WO2010130081A1

WO2010130081A1 - Access terminal and method for redirection from high rate packet data network to different network

Info

Publication number: WO2010130081A1
Application number: PCT/CN2009/071735
Authority: WO
Inventors: 许明霞; 王萦明; 夏共仪
Original assignee: 华为技术有限公司
Priority date: 2009-05-11
Filing date: 2009-05-11
Publication date: 2010-11-18
Also published as: CN102349331B; CN102349331A

Abstract

Embodiments of the present invention disclose an access terminal and a method for redirection from high rate packet data network to a different network, and the method includes: scanning the signal strength of the different network; when the scanned signal strength of the different network meets the service requirement, sending a route update request to the high rate packet data access network, wherein an indication of signals of the different system being available is carried in the route update request; and receiving the redirection message from the high rate packet data access network.

Description

Access terminal and method for redirecting from 髙 rate packet data network to different network

Technical field

The present invention relates to terminal access technologies, and in particular, to an access terminal and a method for redirecting from a high rate packet data network to a different network. Background technique

Since the 1990s, Code Division Multiple Access (CDMA) systems have attracted widespread attention and related research work has been very active. CDMA2000 is one of the mainstream technologies of 3G in CDMA systems. Among them, CDMA2000-1X is the first stage of CDMA2000 system development, and its corresponding protocol versions are "CDMA2000 Release 0", "CDMA2000 Release A" and "CDMA2000 Release B". It is backward compatible with the existing IS_95 standard. High Data Rate (HDR) technology developed by Qualcomm and accepted by the TIA/EIA as the IS-856 standard, also known as High Rate Packet Data (HRPD) or lx EV-DO. IX indicates that it has exactly the same RF bandwidth and chip rate as the CDMA2000 I system, and has good backward compatibility; EV (Evolution) indicates that it is an evolved version of CDMA2000 IX; DO (Data Optimization) indicates that it is specifically targeted Packet data service optimization technology. Lx EV-D0, that is, HRPD is accepted by ITU-R as one of the 3G technical standards.

In addition, Long Term Evolution (LTE) technology is considered to be the mainstream technology of 4G mobile communication systems. The LTE system uses Orthogonal Frequency Division Multiple Access (OFDM) and Multiple Input Multiple Output (MIM0) technology to greatly improve the spectrum utilization and capacity of the communication system. In addition, LTE technology can better support big data download services such as VoIP or video calling. As LTE is the next generation of mainstream technology, some operators are now gradually upgrading from existing HRPD networks to LTE networks. In the process of network upgrade, there are two networks, HRPD and LTE. The coverage of the two networks includes vertical overlap or horizontal plane intersection. Users need to use HRPD-LTE dual-mode access terminal (AT, Access Terminal) for network-wide operation. Roaming.

According to the existing HRPD protocol, the AT is redirected from the HRPD to the idle state and the connected state. The process of the LTE network is as follows:

In the idle state, the AT can temporarily leave the HRPD network at a time other than the paging time to scan the LTE network information so as not to affect the paging. If the LTE signal quality meets the requirements, the AT will directly leave the HRPD network and perform access. After the operation of the different system, after the AT completes the access registration, the data sent by the core network to the AT will be sent to the different system access network, and then sent to the AT. The pre-established session of the AT on the HRPD network will time out and be automatically deleted.

In the connected state, the AT allocates a forward traffic channel and a reverse traffic channel by the HRPD access network (AN, Access Network), and the AT receives data on the forward traffic channel and transmits data on the reverse channel. . Since the HRPD protocol does not specify a specific time interval in the connected state for the AT to measure other systems. Therefore, if the AT needs to measure the different system in the connected state, the AT needs to disconnect and switch to the idle state, and can temporarily leave the HRPD network at a time other than the paging time to scan the LTE network information, if the LTE signal quality If the requirements are met, the AT will leave the HRPD network and perform the operation of accessing the different system. After the AT completes the access registration, the data sent by the core network to the AT will be sent to the different system access network and then sent to the AT. The pre-established session of the AT on the HRPD network will time out and be automatically deleted.

