CN112400340B

CN112400340B - Cell switching method and related equipment

Info

Publication number: CN112400340B
Application number: CN201880095445.9A
Authority: CN
Inventors: 李彦良; 周海飞
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2018-07-09
Filing date: 2018-07-09
Publication date: 2022-02-25
Anticipated expiration: 2038-07-09
Also published as: CN112400340A; WO2020010487A1

Abstract

The invention provides a cell switching method and related equipment, wherein the method comprises the steps that a source base station determines target frequency resources, the source base station sends target frequency resource indication information to a target base station, the source base station receives the indication information sent by the target base station, and the indication information is used for indicating that the terminal to be switched is allowed to be switched to the target frequency resources. Therefore, under the condition that a source base station determines a target frequency resource to be switched and accessed by a terminal to be switched residing in a source cell, the source base station can send a target frequency resource indication message to a target base station, and when the terminal to be switched initiates the access of the target cell, the terminal to be switched can be directly switched to the target frequency resource, so that the accuracy of the terminal to be switched and accessed to the target cell is improved, the possibility that the terminal is accessed to wrong frequency resources is effectively avoided, the success rate of cell switching is improved, and the time delay of cell switching is reduced.

Description

Cell switching method and related equipment

Technical Field

The embodiment of the application relates to the technical field of communication, in particular to a cell switching method and related equipment.

Background

In a 3rd generation partnership project (3 GPP) protocol, a Universal Mobile Telecommunications System (UMTS) terrestrial radio access network (E-ultra) defines a corresponding relationship between each frequency band and frequency, and a 3GPP protocol proposes a multi-frequency band (MFBI) cell based on the corresponding relationship between the frequency band and the frequency.

In an MFBI cell, two frequency bands may be simultaneously supported, one master frequency band and the other slave frequency band, while the operating frequency of the MFBI cell is in an overlapping area of the master frequency band and the slave frequency band, and in the process of switching to the MFBI cell, a terminal supporting the MFBI may have a situation of switching an error frequency point in the scheme shown in the prior art. For example, the frequency band supported by the terminal is located in the master frequency band of the MFBI cell, but the MFBI cell switches the terminal to the slave frequency band of the MFBI cell, or the frequency band supported by the terminal is located in the slave frequency band of the MFBI cell, but the MFBI cell switches the terminal to the master frequency band of the MFBI cell.

Therefore, the situation of switching wrong frequency points can be caused by adopting the switching process of the MFBI cells shown in the prior art, the switching accuracy of the MFBI cells is poor, and the switching time delay is increased.

Disclosure of Invention

The embodiment of the invention provides a cell switching method and related equipment capable of improving cell switching accuracy.

A first aspect of the present invention provides a cell switching method, including:

and step A, the source base station determines target frequency resources.

Specifically, the target frequency resource is a frequency resource to be switched by a terminal to be switched, which requests switching from a source cell to a target cell, the source base station is configured to serve the source cell, and the target cell is served by a target base station;

and step B, the source base station sends a target frequency resource indication message to the target base station.

The target frequency resource indication message is used for indicating the target frequency resource.

And step C, the source base station receives the indication message sent by the target base station.

The indication message is used for indicating that the terminal to be switched is allowed to be switched to the target frequency resource.

By adopting the method shown in this embodiment, the source base station can send the target frequency resource indication message to the target base station, and the target base station can determine the target frequency resource to be accessed by the terminal to be switched according to the target frequency resource indication message.

Based on the first aspect of the embodiment of the present invention, in an optional implementation manner of the first aspect of the embodiment of the present invention, the step a specifically includes:

step A11, the source base station determines at least one main frequency band and at least one slave frequency band supported by the target cell;

step A12, the source base station judges that the frequency point supported by the terminal to be switched is located in the frequency range of the target main frequency band, if yes, step A13 is executed;

step A13, the source base station determines that the target frequency resource is the target main frequency band or the target main frequency point.

Specifically, if the source base station determines that the frequency point supported by the terminal to be switched is located within the frequency range of a target main frequency band, the source base station determines that the target frequency resource is the target main frequency band or the target main frequency point, the target main frequency band is one of the at least one main frequency band supported by the target cell, and the target main frequency point is a frequency point corresponding to the target main frequency band.

By adopting the method, under the condition that the source base station determines that the frequency point supported by the terminal to be switched is located in the frequency range of the target main frequency band, the source base station can directly determine that the target frequency resource is the target main frequency band or the target main frequency point, so that the target frequency resource accessed by the terminal to be switched during cell switching is determined according to the frequency point supported by the terminal to be switched, the accuracy of accessing the terminal to be switched into the target cell is improved, and the possibility of accessing the terminal to be switched into the wrong frequency resource is effectively avoided.

step A21, the source base station determines at least one main frequency band and at least one slave frequency band supported by the target cell;

and A22, the source base station judges whether the frequency point supported by the terminal to be switched is located in the frequency range of the target slave frequency band, if so, the step A23 is executed.

Step A23, the source base station determines that the target frequency resource is the target slave frequency band or the target slave frequency point.

Specifically, if the source base station determines that the frequency point supported by the terminal to be switched is located within the frequency range of the target slave frequency band, the source base station determines that the target frequency resource is the target slave frequency band or the target slave frequency band, the target slave frequency band is one of the at least one slave frequency band supported by the target cell, and the target slave frequency band is a frequency point corresponding to the target slave frequency band.

By adopting the method, under the condition that the source base station determines that the frequency point supported by the terminal to be switched is located in the frequency range of the target slave frequency band, the source base station can directly determine that the target frequency resource is the target slave frequency band or the target slave frequency band, so that the target frequency resource accessed by the terminal to be switched during cell switching is determined according to the frequency point supported by the terminal to be switched, the accuracy of accessing the terminal to be switched into the target cell is improved, and the possibility of accessing the terminal to be switched into the wrong frequency resource is effectively avoided.

step A31, the source base station determines at least one main frequency band and at least one slave frequency band supported by the target cell;

and A32, the source base station judges whether the frequency point supported by the terminal to be switched is simultaneously located in the frequency range of the target main frequency band and the target slave frequency band, if so, the step A33 is executed.

Step A33, the source base station determines that the target frequency resource is the target main frequency band or the target main frequency point.

Specifically, if the source base station determines that the frequency point supported by the terminal to be switched is located in the frequency range of a target master frequency band and a target slave frequency band at the same time, the source base station determines that the target frequency resource is the target master frequency band or the target master frequency point, the target master frequency band is one master frequency band of the at least one master frequency band supported by the target cell, the target slave frequency band is one slave frequency band of the at least one slave frequency band supported by the target cell, and the target master frequency point is a frequency point corresponding to the target master frequency band.

By adopting the method, when the source base station determines that the frequency point supported by the terminal to be switched is simultaneously located in the frequency range of the target master frequency band and the target slave frequency band, the source base station can directly determine that the target frequency resource is the target master frequency band or the target master frequency point, so that the target frequency resource accessed by the terminal to be switched during cell switching is determined according to the frequency point supported by the terminal to be switched, the accuracy of accessing the terminal to be switched into the target cell is improved, and the possibility of accessing the terminal to be switched into the wrong frequency resource is effectively avoided.

step A41, the source base station determines at least one main frequency band and at least one slave frequency band supported by the target cell;

step a42, the source base station creates a priority list.

Specifically, the priority list includes a plurality of frequency bands supported by the destination base station, and the frequency bands are sorted in descending order of transmission bandwidths when a carrier aggregation CA is created between the terminal to be switched and any one of the frequency bands;

step a43, the source base station determines that the target frequency resource is the frequency band with the highest priority in the priority list, or the target frequency resource is the frequency point corresponding to the frequency band with the highest priority in the priority list.

By adopting the aspect, the source base station can create the priority list, so that the source base station can determine that the target frequency resource to be accessed by the terminal to be switched is the frequency band with the highest priority in the priority list, or the target frequency resource is the frequency point corresponding to the frequency band with the highest priority in the priority list, thereby ensuring the speed of data transmission, improving the accuracy of accessing the terminal to be switched to the target cell, and effectively avoiding the possibility that the terminal to be switched is accessed to wrong frequency resources.

Based on the first aspect of the embodiment of the present invention, in an optional implementation manner of the first aspect of the embodiment of the present invention, the step B specifically includes:

step B11, the source base station configures the switching request message.

Specifically, the handover request message is used to instruct the terminal to be handed over to the target cell, and the handover request message includes the target frequency resource indication message;

step B12, the source base station sends the switching request message to the target base station through an X2 interface.

By adopting the method, under the condition that the target frequency resource is determined by the source base station, the source base station can send the switching request message to the target base station, and the switching request message carries the target frequency resource indication information, so that the target base station can accurately determine the target frequency resource to be accessed by the terminal to be switched according to the switching request message, the accuracy of accessing the terminal to be switched to the target cell is further improved, and the possibility of accessing the terminal to be switched to the wrong frequency resource is effectively avoided.

