CN106912084B

CN106912084B - Method and equipment for determining WLAN access point

Info

Publication number: CN106912084B
Application number: CN201510973926.3A
Authority: CN
Inventors: 汪治; 蔡亦钢
Original assignee: Alcatel Lucent SAS
Current assignee: Alcatel Lucent SAS
Priority date: 2015-12-22
Filing date: 2015-12-22
Publication date: 2021-06-04
Anticipated expiration: 2035-12-22
Also published as: WO2017109572A1; CN106912084A

Abstract

The invention aims to provide a method and equipment for selecting a WLAN access point in LWA. The invention sets WLAN access point selection strategy in PCRF, and sends the WLAN access point selection strategy to eNB in UE attachment phase, and then the eNB selects the optimal WLAN access point for the UE in LWA according to the WLAN access point selection strategy. Various real-time, dynamic factors are considered in the WLAN access point selection strategy. By adopting the invention, the selection of the WLAN access point is more reasonable, and various requirements of operators and terminal users can be met. In addition, the invention enables an operator to configure the WLAN access point selection strategy according to various requirements, and also can dynamically adjust the WLAN access point, thereby realizing the optimal selection of the WLAN access point in the LWA.

Description

Method and equipment for determining WLAN access point

Technical Field

The invention relates to the technical field of communication, in particular to an LWA technology.

Background

WiFi and cellular technologies (mainly representing LTE) have now become the two most successful wireless technologies. For many years, they have been complementary in their advantages, and as the demand for wireless capacity increases, it is the best opportunity to promote their convergence with each other. Currently, there are two main solutions for the convergence of WiFi and LTE.

One is to use LTE on Unlicensed bands, i.e., LTE-U (LTE in Unlicensed spectrum) or LTE-LAA (LTE-Licensed Assisted Access).

LTE-U or LTE-LAA is a way to run LTE directly on unlicensed bands, extending the LTE system from licensed to unlicensed bands. This approach may have a reduced coverage advantage by allowing more wireless spectrum to support mobile services.

The other is LTE and WiFi aggregation, lwa (LTE WiFi aggregation).

Fig. 1 illustrates a working principle diagram of the LWA. It can be seen that with LWA, the eNB can separate the LTE data payload, some traffic will be transmitted over WiFi, and the rest will be transmitted over LTE itself, thus greatly improving the performance of LTE services. LWA employs WLAN Access points to augment LTE RAN (Radio Access Network).

The technology which is greatly popularized by high throughput still achieves very similar effects to the LTE-U and the LTE-LAA although the technology has some differences from the LTE-U and the LTE-LAA.

By adopting LWA, WiFi runs on an unlicensed frequency band, and LTE runs on a licensed frequency band, and the combination of the two wireless technologies brings excellent user experience. Both technologies can perform their own advantages, and LTE does not need to perform any abnormal operations. Unlike the deployment of LTE-U or LTE-LAA, which requires entirely new network hardware and entirely new smart phones, LWA can be enabled with only a simple software upgrade.

The WLAN access point may also continue to support non-LWA traffic on independent SSIDs (Service Set ID), which has more advantages than using LTE in unlicensed bands, while avoiding the disadvantages and combining the advantages of both. Therefore, LWA becomes a solution that does not affect the unlicensed band, and can make full use of the existing WLAN access point and improve performance.

In the existing LWA scheme, the eNB only considers the signal strength of the WLAN access point when selecting the WLAN access point, and does not consider other factors such as charging factors, load or processing capability of related network elements, network traffic, and the like. These factors are critical to both the operator and the end user. For example, the user may wish to select a WLAN access point that is inexpensive to charge as much as possible when selecting the WLAN access point. It is desirable for operators to make the right use of network resources to attract more traffic when some WLAN access points are under load, and vice versa to reduce the usage of the access points.

Therefore, the existing LWA schemes cannot flexibly and dynamically select WLAN access points to meet various demands of operators and end users.

Disclosure of Invention

The invention aims to provide a method and equipment for dynamically and flexibly selecting a WLAN access point in LWA.

According to a first aspect of the present invention, there is provided a method in a PCRF of an LWA network for selecting a WLAN access point, the method comprising the steps of: a. receiving a session establishment request from an eNB, wherein the session establishment request is triggered by an attachment request of a UE; b. generating a WLAN access point selection policy for the UE, the WLAN access point selection policy for instructing the eNB to determine an optimal WLAN access point for the UE in LWA; c. sending a session setup request reply to the eNB including the WLAN access point selection policy.

Preferably, the WLAN access point selection policy includes WLAN access points selectable by the UE in the LWA and a priority of each of the selectable WLAN access points.

