreachable, and generates a second indication message;

520, the service gateway obtains the address information of the data sending end;

and 530, the service gateway generates and sends a second indication message according to the indication of the first indication message and the address information of the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message.

For example, after receiving the downlink data, the data gateway P-GW forwards the downlink data to the S-GW, and the S-GW sends a Downlink Data Notification (DDN) message to the MME after receiving the downlink data. The DDN message carries the UE identification. The MME detects that the UE is temporarily unreachable (e.g., PSM or eDRX enabled by the UE), and decides to buffer the downlink data. The MME sends a Downlink Data Notification Acknowledgement (DDNA) message to a serving gateway (S-GW), wherein the DDNA message is used for indicating the S-GW to cache downlink data within the duration and generate a downlink data sending indication message, for example, the downlink data is cached within the duration; the MME determines that downlink data sending indication information needs to be sent to a data sending end according to the identity of the UE, wherein the downlink data sending indication information comprises duration information; and the S-GW determines the number M of the cache data packets according to the MME indication, the cache use condition, the local configuration strategy and other information, and starts a timer T to cache the downlink data. When the timer T times out or the number of received packets exceeds M, the S-GW will no longer buffer the packets. The S-GW acquires IP address information of a data sending end; the method comprises the steps that an S-GW obtains IP address information of a data sending end, the S-GW generates and sends downlink data sending indication information to an MME according to the indication of a DDNA message and the IP address information of the data sending end, the downlink data sending indication information comprises duration information, the MME forwards the downlink data sending indication information to the data sending end, the downlink data sending indication information of the data sending end determines that downlink data of user equipment are sent within the duration, and the downlink data of the UE are not sent in the time except the duration.

Therefore, in the embodiment of the present invention, when the downlink data of the user equipment sent by the data sending end is unreachable, the serving gateway receives the first indication message sent by the mobility management entity, indicates the serving gateway to cache the downlink data of the user equipment which is unreachable by the downlink data sent by the data sending end, generates the second indication message, and obtains the address information of the data sending end; the service gateway generates and sends the second indication message according to the indication of the first indication message and the address information of the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message, for example, the downlink data of the user equipment is sent within the duration, and the downlink data of the UE is not sent in the time except the duration. Therefore, the downlink data can be flexibly transmitted, unnecessary data transmission is avoided, and the network efficiency is improved.

Optionally, the first indication message carries indication information indicating that the serving gateway buffers the downlink data, where the indication information includes a duration and/or a number of data packets,

the second indication message carries indication information.

It should be noted that, in the embodiment of the present invention, whether to feed back the downlink data transmission indication message may be determined based on a request of the AS/SCS, or may be determined based on local configuration information of the MME. The downlink data transmission instruction message may be generated by the MME or the S-GW. The following describes these cases in detail, respectively.

In one case, when the embodiment of the present invention performs feedback of the downlink data transmission indication message based on the request of the AS/SCS, optionally, the first indication message carries address information of the data transmitting end, where in 520, the service gateway obtains the address information of the data transmitting end according to the first indication message.

For example, the AS/SCS sends a downlink data sending indication request message to the SCEF, requesting the network to feed back the indication information when the UE is not reachable. The request message carries the IP address of the AS/SCS, the UE identification and the request validity period. The validity period of the request message may be valid only for the current downlink data transmission of the UE, or may be valid for all downlink data transmissions of the UE within a certain time. The SCEF forwards the request message of the AS/SCS to the MME. The MME stores the request message after receiving the request message and deletes the message after the request message is expired. And when the MME detects that the UE is temporarily unreachable (such as the UE starts PSM and eDRX), determining to cache the downlink data. And simultaneously, the MEE determines that the downlink data transmission indication message needs to be fed back according to the UE identification. The MME sends a Downlink Data Notification Acknowledgement (DDNA) message to the S-GW, indicating that the S-GW needs to cache downlink data, the cache duration T and the cache data packet number N (optional). And meanwhile, the MME informs the S-GW that downlink data transmission indication information needs to be fed back and provides the IP address of the AS/SCS. And the S-GW determines the number M of the cache data packets according to the MME indication, the cache use condition, the local configuration strategy and other information, generates a downlink data transmission indication message and transmits the downlink data transmission indication message to the MME. And the MME forwards the downlink data transmission indication message and transmits the downlink data transmission indication message to the AS/SCS through the SCEF.

Optionally, the first indication message is further used to instruct the service gateway to obtain address information of the data sender,

in 520, the service gateway performs downlink data detection according to the indication of the first indication message, and acquires address information of the data sending end.

Fig. 6 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention. The method of fig. 6 may be performed by a serving gateway, and in particular, the method as shown in fig. 6 includes:

610, the serving gateway receives a first indication message sent by the mobility management entity, where the first indication message is used to indicate that the serving gateway caches downlink data of the user equipment, where the downlink data sent by the data sending end is unreachable, and obtains address information of the data sending end;

620, the service gateway detects the downlink data according to the indication of the first indication message, and acquires the address information of the data sending end;

the service gateway sends address information of the data sending end to the mobility management entity, so that the mobility management entity generates and sends a second indication message to the data sending end according to the address information of the data sending end, and the data sending end sends downlink data of the user equipment according to the second indication message.

For example, the MME detects that the UE is temporarily unreachable (e.g., PSM or eDRX enabled by the UE), and decides to buffer the downlink data. And the MEE inquires a local configuration list according to the UE identification and determines whether downlink data transmission indication information needs to be fed back or not. If feedback is needed, the MME also needs to request the S-GW to provide the IP address of the AS/SCS. That is, the MME sends a Downlink Data Notification Acknowledgement (DDNA) message to the S-GW, indicating that the S-GW needs to cache downlink data and cache duration T, optionally further including number N of cached data packets. At the same time, the MME also requests the S-GW to provide the IP address of the AS/SCS. And the S-GW starts a data packet detection function according to the MME instruction, acquires the IP address of the AS/SCS corresponding to the downlink data packet and feeds back the IP address to the MME. S-GW starts timer T to buffer down data, when timer T is overtime or number of received data packets exceeds M, S-GW will not buffer data packets any more. And the MME generates a downlink data transmission indicating message according to the IP address of the AS/SCS provided by the S-GW and transmits the downlink data transmission indicating message to the AS/SCS through the SCEF. And the AS/SCS determines to send the downlink data of the UE in the duration according to the downlink data sending indication message, and does not send the downlink data of the UE in the time except the duration.