Based on the first aspect of the embodiment of the present invention, in an optional implementation manner of the first aspect of the embodiment of the present invention, the step C specifically includes:

step C11, the source base station receives the switching request response message sent by the target base station through an X2 interface;

specifically, when an X2 interface is configured between the source base station and the destination base station, the source base station may receive a handover request response message sent by the destination base station through an X2 interface, where the handover request response message is used to indicate that the destination base station has successfully received the handover request message, and the handover request message includes the target frequency resource indication message and the indication message;

the method in this aspect further includes step D, the source base station sends the target frequency resource indication message to the terminal to be switched, so that the terminal to be switched is switched to the target frequency resource of the target cell according to the target frequency resource indication message.

When the source base station determines that the terminal to be switched can access the target frequency resource, the source base station can send the target frequency resource indication message to the terminal to be switched.

step B21, the source base station sends a switching indication message to a Mobile Management Entity (MME) through an S1 interface.

Under the condition that an X2 interface is not configured between the source base station and the destination base station, the source base station may send a handover indication message to the MME, where the handover indication message includes the target frequency resource indication message, so that the MME sends a handover request message to the destination base station through an S1 interface, where the handover request message includes the target frequency resource indication message.

step C21, the source base station receives a handover request response message sent by the MME through an S1 interface;

the switching request response message comprises a target frequency resource indication message and the indication message;

the method in this aspect further includes step E, the source base station sends the target frequency resource indication message to the terminal to be switched, so that the terminal to be switched is switched to the target frequency resource of the target cell according to the target frequency resource indication message.

A second aspect of the present invention provides a cell switching method, including:

and step A, the target base station receives a target frequency resource indication message sent by the source base station.

The target frequency resource indication message is used for indicating a target frequency resource, the target frequency resource is a frequency resource to be switched by a terminal to be switched, which requests to be switched from a source cell to a target cell, the source base station is used for serving the source cell, and the target base station is used for serving the target cell;

and step B, the target base station sends an indication message to the source base station.

By adopting the method shown in this embodiment, the target base station can determine the target frequency resource to be accessed by the terminal to be switched according to the target frequency resource indication message sent by the source base station, and then the target base station can determine the target frequency resource to be accessed by the terminal to be switched according to the target frequency resource indication message.

Based on the second aspect of the embodiment of the present invention, in an optional implementation manner of the second aspect of the embodiment of the present invention, the step B further includes: the target base station receives a handover request message through an X2 interface, where the handover request message is used to indicate that the terminal to be handed over is handed over to the target cell, and the handover request message includes the target frequency resource indication message.

Based on the second aspect of the embodiment of the present invention, in an optional implementation manner of the second aspect of the embodiment of the present invention, the step B further includes: a handover request response message sent by the destination base station to the source base station through an X2 interface, where the handover request response message is used to indicate that the destination base station has successfully received the handover request message, and the handover request message includes the target frequency resource indication message and the indication message.

Based on the second aspect of the embodiment of the present invention, in an optional implementation manner of the second aspect of the embodiment of the present invention, the step a further includes: and the target base station receives a handover request message sent by a Mobility Management Entity (MME) through an S1 interface, wherein the handover request message comprises the target frequency resource indication message.

Based on the second aspect of the present invention, in an optional implementation manner of the second aspect of the present invention, the step B further includes the destination base station sending a handover request response message to the MME through an S1 interface, so that the MME sends the handover request response message to the source base station through an S1 interface, where the handover request response message includes a target frequency resource indication message and the indication message.

A third aspect of the embodiments of the present invention provides a source base station, including:

a determining unit, configured to determine a target frequency resource, where the target frequency resource is a frequency resource to be switched by a terminal to be switched, and requests to switch from a source cell to a target cell, where the source base station is configured to serve the source cell, and the target cell is served by a target base station;

a first sending unit, configured to send a target frequency resource indication message to the target base station, where the target frequency resource indication message is used to indicate the target frequency resource;

a receiving unit, configured to receive an indication message sent by the destination base station, where the indication message is used to indicate that the terminal to be switched is allowed to be switched to the target frequency resource.

For a detailed description of the method, the specific implementation procedure, and the beneficial effects of the first aspect of the embodiment of the present invention, please refer to the first aspect of the embodiment of the present invention.

Based on the third aspect of the embodiment of the present invention, in an optional implementation manner of the third aspect of the embodiment of the present invention, the determining unit includes:

a first determining module, configured to determine at least one master frequency band and at least one slave frequency band supported by the destination cell;

the first judging module is configured to determine that the target frequency resource is the target dominant frequency band or the target dominant frequency point if it is judged that the frequency point supported by the terminal to be switched is within a frequency range of the target dominant frequency band, where the target dominant frequency band is one of the at least one dominant frequency band supported by the target cell, and the target dominant frequency point is a frequency point corresponding to the target dominant frequency band.

a second determining module, configured to determine at least one master frequency band and at least one slave frequency band supported by the destination cell;

a second determining module, configured to determine that the target frequency resource is the target slave frequency band or a target slave frequency band if it is determined that the frequency point supported by the terminal to be switched is within a frequency range of the target slave frequency band, where the target slave frequency band is one of the at least one slave frequency band supported by the target cell, and the target slave frequency band is a frequency point corresponding to the target slave frequency band.

a third determining module, configured to determine at least one master frequency band and at least one slave frequency band supported by the destination cell;

a third determining module, configured to determine that the target frequency resource is the target master frequency band or the target master frequency point if it is determined that the frequency point supported by the terminal to be switched is located within a frequency range of both the target master frequency band and the target slave frequency band, where the target master frequency band is one of the at least one master frequency band supported by the target cell, the target slave frequency band is one of the at least one slave frequency band supported by the target cell, and the target master frequency point is a frequency point corresponding to the target master frequency band.

a fourth determining module, configured to determine at least one master frequency band and at least one slave frequency band supported by the destination cell;

a creating module, configured to create a priority list, where the priority list includes multiple frequency bands supported by the target base station, and the multiple frequency bands are sorted according to a descending order of transmission bandwidths when a carrier aggregation CA is created between the terminal to be switched and any one of the multiple frequency bands;

a fifth determining module, configured to determine that the target frequency resource is a frequency band with a highest priority in the priority list, or that the target frequency resource is a frequency point corresponding to the frequency band with the highest priority in the priority list.

Based on the third aspect of the embodiment of the present invention, in an optional implementation manner of the third aspect of the embodiment of the present invention, the first sending unit includes:

a configuration module, configured to configure a handover request message, where the handover request message is used to instruct the terminal to be handed over to the destination cell, and the handover request message includes the target frequency resource instruction message;

a sending module, configured to send the handover request message to the destination base station through an X2 interface.

Based on the third aspect of the embodiment of the present invention, in an optional implementation manner of the third aspect of the embodiment of the present invention, the receiving unit is further configured to receive, through an X2 interface, a handover request response message sent by the destination base station, where the handover request response message is used to indicate that the destination base station has successfully received the handover request message, and the handover request message includes the target frequency resource indication message and the indication message;

the source base station further includes:

a second sending unit, configured to send the target frequency resource indication message to the terminal to be switched, so that the terminal to be switched is switched to the target frequency resource of the target cell according to the target frequency resource indication message.

Based on the third aspect of the present invention, in an optional implementation manner of the third aspect of the present invention, the first sending unit is further configured to send, to a mobility management entity MME through an S1 interface, a handover indication message, where the handover indication message includes the target frequency resource indication message, so that the MME sends, to the target base station, a handover request message through an S1 interface, where the handover request message includes the target frequency resource indication message.

Based on the third aspect of the embodiment of the present invention, in an optional implementation manner of the third aspect of the embodiment of the present invention, the receiving unit is further configured to receive, through an S1 interface, a handover request response message sent by the MME, where the handover request response message includes a target frequency resource indication message and the indication message;

the source base station further includes:

a third sending unit, configured to send the target frequency resource indication message to the terminal to be switched, so that the terminal to be switched is switched to the target frequency resource of the target cell according to the target frequency resource indication message.

A fourth aspect of the present invention provides a destination base station, including:

a receiving unit, configured to receive a target frequency resource indication message sent by a source base station, where the target frequency resource indication message is used to indicate a target frequency resource, the target frequency resource is a frequency resource to be switched by a terminal to be switched, which requests to switch from a source cell to a target cell, the source base station is configured to serve the source cell, and the target base station is configured to serve the target cell;

a sending unit, configured to send an indication message to the source base station, where the indication message is used to indicate that the terminal to be switched is allowed to be switched to the target frequency resource.

For details of the method, the specific implementation process, and the beneficial effects of the second aspect of the embodiment of the present invention, please refer to the second aspect of the embodiment of the present invention, which is not described in detail herein.

Based on the fourth aspect of the present invention, in an optional implementation manner of the fourth aspect of the present invention, the receiving unit is further configured to receive a handover request message through an X2 interface, where the handover request message is used to instruct the terminal to be handed over to switch to the destination cell, and the handover request message includes the target frequency resource indication message.

Based on the fourth aspect of the present invention, in an optional implementation manner of the fourth aspect of the present invention, the sending unit is further configured to send, to the source base station through an X2 interface, a handover request response message, where the handover request response message is used to indicate that the target base station has successfully received the handover request message, and the handover request message includes the target frequency resource indication message and the indication message.