Preferably, the priority is a calculation formula or a calculation rule.

Preferably, the PCRF determines the priority of each optional WLAN access point according to at least one of the following information:

billing information for the WLAN access point;

a location of the UE;

the load of the eNB;

the size of user data traffic;

available bandwidth for connection of a WLAN access point with an eNB;

a stable state of connection of the WLAN access point with the eNB;

historical completion of the WLAN access point handling LWA offloading.

Preferably, the method further comprises: updating the WLAN access point selection strategy according to a real-time monitoring result; notifying the eNB of the updated WLAN access point selection policy.

Preferably, the WLAN access point selection policy further comprises at least one of the following information:

the usage pattern of each optional WLAN access point;

a priority of LTE;

preferred values for each optional WLAN access point.

According to a second aspect of the present invention, there is provided a method in an eNB of an LWA network for selecting a WLAN access point, the method comprising the steps of: A. receiving a session establishment request reply from the PCRF, wherein the session establishment request reply comprises a WLAN access point selection policy, the session establishment request reply is in response to an attachment request of a UE, and the WLAN access point selection policy is used for indicating the eNB to determine an optimal WLAN access point for the UE in LWA; B. sending a configuration message to the UE for instructing the UE to detect an available WLAN access point; C. in response to a measurement report from the UE, the measurement report including available WLAN access points detected by the UE, determining an optimal WLAN access point among the available WLAN access points detected by the UE according to the WLAN access point selection policy; D. and if the optimal WLAN access point exists, dividing data sent to the UE into two parts, wherein one part is directly sent to the UE through LTE, the other part is sent to the optimal WLAN access point, and the optimal WLAN access point is sent to the UE.

Preferably, the WLAN access point selection policy further includes a priority of LTE, and the step of determining the optimal WLAN access point further includes: and if the priority of the WLAN access point with the highest priority is less than that of the LTE, determining that the optimal WLAN access point does not exist.

Preferably, the priority is a calculation formula or a calculation rule, and the calculation formula or the calculation rule contains at least one of the following information:

a location of the UE;

the load of the eNB;

the size of user data traffic;

available bandwidth for connection of a WLAN access point with an eNB;

a stable state of connection of the WLAN access point with the eNB;

historical completion of the WLAN access point handling LWA offloading.

Preferably, the method further comprises: updating the WLAN access point selection strategy according to a real-time monitoring result or a notice containing the updated WLAN access point selection strategy from the PCRF; and D, re-executing the steps B to D according to the updated WLAN access point selection strategy.

According to a third aspect of the present invention, there is provided an apparatus in a PCRF of an LWA network for selecting a WLAN access point, the apparatus comprising: first receiving means for receiving a session establishment request from an eNB, the session establishment request being triggered by an attach request of a UE; a policy generating device, configured to generate a WLAN access point selection policy for the UE, where the WLAN access point selection policy is used to instruct the eNB to determine an optimal WLAN access point for the UE in an LWA; a first sending device, configured to send a session establishment request reply to the eNB, where the session establishment request reply includes the WLAN access point selection policy.

According to a fourth aspect of the present invention, there is provided an apparatus for selecting a WLAN access point in an eNB of an LWA network, the apparatus comprising: second receiving means, configured to receive a session establishment request reply from the PCRF, where the session establishment request reply includes a WLAN access point selection policy, where the session establishment request reply is in response to an attach request of a UE, and the WLAN access point selection policy is used to instruct the eNB to determine an optimal WLAN access point for the UE in the LWA; a second sending device, configured to send a configuration message to the UE, for instructing the UE to detect an available WLAN access point; determining means, responsive to a measurement report from the UE, the measurement report including available WLAN access points detected by the UE, for determining an optimal WLAN access point among the available WLAN access points detected by the UE according to the WLAN access point selection policy; and the LWA executing device is used for dividing the data transmitted to the UE into two parts when the optimal WLAN access point exists, wherein one part is directly transmitted to the UE through LTE, the other part is transmitted to the optimal WLAN access point, and the optimal WLAN access point is transmitted to the UE.

Compared with the existing LWA scheme, the invention provides a dynamic and flexible WLAN access point selection scheme in the LWA. In the process of selecting the WLAN access point, various dynamic factors such as a charging factor, the load of a related network element, the processing capacity of the related network element, network flow and the like are fully considered, so that the selection of the WLAN access point is more reasonable, and various requirements of operators and terminal users can be met. In addition, the invention enables an operator to configure the WLAN access point selection strategy according to various requirements, and also can dynamically adjust the WLAN access point, thereby realizing the optimal selection of the WLAN access point in the LWA.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments made with reference to the following drawings:

fig. 1 shows a schematic diagram of the working principle of the LWA.