Therefore, in the embodiment of the present invention, a first indication message sent by a mobility management entity is received by a serving gateway, where the first indication message is used to indicate that the serving gateway buffers downlink data of a user equipment whose downlink data sent by a data sending end is inaccessible, and obtains address information of the data sending end; detecting downlink data according to the indication of the first indication message, and acquiring address information of a data sending end; and sending the address information of the data sending end to the mobility management entity, so that the mobility management entity generates and sends a second indication message to the data sending end according to the address information of the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message, for example, the downlink data of the user equipment is sent within the duration, and the downlink data is not sent in the time except the duration. Therefore, the downlink data can be flexibly transmitted, unnecessary data transmission is avoided, and the network efficiency is improved.

the second indication message carries indication information.

In the above, the method for data transmission according to the embodiment of the present invention is described from the mobility management entity side in conjunction with fig. 3, the method for data transmission according to the embodiment of the present invention is described from the data sending end side in conjunction with fig. 4, and the method for data transmission according to the embodiment of the present invention is described from the serving gateway side in conjunction with fig. 5 and fig. 6. The following describes the data transmission method according to the embodiment of the present invention in detail with reference to specific examples in fig. 7 to 10.

Fig. 7 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention. The embodiment of fig. 7 describes that the downlink data transmission indication message is generated by the MME and whether to feed back the message is decided based on the request of the AS/SCS.

Specifically, the method shown in fig. 7 includes:

701, the AS/SCS sends a downlink data sending indication request message to the SCEF, requesting the network to feed back the indication information when the UE is not reachable. The request message carries the IP address of the AS/SCS, the UE identification and the request validity period. The validity period of the request message may be valid only for the current downlink data transmission of the UE, or may be valid for all downlink data transmissions of the UE within a certain time.

The SCEF forwards the request message for AS/SCS to the MME 702. The MME stores the request message after receiving the request message and deletes the message after the request message is expired.

703, when the user equipment is in an idle state, the P-GW receives the downlink data and forwards the data to the S-GW.

704, S-GW receives the downlink data and sends the downlink data notification DDN message to MME. The message carries the UE identity.

705, the MME detects that the UE is temporarily unreachable (e.g., PSM, eDRX enabled by the UE), and decides to buffer downlink data.

And 706, the MME sends a downlink data notification acknowledgement DDNA message to the S-GW, indicating that the S-GW needs to cache downlink data and the cache duration T, optionally further including the number N of cache data packets.

707, the MME sends a downlink data transmission indication message to the AS.

Specifically, the MEE determines whether downlink data transmission indication information needs to be fed back according to the UE identifier, and if the UE identifier in the DDN message is the same AS the UE identifier in the AS/SCS request message, the MME generates a downlink data transmission indication message and transmits the downlink data transmission indication message to the AS/SCS via the SCEF.

The downlink data transmission indication message generated by the MME includes a buffer duration T, and optionally may further include a buffer data packet number N decided by the MME.

The AS/SCS optionally sends a downstream data send indication acknowledgement message to the network 708.

709, the S-GW determines the number M of the cache data packets according to the MME indication and information such as cache use condition, local configuration policy, and starts the timer T to cache the downlink data. When the timer T times out or the number of received packets exceeds M, the S-GW will discard the buffered packets.

Therefore, in the embodiment of the invention, the AS/SCS sends the request message to the network to request to feed back the downlink data sending indication message when the UE is not reachable. And the MME generates a downlink data sending indication message based on the request of the AS/SCS and feeds back information such AS the cache duration T, the number N of cache data packets decided by the MME and the like to the AS/SCS. The AS/SCS can decide when to stop sending or retransmitting the downlink data packet according to the indication of the network, thereby avoiding unnecessary data packet transmission and improving the use efficiency of network resources.

Fig. 8 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention. The embodiment of fig. 8 describes that the downlink data transmission indication message is generated by the S-GW and decides whether to feed back the message based on the request of the AS/SCS.

Specifically, the method shown in fig. 8 includes:

801, the AS/SCS sends a downlink data sending indication request message to the SCEF, requesting the network to feed back the indication information when the UE is not reachable. The request message carries the IP address of the AS/SCS, the UE identification and the request validity period. The validity period of the request message may be valid only for the current downlink data transmission of the UE, or may be valid for all downlink data transmissions of the UE within a certain time.

The SCEF forwards the AS/SCS request message to the MME 802. The MME stores the request message after receiving the request message and deletes the message after the request message is expired.

The specific downlink data processing flow is as follows:

803, when the user equipment is in an idle state, the P-GW receives the downlink data and forwards the data to the S-GW.

And 804, the S-GW receives the downlink data and sends a Downlink Data Notification (DDN) message to the MME. The message carries the UE identity.

805, the MME detects that the UE is temporarily unreachable (e.g., PSM, eDRX enabled by the UE), and decides to cache downlink data. And simultaneously, the MEE determines whether downlink data transmission indication information needs to be fed back or not according to the UE identification, and if the UE identification in the DDN information is the same AS the UE identification in the AS/SCS request information, the feedback information needs to be provided.

806, the MME sends a Downlink Data Notification Acknowledge (DDNA) message to the S-GW indicating that the S-GW needs to cache downlink data, as well as the cache duration T and the number of cache packets N (optional). And meanwhile, the MME informs the S-GW that downlink data transmission indication information needs to be fed back and provides the IP address of the AS/SCS.

807, the S-GW transmits a downlink data transmission indication message to the MME.

Specifically, the S-GW determines the number M of cache data packets according to the MME indication, the cache usage, the local configuration policy, and other information, generates a downlink data transmission indication message, and transmits the downlink data transmission indication message to the MME.

The downlink data transmission indication information generated by the S-GW may include a cache duration T and a cache packet number N decided by the S-GW.

808, the MME sends a downlink data transmission indication message to the AS.

Specifically, the MME forwards the downlink data transmission indication message, and transmits the downlink data transmission indication message to the AS/SCS via the SCEF.

809, the AS/SCS optionally sends a downlink data sending indication acknowledgement message to the network.