Based on the fourth aspect of the present invention, in an optional implementation manner of the fourth aspect of the present invention, the receiving unit is further configured to receive, through an S1 interface, a handover request message sent by a mobility management entity MME, where the handover request message includes the target frequency resource indication message.

Based on the fourth aspect of the present invention, in an optional implementation manner of the fourth aspect of the present invention, the sending unit is further configured to send a handover request response message to the MME through an S1 interface, so that the MME sends the handover request response message to the source base station through an S1 interface, where the handover request response message includes a target frequency resource indication message and the indication message.

A fifth aspect of the embodiments of the present invention provides a base station, which includes a processor and a memory, wherein,

a computer readable program stored in the memory;

the processor executes the program in the memory, and when the base station is used as the source base station, the base station is configured to execute the method shown in the first aspect of the embodiment of the present invention, and when the base station is used as the destination base station, the base station is configured to execute the method shown in the second aspect of the embodiment of the present invention.

A sixth aspect of embodiments of the present invention provides a computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by a source base station, cause the source base station to perform the method according to the first aspect of embodiments of the present invention, and which when executed by a destination base station, cause the destination base station to perform the method according to the second aspect of embodiments of the present invention.

By adopting the cell switching method shown in this embodiment, when a source base station determines a target frequency resource to be switched and accessed by a terminal to be switched residing in a source cell, the source base station can send a target frequency resource indication message for indicating the target frequency resource to the target base station, and when the terminal to be switched initiates a target cell access, the terminal to be switched can be directly switched to the target frequency resource, so that the accuracy of the terminal accessing the target cell is improved, the possibility that the terminal accesses to the wrong frequency resource is effectively avoided, the success rate of cell switching is improved, and the time delay of cell switching is reduced.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of a communication system provided in the present invention;

FIG. 2 is a schematic diagram of a cell according to an embodiment of the present invention;

FIG. 3 is a flowchart illustrating a method for cell handover according to an embodiment of the present invention;

FIG. 4 is a flowchart illustrating a method for cell handover according to another embodiment of the present invention;

FIG. 5 is a flowchart illustrating a method for cell handover according to another embodiment of the present invention;

fig. 6 is a schematic structural diagram of a source base station according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a target base station according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a base station according to an embodiment of the present invention.

Detailed Description

The following detailed description and the accompanying drawings are sufficient to describe specific embodiments that enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in or substituted for those of others.

To better understand the method for cell handover provided in the present application, a communication system to which the method for cell handover provided in the present application is applied is first exemplarily described below with reference to fig. 1, where fig. 1 is a schematic structural diagram of an embodiment of the communication system provided in the present invention.

The communication system shown in this embodiment may be Long Term Evolution (LTE) of the universal mobile telecommunications technology as an example, and the communication system may include a core network device 101, a source base station 102, a destination base station 103, and a terminal 104.

The core network device 101 includes a Mobility Management Entity (MME) and a Serving Gateway (SGW). The MME belongs to a control plane part and is responsible for mobility management of the control plane, including user context and mobile state management, user temporary identity allocation and the like; SGW belongs to user interface part and is responsible for initiating paging for downlink data in idle state, managing and storing IP bearing parameters, routing information in network and the like; the MME and the SGWs are connected in a mesh mode, and one MME can control a plurality of SGWs.

The core network device 101 and the source base station 102, the core network device 101 and the destination base station 103 communicate with each other through an S1 interface, and the source base station 102 and the destination base station 103 communicate with each other through an X2 interface.

It should be understood that the source base station 102 and the destination base station 103 shown in this embodiment may be base stations, and may also be access points, which are used to provide services for the terminal 104, and one or more transmitting antennas and one or more receiving antennas are adopted between the source base station 102 and the destination base station 103 and the terminal 104 for signal transmission.

The terminal 104 shown in this embodiment may also be referred to as a Mobile Station (MS) or a mobile terminal (mobile). Which may communicate with the core network device 101 via a Radio Access Network (RAN). And the terminal 104 may be a mobile phone (or referred to as a "cellular" phone), a tablet, a personal digital assistant, and a computer having a mobile terminal, and may also be a portable, pocket, hand-held, computer-included, or vehicle-mounted mobile device.

The terminal 104 shown in this embodiment may perform wireless communication with the source base station 102 in the communication system, specifically, the source base station 102 shown in this embodiment may serve a source cell in a geographic area, and the destination base station 103 shown in this embodiment may serve a destination cell in the geographic area.

An application scenario of the communication system shown in this embodiment is exemplarily described below, where the terminal 104 is located in the source cell and is in a connected state with the source base station 102, and since the terminal 104 needs to be switched from the source cell to the destination cell when the terminal 104 moves between different cells.

The target cell shown in this embodiment is a target cell for the terminal 104 to perform cell handover, and in this embodiment, the target cell is a multi-frequency band indicator (MFBI) cell, and the MFBI-based target cell is described as follows:

the operating frequency of the target cell shown in this embodiment belongs to multiple frequency bands, and the operating frequency of the target cell is in an overlapping area of two frequency bands, the schematic diagram of the target cell is shown in fig. 2 as an example, where the uplink frequency of the target cell 200 is between 704Mhz and 716Mhz, and the downlink frequency is between 734Mhz and 746Mhz, the uplink frequency and the downlink frequency of the target cell both belong to a frequency Band (Band)12 and a Band17, where the primary frequency Band of the target cell 200 is a Band17, and for the same frequency, the frequency points in the Band12 and the Band17 are different and are Earfcn1 and Earfcn2, respectively.

If the terminal 104 wants to obtain service in the destination cell 200, the terminal 104 needs to satisfy the following conditions:

one condition that the terminal 104 needs to satisfy is that the terminal 104 has MFBI functionality and the supported frequency Band of the terminal 104 is Band17, wherein the terminal 104 having MFBI functionality refers to a terminal capable of accessing to an MFBI cell.

Another condition that the terminal 104 needs to satisfy is that the terminal 104 has MFBI functionality and the frequency Band supported by the terminal 104 is Band 12.

To better understand the method for cell handover according to the embodiment of the present invention, first, based on the structure of the communication system applied in the present application shown in fig. 1 to fig. 2, the execution process of the method for cell handover according to the present embodiment is schematically described:

in order to realize the purpose of switching the terminal connected in the source cell to the target cell in the MFBI, in the technical scheme adopted in the prior art, a source base station serving the source cell sends a switching request message to a target base station serving the target cell, and the target base station can only determine that the cell to be switched by the terminal is the target cell based on the switching request message, but the target base station cannot identify whether the terminal is to be switched by a frequency point corresponding to a master frequency band of the target cell or a frequency point corresponding to a slave frequency band of the target cell, so that the terminal may have a situation of switching a wrong frequency point.

By adopting the cell switching method disclosed by the application, the target base station serving the target cell can determine whether the terminal is to be switched to the main frequency band or the slave frequency band of the target cell, so that the condition that the terminal switches to the wrong frequency band is effectively avoided.

The specific implementation procedure of an alternative embodiment of the method for cell handover shown in this embodiment is described in detail below with reference to fig. 3.

Step 301, the source base station determines a target frequency resource.

Specifically, the target frequency resource shown in this embodiment is a frequency resource to be switched by a terminal to be switched, which requests to be switched from a source cell to a target cell, where the source base station is configured to serve the source cell, and the target cell is served by a target base station.

More specifically, the present embodiment does not limit the specific process of determining the target frequency resource by the source base station, as long as the target frequency resource is the frequency resource which the terminal requests to access and belongs to the target cell;

several alternative ways of determining the target frequency resource by the source base station shown in this embodiment are exemplarily described below:

the first alternative is:

firstly, the source base station can determine at least one main frequency band and at least one slave frequency band supported by the target cell;

secondly, the source base station can judge whether the frequency point supported by the terminal to be switched residing in the source cell is located in the frequency range of the target main frequency band;

and if the source base station judges that the frequency point supported by the terminal to be switched is located in the frequency range of the target main frequency section, the source base station can determine that the target frequency resource is the target main frequency section or the target main frequency point, wherein the target main frequency section is one of the at least one main frequency section supported by the target cell, and the target main frequency point is a frequency point corresponding to the target main frequency section.

The second alternative is:

firstly, the source base station determines at least one main frequency band and at least one slave frequency band supported by the target cell;

secondly, the source base station can judge whether the frequency point supported by the terminal to be switched is positioned in the frequency range of the target slave frequency band;

if the source base station judges that the frequency point supported by the terminal to be switched is located in the frequency range of the target slave frequency band, the source base station can determine that the target frequency resource is the target slave frequency band or the target slave frequency band, the target slave frequency band is one of the at least one slave frequency band supported by the target cell, and the target slave frequency band is a frequency point corresponding to the target slave frequency band.

The third alternative is:

secondly, the source base station can judge whether the frequency point supported by the terminal to be switched is positioned in the frequency range of the target master frequency band and the target slave frequency band simultaneously;

if the source base station judges that the frequency point supported by the terminal to be switched is located in the frequency range of a target main frequency band and a target slave frequency band at the same time, the source base station determines that the target frequency resource is the target main frequency band or the target main frequency point, the target main frequency band is one main frequency band in the at least one main frequency band supported by the target cell, the target slave frequency band is one slave frequency band in the at least one slave frequency band supported by the target cell, and the target main frequency point is a frequency point corresponding to the target main frequency band.