Fig. 2 shows a schematic diagram of a process for determining a WLAN access point in an LWA network according to an embodiment of the invention;

fig. 3 shows a schematic diagram of a process for determining a WLAN access point in an LWA network according to an embodiment of the invention;

fig. 4 shows a schematic diagram of an apparatus in a PCRF for determining a WLAN access point according to an embodiment of the present invention;

fig. 5 is a schematic diagram of an apparatus for determining a WLAN access point in an eNB according to another embodiment of the present invention.

The same or similar reference numbers in the drawings identify the same or similar elements.

Detailed Description

The present invention achieves the goal of flexibly and dynamically selecting a WLAN access point by generating a WLAN access point selection policy in the PCRF and enforcing the policy by the eNB, which is used to instruct the eNB to determine the optimal WLAN access point for the UE in the LWA.

The present invention is described in further detail below with reference to the attached drawing figures.

Fig. 2 shows a schematic diagram of a process for determining a WLAN access point in an LWA network according to an embodiment of the invention.

It should be noted that the procedure is improved based on the UE attach procedure specified in section 5.3.2 of 3GPP TS 23.401. Fig. 2 only shows messages related to the invention, and more message flows are shown in section 5.3.2 of 3GPP TS 23.401 and section 7.2 of 3GPP TS 23.203.

The process starts at step S201.

In step S201, the UE20 sends an Attach Request, such as the Attach Request message shown in the figure, to the eNB 21.

Next, in step S202, eNB21 sends an Attach Request, such as the Attach Request message shown in the figure, to MME 22.

Then, in step S203 and step S204, the MME22 sends a Create Session Request, such as a Create Session Request message shown in the figure, to the PGW24 through the SGW 23.

Next, in step S205, the PGW24 sends a Session Establishment request, such as an Indication of IP-CAN Session Establishment message shown in the figure, to the PCRF 25.

Then, in step S206, the PCRF25 generates a WLAN access point selection policy P for the UE20, which is used to instruct the eNB21 to determine an optimal WLAN access point for the UE20 in LWA.

The PCRF25 may generate the WLAN access point selection policy P based on information from the SPR, local configuration information, preset rules, network conditions, etc.

In one embodiment, the WLAN access point selection policy P includes the WLAN access points that the UE20 can select in the LWA and the priority of each of the selected WLAN access points.

The PCRF25 may determine the priority of each optional WLAN access point based on one or more of the following information (but not limited to the following information):

-charging information of WLAN access points

Different priorities may be set according to different rates. If the tariff for a WLAN access point is higher, the corresponding priority is lower.

-time of day

Different priorities may be set for alternative WLAN access points according to the time difference. Such as: considering that the load of a WLAN access point varies with time, the load is higher during the day, and the load is lower at night, the priority of the WLAN access point is lower during the day, and the priority of the WLAN access point is higher at night.

-location of UE

Different priorities may be set for the optional WLAN access points depending on the location of the UE. For example, the priority of the WLAN access point close to the UE is higher, and the priority of the WLAN access point far from the UE is lower.

-user data traffic size

Different priorities may be set for the WLAN access points according to dynamic changes in the UE data traffic. Such as: when the user peak data flow exceeds a certain set value, a higher priority is set for the WLAN access point, and LWA transmission is enabled to be shunted for the eNB. When the peak data flow of the user is lower than a certain set value, for example, a lower priority is set for the WLAN access point, so that data is transmitted by an LTE interface as far as possible, and unnecessary consumption caused by using LWA (Low data traffic) is avoided.

Available bandwidth for connection of WLAN access point with eNB

When the available bandwidth of the connection between the WLAN access point and the eNB is larger than a certain threshold value, a higher priority is set, and conversely, when the available bandwidth of the connection between the WLAN access point and the eNB is smaller than a certain threshold value, a lower priority is set.

Steady state of connection of WLAN access point with eNB

The more stable the connection of the WLAN access point to the eNB, the higher the corresponding priority.

Historical completion of processing LWA offload for WLAN access points

Mainly refers to the processing capability of the WLAN access point, including data traffic, time delay, etc. which can be processed. If the WLAN access point completes well when processing the LWA offload in a certain period of time, its corresponding priority is higher, for example, if the WLAN access point continues to have a delay higher than a certain threshold when processing the offloaded data in a certain period of time, the priority of the WLAN access point is lowered.