The S-GW starts a timer T to buffer the downlink data 810. When the timer T times out or the number of received packets exceeds M, the S-GW will discard the buffered packets.

Therefore, the embodiment of the invention sends the request message to the network through the AS/SCS, and requests to feed back the downlink data sending indication information when the UE is not reachable. The S-GW generates a downlink data sending indication message based on the request of the AS/SCS, and feeds back information such AS the cache duration T and the cache data packet number M decided by the S-GW to the AS/SCS. The AS/SCS can decide when to stop sending or retransmitting the downlink data packet according to the indication of the network, thereby avoiding unnecessary data packet transmission and improving the use efficiency of network resources.

Fig. 9 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention. The embodiment of fig. 9 describes that the downlink data transmission indication message is generated by the MME, and whether to feed back the message is decided based on the local configuration information of the MME. The MME is preconfigured with a list that needs to feed back a downlink data transmission indication message, where the list includes a UE identity, that is, all downlink data of the UE in the list need to provide a feedback message when the UE is not reachable.

Specifically, the method as shown in fig. 9 includes:

901, when the user equipment is in an idle state, the P-GW receives the downlink data and forwards the data to the S-GW.

And 902, the S-GW receives the downlink data and sends a Downlink Data Notification (DDN) message to the MME. The message carries the UE identity.

903, the MME detects that the UE is temporarily unreachable (e.g., PSM, eDRX enabled by the UE), and decides to cache downlink data. And the MEE inquires a local configuration list according to the UE identification and determines whether downlink data transmission indication information needs to be fed back or not. If feedback is needed, the MME also needs to request the S-GW to provide the IP address of the AS/SCS.

904, the MME sends a Downlink Data Notification Acknowledgement (DDNA) message to the S-GW indicating that the S-GW needs to cache downlink data and a cache duration T, optionally further including a number N of cached data packets. At the same time, the MME also requests the S-GW to provide the IP address of the AS/SCS.

905, the S-GW sends the IP address of the AS/SCS to the MME.

Specifically, the S-GW starts a data packet detection function according to the MME instruction, acquires an IP address of an AS/SCS corresponding to the downlink data packet, and feeds back the IP address to the MME.

906, MME sends downlink data sending indication message to AS

Specifically, the MME generates a downlink data transmission indication message according to the AS/SCS IP address provided by the S-GW, and transmits the downlink data transmission indication message to the AS/SCS through the SCEF.

907, the AS/SCS optionally sends a downlink data transmission indication acknowledgement message to the network.

908, the S-GW determines the number M of cache packets according to the MME indication and information such as cache usage, local configuration policy, and starts a timer T to cache downlink data. When the timer T times out or the number of received packets exceeds M, the S-GW will discard the buffered packets.

Therefore, the embodiment of the invention determines whether to feed back the downlink data transmission indication message when the UE is unreachable or not through the MME based on the local configuration information, generates the downlink data transmission indication message by the MME, and feeds back the information such AS the cache duration T, the cache data packet number N and the like to the AS/SCS. The AS/SCS can decide when to stop sending or retransmitting the downlink data packet according to the indication of the network, thereby avoiding unnecessary data packet transmission and improving the use efficiency of network resources.

Fig. 10 is a schematic flow chart of a method of data transmission according to another embodiment of the present invention. The embodiment of fig. 8 describes that the downlink data transmission indication message is generated by the S-GW, and whether to feed back the message is determined based on the local configuration information of the MME. The MME is preconfigured with a list that needs to feed back a downlink data transmission indication message, where the list includes a UE identity, that is, all downlink data of the UE in the list need to provide a feedback message when the UE is not reachable.

Specifically, the method shown in fig. 10 includes:

1001, when the user equipment is in idle state, the P-GW receives the downlink data and forwards the data to the S-GW.

1002, the S-GW receives the downlink data and sends a Downlink Data Notification (DDN) message to the MME. The message carries the UE identity.

1003, the MME detects that the UE is temporarily unreachable (e.g., PSM, eDRX enabled by the UE), and decides to cache downlink data. And the MEE inquires a local configuration list according to the UE identification and determines whether downlink data transmission indication information needs to be fed back or not.

1004, the MME sends a Downlink Data Notification Acknowledgement (DDNA) message to the S-GW indicating that the S-GW needs to cache downlink data and a cache duration T, optionally further including a number N of cache packets. And meanwhile, the MME informs the S-GW that downlink data transmission indication information needs to be fed back.

And 1005, the S-GW sends a downlink data sending indication message to the MME.

Specifically, the S-GW determines the number M of cache packets according to the MME indication and information such as cache usage and local configuration policy. And the S-GW starts a data packet detection function according to the MME instruction, acquires the IP address of the AS/SCS corresponding to the downlink data packet, generates a downlink data transmission instruction message and transmits the downlink data transmission instruction message to the MME.

The downlink data sending indication information generated by the S-GW includes a cache duration T and a cache data packet number N decided by the S-GW.

1006, the MME sends a downlink data transmission indication message to the AS.

1007, the AS/SCS optionally sends a downlink data transmission indication acknowledgement message to the network.

1008, the S-GW starts a timer T to buffer the downlink data. When the timer T times out or the number of received packets exceeds M, the S-GW will discard the buffered packets.

Therefore, in the embodiment of the invention, the MME determines whether to feed back the downlink data transmission indication message when the UE is not reachable or not based on the local configuration information, the S-GW generates the downlink data transmission indication message, and the information such AS the cache duration T and the cache data packet number N is fed back to the AS/SCS. The AS/SCS can decide when to stop sending or retransmitting the downlink data packet according to the indication of the network, thereby avoiding unnecessary data packet transmission and improving the use efficiency of network resources.

The method for data transmission according to the embodiment of the present invention is described in detail with reference to fig. 1 to 10, and the apparatus for data transmission according to the embodiment of the present invention is described with reference to fig. 11 to 17.

It should be understood that the mobility management entity shown in fig. 11 corresponds to the embodiment of the method in fig. 3, and can implement various processes related to the mobility management entity in the implementation of fig. 3, and specific functions of the mobility management entity 1100 shown in fig. 11 may refer to various processes performed by the mobility management entity in fig. 3, and a detailed description is appropriately omitted here to avoid repetition.