As can be seen from the above, according to the existing HRPD protocol, after the AT measures the different system, if the different system meets the requirements, the AT will decide whether to transfer to the different system. When the AT decides to transfer to the different system, the AT will directly leave the HRPD network. The access registration operation is performed in a different system, but the HRPD access network does not know that the AT has left the HRPD network at this time. Therefore, before the AT completes the access registration operation of the different system, the data sent by the core network to the AT still remains. The data is sent to the HRPD access network. The HRPD access network initiates paging. However, the AT has left the HRPD network and will not receive the HRPD page. Therefore, the data cannot be delivered and is lost. Summary of the invention

An embodiment of the present invention provides a method for an access terminal to redirect from a high-rate packet data network to a different network, including:

Scan the signal strength of different networks;

And when the signal strength of the scanned different network meets the service requirement, sending a route update request to the high-rate packet data access network, where the route update request carries an indication of a different system signal available. An embodiment of the present invention further provides an access terminal, including:

a measuring unit for scanning signal strength of the different network;

And a first sending unit, configured to send, to the high-rate packet data access network, a route update request, where the signal strength of the scanned different network meets a service request, where the route update request carries an indication of a different system signal available.

According to the embodiment of the present invention, since the AT notifies the access network after detecting that the signal strength of the different network meets the requirement, even when the AT just leaves the HRPD network and has not completed the access registration and attach operation of the different network, when the AT After receiving the data sent from the core network to the AT, since the M has learned the departure of the AT, the AN will not send the paging to the AT again, that is, the paging resource of the space interface is saved. DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only the present invention. For some embodiments, other drawings may be obtained from those skilled in the art without any inventive labor.

1 is a schematic flowchart of redirecting an AT from an HRPD network to a different network according to an embodiment of the present invention; FIG. 2 is a schematic flowchart of redirecting an AT from an HRPD network to a different network according to another embodiment of the present invention; A structural block diagram of an access terminal in an embodiment;

FIG. 4 is a structural block diagram of an access terminal according to another embodiment of the present invention. detailed description

BRIEF DESCRIPTION OF THE DRAWINGS The technical solutions in the embodiments of the present invention will be described in detail with reference to the accompanying drawings. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative work are within the scope of the present invention. Embodiment 1

This embodiment provides a method for an access terminal to redirect from a high rate packet data network to a different network. (1) When the AT is in an idle state, as shown in FIG. 1, the method includes the following steps: Step 110: Measure a signal strength of the different network.

In this embodiment, the different network may be an LTE network, or may be a network of other access technologies, such as WiMAX. The embodiment is not limited thereto.

In this step, when the AT is in an idle state, according to the information of the broadcast or unicast different network neighboring area received from the HRPD network (including at least the channel number), the time may be outside the paging time, that is, without affecting the search. In the case of the call, the HRPD network is temporarily left to scan the different network, such as the LTE network, to measure whether the signal strength of the different network meets the service requirement.

Step 120: When the measurement result is that the signal strength of the different network meets the service requirement, the AT sends a Route Update message to the HRPD access network, where the route update message carries an indication that the different network signal is available.

The route update message may be sent to the AN through a random access channel.

In the HRPD network air interface protocol version A, the format of the route update message is as shown in Table 1. The length of the entire message is 36+n*23, or 36+n*47, where n is the value of the NumPi lots field in the message, ie It is 0-15. HRPD Network Air Interface Protocol Version A specifies that the message must be added with redundant bits to make up the entire byte. In most cases, the RouteUpdate message needs to add more bits or more bits of redundancy.

In the embodiment of the present invention, a field is added to the redundancy bit of the route update message to transmit information about whether the different network is available to the AN. For example, when the different network is LTE, the added field may be “LTE is available (LTE Avai lable). ) "Field, as shown in Table 2. Since this added field does not increase the message length, no additional overhead is introduced. When the access terminal scans the signal of the LTE network and its signal strength meets the requirements of the LTE rule, the access terminal may set the "LTE is available" field to 1; otherwise, the access terminal sets the field to 0.

According to this step, when the different network signal is available, the AT can report an indication of the different network signal to M.

Table 1. HRPD Network Air Interface Protocol A version of the RouteUpdate message structure

Fields Length Meaning MessagelD 8 original field

MessageSequence 8 original field

Ref erencePi lotPN 9 original field

Ref erencePi lotStrength 6 original field

ReferenceKeep 1 original field

NumPilots 4 original fields

NumPilots occurrences of the following fields appear in the following fields:

Pi lotPNPhase 15 original field

Channel Included 1 original field

Channe 1 0 or 24 original field

Pi lotStrength 6 original field

Keep 1 original field reserved Variable Original field Table 2. RouteUpdate message structure with new fields added

Fields Length Meaning

MessagelD 8 original field

MessageSequence 8 original field

Ref erencePi lotPN 9 original field

Ref erencePi lotStrength 6 original field

ReferenceKeep 1 original field

NumPilots 4 original fields

NumPilots occurrences of the following fields appear in the following fields:

Pi lotPNPhase 15 original field

Channel Included 1 original field

Channe 1 0 or 24 original field

Pi lotStrength 6 original field

Keep 1 original field LTE Available New field reserved variable The original field is as above. In the idle state, after detecting that the signal strength of LTE meets the requirements, the AT notifies the AN through the new field in the RouteUpdate message, and informs the AT to search for the LTE that meets the requirements. Network, the AN can instruct the AT to leave the HRPD network and go to the LTE network. In this way, even when the AT just leaves the HRPD network and has not completed the access registration and attach operation of the LTE network, when the AN receives the data sent from the core network to the AT, since the AN has learned the departure of the AT, the AN also The paging of the AT will not be sent again, that is, the paging resources of the spatial interface are saved.

