WO2010121438A1

WO2010121438A1 - Method, system and user equipment for cell reselection

Info

Publication number: WO2010121438A1
Application number: PCT/CN2009/071464
Authority: WO
Inventors: 黄英; 牛卫国
Original assignee: 华为技术有限公司
Priority date: 2009-04-24
Filing date: 2009-04-24
Publication date: 2010-10-28
Also published as: CN101971524A

Abstract

A method, system and user equipment for cell reselection, wherein the method includes：the user equipment which is in an active state acquires cell reselection dedication priority information of the user equipment and save it(201)；when the cell which the user equipment access to is fault，carry out cell reselection according to cell reselection dedication priority information(202). When the cell which the user equipment access to occurs cell mistake suddenly，the user equipments select different new cell respectively to avoid load shock to the same new cell.

Description

Method, system and user equipment for cell reselection

Technical field

The present invention relates to the field of mobile communications, and in particular, to a method, system, and user equipment for cell reselection.

Background technique

In the mobile communication system, for the continuity of the service or the solution of the coverage problem, in general, the different system cell or the inter-frequency cell may cover the network. As shown in FIG. 1 , a schematic diagram of the same coverage network in the prior art, such as UMTS (Universal Mobile Telecommunications System) cell A and LTE (Long Term Evolution) cell A, covers a common area. . During the operation of the mobile network, if a cell failure occurs suddenly, the cell will not work normally. For the user equipment (User Equipment), RLF (Radio Link Failure) will be detected, and the UE will reselect. To a new cell, then initiate the connection process of the wireless link.

In the process of implementing the present invention, the inventors have found that at least the following problems exist in the prior art: In the prior art, the system sends a public priority through a system broadcast message, or uses a radio resource control release message when the UE is in an active state ( For example, the Radio Resource Control (RRC) Release message delivers a dedicated priority, and the UE transits to the idle state after receiving the RRC release message. The prior art UE cannot use two priorities at the same time, and if a dedicated priority is received, the public priority is ignored. However, this dedicated priority is limited. When the UE enters the active state, or the timer expires, or the PLMN (Public Land Mobile Network) changes, the prior art deletes the dedicated priority. For the UE in the active state, since there is no dedicated priority, when the RLF fault occurs, the UE performs cell reselection according to the radio signal and the common priority, and as a result, many UEs may simultaneously select a new cell. This will bring a load impact to the new community. For the UE in the idle state, many of the public priorities have no dedicated priority, so that the UE will also select the same new cell with a high probability when re-entering the network, which will bring a load impact to the new cell. Summary of the invention

An embodiment of the present invention provides a cell reselection method, where the method includes: acquiring, by a user equipment in an activated state, a cell reselection priority information of the user equipment and saving the cell; At the time, cell reselection is performed according to the cell priority reselection priority information.

On the other hand, an embodiment of the present invention provides a user equipment, where the user equipment includes: an information acquiring unit, configured to acquire, when the user equipment is in an active state, the cell reselection priority information of the user equipment, and save the information; The cell reselection unit is configured to perform cell reselection according to the cell reselection dedicated priority information when a cell failure occurs in the cell accessed by the user equipment.

In another aspect, an embodiment of the present invention further provides a cell reselection system, where the cell reselection system includes at least an access network device and a user equipment as described above.

According to the foregoing technical solution provided by the embodiment of the present invention, the user equipment in the activated state acquires the cell reselection priority information of the user equipment and saves; when the cell accessed by the user equipment fails, the cell priority is reselected according to the cell. The information is used for cell reselection. When the cell accessed by the user equipment in the activated state suddenly has a cell failure, the user equipment selects different new cells respectively, thereby avoiding a load impact on the same new cell.

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 embodiments or the description of the prior art will be briefly described below. Obviously, the embodiments in the following description are attached. The drawings are only some of the embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive labor.