The mobility management entity 1100 as shown in fig. 11 comprises: a first determining unit 1110, a second determining unit 1120, and a transmitting unit 1130.

Specifically, the first determining unit 1110 is configured to send a first indication message to the serving gateway when downlink data of the user equipment sent by the data sending end is not reachable, where the first indication message is used to indicate the serving gateway to cache the downlink data;

the second determining unit 1120 is configured to determine that a second indication message needs to be sent to the data sender;

the sending unit 1130 is configured to send the second indication message to the data sender, so that the data sender sends the downlink data of the user equipment according to the second indication message.

the second indication message carries indication information.

Optionally, as another embodiment, the mobility management entity 1100 further includes:

an obtaining unit, configured to obtain a first request message sent by a data sending end before the first determining unit sends a first indication message to a serving gateway when determining that downlink data of user equipment sent by the data sending end is unreachable, where the first request message is used to request a network to feed back a second indication message when the downlink data of the user equipment is unreachable, and the first request message carries address information of the data sending end and an identifier of the user equipment,

if it is determined that the identifier of the user equipment is the same as the identifier of the user equipment carried in the first request message, the second determining unit 1120 determines that a second indication message needs to be sent to the data sending end.

and the first generating unit is used for generating the second indication message before the sending unit sends the second indication message to the data sending end.

Optionally, as another embodiment, the first indication message is further used to instruct the serving gateway to generate a second indication message, and the mobility management entity 1100 further includes:

and the receiving unit is used for receiving the second indication message sent by the service gateway before the sending unit sends the downlink data to the data sending end to send the second indication message.

Optionally, as another embodiment, if it is determined that the identifier that is the same as the identifier of the user equipment exists in the preset feedback identifier list, the first determining unit 1110 determines that the second indication message needs to be sent to the data sending end, where the preset feedback identifier list includes the identifier of the user equipment that needs to feed back the second indication message.

Optionally, as another embodiment, the first indication message is further used to instruct the serving gateway to send address information of the data sending end to the mobility management entity, and the mobility management entity further includes:

a first receiving unit, configured to receive address information of a data sending end sent by a service gateway before the sending unit sends downlink data sending indication information to the data sending end;

and the second generating unit is used for generating a second indication message before the sending unit sends the downlink data sending indication information to the data sending end, wherein the second indication message carries the address information of the data sending end.

and the second receiving unit is used for receiving the second indication message sent by the service gateway before the sending unit sends the second indication message to the data sending end.

and the third receiving unit is configured to receive a confirmation message sent by the data sending end, where the confirmation message is used to indicate that the data sending end has received the second indication message.

It should be understood that the data sending end shown in fig. 12 corresponds to the embodiment of the method shown in fig. 4, and can implement the various processes related to the data sending end in the implementation of fig. 4, and specific functions of the data sending end 1200 shown in fig. 12 may refer to the various processes performed by the data sending end in fig. 4, and a detailed description is appropriately omitted here to avoid redundancy.

The data transmitting end 1200 shown in fig. 12 includes: an acquisition unit 1210 and a first sending unit 1220.

Specifically, the obtaining unit 1210 is configured to obtain a second indication message, where the second indication message is generated after the serving gateway receives the first indication message, and the first indication message is used to indicate the serving gateway to cache downlink data of the user equipment whose downlink data is unreachable;

the first sending unit 1220 is configured to send downlink data of the user equipment according to the second indication message.

Alternatively, as another embodiment,

the second indication message carries indication information of the service gateway buffer downlink data, the indication information comprises duration and/or number of data packets,

wherein,

when the indication information includes the duration, the first transmitting unit 1220 determines to transmit downlink data of the user equipment for the duration according to the second indication message,

when the indication information includes the number of data packets, the first sending unit 1220 sends the downlink data of the user equipment according to the second indication message, and the number of data packets of the downlink data of the user equipment sent by the data sending end is less than or equal to the number of data packets,

when the indication information includes the duration and the number of data packets, the first sending unit 1220 determines to send the downlink data of the user equipment within the duration according to the second indication message, and the number of data packets of the downlink data of the user equipment sent by the data sending end within the duration is less than or equal to the number of data packets.

Optionally, as another embodiment, when the indication information includes a duration, or the indication information includes a duration and a number of data packets, the data sending end 1200 further includes:

and a determining unit, configured to determine not to send downlink data of the user equipment at a time other than the duration according to the second indication message.

Optionally, as another embodiment, the data sending end 1200 further includes:

a second sending unit, configured to send a first request message before the obtaining unit 1210 obtains the second indication message, where the first request message is used to request the network to feed back the second indication message when downlink data of the user equipment is not reachable, and the first request message carries address information of a data sending end and an identifier of the user equipment.

Optionally, as another embodiment, the data sending end 1200 further includes:

and a third sending unit, configured to send a downlink data sending confirmation message to the mobility management entity, where the confirmation message is used to indicate that the data sending end has received the second indication message.

It should be understood that the server shown in fig. 13 corresponds to the embodiment of the method shown in fig. 5, and can implement the processes related to the serving gateway in the implementation of fig. 5, and the specific functions of the serving gateway 1300 shown in fig. 13 may refer to the processes performed by the serving gateway in fig. 5, and a detailed description is appropriately omitted here to avoid redundancy.

The service gateway 1300 shown in fig. 13 includes: a receiving unit 1310, an obtaining unit 1320, and a transmitting unit 1330.

Specifically, the receiving unit is configured to receive a first indication message sent by the mobility management entity, where the first indication message is used to indicate that the serving gateway buffers downlink data of the user equipment whose downlink data sent by the data sending end is unreachable, and generates a second indication message;

the obtaining unit 1320 is configured to obtain address information of a data sending end;

the sending unit 1330 is configured to generate and send a second indication message according to the indication of the first indication message and the address information of the data sending end, so that the data sending end sends downlink data of the user equipment according to the second indication message.

the second indication message carries indication information.

Optionally, as another embodiment, the first indication message carries address information of the data sending end,

the obtaining unit 1320 obtains address information of the data sending end according to the first indication message.

Optionally, as another embodiment, the first indication message is also used to instruct the service gateway to obtain address information of the data sender,

the obtaining unit 1320 performs detection on the downlink data according to the instruction of the first instruction message, and obtains address information of the data sending end.

