WO2012155779A1

WO2012155779A1 - Selection method, device and system for reestablishing cell in lte system

Info

Publication number: WO2012155779A1
Application number: PCT/CN2012/074689
Authority: WO
Inventors: 许兵舰; 王润荣
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-07-18
Filing date: 2012-04-25
Publication date: 2012-11-22
Also published as: CN102892160A

Abstract

The present invention relates to the communications field, in particular, to an LTE system, and particularly to a selection method, device and system for reestablishing a cell in an LTE system. The method comprises the following steps: a network side determining whether a neighboring cell of a serving cell where a UE locates and the serving cell belong to the same eNodeB; and the network side sending to the UE corresponding identification information representing whether the neighboring cell and the serving cell belong to the same eNodeB. In the method provided by the present invention, the identification indicating the relation of the neighboring cell and the serving cell is added in content of a system message, so as to indicate whether the neighboring cell and the serving cell belong to the same eNodeB, thereby solving the problem of low reestablishment success rate during the reestablishment of a cell.

Description

Method, device and system for selecting re-established cell in LTE system

The present invention relates to the field of communications, and in particular, to a Long Term Evolution (LTE) system, and more particularly to a method, apparatus, and system for re-establishing a cell in an LTE system. Background technique

With the continued development of the third-generation mobile system (3G), the LTE project was proposed in The 3rd Generation Partnership Project (3GPP), as higher users can be obtained. The advantages of data rate, system capacity and coverage, and reasonable and flexible allocation of spectrum resources have led to the rapid development of LTE. Currently, many operators plan or are deploying LTE systems.

In an LTE network, a user equipment (User Equipment, UE) in a radio resource control (RRC) connection state initiates re-establishment because a scenario such as a radio link failure (RLF) is in a secure activation. process. The condition that the base station side accepts the re-establishment request is that the base station must contain the context information of the UE and its access stratum (AS) is securely activated. Therefore, in the process of re-establishment, only the cell that is selected to belong to an evolved base station (evolved NodeB, eNodeB) with the original camped cell (the cell that resides before the reestablishment) or the handover target cell is successfully reconstructed. Some protocols cannot guarantee that the selected cell meets the re-establishment requirement, and thus the success rate of re-establishment cannot be guaranteed. Summary of the invention

The invention provides a method, a device and a system for re-establishing a cell in an LTE system, which solves the shortcomings of low re-establishment success rate.

A method for selecting a re-established cell in an LTE system includes the following steps:

The network side determines a neighboring cell of the serving cell where the user terminal UE is located, and the neighboring zone and the service Whether the cell belongs to a cell under the same eNodeB;

The network side sends corresponding identification information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB, and sends the corresponding identifier information to the UE.

The network side sends the corresponding identifier information indicating whether the neighboring cell and the serving cell belong to the same eNodeB to the UE:

The network side carries, in the system message, corresponding identifier information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB, and sends the corresponding identifier information to the UE; or

The network side carries, in the configuration command, corresponding identifier information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB, and sends the corresponding identifier information to the UE.

The network side carries, in the system message, corresponding identifier information indicating that the neighboring cell and the serving cell belong to a cell under the same eNodeB, and sends the corresponding identifier information to the UE:

The network side carries the corresponding identification information indicating whether the neighboring cell and the serving cell belong to the cell under the same eNodeB, and the neighboring cell information in the system message block type SIB4 or the system message block type SIB5 is sent to the UE.

Receiving, by the UE, corresponding identifier information that is sent by the network side, indicating whether the serving cell of the UE and the neighboring cell of the serving cell belong to a cell under the same eNodeB;

When the UE determines that the re-establishment request is to be initiated, determining, according to the corresponding identifier information, a neighboring cell that belongs to the same eNodeB as the serving cell;

The UE selects a cell that satisfies the re-establishment request as the target cell in the neighboring cell that belongs to the same eNodeB as the serving cell;

The UE initiates a re-establishment process to the target cell.

Further, the method further includes:

When the UE determines that there is no cell that belongs to the same eNodeB as the serving cell, or cannot select a cell that satisfies the re-establishment request as the target cell, the AS of the UE will go to the non-access stratum of the UE (NAS) The transmission re-establishment cell selection failed. A base station comprising:

a determining unit, configured to determine a neighboring cell of the serving cell where the UE is located, and whether the neighboring cell and the serving cell belong to a cell under the same eNodeB;

And a sending unit, configured to send, to the UE, corresponding identifier information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB.