1 is a schematic diagram of a same covering network in the prior art;

2 is a flowchart of a method for cell reselection according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a user equipment according to an embodiment of the present disclosure;

FIG. 4 is a flowchart of another method for cell reselection according to an embodiment of the present invention; 5 is a schematic diagram of a mapping relationship between an application instance index value and a cell reselection priority priority according to the present invention;

FIG. 6 is a flowchart of still another method for cell reselection according to an embodiment of the present invention;

FIG. 7 is a flowchart of still another method for cell reselection according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be described with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

As shown in FIG. 2, it is a flowchart of a method for cell reselection according to an embodiment of the present invention, where the method includes:

Step 201: The user equipment in the activated state acquires the cell reselection priority information of the user equipment and saves the information.

Step 202: When a cell fault occurs in the cell accessed by the user equipment, perform cell reselection according to the specific priority information of the cell reselection.

The foregoing method embodiment of the present invention acquires the cell reselection priority information of the user equipment by using the user equipment in the activated state, and saves; when the cell accessed by the user equipment is faulty, the cell is reselected according to the cell priority reselection priority information. Reselection, when the cell accessed by the user equipment in the activated state suddenly has a cell failure, the user equipment is selected to a different new cell, thereby avoiding a load impact on the same new cell.

FIG. 3 is a schematic structural diagram of a user equipment according to an embodiment of the present invention, where the user equipment can implement the cell reselection method provided by the foregoing embodiment. User equipment 30 includes:

The information obtaining unit 301 is configured to acquire the cell reselection priority information of the user equipment and save the user equipment 30 when the user equipment 30 is in an active state, and the cell reselection unit 302 is configured to be accessed by the user equipment in the activated state. When a cell failure occurs in a cell, cell reselection is performed according to the cell priority reselection priority information. Optionally, the foregoing information acquiring unit 301 may further be used by the user equipment 30 in the activated state to receive the cell reselection dedicated priority information by using the system broadcast, or further used to receive the cell weight received by the system broadcast when the user equipment is in an idle state. Dedicated priority information is selected, and the above-mentioned cell reselection priority information is retained after the user equipment is transferred to the activation state. The cell reselection priority information includes a mapping relationship between the index value and the cell reselection priority. The cell reselection unit 302 calculates an index value of the user equipment according to the international mobile subscriber identity of the user equipment, and selects the index. The cell corresponding to the value reselects the dedicated priority information, and performs cell reselection according to the cell priority reselection priority information.

Optionally, the information acquiring unit 301 may be further configured to: when the user equipment is in an active state, receive a cell reselection priority of the user equipment by using a radio resource control message. The information acquiring unit 301 may be further configured to reserve the cell reselection priority information delivered by the RRC release message when the user equipment enters the activation state.

Optionally, the information acquiring unit 301 may be configured to: receive, by using the handover message, the cell reselection priority information that is sent by the source cell, the target cell access information that the user equipment is to access, and the resource reservation situation; The reselection unit 302 performs cell reselection according to the cell priority reselection priority information and the target cell access information and resource reservation conditions to be accessed by the user equipment.

The embodiment of the present invention further provides a cell reselection system, where the cell reselection system includes at least an access network device and the foregoing user equipment. In the LTE system, the access network device is an eNB. In the UMTS system, the access network device is an RNC (Radio Network Controller).

Optionally, the access network device may be configured to determine, according to the adjacency relationship priority, and/or the priority of the user equipment, and/or whether the same coverage is prioritized, the user equipment that needs to send the cell reselection priority priority. The access network device may be further configured to use, according to the service distribution information of the user equipment, the load information of the user equipment cell, the user information of different types of the user equipment, the service information of the user equipment, the user equipment network support capability information, and the foregoing User equipment One or more of the distribution information in different networks obtains the cell reselection-specific priority information.

According to the foregoing apparatus and system embodiment of the present invention, the user equipment in the activated state can select different new cells when the connected cell suddenly experiences a cell failure, thereby avoiding a load impact on the same new cell.