It should be understood that the server shown in fig. 14 corresponds to the embodiment of the method shown in fig. 6, and can implement the various processes related to the service gateway in the implementation of fig. 6, and the specific functions of the service gateway 1400 shown in fig. 14 may refer to the various processes performed by the service gateway in fig. 6, and a detailed description is appropriately omitted here to avoid redundancy.

The service gateway 1400 shown in fig. 14 includes: a receiving unit 1410, an obtaining unit 1420, and a transmitting unit 1430.

Specifically, the receiving unit 1410 is configured to receive a first indication message sent by the mobility management entity, where the first indication message is used to indicate that the serving gateway buffers downlink data of the user equipment whose downlink data sent by the data sending end is unreachable, and obtains address information of the data sending end;

the obtaining unit 1420 is configured to perform downlink data detection according to the indication of the first indication message, and obtain address information of the data sending end;

the sending unit 1430 is configured to send address information of the data sending end to the mobility management entity, so that the mobility management entity generates and sends a second indication message to the data sending end according to the address information of the data sending end, so that the data sending end sends downlink data of the user equipment according to the second indication message.

Therefore, in the embodiment of the present invention, a first indication message sent by a mobility management entity is received by a serving gateway, where the first indication message is used to indicate that the serving gateway buffers downlink data of a user equipment whose downlink data sent by a data sending end is inaccessible, and obtains address information of the data sending end; detecting downlink data according to the indication of the first indication message, and acquiring address information of a data sending end; and sending the address information of the data sending end to the mobility management entity, so that the mobility management entity generates and sends a second indication message to the data sending end according to the address information of the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message, for example, the downlink data of the user equipment is sent within the duration, and the downlink data is not sent in the time except the duration. Therefore, the downlink data can be flexibly transmitted, unnecessary data transmission is avoided, and the network efficiency is improved. Optionally, as another embodiment, the first indication message carries indication information indicating that the serving gateway buffers the downlink data, where the indication information includes a duration and/or a number of data packets,

the second indication message carries indication information.

Fig. 15 is a schematic block diagram of a mobility management entity according to another embodiment of the present invention. The mobility management entity 1500 as shown in fig. 15 comprises: a processor 1510, a memory 1520, a bus system 1530, and a transceiver 1540.

It should be understood that the receiving end device 1500 shown in fig. 15 corresponds to the mobility management entity shown in fig. 11, and can implement the respective processes related to the mobility management entity in the method embodiment shown in fig. 3, and specific functions of the mobility management entity 1500 shown in fig. 15 may refer to the respective processes performed by the mobility management entity in fig. 3, and a detailed description is appropriately omitted here to avoid repetition.

Specifically, the processor 1510 is configured to invoke a code stored in the memory 1520 through the bus system 1530, and send a first indication message to the serving gateway when downlink data of the user equipment sent by the data sending end is not reachable, where the first indication message is used to indicate the serving gateway to cache the downlink data; and determines that the second indication message needs to be sent to the data sending end, the transceiver 1540 sends the second indication message to the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message.

The method disclosed in the above embodiments of the present invention may be applied to the processor 1510 or implemented by the processor 1510. The processor 1510 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by instructions in the form of hardware, integrated logic circuits, or software in the processor 1510. The Processor 1510 may be a general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf programmable Gate Array (FPGA) or other programmable logic device, discrete Gate or transistor logic device, or discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in a Random Access Memory (RAM), a flash Memory, a Read-Only Memory (ROM), a programmable ROM, an electrically erasable programmable Memory, a register, or other storage media that are well known in the art. The storage medium is located in the memory 1520, the processor 1510 reads the information in the memory 1520, and the steps of the above method are completed in combination with the hardware thereof, and the bus system 1530 may include a power bus, a control bus, a status signal bus, and the like in addition to the data bus. For clarity of illustration, however, the various buses are designated in the figure as the bus system 1530.

the second indication message carries indication information.

Optionally, as another embodiment, the processor 1510 is further configured to, when downlink data of the user equipment sent by the data sending end is not reachable, obtain a first request message sent by the data sending end before sending the first indication message to the serving gateway, where the first request message is used to request the network to feed back a second indication message when the user equipment is not reachable, and the first request message carries address information of the data sending end and an identifier of the user equipment,

if the processor 1510 determines that the identifier of the user equipment is the same as the identifier of the user equipment carried in the first request message, it determines that a second indication message needs to be sent to the data sending end.

Optionally, as another embodiment, the processor 1510 is further configured to generate the second indication message before the transceiver 1540 sends the second indication message to the data sender.

Optionally, as another embodiment, the first indication message is further used to instruct the service gateway to generate a second indication message, and the transceiver 1540 is further used to receive the second indication message sent by the service gateway before the sending unit sends the downlink data to the data sender to send the second indication message.

Optionally, as another embodiment, if it is determined that the identifier that is the same as the identifier of the user equipment exists in the preset feedback identifier list, the processor 1510 determines that the second indication message needs to be sent to the data sending end, where the preset feedback identifier list includes the identifier of the user equipment that needs to feed back the second indication message.

Optionally, as another embodiment, the first indication message is further used to indicate that the serving gateway sends address information of the data sending end to the mobility management entity, and before the transceiver 1540 sends the downlink data sending indication information to the data sending end, the transceiver 1540 is further used to receive the address information of the data sending end sent by the serving gateway;

the processor 1510 is further configured to generate a second indication message, where the second indication message carries address information of the data sending end.

Optionally, as another embodiment, the first indication message is further used to instruct the service gateway to generate a second indication message, and the transceiver 1540 is further used to receive the second indication message sent by the service gateway before the sending unit sends the second indication message.

Optionally, as another embodiment, the transceiver 1540 is further configured to receive an acknowledgement message sent by the data sender, where the acknowledgement message is used to indicate that the data sender has received the second indication message.

Fig. 16 is a schematic block diagram of a data transmitting end according to another embodiment of the present invention. The data transmitting end shown in fig. 16 includes: a processor 1610, a memory 1620, a bus system 1630, and a transceiver 1640.