The sending unit is specifically configured to: send, in the system message, corresponding identifier information that indicates whether the neighboring cell and the serving cell belong to a cell under the same eNodeB, and send the corresponding identifier information to the UE; or

Corresponding identification information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB is sent to the UE in the configuration command.

The sending unit, configured to carry, in the neighboring cell information in the system message block type SIB4 or the system message block type SIB5, corresponding identifier information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB Sent to the UE.

A UE, comprising:

a receiving unit, configured to receive, by the network side, corresponding identifier information indicating whether a serving cell of the UE and a neighboring cell of the serving cell belong to a cell under the same eNodeB;

a determining unit, configured to determine, according to the corresponding identifier information, a neighboring area that belongs to the same eNodeB as the serving cell, when determining that a re-establishment request is to be initiated;

a selecting unit, configured to select, as the target cell, a cell that meets the re-establishment request in the neighboring cell that belongs to the same eNodeB as the serving cell;

And a sending unit, configured to initiate a re-establishment process to the target cell.

The determining unit is further configured to: when the cell that is not in the same eNodeB as the serving cell is determined, notify the sending unit;

The selecting unit is further configured to notify the sending unit when the cell that satisfies the re-establishment request cannot be selected as the target cell.

A system for reestablishing a cell in an LTE system, including a base station and a UE, The base station is configured to determine whether a neighboring cell of the serving cell where the UE is located, and whether the neighboring cell and the serving cell belong to a cell under the same eNodeB, and is further configured to indicate whether the neighboring cell and the serving cell belong to the same Corresponding identification information of a cell under one eNodeB is sent to the UE;

The user terminal is configured to receive, by the network side, corresponding identifier information that indicates whether a neighboring cell of the serving cell and the serving cell belongs to a cell under the same eNodeB, and is used to determine that a re-establishment request is to be initiated, according to the And determining, by the corresponding identifier information, a neighboring cell that belongs to the same eNodeB as the serving cell, and is further configured to: select, in the neighboring cell that belongs to the same eNodeB as the serving cell, a cell that meets the re-establishment request as a target. a cell, and initiating a re-establishment process to the target cell.

Further, the UE is further configured to: determine that a cell that is not in the same eNodeB as the serving cell; or that cannot select a cell that meets the re-establishment request as the target cell, the AS of the AS sends a re-establishment to the NAS. The cell selection failed.

The method and device and system for selecting a re-established cell in the LTE system provided by the present invention, by using the identifier of the relationship between the neighboring cell and the serving cell in the content of the system message, is used to identify whether the neighboring cell (Neighboring Cell) and the service are The serving cell belongs to the same eNodeB, thereby solving the problem of low success rate of reestablishing the cell. DRAWINGS

Figure 1 is a flow chart of the method of the present invention;

Figure 2 is a further flow chart of the method of the present invention;

3 is a structural block diagram of a base station in the present invention;

4 is a structural block diagram of a UE in the present invention;

Figure 5 is a block diagram showing the structure of the system of the present invention;

Figure 6 is a normal re-establishment scenario re-establishment success process;

Figure 7 is a normal re-establishment scenario re-establishment failure process;

8 is a handover scenario re-establishment back to the handover source side establishment success process; FIG. 9 is a process for reestablishing a handover scenario to a handover target side re-establishment;

Figure 10 shows the process of re-establishing a handover scenario to another eNodeB. detailed description

A method for selecting a re-established cell in an LTE system, as shown in FIG. 1 , includes the following steps: Step 11: The network side determines a neighboring cell of the serving cell where the UE is located, and whether the neighboring cell and the serving cell belong to the same a cell under the eNodeB;

Step 12: The network side sends corresponding identifier information indicating whether the neighboring cell and the serving cell belong to the same eNodeB to the UE.

In the method, the network side sends corresponding identifier information indicating whether the neighboring cell and the serving cell belong to a cell in the same eNodeB, to the UE, specifically:

The network side carries, in the system message, corresponding identifier information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB, and sends the corresponding identifier information to the UE, or

In the method, the network side carries, in the system message, corresponding identifier information that indicates whether the neighboring cell and the serving cell belong to a cell under the same eNodeB, and sends the corresponding identifier information to the UE, specifically:

A method for selecting a re-established cell in an LTE system, as shown in FIG. 2, includes the following steps: Step 21: The UE receives a corresponding identifier of a cell that is sent by the network side and indicates whether the serving cell and the neighboring cell of the UE belong to the same eNodeB. information; Step 22: When the UE determines that a re-establishment request is to be initiated, determining, according to the corresponding identifier information, a neighboring cell that belongs to the same eNodeB as the service 'j, the area;

Step 23: The UE selects a cell that meets the re-establishment request as the target cell in the neighboring cell that belongs to the same eNodeB as the serving cell.