As shown in FIG. 4, it is an embodiment of a method for reselecting another cell according to an embodiment of the present invention. This embodiment can be implemented by the above user equipment and system. In the cell reselection method provided by this embodiment, the user equipment acquires the cell reselection dedicated priority information through the system broadcast, and thereby obtains its own cell reselection dedicated priority information. In this embodiment, the LTE system is used as an example, and the user equipment obtains the cell reselection priority information that is sent by the eNB (evolved NodeB, evolved base station) through the system broadcast. Specific methods include:

Step 401. The active user equipment receives the cell reselection priority information delivered by the evolved base station through the system broadcast. Specifically, the cell reselection dedicated priority information is a correspondence between an index value and a cell reselection dedicated priority. The index value corresponds to a cell reselection priority relationship of different cells, for example, a mapping relationship between the index value and the cell reselection priority priority shown in FIG. 5.

Step 402: The user equipment obtains its own cell reselection priority by using the index value and the cell reselection priority priority according to its own index value. Specifically, the user equipment may calculate its own index value according to an algorithm specified by the system. For example, the UE may calculate the index value according to an IMSI (International Mobile Subscriber Identity) mod, and the remainder is Index value. It should be noted, however, that the embodiment of the present invention is not limited thereto. In the specific implementation process, the system may set an algorithm for calculating an index value according to the situation.

Step 403. When a cell failure occurs in the cell accessed by the user equipment, the user equipment performs cell reselection according to the cell reselection priority of the user equipment obtained in the foregoing step 402.

For example, as shown in FIG. 5, UE1 calculates that its own index value is 1, when UE1 generates a cell. In the case of the cell failure, when the UE1 performs cell reselection, the preferred cell is the cell of the LTE frequency point fl of the system. UE2 calculates that its own index value is 2. When UE2 performs cell reselection when UE2 performs cell reselection, the preferred cell is a UMTS cell.

The embodiment of the present invention further provides another method for cell reselection. The method for the user equipment in the activated state to obtain the cell reselection priority is: retaining the cell of the user equipment that is received by the user equipment through the system broadcast in the idle state. Re-select dedicated priority information. That is, when the user equipment enters the active state from the idle state, the cell reselection priority information of the user equipment that is received by the user equipment through the system broadcast in the idle state is not deleted. Specifically, the cell reselection dedicated priority information is a correspondence between an index value and a cell reselection dedicated priority. The method for obtaining the cell reselection priority of the user equipment by using the index value and performing cell reselection is the same as the method and the example in steps 402 and 403, and details are not described herein again. In addition, when the UE enters the active state and receives a new cell reselection dedicated priority, the new cell reselection dedicated priority is used to update instead of the old cell reselection priority.

The embodiment of the present invention solves the problem that when a cell in an active state suddenly experiences a cell failure, a large number of UEs in the faulty cell simultaneously select the same new cell to bring a load impact to the new cell, and the cell broadcast by the system is dedicated. Reselecting the priority information enables the UE to effectively and reasonably distribute to different new cells to ensure the success rate of subsequent access.

FIG. 6 is a schematic diagram of another method for cell reselection according to an embodiment of the present invention. This embodiment can be implemented by the above user equipment and system. In the cell reselection method provided by this embodiment, the user equipment in the active state receives the cell reselection priority information through the radio resource control message. In this embodiment, the LTE system is used as an example. The user equipment in the active state receives the cell reselection priority information delivered by the eNB through the RRC message, that is, the eNB notifies the UE of the cell reselection priority. For example, the eNB informs the UE of the cell reselection dedicated priority through an RRC reconfiguration message or other RRC message. The method for cell reselection provided in this embodiment includes: Step 601. The UE in the active state receives the cell reselection priority of the UE delivered by the eNB through the RRC message and saves it. The foregoing radio resource control message may include: A resource control reconfiguration message, or a radio resource control release message, or a radio bearer setup message, or a radio resource control dedicated message or other RRC message.

Step 602. When the cell has the cell failure, the UE performs cell reselection according to the cell reselection priority of the UE.

In the UMTS system, the RNC corresponds to the foregoing eNB, the IU port corresponds to the S1 port, the message of the IU port may have a RAB ASSIGNMENT REQUEST, and other RRC messages may include a radio bearer setup message (for example, a Radio Bearer). Setup message), or RRC dedicated message or other newly constructed RRC message that can achieve the same function.