It should be understood that the data transmitting end 1600 shown in fig. 16 corresponds to the data transmitting end shown in fig. 12, and can implement various processes related to the data transmitting end in the implementation of fig. 4, and specific functions of the data transmitting end 1600 shown in fig. 16 may refer to various processes performed by the data transmitting end in fig. 4, and a detailed description is appropriately omitted here to avoid redundancy.

Specifically, the processor 1610 is configured to call, through the bus system 1630, a code stored in the memory 1620, and obtain a second indication message, where the second indication message is generated after the service gateway receives a first indication message, and the first indication message is used to instruct the service gateway to cache downlink data of the user equipment whose downlink data is not reachable; the transceiver 1640 is configured to send downlink data of the user equipment according to the second indication message.

The method disclosed in the embodiments of the present invention may be implemented in the processor 1610 or implemented by the processor 1610. Processor 1610 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by instructions in the form of hardware, integrated logic circuits or software in the processor 1610. The Processor 1610 may be a general-purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf programmable Gate Array (FPGA) or other programmable logic device, discrete Gate or transistor logic device, or discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in a Random Access Memory (RAM), a flash Memory, a Read-Only Memory (ROM), a programmable ROM, an electrically erasable programmable Memory, a register, or other storage media that are well known in the art. The storage medium is located in a memory 1620, the processor 1610 reads the information in the memory 1620, and the steps of the above method are performed by combining hardware thereof, and the bus system 1630 may include a power bus, a control bus, a status signal bus, and the like, in addition to a data bus. But for purposes of clarity, the various buses are identified in the figure as bus system 1630.

Optionally, as another embodiment, the second indication message carries indication information of the serving gateway buffering the downlink data, where the indication information includes a duration and/or a number of data packets, where,

when the indication information includes the duration, the transceiver 1640 determines to transmit the downlink data of the user equipment for the duration according to the second indication message,

when the indication information includes the number of data packets, the transceiver 1640 transmits the downlink data of the user equipment according to the second indication message, and the number of data packets of the downlink data of the user equipment transmitted by the data transmitting end is less than or equal to the number of data packets,

when the indication information includes the duration and the number of packets, the transceiver 1640 determines, according to the second indication message, that the downlink data of the user equipment is transmitted within the duration, and the number of packets of the downlink data of the user equipment transmitted by the data transmitting end within the duration is less than or equal to the number of packets.

Optionally, as another embodiment, when the indication information includes the duration, or the indication information includes the duration and the number of data packets, the transceiver 1640 is further configured to determine not to transmit the downlink data of the user equipment at a time other than the duration according to the second indication message.

Optionally, as another embodiment, the transceiver 1640 is further configured to send a first request message before obtaining the second indication message, where the first request message is used to request the network to feed back the second indication message when the user equipment is not reachable, and the first request message carries address information of the data sender and an identifier of the user equipment.

Optionally, as another embodiment, the transceiver 1640 is further configured to send a downlink data transmission acknowledgement message to the mobility management entity, where the acknowledgement message is used to indicate that the data sender has received the second indication message.

Figure 17 is a schematic block diagram of a serving gateway according to another embodiment of the present invention. The service gateway shown in fig. 17 includes: a processor 1710, a memory 1720, a bus system 1730, and a transceiver 1740.

It should be understood that the service gateway 1700 shown in fig. 17 corresponds to the service gateway shown in fig. 13 and can implement the various processes related to the service gateway in the implementation of fig. 5, and the specific functions of the service gateway 1700 shown in fig. 17 can refer to the various processes performed by the service gateway in fig. 5, and a detailed description is appropriately omitted here to avoid redundancy.

Specifically, the processor 1710 is configured to invoke, through the bus system 1730, a code stored in the memory 1720, receive a first indication message sent by the mobility management entity, where the first indication message is used to indicate that the serving gateway caches downlink data of the user equipment, where the downlink data sent by the data sending end is unreachable, generate a second indication message, and obtain address information of the data sending end; the transceiver 1740 is configured to generate and send a second indication message according to the indication of the first indication message and the address information of the data sending end, so that the data sending end sends downlink data of the user equipment according to the second indication message.

The method disclosed by the embodiment of the invention can be applied to the processor 1710 or implemented by the processor 1710. The processor 1710 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by instructions in the form of hardware, integrated logic circuits, or software in the processor 1710. The Processor 1710 may be a general-purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf programmable Gate Array (FPGA) or other programmable logic device, discrete Gate or transistor logic, or discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in a Random Access Memory (RAM), a flash Memory, a Read-Only Memory (ROM), a programmable ROM, an electrically erasable programmable Memory, a register, or other storage media that are well known in the art. The storage medium is located in the memory 1720, the processor 1710 reads the information in the memory 1720, and the bus system 1730 can include a power bus, a control bus, a status signal bus, etc. in addition to the data bus, and combines the hardware to perform the above-described method steps. But for purposes of clarity, the various buses are identified in the figure as bus system 1730.

the second indication message carries indication information.

the transceiver 1740 obtains address information of the data transmitting end according to the first indication message.

the processor 1710 performs downlink data detection according to the indication of the first indication message, and obtains address information of the data sending end.

Figure 18 is a schematic block diagram of a serving gateway according to another embodiment of the present invention. The service gateway shown in fig. 18 includes: a processor 1810, a memory 1820, a bus system 1830, and a transceiver 1840.

It should be understood that the service gateway 1800 shown in fig. 18 corresponds to the service gateway shown in fig. 14, and can implement the various processes related to the service gateway in the implementation of fig. 6, and the specific functions of the service gateway 1800 shown in fig. 18 can refer to the various processes performed by the service gateway in fig. 6, and a detailed description is appropriately omitted here to avoid redundancy.

Specifically, the transceiver 1840 is configured to receive a first indication message sent by a mobility management entity, where the first indication message is used to indicate that a serving gateway buffers downlink data of a user equipment whose downlink data sent by a data sending end is unreachable, and obtains address information of the data sending end; the processor 1810 is configured to invoke codes stored in the memory 1820 through the bus system 1830, perform detection on downlink data according to an instruction of the first instruction message, and acquire address information of a data sending end; the transceiver 1840 transmits the address information of the data transmitting end to the mobility management entity, so that the mobility management entity generates and transmits a second indication message to the data transmitting end according to the address information of the data transmitting end, so that the data transmitting end transmits downlink data of the user equipment according to the second indication message.