In one embodiment, the priority is a specific value, and the PCRF25 may determine the specific value of the priority according to the above information. In yet another embodiment, the priority is a calculation formula or calculation rule, and PCRF25 may include the above information in the calculation formula or calculation rule.

In yet another embodiment, the WLAN access point selection policy P further comprises at least one of the following information:

usage pattern of each optional WLAN access point

It is indicated how to use the WLAN access point, e.g. for downlink data only, for uplink data only or for both uplink and downlink data.

-priority of LTE

The WLAN access point selection policy P may also contain an LTE priority, which may only be selected if the priority of the WLAN access point is higher than the LTE priority.

At this time, PCRF25 may also determine the priority of each optional WLAN access point based on the eNB's load. In particular, different priorities may be set for the selectable WLAN access points according to dynamic load changes of the eNB serving the UE. When the eNB load continues to increase, this means that the overhead of using LTE transmissions is increasing, i.e. the relative positions of the priority of the WLAN access point and the priority of LTE start to change, and the priority of the WLAN access point relative to LTE is increasing. To reflect this change, the priority of the optional WLAN access point may be increased by one level for each increase in the loading of the eNB above a certain threshold. Such as: the initial LTE priority is 7 and the WLAN access point priority is 5. Because LTE is a high priority (using the WLAN access point is more expensive than using existing LTE bearers), the WLAN access point is not selected. I.e. data is transmitted only over LTE and not LWA. But when the corresponding eNB load continues to increase to 75%, the priority of the WLAN access point increases to 8, and the WLAN access point is selected and the LWA mode is used for data transmission.

-preferred value of each optional WLAN access point

If the priority of the two WLAN access points is the same, the WLAN access point with the high preference value may be preferentially selected.

After the PCRF25 generates the WLAN access point selection policy P, in step S207, the PCRF25 sends a Session establishment request reply, such as an acknowledgement of IP-CAN Session establishment established message shown in the figure, to the PGW24, where the WLAN access point selection policy P is included. The PCRF25 may add an AVP (Attribute Value Pair) in the existing acknowledgement of IP-CAN Session establishment message to carry the information of the WLAN access point selection policy P.

In steps S208 and S209, the PGW24 sends a Create Session reply, such as a Create Session Response message shown in the figure, to the MME22 via the SGW23, where the WLAN access point selection policy P is included. The information of the WLAN access point selection policy P may be carried by adding a new AVP in the existing Create Session Response message.

Next, in step S210, the MME22 sends an Attach complete message, such as an Initial Context Setup Request or an Attach Accept message shown in the figure, to the eNB21, where information of the WLAN access point selection policy P is included. The information of the WLAN access point selection policy P may be carried by adding a new AVP in the existing Initial Context Setup Request or Attach Accept message.

After receiving the information of the WLAN access point selection policy P, the eNB21 stores the WLAN access point selection policy P. The eNB21 will select the optimal WLAN access point for the UE20 in LWA according to the WLAN access point selection policy P.

In another embodiment, the process further includes steps S211 (not shown in the figure) and S212 (not shown in the figure).

In step S211, the PCRF25 updates the WLAN access point selection policy P according to the real-time monitoring result. The data monitored here may be the various parameters described above for determining the priority of the WLAN access point. For example, if the priority of the WLAN access point is determined by the charging information, the PCRF25 updates the WLAN access point selection policy P according to the change of the charging information of the corresponding WLAN access point.

Then, in step S212, the PCRF25 notifies the eNB21 of the updated WLAN access point selection policy. The eNB21 will select the optimal WLAN access point for the UE20 in LWA according to the updated WLAN access point selection policy.

Fig. 3 shows a schematic diagram of a process for determining a WLAN access point in an LWA network according to another embodiment of the present invention.

The process starts in step S301. It should be noted that the process refers to the LWA process proposed by the general company.

In step S301, the UE20 and the eNB21 perform an ELS (Extended LTE Signaling) discovery procedure.

In step S302, the eNB21 queries the UE20 for its ELS capabilities (i.e., capabilities for LWA support). The UE20 replies to the eNB21 with an indication that it supports LWA.

Then, in step S303, the eNB21 sends an RRC (Radio Resource Control) configuration request to the UE20, instructing the UE20 to detect an available WLAN access point. The configuration request may contain a threshold value instructing the UE20 to detect WLAN access points with energy greater than the threshold value.

In step S304, the UE20 sends a measurement report to the eNB21, the measurement report containing the available WLAN access points detected by the UE 20.

Then, in step S305, the eNB21 determines an optimal WLAN access point from the available WLAN access points detected by the UE20 according to the locally stored WLAN access point selection policy P obtained from the PCRF25 in the UE20 attach procedure.