The fourth alternative is:

secondly, the source base station creates a priority list, the priority list comprises a plurality of frequency bands supported by the target base station, and the frequency bands are sequenced according to the sequence from large to small of transmission bandwidth when a carrier aggregation CA is created between the terminal to be switched and any frequency band in the frequency bands;

under the condition that the source base station successfully creates the priority list, the source base station can determine that the target frequency resource is the frequency band with the highest priority in the priority list, or the target frequency resource is the frequency point corresponding to the frequency band with the highest priority in the priority list.

Step 302, the source base station sends a target frequency resource indication message to the destination base station.

In this embodiment, when the source base station determines the target frequency resource, the source base station may configure a target frequency resource indication message, where the target frequency resource indication message is used to indicate the target frequency resource, the source base station may send the configured target frequency resource indication message to a target base station, and the target base station may determine the target frequency resource to be switched by the terminal to be switched according to the target frequency resource indication message, where details of the target frequency resource are shown in step 301, and are not described in this step.

Step 303, the source base station receives the indication message sent by the destination base station.

And under the condition that the target base station determines the target frequency resource to be switched by the terminal to be switched, the target base station can configure an indication message, wherein the indication message is used for indicating that the terminal to be switched is allowed to be switched to the target frequency resource.

Specifically, the indication message shown in this embodiment is used to indicate that the terminal to be switched can be switched to the target frequency resource.

By adopting the method for cell switching shown in this embodiment, a source base station can send a target frequency resource indication message to a target base station, and the target base station can determine a target frequency resource to be accessed by the terminal to be switched according to the target frequency resource indication message.

To better understand the method for cell handover shown in the embodiment of the present invention, the following description is made with reference to a specific embodiment, and first, with reference to fig. 4, a detailed description is made of a specific implementation procedure of an alternative embodiment of the method for cell handover shown in this embodiment.

First, an exemplary description is given of a cell handover method shown in fig. 4, where a base station serving the source cell and a base station serving the destination cell belong to different base stations, that is, as shown in fig. 1, the base station serving the source cell is the source base station, the base station serving the destination cell is the destination base station, and the source base station and the destination base station have an X2 interface therebetween, that is, an X2 relationship is configured between the source base station and the destination base station, so that the source base station and the destination base station have X2 handover enabling capability.

The enabling of the X2 handover between the source base station and the destination base station in this embodiment means that the source base station and the destination base station exchange required application layer data, so that the source base station and the destination base station perform information interaction through an X2 interface.

Step 401, the source base station sends a measurement configuration message to the terminal to be switched.

In this embodiment, the terminal to be switched is a terminal that needs to be switched to the target cell, and for a specific description of the terminal to be switched, please refer to the terminal shown in fig. 1 and fig. 2, which is not described in detail in this embodiment.

When a terminal to be switched residing in the source cell is in a connected state, a source base station serving the source cell may send a measurement configuration message to the terminal to be switched, where the measurement configuration message shown in this embodiment is used to instruct the terminal to be switched to measure a communication environment of the terminal to be switched according to the instruction of the measurement configuration message, and report a measurement report message to the source base station, and the source base station may determine whether the terminal to be switched needs to perform cell switching according to the measurement report message reported by the terminal to be switched.

Optionally, when the to-be-switched terminal and the source base station establish a radio bearer, the source base station issues Radio Resource Control (RRC) to the to-be-switched terminal, where the RRC may include the Measurement Configuration message (Measurement Configuration) configured by the source base station, and the Measurement Configuration is used to control a Measurement process of a connection state of the to-be-switched terminal.

The present embodiment does not limit the specific content indicated by the measurement configuration message, as long as the terminal to be switched can perform measurement of the communication environment according to the measurement configuration message, so as to enable the source base station to determine whether the terminal to be switched needs to perform cell switching, for example, the source base station may indicate, through the measurement configuration message, a measurement object, a measurement period, a measurement condition, and the like for the terminal to be switched that resides in the source cell to perform measurement. The measurement condition is used for indicating that the terminal to be switched measures a measurement object to generate a measurement result, and when the measurement result meets the measurement condition, the terminal to be switched can report a measurement report message to the source base station.

Step 402, the terminal to be switched sends a measurement report message to the source base station.

After the terminal to be switched shown in this embodiment receives the measurement configuration message, the terminal to be switched can measure the communication environment according to the measurement configuration message.

Specifically, the measurement configuration message may include a measurement event identifier AX used for indicating the terminal to be switched to perform measurement, the terminal to be switched may be pre-stored with a corresponding list, where the corresponding list includes a corresponding relationship between different measurement event identifiers AX and different measurement events, so that when the terminal to be switched receives the measurement event identifier AX, the terminal to be switched may determine a corresponding measurement event according to the corresponding list, and the terminal to be switched may determine that the terminal to be switched reports the measurement report message when the measurement event corresponding to the measurement event identifier AX is satisfied.

Two cases of cell handover are exemplified in this embodiment:

an example scenario for a first cell handover is as follows:

the measurement configuration message configured by the source base station may include a measurement event identifier a4, where a measurement event corresponding to the measurement event identifier a4 is to measure the quality of an adjacent cell, and if the quality of the adjacent cell is greater than or equal to the quality of the source cell, a measurement report message is reported.

It can be seen that, after the terminal to be switched receives the measurement configuration message, the terminal to be switched can parse the measurement event identifier a4 included in the measurement configuration message, the terminal to be switched can query the measurement event corresponding to the measurement event identifier a4 according to the corresponding list, the terminal to be switched can measure the adjacent cell according to the measurement event corresponding to the measurement event identifier a4, and if the signal quality of the adjacent cell is greater than or equal to the signal quality of the source cell, the measurement report message is reported.

In the adjacent cells determined by the terminal to be switched, the cell with the cell signal quality greater than or equal to the signal quality of the source cell is the target cell, and the terminal to be switched can report a measurement report message including a measurement event identifier a4 and a Physical Cell Identifier (PCI) of the target cell to the source base station.

The following describes a specific process of the terminal to be switched for determining that the signal quality of the target cell is greater than or equal to the signal quality of the source cell:

and the terminal to be switched determines that the signal quality of the target cell is greater than or equal to that of the source cell in a preset time period, and the signal quality of the target cell is greater than or equal to that of the source cell, which can mean that Mn + Ofn + Ocn-Hys is greater than Ms + Ofs + Ocs + Off and the preset time period is maintained.

Wherein the Mn refers to the target cell measurement value, the Ofn refers to the target cell frequency offset, the Ocn refers to the target cell offset, and the Hys refers to a hysteresis value; and the Ms refers to the source cell measurement value, the Ofs refers to the source cell frequency offset, the Ocs refers to the source cell offset, and the Off refers to an offset value.

An example case of a second cell handover is as follows:

the measurement configuration message may include a measurement event identifier a2, and the measurement event corresponding to the measurement event identifier a2 is: and reporting a measurement report message when the quality of the source cell is less than or equal to a preset threshold.

As can be seen, after the terminal to be switched receives the measurement configuration message, the terminal to be switched can analyze the measurement event identifier a2 included in the measurement configuration message, and the terminal to be switched can query the measurement event corresponding to the measurement event identifier a2 according to the corresponding list.

According to the measurement event corresponding to the measurement event identifier a2, the terminal to be switched can measure the source cell to obtain the quality of the source cell.

Optionally, the quality of the source cell may refer to Reference Signal Receiving Power (RSRP) of the source cell, and the RSRP unit is dBm; also optionally, the quality of the source cell may also refer to Reference Signal Receiving Quality (RSRQ), which may be in dB. In this embodiment, an explanation of a parameter for measuring the quality of the source cell is an optional example, and is not specifically limited in this embodiment, as long as the quality of the source cell is greater than the preset threshold, the source cell can satisfy the continuity of the service of the terminal to be switched, and when the quality of the source cell is less than or equal to the preset threshold, the source cell cannot satisfy the continuity of the service of the terminal to be switched.

If the terminal to be switched determines that the quality of the source cell is less than or equal to the preset threshold, the terminal to be switched may report the measurement report message to a source base station, where the measurement report message may include the measurement event a2, and after receiving the measurement report message, the source base station may determine that the quality of the source cell is less than or equal to the preset threshold according to the measurement event a2 included in the measurement report message, and then send the measurement event identifier a4 to the terminal to be switched, and the terminal to be switched receives a processing procedure of the measurement event identifier a4, which is shown in the above description and is not repeated.

And in the adjacent cells determined by the terminal to be switched, the cell with the cell signal quality greater than or equal to the signal quality of the source cell is the target cell, and the terminal to be switched can report a measurement report message comprising a measurement event identifier A4 and the PCI of the target cell to the source base station.

Step 403, the source base station sends a handover request message to the destination base station.

After the source base station receives the measurement report message, the source base station can perform switching judgment according to the measurement report message to judge whether the terminal to be switched is switched to the target cell.