More specifically, before the step 601, when the UE initiates a service request, the eNB obtains an initial context request setup message (for example, an intial context request setup message) sent by the MME (Mobility Management Entity) to obtain the UE. QCI

(service type), SPID (priority) and other information, or other S1 port messages. After the eNB obtains the information, the neighboring cell characteristics are comprehensively considered, and the cell reselection priority of the UE is obtained, and then sent to the UE by using a radio resource control message.

Optionally, before the foregoing step 601, the eNB may further determine, according to the adjacency relationship priority, the priority of the UE, and whether the same coverage is prioritized, which UEs need to send the cell reselection priority of the UE; or each time the handover is performed. At the time, it is sent to the UE along with the handover command. The method for determining whether the same coverage is performed includes: determining, according to a proportional relationship between a user equipment that can measure the second cell in the first cell and a user equipment that can measure the first cell in the second cell, determining the first cell And a coverage relationship of the second cell. In the embodiment of the present invention, according to the radio resource management algorithm, it is determined whether the neighboring cell is covered, and whether the coverage is the same according to the proportional relationship of the coverage area. For example: 1) The source cell triggers all UEs in the cell to measure the neighboring cell. If all the UEs can detect a neighboring cell multiple times, it is determined that the neighboring cell is within the coverage of the cell. 2) If the neighboring cell performs the above 1) measurement on the local cell, the result is that all the UEs can detect the local cell multiple times, and 1) can determine that the two cells are the same coverage; if the neighboring cell measures only the local cell, If the UE can detect the coverage, the local cell and the neighboring cell are the size coverage. Further, if the neighboring cell can measure that the UE ratio of the cell is not much different, the ratio of the coverage area of the two cells can be determined. relationship. 3) If only some UEs in the source cell detect the neighboring cell, and only some UEs in the neighboring cell can detect the cell, the two cells are partially overlapped; if the result of multiple measurements is detected, the UE in the neighboring cell is detected. If the ratios of the two cells are not much different, the ratio of the overlapping regions of the two cells to the neighboring cells may be determined; further, the proportional relationship between the coverage areas of the two cells may be determined. In addition, the network can also randomly select a part of the UE to perform the above measurements 1 to 3, and measure multiple times (more than the above method), and similar results can be determined similarly to the above 1) to 3). However, the embodiments of the present invention are not limited thereto.

The embodiment of the present invention solves the problem that when a cell in activating state suddenly experiences a cell failure, a large number of UEs in the faulty cell simultaneously select the same new cell, causing a load impact on the new cell, when the user equipment is in an active state, The radio resource control message is used to receive the cell reselection priority information that is sent by the eNodeB, so that the UE can be effectively and appropriately distributed to different new cells to ensure the success rate of subsequent access.

The embodiment of the invention further provides an embodiment of a method for cell reselection. This embodiment can be implemented by the above user equipment and system. The cell reselection method provided in this embodiment keeps the cell reselection priority of the UE in the idle state when the UE enters the active state, that is, saves in the active state and continues to use the cell reselection priority of the UE. And when the RLF occurs in the UE, cell reselection is performed according to the cell reselection dedicated priority. The cell reselection priority priority of the UE that is sent by the UE in the idle state is the cell reselection priority of the UE that is sent when the RRC release is released. That is, in this embodiment, the method for the UE to obtain the cell reselection priority priority when the UE enters the active state is to reserve the cell reselection priority information delivered by the RRC release message.

The embodiment of the present invention solves the problem that when a UE suddenly occurs RLF, a large number of UEs in the faulty cell simultaneously select the same new cell to bring a load impact to the new cell, and use the radio resource control release message to deliver the cell weight. Selecting a dedicated priority enables the UE to effectively and reasonably spread to different The new cell guarantees the success rate of subsequent access.

In addition, the technical solutions in the foregoing various embodiments of the present invention may calculate the dedicated priority of cell reselection by using the following method:

1) According to the service distribution strategy, for example: prioritize different services in different systems to generate service priorities of different cells.

2) Optimize the initial priority according to the load information of the cell, for example: If the load of the cell exceeds the preset threshold TIRATLB-High, the priority of the cell is reduced by one level, and if the cell exceeds the overload threshold, the minimum is priority. If the performance of the cell (such as the admission success rate, the dropped call rate, and the handover success rate) is lower than the preset threshold Tper2, the priority of the cell is lowered by one priority.