Step 130: The AT receives a redirect (Redirect) message from the HRPD access network, and performs access to the different network according to the redirect message.

After the HRPD access network AN receives the Rout eUpdat e message sent by the AT, if the value of the "LTE Availability" field carried in the message is 0, it indicates that the AT does not have a suitable LTE network available. In this case, the AN can According to the prior art, dedicated channel resources are allocated to the AT as needed or the location information of the AT is updated on the network side.

If the AN parses the value of the "LTE Availability" field carried in the RouteUpdate message, it indicates that the AT has a good LTE network available, and the AN can decide whether to instruct the AT to leave the HRPD network and access the LTE network.

If the AN grants the AT access to the LTE network, it will send a unicast Redirect message to the AT, instructing the AT to leave the HRPD network and access the LTE network. The Redirect message can be sent to the AT through the forward control channel.

If the AN does not allow the AT to access the LTE network, the AN will not send a unicast Redirect message. If the AT does not receive the unicast Redirect message, the AT will continue to reside in the original HRPD network.

If the AN chooses not to send a Redirect message to the AT, the AN will not allocate dedicated channel resources to the AT. In this way, the AT will continue to reside within the HRPD network.

Optionally, the Redirect message may carry the LTE frequency information that is available to the AT, and the specific message The format is shown in Figure 3. The newly added RedirectFrequencylncluded field indicates whether the LTE frequency information is included in the message. If the LTE frequency information is included, the field is set to. If the LTE frequency information is not included, the field may be omitted and the Reserved field is followed. All other fields; if RedirectFrequencylncluded is, then the NumEARFCN field indicates the number of occurrences of the next EUTRADup lexMode and EARFCN fields; the EUTRADup lexMode field indicates that the duplex mode of the LTE network is Frequency Division Duplex (FDD) or Time Division Duplex (TDD) EARFCN is the LTE radio frequency channel number, indicating the operating frequency of the LTE network. Reserved indicates a 0-7 bit padding, so that the length of the message is an integer multiple of bytes, and the sender should set these bits to '0'.

Table 3. Redirect message format

According to the above steps of the embodiment of the present invention, the HRPD network can actively control whether the AT can be reselected to the different system.

In another embodiment of the present invention, the method may also be simplified as follows:

After the AT sends the route update message to the AN through the step 120, the AT can directly access the different network without waiting for the Redirect message of the AN. In this way, even when the AT just leaves the HRPD network and has not completed the access registration and attach operation of the LTE network, when the AN receives the data sent from the core network to the AT, since the AN has learned the departure of the AT, the AN also The paging of the AT will not be sent again, that is, the paging resources of the spatial interface are saved.

(2) When the AT is in the connected state, as shown in FIG. 2, the method for redirecting the AT from the HRPD network to the different network in the embodiment includes the following steps:

Step 210: Optionally, the AT negotiates with the AN message for a period of time, during which the AT will temporarily leave the HRPD network.

The purpose of this step is to notify the AN before the AT leaves the HRPD network temporarily, so as to avoid the occurrence of lost packets caused by the AT being sent to the AT while the AT has tune away from the HRPD network.

Step 220: Measure the signal strength of the different network.

In this step, in the connected state, the AT temporarily leaves the HRPD network to scan the different network, such as the LTE network, according to the information of the broadcast or unicast different network neighboring area (including at least the channel number) received from the HRPD network, to measure the difference. Whether the signal strength of the network meets the service requirements.

Step 230: When the measurement result is that the signal strength of the different network meets the service requirement, the AT sends a Route Update message to the HRPD access network, where the route update message carries an indication of the different network signal available.

The route update message may be sent to the AN through a reverse traffic channel.

The AT may send a RouteUpdate message to the HRPD network, and the indication message carrying an LTE signal in the message is reported to the AN (the message can be sent through the reverse traffic channel). The format of the RouteUpdate message is shown in Table 2.

When the access terminal scans the signal of the LTE network and its signal strength meets the LTE rule requirements, the access terminal may set the "LTE is available" field to 1; otherwise, the access terminal sets the field to 0.