The following describes the process of the source base station making a decision on the measurement report message:

in step 402, it can be known that, if the measurement report message received by the source base station includes the PCI of the target cell measured by the terminal to be switched, the source base station can determine the target cell;

optionally, if the source base station may maintain a blacklist, where the blacklist includes a PCI of at least one cell, if the source base station determines that the PCI of the target cell is located in the blacklist, the source base station may determine that the terminal to be switched may not be switched to the target cell, and if the PCI of the target cell is not located in the blacklist, the source base station may determine that the terminal to be switched may be switched to the target cell.

In this embodiment, the process of creating the blacklist by the source base station is not limited, as long as the source base station configures the PCI of the cell that is determined to be unable to be switched in the blacklist, for example, the source base station determines that a destination cell is in a maintenance state, a failure state, and the like, and the source base station may configure the PCI of the destination cell in the blacklist.

For another example, the source base station may determine whether a Public Land Mobile Network (PLMN) of the destination cell is the same as the PLMN of the source cell, if so, the source base station may determine that the source cell and the destination cell belong to the same operator, and then the source base station may determine that the terminal to be switched may be switched to the destination cell, and if not, the source base station may determine that the source cell and the destination cell do not belong to the same operator, and then the source base station may determine that the terminal to be switched may not be switched to the destination cell.

And under the condition that the source base station determines that the terminal to be switched can be switched to the target cell, the source base station can configure the switching Request message (Handover Request) and send the configured switching Request message to the target base station through an X2 interface.

The following exemplifies specific contents included in the handover request message:

the handover request message shown in this embodiment may include a global cell identity (CGI) of the destination cell, where the CGI of the destination cell is used to indicate an area covered by the destination cell.

In this embodiment, the handover request message includes a target frequency resource indication message, where the target frequency resource indication message is used to indicate a target frequency resource to be accessed by the terminal to be handed over.

The following is an exemplary description of how the source base station determines the target frequency resource;

firstly, it should be clear that, before the source base station determines the target frequency resource, the source base station may obtain in advance a resource allocation condition of an adjacent cell, where the resource allocation condition includes, but is not limited to, a frequency band supported by the adjacent cell of the source base station and a frequency point corresponding to each frequency point.

The first way is that, when the source base station determines that the terminal to be switched needs to be accessed to the target cell, the source base station may obtain at least one master frequency band and at least one slave frequency band supported by the target cell, and if the source base station determines that the frequency point supported by the terminal to be switched is located within a frequency range of a target master frequency band, where the target master frequency band is one of the at least one master frequency band supported by the target base station, the switching request message includes the target frequency resource indication message, and the target frequency resource indicated by the target frequency resource indication message is the target master frequency band.

For example, the frequency points supported by the terminal to be switched are frequency point 1, frequency point 2, and frequency point 3, and the source base station determines that the frequency point 2 supported by the terminal to be switched is located within the frequency range of the target main frequency band, so that the target frequency resource indicated by the target frequency resource indication message is the target main frequency band in which the frequency point 2 is located.

In a second manner, when the source base station determines that the frequency point supported by the terminal to be switched is located within the frequency range of the target dominant frequency band, the source base station may determine a target dominant frequency point corresponding to the target dominant frequency band, and then the source base station may determine that the target dominant frequency point is the target frequency resource, and then the target frequency resource indicated by the target frequency resource indication message is the target dominant frequency point.

In a third manner, if the source base station determines that the frequency point supported by the terminal to be switched is located in a frequency range of a target slave frequency band, where the target slave frequency band is one slave frequency band in at least one slave frequency band supported by the target base station, the switching request message includes the target frequency resource indication message, and the target frequency resource indicated by the target frequency resource indication message is the target slave frequency band.

For example, the frequency points supported by the terminal to be switched are frequency point 1, frequency point 2, and frequency point 3, and the source base station determines that the frequency point 3 supported by the terminal to be switched is located within the frequency range of the target slave frequency band, so that the target frequency resource indicated by the target frequency resource indication message is the target slave frequency band in which the frequency point 3 is located.

In a fourth aspect, when the source base station determines that the frequency point supported by the terminal to be switched is located within the frequency range of the target slave frequency band, the source base station may determine a target slave frequency point corresponding to the target slave frequency band, and then the source base station may determine that the target slave frequency point is the target frequency resource, and then the target frequency resource indicated by the target frequency resource indication message is the target slave frequency point.

A fifth way is that, if the source base station determines that the frequency point supported by the terminal to be switched is located in the frequency range of the target master frequency band and the target slave frequency band at the same time, the target frequency resource indicated by the target frequency resource indication message included in the switching request message is the master frequency band.

The sixth mode is that the source base station obtains a first transmission bandwidth, where the first transmission bandwidth is a transmission bandwidth before the terminal to be switched and the destination base station if Carrier Aggregation (CA) is created between the terminal to be switched and the main frequency band of the destination base station, and the source base station obtains a second transmission bandwidth, where the second transmission bandwidth is a transmission bandwidth before the terminal to be switched and the destination base station if CA is created between the terminal to be switched and the main frequency band of the destination base station.

If the source base station determines that the first transmission bandwidth is larger than the second transmission bandwidth, the source base station determines that the target frequency resource is the master frequency band of the target base station, and if the source base station determines that the first transmission bandwidth is smaller than the second transmission bandwidth, the source base station determines that the target frequency resource is the slave frequency band of the target base station.

Optionally, if the number of the frequency bands included in the destination base station is multiple, the source base station creates a priority list, where the priority list includes multiple frequency bands of the destination base station, and the multiple frequency bands are sorted in an order from large to small according to transmission bandwidths when a CA is created between a terminal to be switched and any one of the multiple frequency bands, and the source base station may determine that the frequency band with the highest priority in the priority list is the target frequency resource.

In a seventh case, the source base station may determine that the target frequency resource is a frequency point corresponding to a frequency band with a highest priority in the priority list.

In this embodiment, the number of the destination cells determined by the source base station may be one or more, and if the source base station determines that the number of the destination cells is multiple, the source base station may send the handover request message to a destination base station serving any one of the determined destination cells.

It should be clear that, in this embodiment, an example is given in which the source base station sends the target frequency resource indication message to the destination base station through the handover request message, in other embodiments, the source base station may also send the target frequency resource indication message to the destination base station through other messages, or for example, the source base station may also send the target frequency resource indication message to the destination base station alone.

Step 404, the destination base station sends a handover request response message to the source base station.

When the target base station receives the Handover Request message, the target base station may send a Handover Request response message (Handover Request Acknowledge) to the source base station, where the Handover Request response message is used to indicate that the target base station has successfully received the Handover Request message.

The handover request response message shown in this embodiment further includes an indication message, where the indication message is used to indicate that the target base station allows the terminal to be handed over to access the target frequency resource.

In this embodiment, when the target base station receives the handover request message, the target base station may reserve resources for the terminal to be handed over, so that when the terminal to be handed over is handed over to the target cell, the terminal to be handed over may access the reserved resources of the target base station, thereby effectively improving the success rate of accessing the terminal to be handed over to the target cell.

Because the handover request message received by the target base station includes the target frequency resource indication message, the target base station can identify the target frequency resource to which the terminal to be handed over is to be accessed according to the target frequency resource indication message, and the target base station can perform resource reservation for the terminal to be handed over at the target frequency resource.

Specifically, if the target frequency resource to be accessed by the terminal to be switched is the dominant frequency point corresponding to the dominant frequency band of the target base station, the target base station may determine that the terminal to be switched is randomly accessed to the dominant frequency point corresponding to the dominant frequency band of the target base station.

If the target frequency resource to be accessed by the terminal to be switched is the slave frequency point corresponding to the slave frequency band of the target base station, the target base station can determine the slave frequency point corresponding to the slave frequency band of the target base station to which the terminal to be switched is randomly accessed.

For example, the frequency bands supported by the terminal to be switched are band4, band12 and band17, the frequency band supported by the source cell is band4, the destination cell is an MFBI cell, the master frequency band of the destination cell is band17, and the slave frequency band is band12, when the terminal to be switched needs to be switched from band4 to band12, because the target frequency resource indication message carried in the handover request message includes the target frequency resource to be accessed by the terminal to be switched, the target frequency resource corresponds to band12 to be switched by the terminal to be switched, the destination base station may determine whether the master frequency band to be randomly accessed by the terminal to be switched is the slave frequency band according to the target frequency resource, for example, if the destination base station determines that the target frequency resource belongs to band17, the destination base station may determine that the frequency band to be accessed by the terminal to be switched is the master frequency band of the destination base station, if the target base station determines that the target frequency resource belongs to band12, the target base station may determine that the frequency band to be accessed by the terminal to be switched is the slave frequency band of the target base station, wherein the target base station determines that the target frequency resource corresponds to the band12 to be switched by the terminal to be switched, and the target base station may determine that the frequency band to be accessed by the terminal to be switched is the slave frequency band.

After the target base station determines a target frequency resource to which the terminal to be switched is to access, an indication message can be configured, where the indication message is used to indicate the target base station to perform resource reservation for the terminal to be switched on the target frequency resource, and then the target base station can send the switching request response message carrying the indication message to the source base station, so that the source base station determines that the target base station has performed resource reservation for the terminal to be switched according to the indication message.