3) There are different re-selection priorities and restrictions for different categories of users. Users can be classified into different categories according to the subscription information (such as subscription profile) in the user's SPID. Different categories of users have different cell reselection priorities.

4) According to the service information of the UE and the ability of different cells to support the service, different cell reselection priorities are set for different UE services.

5) According to the network support capability of the UE, if a certain UE does not support a certain system, the cell reselection priority of the system is set to the lowest.

6) In order to avoid a large number of UE services causing system congestion in a system, it may be considered that the UEs are distributed in different networks according to a certain proportion, and the proportional relationship may be determined according to an operator's policy or according to the capacity of the network. For example, if the operator wants LTE, UMTS, and GSM to bear 20%, 40%, and 40% of the load, then the ratio is 2: 4: 4.

The cell reselection priority of the embodiment of the present invention may be calculated according to one or more of the foregoing methods 1) to 6), but the embodiment of the present invention is not limited thereto.

As shown in FIG. 7, an embodiment of a method for reselecting another cell according to an embodiment of the present invention is shown. This embodiment can be implemented by the above user equipment and system. When the user equipment is to perform handover, if the source cell sends a handover request to multiple target cells, after receiving the target cell handover response, the source cell is based on the source cell. The previous handover statistical success rate or radio resource management algorithm sets a cell reselection priority for each target cell. In this embodiment, the method specifically includes:

Step 701: The user equipment receives, by using a handover message, a cell reselection priority priority corresponding to a plurality of target cells delivered by the source cell, and access information and a resource reservation situation of the target cell. Specifically, the user equipment may be notified by the handover message of a plurality of different priority switching containers, where the container includes the access information of the target cell and the resource reservation, and the user equipment saves after receiving the information;

Step 702: The user equipment reselects the dedicated priority information according to the foregoing cell, and performs cell reselection according to the access information of the target cell to be accessed by the user equipment and the resource reservation situation.

The embodiment of the present invention solves the problem that a large number of UEs simultaneously select the same new cell and bring a load impact to the new cell, and the UE is effectively and reasonably dispersed to different new ones by using the cell reselection dedicated priority sent by the source cell. The cell guarantees the success rate of subsequent access.

A person skilled in the art can understand that all or part of the steps of implementing the above embodiments can be completed by a program instructing related hardware, and the program can be stored in a computer readable storage medium. The storage medium includes all or part of the above steps, such as a ROM/RAM, a magnetic disk, an optical disk, and the like.

The specific embodiments described above are only the specific embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalents, improvements, etc. are made within the spirit and principles of the present invention. All should be included in the scope of protection of the present invention.

Claims

Claim

A method for cell reselection, the method comprising:

The user equipment in the activated state acquires the cell reselection priority information of the user equipment and saves the information;

When a cell fault occurs in the cell accessed by the user equipment, cell reselection is performed according to the cell reselection priority information.

2. The method according to claim 1, wherein the obtaining the cell priority specific priority information of the user equipment comprises:

The user equipment in the activated state receives the cell reselection dedicated priority information through a system broadcast.

The method according to claim 1, wherein the obtaining the cell reselection priority information of the user equipment comprises:

When the user equipment enters an active state, the cell reselection priority priority information received by the user equipment in the idle state through the system broadcast is reserved.

4. The method of claim 2 or 3, characterized in that

The cell reselection dedicated priority information includes: a correspondence between an index value and a cell reselection dedicated priority.

The method according to claim 4, wherein the performing cell reselection according to the cell reselection priority information includes:

Determining a cell reselection priority corresponding to the index value of the user equipment according to an index value of the user equipment and a correspondence between the index value and a cell reselection priority, and according to the user The cell reselection priority corresponding to the index value of the device performs cell reselection.

6. The method according to claim 5, wherein the index value of the user equipment is obtained according to an international mobile subscriber identity of the user equipment.

The method of claim 1, wherein the obtaining the cell reselection priority information of the user equipment comprises: the user equipment in the activated state by using a radio resource control message Receiving cell reselection dedicated priority information of the user equipment.