Step 24: The UE initiates a re-establishment process to the target cell.

In the method, the UE determines that any of the neighboring cells and the service d and the zone belong to a cell under the same eNodeB; or

The cell that satisfies the re-establishment request cannot be selected as the target cell, and the AS of the user terminal UE sends a re-establishment cell selection failure to the non-access stratum (NAS) of the UE.

As shown in FIG. 3, a base station 1 includes:

a determining unit 111, configured to determine a neighboring cell of the serving cell where the UE is located, and whether the neighboring cell and the serving cell belong to a cell under the same eNodeB;

The sending unit 112 is configured to send, to the UE, corresponding identifier information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB.

In the base station 1, the sending unit 112 is configured to send, to the UE, corresponding identifier information that indicates that the neighboring cell and the serving cell belong to a cell under the same eNodeB:

The sending unit 112 is specifically configured to: send, in the system message, corresponding identifier information that indicates whether the neighboring cell and the serving cell belong to a cell in the same eNodeB, and send the corresponding identifier information to the UE, or specifically,

In the base station 1, the sending unit 112 is configured to: send, in the system message, corresponding identifier information that indicates that the neighboring cell and the serving cell belong to a cell under the same eNodeB, and send the corresponding identifier information to the UE, specifically:

The sending unit 112 is specifically due to the system message block type SIB4 or system message The neighboring cell information in the block type SIB5 carries corresponding identifier information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB, and sends the corresponding identifier information to the UE.

As shown in FIG. 4, a UE 2 includes:

The receiving unit 221 is configured to receive, by the network side, corresponding identifier information indicating whether the serving cell and the neighboring cell of the network belong to the same eNodeB;

The determining unit 222 is configured to determine, according to the corresponding identifier information, a neighboring area that belongs to the same eNodeB as the serving cell, when the re-establishment request is to be initiated;

The selecting unit 223 is configured to select, as the target cell, a cell that meets the re-establishment request in the neighboring cell that belongs to the same eNodeB as the serving cell.

The sending unit 224 is configured to initiate a re-establishment process to the target cell.

The determining unit 222 is further configured to notify the sending unit 224 when any of the neighboring cells and the serving cell belong to a cell under the same eNodeB;

The selecting unit 223 is further configured to notify the sending unit 224 when the cell that satisfies the re-establishment request cannot be selected as the target cell.

As shown in FIG. 5, a system for reestablishing a cell in an LTE system, including a base station 1 and a UE 2, the base station 1 is configured to determine a neighboring cell of a serving cell where the UE 2 is located, and the neighboring cell and the service Whether the cell belongs to the cell under the same eNodeB, and is further configured to send corresponding identifier information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB

UE 2;

The UE 2 is configured to receive, according to the corresponding identifier information, the corresponding identifier information that is sent by the network side to indicate whether the serving cell and the neighboring cell belong to the cell under the same eNodeB; And a neighboring cell that is in the same eNodeB as the serving cell; and is configured to select, as the target cell, a cell that meets the re-establishment request in the neighboring cell that belongs to the same eNodeB as the serving cell, and The target cell initiates a re-establishment process.

In the system, the UE 2 is further configured to determine that none of the neighboring cells and the service are small. If the area belongs to the cell under the same eNodeB; or if the cell that satisfies the re-establishment request cannot be selected as the target cell, the AS of the UE 2 sends a re-establishment cell selection failure to the NAS of the UE 2.

As shown in FIG. 6, the UE initiates a re-establishment request, and successfully selects a cell that belongs to the same eNodeB as the original serving cell, and the base station accepts the re-establishment process.

The UE detects that a re-establishment process needs to be initiated, and performs the following steps:

Step 601: The UE first selects a cell that belongs to the same eNodeB as the candidate cell, and then according to the cell in the TS36.304, according to the relationship between the neighboring cell and the serving cell, and the cell that belongs to the same eNodeB as the cell that the UE successfully camped on before re-establishment. Selecting a standard algorithm to select a cell that meets the re-establishment condition as the target cell, and the target cell is successfully selected;

Step 602: Send an RRC connection re-establishment request to the selected target cell.

Step 603: The target cell receives the re-establishment request, and sends an RRC connection re-establishment to the UE. Step 604: After receiving the RRC connection re-establishment, the UE returns the RRC connection re-establishment completion to the target cell, and the target cell receives the RRC connection re-establishment. The RRC connection re-establishment process ends.