Step 405, the source base station sends a switching reconfiguration message to the terminal to be switched.

Specifically, after receiving the handover request response message, the source base station shown in this embodiment may determine that the target base station has determined that the terminal to be handed over needs to be handed over to the target cell served by the target base station, and then the source base station may successfully handover the terminal to be handed over to the target cell, and the source base station may send a handover Reconfiguration message (RRC Connection Reconfiguration) to the terminal to be handed over.

In order to ensure that the terminal to be switched is successfully accessed to the target cell, the switching reconfiguration message may further include the PCI of the target cell, and the terminal to be switched may be accessed to the target cell having the PCI indicated by the switching reconfiguration message according to the switching reconfiguration message.

The handover reconfiguration message shown in this embodiment further includes the indication message and the target frequency resource indication message, and the terminal to be handed over can determine the target frequency resource according to the handover reconfiguration message, and then the terminal to be handed over can access the reserved resource of the target cell for access.

Step 406, the source base station sends a serial number state change message to the destination base station.

Specifically, after the source base station receives the handover request response message, the source base station may send a serial number Status Transfer message (SN Status Transfer) to the destination base station, where the serial number Status Transfer message transmits a Status of a Packet Data Convergence Protocol (PDCP) of an uplink and a downlink to the destination base station, so that the destination base station obtains a data transmission condition between the source base station and the terminal to be handed over according to the serial number Status Transfer message, and the destination base station may synchronize data transmission between the terminal to be handed over and the source base station according to the serial number Status Transfer message, thereby reducing transmission delay.

Step 407, the terminal to be switched sends a reconfiguration complete message to the destination base station.

In this embodiment, after the terminal to be switched receives the switching reconfiguration message, the terminal to be switched can be randomly accessed to the target cell.

Specifically, if the terminal to be switched determines that a random access Preamble (Preamble) is configured in the handover reconfiguration message, the terminal to be switched can access the target cell by using a non-contention random access procedure.

And if the terminal to be switched judges that the Preamble is not configured in the switching reconfiguration message, the terminal to be switched accesses the target cell by using a competitive random access process.

In order to realize the random access of the terminal to be switched to the target cell, the terminal to be switched may send a switching Reconfiguration Complete message (RRC Connection Reconfiguration Complete) to the target base station, where the switching Reconfiguration Complete message is used to confirm that the process of switching to the target cell is completed to the target base station.

Step 408, the destination base station sends a switching path change message to the core network device.

In this embodiment, after the destination base station receives the reconfiguration complete message, the destination base station may send a switching Path change message (Path Switch Request) to the core network device, where the switching Path change message is used to notify the core network device that the base station to which the terminal to be switched is accessed is changed from the source base station to the destination base station.

After the core network device receives the switching path change message, the core network device does not send user plane data of the terminal to be switched to the source base station any more, but switches a data transmission path to the destination base station side, that is, before the terminal to be switched is switched to the destination cell, the core network device creates the data transmission path between the source base station and the terminal to be switched, and after the terminal to be switched is switched to the destination cell, the core network device creates the data transmission path between the destination base station and the terminal to be switched.

Step 409, the core network equipment sends the switching path change response message to the target base station.

After receiving the switching Path change message, the core network device may send a switching Path change response message (Path Switch Request acknowledgement) to the destination base station.

Step 410, the destination base station sends a release message of the context of the terminal to be switched to the source base station.

In this embodiment, after the target base station receives the switching path change response message sent by the core network device, the target base station may determine that the core network device has created a data transmission path between the target base station and the terminal to be switched, which indicates that the terminal to be switched is successfully switched to the target cell, and in order to reduce system power consumption, the target base station may send a context release message to the source base station.

Step 411, the source base station receives the context release message.

In this embodiment, after the source base station receives the context release message, the source base station may release the context corresponding to the terminal to be switched according to the context release message.

By adopting the method for cell switching shown in this embodiment, a source base station can send a switching request message carrying a target frequency resource indication message to a target base station, and the target base station can determine a target frequency resource to be accessed by the terminal to be switched according to the target frequency resource indication message.

The specific implementation procedure of an alternative embodiment of the method for cell handover shown in this embodiment is described in detail below with reference to fig. 5.

First, an exemplary description is given of a cell handover method shown in fig. 5, where a base station serving the source cell and a base station serving the destination cell belong to different base stations, that is, as shown in fig. 1, the base station serving the source cell is the source base station, and the source base station and the destination base station do not have an X2 interface or an X2 interface between the source base station and the destination base station is unavailable, and as shown in this application scenario, S1 interfaces are configured between the MME and the source base station and between the MME and the destination base station, so that information interaction is performed between the source base station and the MME and between the destination base station and the MME through an S1 interface.

Step 501, the source base station sends a measurement configuration message to the terminal to be switched.

Step 502, the terminal to be switched sends a measurement report message to the source base station.

For details of the specific execution process from step 501 to step 502 shown in this embodiment, please refer to steps 401 to 402 shown in fig. 4, and the specific execution process is not described in detail in this embodiment.

Step 503, the source base station sends a handover indication message to the MME.

For a detailed description of the process of the source base station deciding the measurement report message, please refer to the embodiment shown in fig. 3, which is not described in detail in this embodiment.

When the source base station determines that the terminal to be switched needs to be switched to the target cell, the source base station may send the switching indication message through the MME via an S1 interface.

The specific content included in the handover indication message configured by the source base station is please refer to the handover request message shown in fig. 3, which is not repeated in this embodiment specifically, that is, the handover indication message shown in this embodiment includes the CGI of the destination cell and the target frequency resource indication message, and the specific description of the target frequency resource indication message is please refer to the embodiment shown in fig. 3 specifically, which is not repeated in this embodiment.

In this embodiment, after receiving the handover indication message sent by the source base station, the MME determines whether the handover indication message is valid, and if the MME determines that the handover indication message is valid, the MME triggers a process in which the MME sends a handover request message to the destination base station.

Specifically, in this embodiment, the MME judges whether a field of the handover indication message meets a preset requirement, and if the MME judges that the field included in the handover indication message meets the preset requirement, the MME can successfully identify the CGI of the target cell and the target frequency resource indication message included in the request indication message.

And when the MME judges that the switching indication message meets the preset requirement, the MME can determine that the switching indication message is legal.

Step 504, the MME sends a handover request message to the destination base station.

And when the MME judges that the switching indication message is legal, the MME can configure the switching request message, wherein the switching request message comprises a CGI (common gateway interface) used for indicating the target cell to the target base station and a target frequency resource indication message.

Specifically, the MME sends the handover request message to the target base station through an S1 interface, where the handover request message includes the target frequency resource indication message, so that the target base station can obtain the target frequency resource to be accessed by the terminal to be handed over according to the handover request message.

And step 505, the target base station sends a switching request response message to the MME.

Specifically, after receiving the request message, the destination base station may send the handover request response message to the MME through an S1 interface.

For a specific description of the handover request response message, please refer to step 404 shown in fig. 4 in detail, which is not described in detail in this embodiment specifically, as long as the handover request response message shown in this embodiment includes the indication message.

The target base station may perform resource reservation for the terminal to be switched after receiving the request message, and a detailed description of the process of performing resource reservation for the terminal to be switched by the target base station is please refer to the embodiment shown in fig. 3, which is not repeated in this embodiment.

Step 506, the MME sends a handover command message to the source base station.

The MME in this embodiment sends the Handover Command message (Handover Command) to the base station, and indicates to the source base station that the terminal to be handed over may access to the destination cell.

And step 507, the source base station sends a switching reconfiguration message to the terminal to be switched.

The specific execution process of step 507 shown in this embodiment is shown in step 306 shown in fig. 3, and the specific execution process is not described in detail in this embodiment.

Step 508, the source base station sends a base station status change message to the MME.

Specifically, after the source base station receives the handover request response message, the source base station may send a base station Status Transfer message (eNodeB Status Transfer) to the MME, and the MME may determine, according to the base station Status Transfer message, that the cell to which the terminal to be handed over is accessed is changed from the source cell to the destination cell, so that the MME creates a data transmission path between the destination base station and the terminal to be handed over.

And under the condition that the MME acquires the base station state change message, the MME can acquire the data transmission condition between the source base station and the terminal to be switched and configures an MME state change message (MME Status Transfer) for indicating the data transmission condition between the source base station and the terminal to be switched.

In step 509, the MME sends an MME state change message to the destination base station.

In this embodiment, the MME may send the configured MME state change message to the destination base station, the destination base station may obtain a data transmission condition between the source base station and the terminal to be switched according to the MME state change message, and the destination base station may synchronize data transmission between the terminal to be switched and the source base station according to the MME state change message, thereby reducing transmission delay.

And step 510, the terminal to be switched sends a reconfiguration completion message to the target base station.

The specific execution process of step 510 shown in this embodiment is shown in step 407 shown in fig. 4 for details, which are not described in detail in this embodiment.

Step 511, the destination base station sends a handover complete notification message to the MME.