8. The method according to claim 7, wherein the radio resource control message comprises: a radio resource control reconfiguration message, or a radio resource control release message, or a radio bearer setup message, or a radio resource control dedicated message.

9. The method according to claim 7, wherein the method further comprises: determining, according to the adjacency relationship priority, and/or the priority of the user equipment, and/or whether the coverage is prioritized, determining that the radio resource control is required. The message is sent to the user equipment of the user equipment to reselect the dedicated priority user equipment.

The method according to claim 9, wherein the method for determining the same coverage comprises: determining, according to the user equipment capable of measuring the second cell in the first cell, and the second cell The proportion relationship of the user equipments of the first cell determines the coverage relationship of the first cell and the second cell.

11. The method of claim 2 or 7, wherein

The cell reselection-specific priority information is based on the service distribution information of the user equipment, the load information of the user equipment cell, the user information of different types of the user equipment, the service information of the user equipment, and the user. One or more of the device network support capability information and the distribution information of the user equipment in different networks are obtained.

The method of claim 1, wherein the obtaining the cell reselection priority information of the user equipment comprises:

When the user equipment enters an active state, the cell reselection dedicated priority information delivered by the RRC release message is reserved.

The method of claim 1, wherein the obtaining the cell priority specific priority information of the user equipment comprises:

Receiving, by using the handover message, the cell reselection priority information that is sent by the source cell, the target cell access information that the user equipment is to access, and the resource reservation situation;

Dedicating priority information according to the cell reselection and a target cell to be accessed by the user equipment Incoming information and resource reservation for cell reselection.

A user equipment, the user equipment comprising:

An information obtaining unit, configured to acquire, when the user equipment is in an active state, the cell reselection priority information of the user equipment, and save the information; and

And a cell reselection unit, configured to perform cell reselection according to the cell reselection dedicated priority information when a cell failure occurs in the cell accessed by the user equipment.

15. The user equipment of claim 14, wherein

The information acquiring unit is further configured to receive, by using a system broadcast, cell reselection dedicated priority information.

16. The user equipment of claim 15 wherein:

The information acquiring unit is further configured to use a correspondence between an index value received by the system broadcast and a cell reselection dedicated priority.

17. The user equipment of claim 16 wherein:

The cell reselection unit is further configured to calculate an index value of the user equipment according to an international mobile subscriber identity of the user equipment, and select a cell reselection priority priority information corresponding to the index value, according to the cell. Reselect the dedicated priority information for cell reselection.

18. The user equipment of claim 14 wherein:

And the information acquiring unit is further configured to: when the user equipment enters an active state, retain the cell reselection priority priority information that is received by the user equipment in the idle state by using a system broadcast.

19. The user equipment of claim 14 wherein:

The information acquiring unit is further configured to: when the user equipment is in an active state, receive a cell reselection priority of the user equipment by using a radio resource control message.

20. The user equipment of claim 14, wherein

The information obtaining unit is further configured to: when the user equipment enters an active state, retain the cell reselection priority information that is sent by the RRC release message.

21. The user equipment of claim 14 wherein: The information acquiring unit is further configured to: receive, by using a handover message, a cell reselection priority information that is sent by the source cell, and a target cell access information and a resource reservation situation that the user equipment is to access;

The cell reselection unit is further configured to perform cell reselection according to the cell reselection dedicated priority information and target cell access information and resource reservation conditions to be accessed by the user equipment.

A cell reselection system, characterized in that the cell reselection system comprises at least an access network device and a user equipment according to claims 14-21.

23. The cell reselection system of claim 22, wherein:

The access network device is configured to determine, according to the adjacency relationship priority, and/or the priority of the user equipment, and/or whether the same coverage is prioritized, to determine that the cell reselection needs to be sent by using the radio resource control message Priority user equipment.

24. The cell reselection system of claim 22, wherein:

The access network device is configured to: according to the service distribution information of the user equipment, the load information of the user equipment cell, the user information of different types of the user equipment, the service information of the user equipment, and the user equipment. The network re-selection priority information is obtained by one or more of the network support capability information and the distribution information of the user equipment in different networks.