Therefore, in the embodiment of the present invention, a first indication message sent by a mobility management entity is received by a serving gateway, where the first indication message is used to indicate that the serving gateway buffers downlink data of a user equipment whose downlink data sent by a data sending end is inaccessible, and obtains address information of the data sending end; detecting downlink data according to the indication of the first indication message, and acquiring address information of a data sending end; and sending the address information of the data sending end to the mobility management entity, so that the mobility management entity generates and sends a second indication message to the data sending end according to the address information of the data sending end, so that the data sending end sends the downlink data of the user equipment according to the second indication message, for example, the downlink data of the user equipment is sent within the duration, and the downlink data is not sent in the time except the duration. Therefore, the downlink data can be flexibly transmitted, unnecessary data transmission is avoided, and the network efficiency is improved. The method disclosed in the embodiments of the present invention may be implemented in the processor 1810 or implemented by the processor 1810. Processor 1810 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware or instructions in the form of software in the processor 1810. The processor 1810 may be a general-purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, or discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in a Random Access Memory (RAM), a flash Memory, a Read-Only Memory (ROM), a programmable ROM, an electrically erasable programmable Memory, a register, or other storage media that are well known in the art. The storage medium is located in the memory 1820, the processor 1810 can read the information in the memory 1820, and complete the steps of the method in combination with the hardware, and the bus system 1830 can include a power bus, a control bus, a status signal bus, and the like in addition to a data bus. But for purposes of clarity the various buses are labeled in the figure as bus system 1830.

the second indication message carries indication information.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in various embodiments of the present invention, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

Additionally, the terms "system" and "network" are often used interchangeably herein. The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be understood that in the present embodiment, "B corresponding to a" means that B is associated with a, from which B can be determined. It should also be understood that determining B from a does not mean determining B from a alone, but may be determined from a and/or other information.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the examples described in connection with the embodiments disclosed herein may be embodied in electronic hardware, computer software, or combinations of both, and that the components and steps of the examples have been described in a functional general in the foregoing description for the purpose of illustrating clearly the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may also be an electric, mechanical or other form of connection.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment of the present invention.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

From the above description of the embodiments, it is clear to those skilled in the art that the present invention can be implemented by hardware, firmware, or a combination thereof. When implemented in software, the functions described above may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. Taking this as an example but not limiting: computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Furthermore, the method is simple. Any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, a server, or other remote source using a coaxial cable, a fiber optic cable, a twisted pair, a Digital Subscriber Line (DSL), or a wireless technology such as infrared, radio, and microwave, the coaxial cable, the fiber optic cable, the twisted pair, the DSL, or the wireless technology such as infrared, radio, and microwave are included in the fixation of the medium. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy Disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

In short, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method of data transmission, comprising:

when downlink data of user equipment sent by a data sending end is not reachable, a mobility management entity sends a first indication message to a service gateway, wherein the first indication message is used for indicating the service gateway to cache the downlink data;

the mobility management entity sends the second indication message to the data sending end, so that the data sending end sends downlink data of the user equipment according to the second indication message;

the first indication message carries indication information indicating that the serving gateway buffers the downlink data, where the indication information includes a duration of the serving gateway buffering the downlink data and/or a number of data packets of the serving gateway buffering the downlink data,

the second indication message carries the indication information;

wherein,

when the indication information comprises the duration, sending downlink data of the user equipment within the duration;

when the indication information comprises the number of the data packets, the number of the data packets of the downlink data of the user equipment is less than or equal to the number of the data packets;

when the indication information comprises the duration and the number of the data packets, sending the downlink data of the user equipment in the duration, wherein the number of the data packets of the downlink data of the user equipment sent in the duration is less than or equal to the number of the data packets.

2. The method of claim 1,

before the sending, by the mobility management entity, the first indication message to the serving gateway when the downlink data of the user equipment sent by the data sending end is not reachable, the method further includes:

the mobility management entity obtains a first request message sent by the data sending end, the first request message is used for requesting a network to feed back the second indication message when downlink data of the user equipment is unreachable, the first request message carries address information of the data sending end and an identifier of the user equipment,

3. The method according to claim 1 or 2, before the mobility management entity sends the second indication information to the data sender, further comprising:

the mobility management entity generates the second indication message.

4. The method according to claim 1 or 2, wherein the first indication message is further used to instruct the service gateway to generate the second indication message,

and the mobility management entity receives the second indication message sent by the service gateway.

5. The method of claim 1,

the determining, by the mobility management entity, that a second indication message needs to be sent to the data sending end includes:

6. The method of claim 5,

the first indication message is further configured to instruct the serving gateway to send address information of the data sending end to the mobility management entity, and before the mobility management entity sends the second indication message to the data sending end, the method further includes:

the mobility management entity receives address information of the data sending end sent by the service gateway;

and the mobility management entity generates the second indication message, wherein the second indication message carries the address information of the data sending end.

7. The method of claim 5,

the first indication message is further for instructing the service gateway to generate the second indication message,

8. The method of claim 1 or 2, further comprising:

and the mobility management entity receives a confirmation message sent by the data sending end, wherein the confirmation message is used for indicating that the data sending end has received the second indication message.

9. A method of data transmission, comprising:

a data sending end acquires a second indication message, wherein the second indication message is generated after a service gateway receives a first indication message, and the first indication message is used for indicating the service gateway to cache downlink data of user equipment with unreachable downlink data;

the data sending end sends downlink data of the user equipment according to the second indication message;

the second indication message carries the indication information;

wherein,

the data sending end determines to send the downlink data of the user equipment within the duration according to the second indication message,

the data sending end sends the downlink data of the user equipment according to the second indication message, and the number of data packets of the downlink data of the user equipment sent by the data sending end is less than or equal to the number of the data packets,

10. The method of claim 9,

when the indication information includes the duration or the indication information includes the duration and the number of data packets, the method further includes:

11. The method according to claim 9 or 10,

before the data sending end acquires the second indication message, the method further comprises the following steps:

12. The method of claim 9 or 10, further comprising:

and the data sending end sends a confirmation message to a mobile management entity, wherein the confirmation message is used for indicating that the data sending end has received the second indication message.