In this embodiment, when the target base station determines that the terminal to be switched has been successfully accessed to the target cell according to the reconfiguration complete message, the target base station may send a Handover complete notification message (Handover Notify) to the MME, where the Handover complete notification message is used to Notify the MME that the terminal to be switched has been successfully accessed to the target cell.

Step 512, the MME sends a release message of the context of the terminal to be switched to the source base station.

In this embodiment, after the MME receives the handover completion notification message, the MME may send a context release message to the source base station.

Step 513, the source base station receives the context release message.

By adopting the method for cell switching shown in this embodiment, the source base station can send the target frequency resource indication message to the target base station through the MME, and the target base station can determine the target frequency resource to be accessed by the terminal to be switched according to the target frequency resource indication message.

The following describes, with reference to fig. 6, a specific structure of a source base station provided in the present application from the perspective of a function module, where for the specific description of the source base station shown in this embodiment, please refer to fig. 1 and fig. 2, and the method for performing cell handover by the source base station shown in this embodiment, a specific execution process of the method for performing cell handover, please refer to fig. 3 to fig. 5 in detail:

the source base station includes:

a determining unit 601, configured to determine a target frequency resource, where the target frequency resource is a frequency resource to be switched by a terminal to be switched, which requests to switch from a source cell to a destination cell, and the source base station is configured to serve the source cell, and the destination cell is served by a destination base station;

optionally, the determining unit 601 specifically includes:

a first determining module 6011, configured to determine at least one master frequency band and at least one slave frequency band supported by the destination cell;

a first determining module 6012, configured to determine the target frequency resource as the target dominant frequency band or a target dominant frequency point if it is determined that the frequency point supported by the terminal to be switched is within a frequency range of the target dominant frequency band, where the target dominant frequency band is one of the at least one dominant frequency band supported by the target cell, and the target dominant frequency point is a frequency point corresponding to the target dominant frequency band.

Optionally, the determining unit 601 specifically includes:

a second determining module 6013, configured to determine at least one master frequency band and at least one slave frequency band supported by the destination cell;

a second determining module 6014, configured to determine the target frequency resource as a target slave frequency band or a target slave frequency band if it is determined that the frequency point supported by the terminal to be switched is within a frequency range of the target slave frequency band, where the target slave frequency band is one of the at least one slave frequency band supported by the target cell, and the target slave frequency band is a frequency point corresponding to the target slave frequency band.

Optionally, the determining unit 601 specifically includes:

a third determining module 6015, configured to determine at least one master frequency band and at least one slave frequency band supported by the destination cell;

a third determining module 6016, configured to determine that the target frequency resource is the target master frequency band or the target master frequency point if it is determined that the frequency point supported by the terminal to be switched is located within a frequency range of a target master frequency band and a target slave frequency band at the same time, where the target master frequency band is one of the at least one master frequency band supported by the target cell, the target slave frequency band is one of the at least one slave frequency band supported by the target cell, and the target master frequency point is a frequency point corresponding to the target master frequency band.

Optionally, the determining unit 601 specifically includes:

a fourth determining module 6017, configured to determine at least one master frequency band and at least one slave frequency band supported by the destination cell;

a creating module 6018, configured to create a priority list, where the priority list includes multiple frequency bands supported by the target base station, and the multiple frequency bands are sorted according to a descending order of transmission bandwidths when a carrier aggregation CA is created between the terminal to be switched and any frequency band of the multiple frequency bands;

a fifth determining module 6019, configured to determine the target frequency resource as the frequency band with the highest priority in the priority list, or determine the target frequency resource as the frequency point corresponding to the frequency band with the highest priority in the priority list.

A first sending unit 602, configured to send a target frequency resource indication message to the destination base station, where the target frequency resource indication message is used to indicate the target frequency resource;

optionally, the first sending unit 602 specifically includes:

a configuration module 6021, configured to configure a handover request message, where the handover request message is used to instruct the terminal to be handed over to the destination cell, and the handover request message includes the target frequency resource instruction message;

a sending module 6022, configured to send the handover request message to the destination base station through an X2 interface.

Optionally, the first sending unit 602 is further configured to send a handover indication message to a mobility management entity MME through an S1 interface, where the handover indication message includes the target frequency resource indication message, so that the MME sends a handover request message to the destination base station through an S1 interface, where the handover request message includes the target frequency resource indication message.

A receiving unit 603, configured to receive an indication message sent by the destination base station, where the indication message is used to indicate that the terminal to be switched is allowed to be switched to the target frequency resource.

Optionally, the receiving unit 603 is further configured to receive, through an X2 interface, a handover request response message sent by the destination base station, where the handover request response message is used to indicate that the destination base station has successfully received the handover request message, and the handover request message includes the target frequency resource indication message and the indication message;

optionally, the receiving unit 603 is further configured to receive, through an S1 interface, a handover request response message sent by the MME, where the handover request response message includes a target frequency resource indication message and the indication message;

a second sending unit 604, configured to send the target frequency resource indication message to the terminal to be switched, so that the terminal to be switched is switched to the target frequency resource of the target cell according to the target frequency resource indication message.

A third sending unit 605, configured to send the target frequency resource indication message to the terminal to be switched, so that the terminal to be switched is switched to the target frequency resource of the target cell according to the target frequency resource indication message.

For a description of the beneficial effect of the method for performing cell switching by the source base station in this embodiment, please refer to the foregoing embodiments for details, which are not described in detail in this embodiment.

The following describes, with reference to fig. 7, a specific structure of a target base station provided in the present application from the perspective of a function module, where for the specific description of the target base station shown in this embodiment, please refer to fig. 1 and fig. 2, and the target base station shown in this embodiment is used for performing a cell handover method, and a specific execution process of the cell handover method is detailed in fig. 3 to fig. 5:

the destination base station comprises:

a receiving unit 701, configured to receive a target frequency resource indication message sent by a source base station, where the target frequency resource indication message is used to indicate a target frequency resource, the target frequency resource is a frequency resource to be switched by a terminal to be switched, which requests to switch from a source cell to a target cell, the source base station is configured to serve the source cell, and the target base station is configured to serve the target cell;

optionally, the receiving unit 701 is further configured to receive a handover request message through an X2 interface, where the handover request message is used to instruct the terminal to be handed over to the destination cell, and the handover request message includes the target frequency resource indication message.

Optionally, the receiving unit 701 is further configured to receive, through an S1 interface, a handover request message sent by a mobility management entity MME, where the handover request message includes the target frequency resource indication message.

A sending unit 702, configured to send an indication message to the source base station, where the indication message is used to indicate that the terminal to be switched is allowed to be switched to the target frequency resource.

Optionally, the sending unit 702 is further configured to send, to the source base station through an X2 interface, a handover request response message, where the handover request response message is used to indicate that the handover request message has been successfully received by the destination base station, and the handover request message includes the target frequency resource indication message and the indication message.

Optionally, the sending unit 702 is further configured to send a handover request response message to the MME through an S1 interface, so that the MME sends the handover request response message to the source base station through an S1 interface, where the handover request response message includes a target frequency resource indication message and the indication message.

For a description of the beneficial effect of the method for performing cell handover by the target base station in this embodiment, please refer to the foregoing embodiments for details, which are not described in detail in this embodiment.

A structure of a base station is exemplarily described below from the perspective of physical hardware, where the base station shown in this embodiment may be a source base station shown in the foregoing embodiment or a destination base station shown in the foregoing embodiment, and the base station shown in this embodiment is used for executing the method for cell handover shown in the foregoing embodiment, and a specific execution process is shown in the foregoing embodiment and is not described in detail in this embodiment.

As shown in fig. 8, the base station 800 includes at least one processor 801, a communication bus 802, a memory 803, and at least one communication interface 804.

The processor 801 may be a general-purpose Central Processing Unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more ics for controlling the execution of programs in accordance with the present invention.

The communication bus 802 may include a path that conveys information between the aforementioned components.

The communication interface 804 may be any device, such as a transceiver, for communicating with other devices or communication networks, such as an ethernet, a Radio Access Network (RAN), a Wireless Local Area Network (WLAN), etc.

The memory 803 may be, but is not limited to, a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a Random Access Memory (RAM) or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disk read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact disk, laser disk, optical disk, digital versatile disk, blu-ray disk, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory may be self-contained and coupled to the processor via a bus. The memory may also be integral to the processor.

The memory 803 is used for storing application program codes for executing the present invention, and the execution of the application program codes is controlled by the processor 801. The processor 801 is configured to execute the application program codes stored in the memory 803 to implement the logic functions to implement the method of cell handover shown in the above embodiments.

In particular implementations, processor 801 may include one or more CPUs such as CPU0 and CPU1 in fig. 8, for example, as an example.

In particular implementations, base station 800 may include multiple processors, such as processor 801 and processor 808 of fig. 8, for example, as an example. Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, and/or processing cores for processing data (e.g., computer program instructions).

In particular, the present application also includes a computer readable storage medium storing one or more programs, which include instructions, which when executed by a source base station or a destination base station, can implement the method for cell handover as shown in the above embodiments.