As shown in FIG. 7, the UE initiates a re-establishment request, and fails to select a cell that belongs to the same eNodeB as the original serving cell, and the RRC layer of the UE fails to re-establish the Evloved Mobility Management (EMM) layer of the UE. The EMM layer notifies the RRC layer to initiate an RRC connection establishment request process according to the current situation.

The UE detects that a re-establishment process needs to be initiated;

The UE first selects a cell that belongs to the same eNodeB as the candidate cell, and then according to the cell selection algorithm in TS36.304, according to the relationship between the neighboring cell and the serving cell, first, the cell that belongs to the same eNodeB as the original serving cell (the cell that the UE successfully camped on before re-establishment) is selected as the candidate cell. A cell that satisfies the re-establishment condition is selected as a target among the candidate cells, and the target cell selection fails;

Step 701: The RRC layer of the UE notifies the UE that the EMM layer fails to be reestablished. If the EMM does not send data, the EMM notifies the RRC layer to establish an RRC connection for the TAU process. If there is data to be sent, the service request process is initiated, and the RRC layer performs the RRC layer again. TS36.304 cell selection process, selection A suitable target cell initiates an RRC connection request;

Step 702: The UE sends an RRC connection request (RRC Connection Request) to the selected target cell.

Step 703: The target cell sends an RRC Connection Setup to the UE. Step 704: The UE sends an RRC Connection Setup Complete to the target cell, and the target cell receives the RRC connection establishment, and the RRC connection establishment process ends. .

As shown in FIG. 8, the UE initiates re-establishment, and selects a cell that belongs to one eNodeB in the same manner as the handover source side serving cell, and the base station receives the re-establishment request.

The UE detects that a re-establishment process needs to be initiated;

Step 801: The UE preferentially selects, according to the relationship between the neighboring cell and the serving cell, a cell that belongs to the same eNodeB as the candidate cell, and then according to TS36.304, and the cell that belongs to the same eNodeB as the cell that is successfully camped before the re-establishment of the UE. The cell selection criterion algorithm selects a cell that satisfies the re-establishment condition as a target, and the target cell selection succeeds;

Step 802: Send an RRC connection re-establishment request to the selected target cell.

Step 803: The target cell (the cell selected by the UE) receives the re-establishment request, and sends an RRC connection re-establishment;

Step 804: After receiving the RRC connection re-establishment, the UE replies to the RRC connection re-establishment to the target cell, and the target cell receives the RRC connection re-establishment, and the RRC connection re-establishment process ends.

As shown in FIG. 9, the UE initiates re-establishment, and selects a cell that belongs to one eNodeB in the same manner as the handover target-side target cell, and the base station accepts the re-establishment request.

The UE detects that a re-establishment process needs to be initiated;

Step 901: The UE preferentially selects, according to the relationship between the neighboring cell and the serving cell, a cell that belongs to the same eNodeB as the candidate cell, and then the cell according to the protocol, and the cell that belongs to the same eNodeB. Selecting a standard algorithm to select a cell that meets the re-establishment condition as a target, the target cell selection fails, and the cell selection machine according to the protocol specified after the failure is selected Selecting a cell other than the candidate cell, and successfully selecting a cell that belongs to one eNodeB in the same target cell or handover target cell;

Step 902: Send an RRC connection re-establishment request to the selected target cell.

Step 903: The target cell (the cell selected by the UE) receives the re-establishment request, and sends an RRC connection to the UE.

Step 904: After receiving the RRC connection re-establishment, the UE replies to the RRC connection re-establishment to the target cell, and the target cell receives the RRC connection re-establishment, and the RRC connection re-establishment process ends.

As shown in FIG. 10, the UE initiates re-establishment, and selects a cell that belongs to an eNodeB in the same manner as the handover target-side target cell, and the base station receives the re-establishment request.

The UE detects that a re-establishment process needs to be initiated;

The UE preferentially selects, according to the relationship between the neighboring cell and the serving cell, a cell that belongs to the same eNodeB as the candidate cell, and then the cell selection criterion algorithm according to the protocol. A cell that meets the re-establishment condition is selected as the target cell, and the target cell selection fails. After the selection fails, the cell other than the candidate cell is selected as the target cell according to the cell selection mechanism specified by the protocol, and the target cell selects another eNodeB (non-switching source side and Switching the cell under the eNodeB on the target side;

Sending an RRC Connection Reestablishment Request to the selected target cell;

The target cell (the cell selected by the UE) rejects the re-establishment request, and sends an RRC connection reestablishment to the UE. After the UE receives the reestablishment rejection, the RRC connection re-establishment process ends.