In one embodiment, the WLAN access point selection policy P includes the WLAN access points that the UE20 can select in the LWA and the priority of each of the selected WLAN access points. The eNB21 may determine the optimal WLAN access point according to a preset rule, such as determining the WLAN access point with the highest priority as the optimal WLAN access point, or determining the optimal WLAN access point from the WLAN access points with priority higher than a certain threshold.

In one embodiment, the priority is a specific value, and the eNB21 may determine an optimal WLAN access point directly from the priority value of each WLAN access point.

In yet another embodiment, the priority is a calculation formula or a calculation rule. The eNB21 may calculate the priority of each WLAN access point and then determine an optimal WLAN access point. The calculation formula or calculation rule may contain one or more of the following information (but not limited to the following information):

-time of day

The calculation formula or calculation rule may set different priorities for the selectable WLAN access points according to different times. Such as: considering that the load of a WLAN access point varies with time, the load is higher during the day, and the load is lower at night, the priority of the WLAN access point is lower during the day, and the priority of the WLAN access point is higher at night.

-location of UE

The calculation formula or calculation rule may set different priorities for the selectable WLAN access points according to the location of the UE. For example, the priority of the WLAN access point close to the UE is higher, and the priority of the WLAN access point far from the UE is lower.

-user data traffic size

The calculation formula or calculation rule may set different priorities for the WLAN access point according to dynamic changes of the UE data traffic. Such as: when the user peak data flow exceeds a certain set value, a higher priority is set for the WLAN access point, and LWA transmission is enabled to be shunted for the eNB. When the peak data flow of the user is lower than a certain set value, for example, a lower priority is set for the WLAN access point, so that data is transmitted by an LTE interface as far as possible, and unnecessary consumption caused by using LWA (Low data traffic) is avoided.

Available bandwidth for connection of WLAN access point with eNB

The calculation formula or calculation rule may set: when the available bandwidth of the connection between the WLAN access point and the eNB is larger than a certain threshold value, setting a higher priority; conversely, a lower priority is set when the available bandwidth of the connection of the WLAN access point to the eNB is less than a certain threshold.

Steady state of connection of WLAN access point with eNB

The calculation formula or calculation rule may set: the more stable the connection of the WLAN access point to the eNB, the higher the corresponding priority.

Historical completion of processing LWA offload for WLAN access points

The calculation formula or calculation rule may set different priorities according to the processing capability of the WLAN access point (including processable data traffic, time delay, etc.) of the WLAN access point. If the WLAN access point completes well when processing the LWA offload in a certain period of time, its corresponding priority is higher, for example, if the WLAN access point continues to have a delay higher than a certain threshold when processing the offloaded data in a certain period of time, the priority of the WLAN access point is lowered.

In another embodiment, the WLAN access point selection policy P further includes a priority of LTE, and step S305 further includes: and if the priority of the WLAN access point with the highest priority is less than that of the LTE, determining that the optimal WLAN access point does not exist. When LTE priority is added to the WLAN access point selection policy, only WLAN access points with priority higher than LTE priority may be selected for LWA. This is because the priority indicates the cost of data transmission to some extent, and if the cost of using WLAN access points is higher than that of LTE, it is not necessary to use LWA at this time, and only LTE transmission is used. For example, when charging is used as a basis for generating the priority, since the charging policy of LTE is different from that of WLAN, the priority of LTE is also generated by PCRF and carried in the WLAN access point selection policy to be handed over to eNB. A WLAN access point with a lower priority than LTE will not be chosen by the eNB since this means that it is more expensive to use than existing LTE bearers.

At this time, the calculation formula or the calculation rule as the priority may further include information of the load of the eNB. In particular, different priorities may be set for the selectable WLAN access points according to dynamic load changes of the eNB serving the UE. When the eNB load continues to increase, this means that the overhead of using LTE transmissions is increasing, i.e. the relative positions of the priority of the WLAN access point and the priority of LTE start to change, and the priority of the WLAN access point relative to LTE is increasing. To reflect this change, the priority of the optional WLAN access point may be increased by one level for each increase in the loading of the eNB above a certain threshold.

Such as: the initial LTE priority is 7 and the WLAN access point priority is 5. Because LTE is a high priority (using the WLAN access point is more expensive than using existing LTE bearers), the WLAN access point is not selected. I.e. data is transmitted only over LTE and not LWA. But when the corresponding eNB load continues to increase to 75%, the priority of the WLAN access point increases to 8, and the WLAN access point is selected and the LWA mode is used for data transmission.

In this embodiment, the eNB21 determines that the optimal WLAN access point is the WLAN access point 30 after executing step S305.