Through the above steps, in the connected state, after detecting that the signal strength of the LTE meets the requirements, the AT notifies the AN through the new field in the RouteUpdate message, and informs the AT to search for the LTE network that meets the requirements, and the AN can instruct the AT to leave the HRPD network. Go to the LTE network. In this way, even when the AT just leaves the HRPD network and has not completed the access registration and attach operation of the LTE network, since the AN has been known When the AT leaves, the AN can inform the upper-level network element packet data service network (PDSN) of the AN in the HRPD network to cache all data sent to the AT without being sent to the AN to reduce data loss.

Step 240: Receive a redirect (Redirect) message from the HRPD access network, and perform access to the different network according to the redirect message.

After the HRPD access network receives the RouteUpdate message sent by the AT, if the value of the "LTE Availability" field carried in the message is 0, the description indicates that the AT does not have a suitable LTE network available, and the AN will follow the prior art. The location information of the AT is updated on the network side as needed.

If the value of the "LTE Availability" field carried in the message is parsed, the value of the LTE indicates that the AT has a good LTE network, and the AN can decide whether to instruct the AT to leave the HRPD network and access the LTE network.

If the AN grants the AT access to the LTE network, it will send a unicast Redirect message to the AT, instructing the AT to leave the HRPD network and access the LTE network. The Redirect message can be sent through the forward traffic channel.

If the AN chooses not to send a Redirect message to the AT, the AN updates the location information of the AT on the network side or closes the connection with the AT according to the prior art.

After the AT sends the route update message to the AN through the step 230, the AT can directly access the different network without waiting for the Redirect message of the AN.

In this way, even when the AT just leaves the HRPD network and has not completed the access registration and attach operation of the LTE network, when the AN receives the data sent from the core network to the AT, since the AN has learned the departure of the AT, the AN also The paging of the AT will not be sent again, that is, the paging resources of the spatial interface are saved.

The present invention is also applicable to the case where multiple access technologies and HRPDs coexist, from HRPD reselection to other access technologies. In this case, network information of the corresponding access technology needs to be obtained and sent to the HRPD network. The measurement results of the corresponding access technology.

A person skilled in the art can understand that all or part of the process of implementing the above embodiment method can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium. In execution, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

Example 2

The embodiment provides an access terminal having a function of redirecting from a high-rate packet data network to a different network. As shown in FIG. 3, the access terminal 300 includes:

The measuring unit 310 is configured to scan the signal strength of the different network.

The first sending unit 320 is configured to send, when the signal strength of the scanned different network meets the service requirement, a routing update request to the high-rate packet data access network, where the routing update request carries an indication that the different system signal is available .

In another embodiment of the present invention, the inoculation terminal further includes:

The receiving unit 330 is configured to receive a redirect message from the high rate packet data access network. The redirect message carries the different system frequency point information available to the access terminal.

In another embodiment of the present invention, as shown in FIG. 4, the access terminal further includes:

The second sending unit 340 is configured to send an indication message to the high-rate packet data access network before the measuring unit scans the signal strength of the different network, to instruct the access terminal to temporarily leave the high-rate packet data network.

The above described specific embodiments of the present invention are further described in detail, and are intended to be illustrative of the embodiments of the present invention. The scope of the protection, any modifications, equivalents, improvements, etc., made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

Claim

A method for redirecting an access terminal from a high-rate packet data network to a different network, comprising:

Scan the signal strength of different networks;

And when the signal strength of the scanned different network meets the service requirement, sending a route update request to the high-rate packet data access network, where the route update request carries an indication of a different system signal available.

2. The method according to claim 1, further comprising:

A redirect message is received from a high rate packet data access network.

3. The method of claim 1 wherein:

The redirect message carries different system frequency point information that is available to the access terminal.

The method according to claim 1, wherein before the scanning the different network, the method further comprises: sending an indication message to the high-rate packet data access network when the access terminal is in an idle state, indicating The access terminal temporarily leaves the high rate packet data network.

5. A method according to any one of claims 1 to 4, characterized in that:

The different network is a long term evolution network.

6. An access terminal having a function of redirecting from a high rate packet data network to a different network, characterized in that:

a measuring unit for scanning signal strength of the different network;

The access terminal according to claim 6, further comprising:

And a receiving unit, configured to receive a redirect message from the high rate packet data access network.

8. The access terminal according to claim 6, wherein:

The access terminal according to claim 6, further comprising: a second sending unit, configured to send, to the high-rate packet data access network, before the measuring unit scans a signal strength of the different network An indication message indicating that the access terminal temporarily leaves the high rate packet data network.

The access terminal according to any one of claims 6 to 9, wherein the different network is a long term evolution network.