13. A method of data transmission, comprising:

a service gateway receives a first indication message sent by a mobility management entity, wherein the first indication message is used for indicating that the service gateway caches downlink data of user equipment with unreachable downlink data sent by a data sending end, and generates a second indication message;

the service gateway acquires address information of the data sending end;

the service gateway generates and sends a second indication message according to the indication of the first indication message and the address information of the data sending end, so that the data sending end sends downlink data of the user equipment according to the second indication message;

the second indication message carries the indication information;

wherein,

14. The method of claim 13, wherein the first indication message carries address information of the data sender,

the acquiring, by the serving gateway, address information of the data sending end includes:

15. The method of claim 13, wherein the first indication message is further used to instruct the serving gateway to obtain address information of the data sender,

and the service gateway detects the downlink data according to the indication of the first indication message and acquires the address information of the data sending end.

16. A method of data transmission, comprising:

a service gateway receives a first indication message sent by a mobility management entity, wherein the first indication message is used for indicating that the service gateway caches downlink data of user equipment with unreachable downlink data sent by a data sending end and acquiring address information of the data sending end;

the service gateway sends the address information of the data sending end to the mobility management entity, so that the mobility management entity generates and sends a second indication message to the data sending end according to the address information of the data sending end, and the data sending end sends downlink data of the user equipment according to the second indication message;

the second indication message carries the indication information;

wherein,

17. A mobility management entity, comprising:

a sending unit, configured to send the second indication message to the data sending end, so that the data sending end sends downlink data of the user equipment according to the second indication message;

the second indication message carries the indication information;

wherein,

18. The mobility management entity according to claim 17, further comprising:

an obtaining unit, configured to obtain a first request message sent by a data sending end before a first determining unit sends a first indication message to a serving gateway when downlink data of user equipment sent by the data sending end is unreachable, where the first request message is used to request a network to feed back a second indication message when the downlink data of the user equipment is unreachable, and the first request message carries address information of the data sending end and an identifier of the user equipment,

and if the second determining unit determines that the identifier of the user equipment is the same as the identifier of the user equipment carried in the first request message, determining that the second indication message needs to be sent to the data sending end.

19. The mobility management entity according to claim 17 or 18, further comprising:

20. The mobility management entity according to claim 17 or 18, wherein the first indication message is further configured to instruct the serving gateway to generate the second indication message, and wherein the mobility management entity further comprises:

a receiving unit, configured to receive the second indication message sent by the service gateway before the sending unit sends the second indication message to the data sending end.

21. The mobility management entity according to claim 17,

and if determining that the identifier identical to the identifier of the user equipment exists in a preset feedback identifier list, the first determining unit determines that the second indication message needs to be sent to the data sending end, wherein the preset feedback identifier list comprises the identifier of the user equipment needing to feed back the second indication message.

22. The mobility management entity according to claim 21,

the first indication message is further configured to instruct the serving gateway to send address information of the data sending end to the mobility management entity, where the mobility management entity further includes:

a first receiving unit, configured to receive address information of the data sending end sent by the service gateway before the sending unit sends the second indication message to the data sending end;

a second generating unit, configured to generate the second indication message before the sending unit sends the second indication message to the data sending end, where the second indication message carries address information of the data sending end.

23. The mobility management entity according to claim 21, wherein the first indication message is further used for instructing the serving gateway to generate the second indication message, and wherein the mobility management entity further comprises:

24. The mobility management entity according to claim 17 or 18, further comprising:

a third receiving unit, configured to receive a confirmation message sent by the data sending end, where the confirmation message is used to indicate that the data sending end has received the second indication message.

25. A data transmitting end, comprising:

an obtaining unit, configured to obtain a second indication message, where the second indication message is generated after a service gateway receives a first indication message, and the first indication message is used to indicate that the service gateway caches downlink data of a user equipment whose downlink data is unreachable;

a first sending unit, configured to send downlink data of the user equipment according to the second indication message;

the second indication message carries indication information of the serving gateway caching the downlink data, and the indication information includes duration of the serving gateway caching the downlink data and/or number of data packets of the serving gateway caching the downlink data;

wherein,

when the indication information includes the number of the data packets, the first sending unit sends the downlink data of the user equipment according to the second indication message, and the number of the data packets of the downlink data of the user equipment sent by the data sending end is less than or equal to the number of the data packets,

when the indication information includes the duration and the number of data packets, the first sending unit determines to send the downlink data of the user equipment within the duration according to a second indication message, and the number of data packets of the downlink data of the user equipment sent by the data sending end within the duration is less than or equal to the number of data packets.

26. The data sender according to claim 25,

when the indication information includes the duration, or the indication information includes the duration and the number of data packets, the data transmitting end further includes:

a determining unit, configured to determine, according to the second indication message, that downlink data of the user equipment is not to be sent at a time other than the duration.

27. The data transmitting end according to claim 25 or 26, further comprising:

28. The data transmitting end according to claim 25 or 26, further comprising:

a third sending unit, configured to send a confirmation message to a mobility management entity, where the confirmation message is used to indicate that the data sending end has received the second indication message.

29. A serving gateway, comprising:

a receiving unit, configured to receive a first indication message sent by a mobility management entity, where the first indication message is used to indicate that downlink data of a user equipment, which is unreachable by downlink data sent by a data sending end, is cached by the serving gateway, and generate a second indication message;

a sending unit, configured to generate and send a second indication message according to the indication of the first indication message and the address information of the data sending end, so that the data sending end sends downlink data of the user equipment according to the second indication message;

the second indication message carries the indication information;

wherein,

30. The serving gateway of claim 29, wherein the first indication message carries address information of the data sender,

31. The serving gateway of claim 29, wherein the first indication message is further used to instruct the serving gateway to obtain address information of the data sender,

32. A serving gateway, comprising:

a receiving unit, configured to receive a first indication message sent by a mobility management entity, where the first indication message is used to indicate that a serving gateway caches downlink data of a user equipment whose downlink data sent by a data sending end is unreachable, and acquire address information of the data sending end;

a sending unit, configured to send address information of the data sending end to the mobility management entity, so that the mobility management entity generates and sends a second indication message to the data sending end according to the address information of the data sending end, so that the data sending end sends downlink data of the user equipment according to the second indication message;

the second indication message carries the indication information;

wherein,