Then, in step S306, the eNB21 establishes a bearer with the WLAN access point 30.

In step S307, the eNB21 configures the UE20 and the WLAN access point 30 to establish a connection.

At the same time, data between eNB21 and UE20 is still transmitted over LTE.

In step S308, the UE20 and the WLAN access point 30 authenticate.

Then, in step S309, the eNB21 divides data transmitted to the UE20 into two parts, one part is directly transmitted to the UE20 via LTE, the other part is transmitted to the WLAN access point 30, and is transmitted to the UE20 by the WLAN access point 30, thereby implementing LWA.

In yet another embodiment, the process further includes step S311 (not shown in the figure) and step S312 (not shown in the figure).

In step S311, the eNB21 updates the WLAN access point selection policy P according to the real-time monitoring result or the notification from the PCRF that includes the updated WLAN access point selection policy. The data monitored here may be the various parameters described above to determine WLAN access point priority, such as the loading of eNB 21.

In step S312, the eNB21 re-executes steps S303 to 309 according to the updated WLAN access point selection policy.

Figure 4 shows a schematic diagram of an apparatus in PCRF25 for determining a WLAN access point, according to an embodiment of the present invention. The apparatus 400 comprises: a first receiving means 401, a policy generating means 402 and a first transmitting means 403.

The operation of the apparatus 400 is described in detail below with reference to fig. 2.

First, the first receiving device 401 receives a Session Establishment request from the UE20, such as an Indication of IP-CAN Session Establishment message shown in fig. 2. The session establishment Request is triggered by an Attach Request (such as the Attach Request shown in fig. 2) sent by the UE 20.

Then, the policy generation means 402 generates a WLAN access point selection policy P for the UE20, which is used to instruct the eNB21 to determine the optimal WLAN access point for the UE20 in LWA.

The policy generation means 402 may generate the WLAN access point selection policy P based on information from the SPR, local configuration information, a preset rule, network conditions, and the like.

The policy generation means 402 may determine the priority of each optional WLAN access point according to one or more of the following information (but not limited to the following information):

-charging information of WLAN access points

-time of day

-location of UE

-user data traffic size

Available bandwidth for connection of WLAN access point with eNB

Steady state of connection of WLAN access point with eNB

Historical completion of processing LWA offload for WLAN access points

In one embodiment, the priority is a specific value, and the policy generation device 402 may determine the specific value of the priority according to the above information. In another embodiment, the priority is a calculation formula or a calculation rule, and the policy generation device 402 may include the above information in the calculation formula or the calculation rule.

usage pattern of each optional WLAN access point

-priority of LTE

At this time, the policy generating means 402 may also determine the priority of each optional WLAN access point according to the load of the eNB. In particular, different priorities may be set for the selectable WLAN access points according to dynamic load changes of the eNB serving the UE. When the eNB load continues to increase, this means that the overhead of using LTE transmissions is increasing, i.e. the relative positions of the priority of the WLAN access point and the priority of LTE start to change, and the priority of the WLAN access point relative to LTE is increasing. To reflect this change, the priority of the optional WLAN access point may be increased by one level for each increase in the loading of the eNB above a certain threshold.

-preferred value of each optional WLAN access point

After the policy generating device 402 generates the WLAN access point selection policy P, the first sending device 403 sends a Session establishment request reply, such as an acknowledgement of IP-CAN Session establishment acknowledgement message shown in fig. 2, to the PGW24, where the WLAN access point selection policy P is included. The first sending device 403 may add an AVP (Attribute Value Pair) to the existing acknowledgement of IP-CAN Session establishment message to carry the information of the WLAN access point selection policy P. This message reaches the eNB21 via the SGW23 and MME22, from which the eNB21 gets the WLAN access point selection policy P generated by the PCRF 25.

Fig. 5 shows a schematic diagram of an apparatus for determining a WLAN access point in an eNB21 according to another embodiment of the present invention. The apparatus 500 comprises: a second receiving means 501, a second transmitting means 502, a determining means 503, and an LWA executing means 504.

The operation of the apparatus 500 is described in detail below with reference to fig. 2 and 3.

First, the second receiving device 501 receives a Session establishment request reply from the PCRF25, such as an acknowledgement of IP-CAN Session establishment message shown in fig. 2, which includes the WLAN access point selection policy P. The session establishment Request replies with an Attach Request, such as the Attach Request shown in fig. 2, in response to the UE 20. The WLAN access point selection policy P is used to instruct the eNB21 to determine the optimal WLAN access point for the UE20 in LWA.