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

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

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

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

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A method of cell handover, comprising:

a source base station determines a target frequency resource, wherein the target frequency resource is a frequency resource to be switched by a terminal to be switched, which requests to be switched from a source cell to a target cell, the source base station is used for serving the source cell, and the target cell is served by a target base station, wherein the target frequency resource is a frequency band or a frequency point included in a priority list, the priority list includes a plurality of frequency bands supported by the target base station, and the plurality of frequency bands are ordered according to a sequence from large transmission bandwidth to small transmission bandwidth when a carrier aggregation CA is established between the terminal to be switched and any one of the plurality of frequency bands;

the source base station sends a target frequency resource indication message to the target base station, wherein the target frequency resource indication message is used for indicating the target frequency resource;

and the source base station receives an indication message sent by the target base station, wherein the indication message is used for indicating that the terminal to be switched is allowed to be switched to the target frequency resource.

2. The method of claim 1, wherein the source base station determining the target frequency resource comprises:

the source base station determines at least one main frequency band and at least one slave frequency band supported by the target cell;

and if the source base station judges that the frequency point supported by the terminal to be switched is located in the frequency range of the target main frequency section, the source base station determines that the target frequency resource is the target main frequency section or the target main frequency point, the target main frequency section is one of the at least one main frequency section supported by the target cell, and the target main frequency point is a frequency point corresponding to the target main frequency section.

3. The method of claim 1, wherein the source base station determining the target frequency resource comprises:

if the source base station judges that the frequency point supported by the terminal to be switched is located in the frequency range of the target slave frequency band, the source base station determines that the target frequency resource is the target slave frequency band or the target slave frequency band, the target slave frequency band is one of the at least one slave frequency band supported by the target cell, and the target slave frequency band is a frequency point corresponding to the target slave frequency band.

4. The method of claim 1, wherein the source base station determining the target frequency resource comprises:

5. The method of claim 1, wherein the source base station determining the target frequency resource comprises:

the source base station creates the priority list;

and the source base station determines that the target frequency resource is the frequency band with the highest priority in the priority list, or the target frequency resource is the frequency point corresponding to the frequency band with the highest priority in the priority list.

6. The method according to any of claims 1 to 5, wherein the source base station sending a target frequency resource indication message to the destination base station comprises:

the source base station configures a switching request message, wherein the switching request message is used for indicating the terminal to be switched to the target cell, and the switching request message comprises the target frequency resource indication message;

and the source base station sends the switching request message to the target base station through an X2 interface.

7. The method of claim 6, wherein the receiving, by the source base station, the indication message sent by the destination base station comprises:

the source base station receives a handover request response message sent by the destination base station through an X2 interface, where the handover request response message is used to indicate that the destination base station has successfully received the handover request message, and the handover request message includes the target frequency resource indication message and the indication message;

after the source base station receives the indication message sent by the destination base station, the method further includes:

and the source base station sends the target frequency resource indication message to the terminal to be switched so that the terminal to be switched is switched to the target frequency resource of the target cell according to the target frequency resource indication message.

8. The method according to any of claims 1 to 5, wherein the source base station sending a target frequency resource indication message to the destination base station comprises:

the source base station sends a handover indication message to a Mobility Management Entity (MME) through an S1 interface, wherein the handover indication message includes the target frequency resource indication message, so that the MME sends a handover request message to the target base station through an S1 interface, and the handover request message includes the target frequency resource indication message.

9. The method of claim 8, wherein the receiving, by the source base station, the indication message sent by the destination base station comprises:

the source base station receives a handover request response message sent by the MME through an S1 interface, wherein the handover request response message comprises a target frequency resource indication message and the indication message;

10. A method of cell handover, comprising:

a target base station receives a target frequency resource indication message sent by a source base station, wherein the target frequency resource indication message is used for indicating a target frequency resource, the target frequency resource is a frequency resource to be switched by a terminal to be switched, which requests to be switched, and is switched from a source cell to a target cell, the source base station is used for serving the source cell, and the target base station is used for serving the target cell, wherein the target frequency resource is a frequency band or a frequency point included in a priority list, the priority list includes a plurality of frequency bands supported by the target base station, and the plurality of frequency bands are sorted according to a sequence from large transmission bandwidth to small transmission bandwidth when a carrier aggregation CA is established between the terminal to be switched and any one of the plurality of frequency bands;

and the target base station sends an indication message to the source base station, wherein the indication message is used for indicating that the terminal to be switched is allowed to be switched to the target frequency resource.

11. The method of claim 10, wherein the receiving, by the destination base station, the target frequency resource indication message sent by the source base station comprises:

the target base station receives a handover request message through an X2 interface, where the handover request message is used to indicate that the terminal to be handed over is handed over to the target cell, and the handover request message includes the target frequency resource indication message.

12. The method of claim 10, wherein the transmitting, by the destination base station, the indication message to the source base station comprises:

a handover request response message sent by the destination base station to the source base station through an X2 interface, where the handover request response message is used to indicate that the destination base station has successfully received the handover request message, and the handover request message includes the target frequency resource indication message and the indication message.

13. The method of claim 12, wherein the receiving, by the destination base station, the target frequency resource indication message sent by the source base station comprises:

and the target base station receives a handover request message sent by a Mobility Management Entity (MME) through an S1 interface, wherein the handover request message comprises the target frequency resource indication message.

14. The method of claim 13, wherein the transmitting, by the destination base station, the indication message to the source base station comprises:

the destination base station sends a handover request response message to the MME through an S1 interface, so that the MME sends the handover request response message to the source base station through an S1 interface, wherein the handover request response message comprises a target frequency resource indication message and the indication message.

15. A source base station, comprising:

a determining unit, configured to determine a target frequency resource, where the target frequency resource is a frequency resource to be switched by a terminal to be switched, and the terminal is requested to be switched from a source cell to a destination cell, where the source base station is configured to serve the source cell, and the destination cell is served by a destination base station, where the target frequency resource is a frequency band or a frequency point included in a priority list, the priority list includes multiple frequency bands supported by the destination base station, and the multiple frequency bands are ordered according to a descending order of transmission bandwidths when a carrier aggregation CA is created between the terminal to be switched and any one of the multiple frequency bands;

16. The source base station of claim 15, wherein the determining unit comprises:

17. The source base station of claim 15, wherein the determining unit comprises:

18. The source base station of claim 15, wherein the determining unit comprises:

19. The source base station of claim 15, wherein the determining unit comprises:

a creation module for creating the priority list;

20. The source base station according to any of claims 15 to 19, wherein the first sending unit comprises:

21. The source base station of claim 20, wherein the receiving unit is further configured to receive a handover request response message sent by the destination base station through an X2 interface, wherein the handover request response message is used to indicate that the handover request message has been successfully received by the destination base station, and the handover request message includes the target frequency resource indication message and the indication message;

the source base station further includes:

22. The source base station of any of claims 15 to 19, wherein the first sending unit is further configured to send a handover indication message to a Mobility Management Entity (MME) via an S1 interface, wherein the handover indication message includes the target frequency resource indication message, so that the MME sends a handover request message to the destination base station via an S1 interface, and wherein the handover request message includes the target frequency resource indication message.

23. The source base station of claim 22, wherein the receiving unit is further configured to receive a handover request response message sent by the MME through an S1 interface, and wherein the handover request response message includes a target frequency resource indication message and the indication message;

the source base station further includes:

24. A destination base station, comprising:

a receiving unit, configured to receive a target frequency resource indication message sent by a source base station, where the target frequency resource indication message is used to indicate a target frequency resource, the target frequency resource is a frequency resource to be switched by a terminal to be switched, which requests to be switched from a source cell to a target cell, the source base station is used to serve the source cell, and the target base station is used to serve the target cell, where the target frequency resource is a frequency band or a frequency point included in a priority list, the priority list includes multiple frequency bands supported by the target base station, and the multiple frequency bands are sorted according to a sequence from large transmission bandwidth to small transmission bandwidth when a carrier aggregation CA is created between the terminal to be switched and any one of the multiple frequency bands;

25. The destination base station according to claim 24, wherein the receiving unit is further configured to receive a handover request message through an X2 interface, the handover request message is used to instruct the terminal to be handed over to the destination cell, and the handover request message includes the target frequency resource indication message.

26. The destination base station according to claim 24, wherein the sending unit is further configured to send a handover request response message to the source base station through an X2 interface, wherein the handover request response message is used to indicate that the handover request message has been successfully received by the destination base station, and the handover request message includes the target frequency resource indication message and the indication message.

27. The destination base station according to claim 26, wherein the receiving unit is further configured to receive, through an S1 interface, a handover request message sent by a mobility management entity MME, and the handover request message includes the target frequency resource indication message.

28. The destination base station of claim 27, wherein the sending unit is further configured to send a handover request response message to the MME over an S1 interface, so that the MME sends the handover request response message to the source base station over an S1 interface, and wherein the handover request response message comprises a target frequency resource indication message and the indication message.

29. A base station comprising a processor and a memory, wherein,

a computer readable program stored in the memory;

the processor is configured to execute the method of any one of claims 1 to 9 when the base station is a source base station and the method of any one of claims 10 to 14 when the base station is a destination base station by executing a program in the memory.

30. A computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by a source base station, cause the source base station to perform the method of any of claims 1 to 9, and which when executed by a destination base station, cause the destination base station to perform the method of any of claims 10 to 14.