Step 1001: The RRC layer of the UE notifies the UE that the EMM layer fails to be reestablished. If there is no data transmission, the EMM layer notifies the RRC layer to establish an RRC connection for the TAU process. If there is data to be sent, the service request process is initiated, and the RRC layer is initiated. The cell selection process of TS36.304 is performed again, and an appropriate target cell is selected to initiate an RRC connection request;

Step 1002: The UE sends an RRC connection setup request (RRC Connection Request) to the selected target cell. Step 1003: The target cell sends an RRC Connection Setup to the UE. Step 1004: The UE sends an RRC Connection Setup Complete to the target cell, and the target cell receives the RRC connection establishment, and the RRC connection establishment process ends. .

The invention adds an identifier of the relationship between the neighboring cell and the serving cell in the content of the system message, and is used to identify whether the neighboring cell (Neighboring Cell) belongs to the same eNodeB as the serving cell (Serving Cell), thereby solving the process of reestablishing the cell. Re-establishing the problem of lower success rate improves the success rate of the cell re-establishment process.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Thus, the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, the invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) including computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart and/or block diagrams, and combinations of flows and/or blocks in the flowcharts and/or block diagrams can be implemented by computer program instructions. These computer program instructions may be provided to a general purpose computer, a special machine, such that instructions executed by a processor of a computer or other programmable data processing device are used to implement a block or a block and/or block diagram of a flowchart or A device that has multiple functions specified in the box.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart. These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

While the preferred embodiment of the invention has been described, the subject matter Therefore, it is intended that the appended claims be interpreted as including

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

Claims

Claim

A method for selecting a re-established cell in a long-term evolution LTE system, characterized in that the method comprises:

Determining, by the network side, a neighboring cell of the serving cell where the user terminal UE is located, and whether the neighboring cell and the serving cell belong to a cell under the same eNodeB;

The method according to claim 1, wherein the network side sends, to the UE, corresponding identification information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB:

The method according to claim 2, wherein the network side carries, in the system message, corresponding identifier information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB, and sends the corresponding identifier information to the The UE is:

A method for selecting a re-established cell in an LTE system, the method comprising:

When the UE determines that a re-establishment request needs to be initiated, determining, according to the corresponding identifier information, a neighboring cell under the same eNodeB as the serving cell;

The UE initiates a re-establishment process to the target cell.

The method according to claim 4, wherein the method further comprises: when the UE determines that there is no cell belonging to the same eNodeB as the serving cell, or cannot select to satisfy a re-establishment request. When the cell is the target cell, the access layer AS of the UE sends a re-establishment cell selection failure to the non-access stratum NAS of the UE.

6. A base station, comprising:

The base station according to claim 6, wherein the sending unit is configured to: carry, in the system message, corresponding identifier information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB Sent to the UE; or

The base station according to claim 6, wherein the sending unit is configured to carry, in the neighbor information in the system message block type SIB4 or the system message block type SIB5, the neighboring area and the service. Corresponding identification information of whether the cell belongs to the cell under the same eNodeB is sent to the UE.

9. A UE, comprising:

a determining unit, configured to determine, when the re-establishment request is to be initiated, according to the corresponding identifier information Determining a neighboring cell under the same eNodeB as the serving cell;

10. The UE of claim 9, wherein:

A system for re-establishing a cell in an LTE system, comprising a base station and a UE, wherein the base station is configured to determine whether a neighboring cell of the serving cell where the UE is located, and whether the neighboring cell and the serving cell belong to the same a cell under the eNodeB; and corresponding identifier information indicating whether the neighboring cell and the serving cell belong to a cell under the same eNodeB, and sent to the UE;

The UE is configured to receive, by the network side, corresponding identifier information that indicates whether the neighboring cell of the serving cell and the serving cell belongs to a cell under the same eNodeB; and when determining that a re-establishment request is to be initiated, according to the corresponding identifier Determining a neighboring cell that belongs to the same eNodeB as the serving cell; and selecting a cell that satisfies the re-establishment request as the target cell in the neighboring cell that belongs to the same eNodeB as the serving cell, and The target cell initiates a re-establishment process.

The system according to claim 11, wherein the UE is further configured to determine that the cell does not belong to the same eNodeB as the serving cell; or that the cell that meets the re-establishment request cannot be selected as the target cell. At this time, its own AS will send a re-establishment cell selection failure to the NAS.