Then, the second transmitting device 502 transmits an RRC (Radio Resource Control) configuration request to the UE20, for instructing the UE20 to detect an available WLAN access point. The configuration request may contain a threshold value instructing the UE20 to detect WLAN access points with energy greater than the threshold value.

Next, the determining device 503 determines an optimal WLAN access point among the available WLAN access points detected by the UE20 according to the locally stored WLAN access point selection policy P acquired from the PCRF25 in the UE20 attach procedure in response to the measurement report from the UE20, where the measurement report includes the available WLAN access points detected by the UE 20.

In one embodiment, the WLAN access point selection policy P includes the WLAN access points that the UE20 can select in the LWA and the priority of each of the selected WLAN access points. The determining means 503 may determine the optimal WLAN access point according to a preset rule, for example, determine the WLAN access point with the highest priority as the optimal WLAN access point, or determine the optimal WLAN access point from the WLAN access points with priority higher than a certain threshold.

In one embodiment, the priority is a specific value, and the determining means 503 may determine an optimal WLAN access point directly according to the priority value of each WLAN access point.

In yet another embodiment, the priority is a calculation formula or a calculation rule. The determining means 503 may calculate the priority of each WLAN access point, and then determine an optimal WLAN access point. The calculation formula or calculation rule may contain one or more of the following information (but not limited to the following information):

-time of day

-location of UE

-user data traffic size

Available bandwidth for connection of WLAN access point with eNB

Steady state of connection of WLAN access point with eNB

Historical completion of processing LWA offload for WLAN access points

In another embodiment, the WLAN access point selection policy P further includes a priority of LTE, and the determining device 503 is further configured to: and if the priority of the WLAN access point with the highest priority is less than that of the LTE, determining that the optimal WLAN access point does not exist. When LTE priority is added to the WLAN access point selection policy, only WLAN access points with priority higher than LTE priority may be selected for LWA.

In this embodiment, the determining device 503 determines that the optimal WLAN access point is the WLAN access point 30.

Then, the LWA performing apparatus 504 divides the data transmitted to the UE20 into two parts, one part is directly transmitted to the UE20 via LTE, and the other part is transmitted to the WLAN access point 30 and then transmitted to the UE20 by the WLAN access point 30, thereby achieving LWA.

It should be noted that the present invention may be implemented in software and/or in a combination of software and hardware, for example, as an Application Specific Integrated Circuit (ASIC), a general purpose computer or any other similar hardware device. In one embodiment, the software program of the present invention may be executed by a processor to implement the steps or functions described above. Also, the software programs (including associated data structures) of the present invention can be stored in a computer readable recording medium, such as RAM memory, magnetic or optical drive or diskette and the like. Further, some of the steps or functions of the present invention may be implemented in hardware, for example, as circuitry that cooperates with the processor to perform various steps or functions.

In addition, some of the present invention can be applied as a computer program product, such as computer program instructions, which when executed by a computer, can invoke or provide the method and/or technical solution according to the present invention through the operation of the computer. Program instructions which invoke the methods of the present invention may be stored on a fixed or removable recording medium and/or transmitted via a data stream on a broadcast or other signal-bearing medium and/or stored within a working memory of a computer device operating in accordance with the program instructions. An embodiment according to the invention herein comprises an apparatus comprising a memory for storing computer program instructions and a processor for executing the program instructions, wherein the computer program instructions, when executed by the processor, trigger the apparatus to perform a method and/or solution according to embodiments of the invention as described above.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned. Furthermore, it is obvious that the word "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. A plurality of units or means recited in the apparatus claims may also be implemented by one unit or means in software or hardware. The terms first, second, etc. are used to denote names, but not any particular order.

Claims

1. A method in a PCRF of an LWA network for selecting a WLAN access point, the method comprising the steps of:

a. receiving a session establishment request from an eNB, wherein the session establishment request is triggered by an attachment request of a UE;

b. generating a WLAN access point selection policy for the UE, the WLAN access point selection policy for instructing the eNB to determine an optimal WLAN access point for the UE in LWA;

c. sending a session setup request reply to the eNB including the WLAN access point selection policy,

wherein the WLAN access point selection policy contains selectable WLAN access points for the UE in LWA, a priority of each selectable WLAN access point, and a usage pattern of each selectable WLAN access point, wherein the usage pattern indicates at least one of: the WLAN access point is only used for downlink data, the WLAN access point is only used for uplink data, and the uplink data and the downlink data of the WLAN access point are available.

2. The method of claim 1, wherein the priority is a calculation formula or a calculation rule.

3. The method of claim 1 or 2, wherein the PCRF determines the priority of each optional WLAN access point in dependence on at least one of:

billing information for the WLAN access point;

a location of the UE;

the load of the eNB;

the size of user data traffic;

available bandwidth for connection of a WLAN access point with an eNB;

a stable state of connection of the WLAN access point with the eNB;

historical completion of the WLAN access point handling LWA offloading.

4. The method according to claim 1 or 2, wherein the method further comprises:

updating the WLAN access point selection strategy according to a real-time monitoring result;

notifying the eNB of the updated WLAN access point selection policy.

5. The method of claim 1, wherein the WLAN access point selection policy further comprises at least one of:

a priority of LTE;

preferred values for each optional WLAN access point.

6. A method in an eNB of an LWA network for selecting a WLAN access point, the method comprising the steps of:

A. receiving a session establishment request reply from the PCRF, wherein the session establishment request reply comprises a WLAN access point selection policy, the session establishment request reply is in response to an attachment request of a UE, and the WLAN access point selection policy is used for indicating the eNB to determine an optimal WLAN access point for the UE in LWA;

B. sending a configuration message to the UE for instructing the UE to detect an available WLAN access point;

C. in response to a measurement report from the UE, the measurement report including available WLAN access points detected by the UE, determining an optimal WLAN access point among the available WLAN access points detected by the UE according to the WLAN access point selection policy;

D. if there is an optimal WLAN access point, data transmitted to the UE is divided into two parts, one part is directly transmitted to the UE via LTE, the other part is transmitted to the optimal WLAN access point, and the optimal WLAN access point is transmitted to the UE,

7. The method of claim 6, wherein the WLAN access point selection policy further includes LTE priority, and the step of determining the optimal WLAN access point further comprises: and if the priority of the WLAN access point with the highest priority is less than that of the LTE, determining that the optimal WLAN access point does not exist.

8. The method of claim 6, wherein the priority is a calculation formula or a calculation rule, the calculation formula or calculation rule including at least one of the following information:

a location of the UE;

the load of the eNB;

the size of user data traffic;

available bandwidth for connection of a WLAN access point with an eNB;

a stable state of connection of the WLAN access point with the eNB;

historical completion of the WLAN access point handling LWA offloading.

9. The method of claim 6, wherein the method further comprises:

updating the WLAN access point selection strategy according to a real-time monitoring result or a notice containing the updated WLAN access point selection strategy from the PCRF;

and D, re-executing the steps B to D according to the updated WLAN access point selection strategy.

10. An apparatus in a PCRF of an LWA network for selecting a WLAN access point, the apparatus comprising:

first receiving means for receiving a session establishment request from an eNB, the session establishment request being triggered by an attach request of a UE;

policy generating means for generating a WLAN access point selection policy for the UE, the WLAN access point selection policy being used to instruct the eNB to determine an optimal WLAN access point for the UE in an LWA, wherein the WLAN access point selection policy includes WLAN access points selectable by the UE in the LWA, a priority of each of the selectable WLAN access points, and a usage manner of each of the selectable WLAN access points, wherein the usage manner indicates at least one of: the WLAN access point is only used for downlink data, the WLAN access point is only used for uplink data, and the uplink data and the downlink data of the WLAN access point are both available;

a first sending device, configured to send a session establishment request reply to the eNB, where the session establishment request reply includes the WLAN access point selection policy.

11. An apparatus in an eNB of an LWA network for selecting a WLAN access point, the apparatus comprising:

second receiving means, configured to receive a session establishment request reply from the PCRF, where the session establishment request reply includes a WLAN access point selection policy, where the session establishment request reply is in response to an attach request of a UE, and the WLAN access point selection policy is used to instruct the eNB to determine an optimal WLAN access point for the UE in the LWA;

a second sending device, configured to send a configuration message to the UE, for instructing the UE to detect an available WLAN access point;

determining means, responsive to a measurement report from the UE, the measurement report including available WLAN access points detected by the UE, for determining an optimal WLAN access point among the available WLAN access points detected by the UE according to the WLAN access point selection policy;

LWA execution means for dividing data transmitted to the UE into two parts, one part being directly transmitted to the UE via LTE, the other part being transmitted to the optimal WLAN access point, transmitted to the UE by the optimal WLAN access point, when there is an optimal WLAN access point,

wherein the WLAN access point selection policy includes selectable WLAN access points for the UE in LWA, a priority of each selectable WLAN access point, and a usage pattern of each selectable WLAN access point, wherein the usage pattern indicates at least one of: the WLAN access point is only used for downlink data, the WLAN access point is only used for uplink data, and the uplink data and the downlink data of the WLAN access point are available.