CN101998552B - Method for performing switchover and relay node - Google Patents

Abstract

The invention discloses a method for performing switchover, which comprises the following steps that: a relay node (RN) acquires indication information of an X2 interface between base station equipment where the RN is positioned and a neighbour cell of the RN; when user equipment under the RN performs switchover, the RN judges whether the X2 interface exists between the base station equipment where the RN is positioned and the neighbour cell of the RN according to the indication information of the X2 interface, if so, the RN performs X2 switchover, otherwise the RN performs S1 switchover. The technical scheme of the embodiment of the invention has the advantage that: the RN determines how to perform the switchover according to the indication information of the X2 interface between the base station equipment where the RN is positioned and the neighbour cell of the RN when the UE performs the switchover, thereby improving the success rate of the switchover.

Description

A method and relay node for initiating handover

technical field

The invention relates to the technical field of mobile communication, in particular to a method for initiating handover and a relay node. the

Background technique

Future mobile communication systems, such as B3G (Beyond three Generation) systems or LTE-A (Long Term Evolution Advanced, advanced long-term evolution systems), will provide higher peak data rates and cell throughput, but also require more large bandwidth. At present, there are very few unallocated bandwidths below 2GHz, and part or all of the bandwidth required by the B3G system can only be found in higher frequency bands, such as above 3GHz. The higher the frequency band, the faster the attenuation of radio wave propagation and the shorter the transmission distance. Therefore, in the same coverage area, to ensure continuous coverage, more base stations are required. Since base stations usually have a higher cost, it will undoubtedly increase the cost of network deployment. the

In order to solve the problem of network deployment costs, various manufacturers and standardization organizations have begun to study introducing RN (RelayNode, relay node) into the cellular system to increase network coverage. As shown in Figure 1, it is a schematic diagram of the network architecture of the LTE-A system after the introduction of the RN. The RN accesses the core network through the donor cell (donor cell) under the DeNB (Donor Node B, Donor Node B). The direct wireless interface, the interface between the DeNB and the RN is a wireless Un interface. Each RN can control one or more cells, which is equivalent to an eNB. RN and DeNB establish an X2 interface. For other eNBs other than DeNB, RN is equivalent to a cell under DeNB. DeNB terminates RN and other eNB/RN between the X2 interface. As shown in FIG. 2 , it is a schematic diagram of the protocol stack architecture of RN, DeNB and eNBs other than DeNB, wherein both RN and DeNB support X2-AP (Authentication Protocol, authentication protocol). the

In the process of realizing the present invention, the inventor finds that there are at least the following problems in the prior art:

At present, the 3GPP (3rd Generation Partnership Project, 3rd Generation Partnership Project) specification does not define how the RN knows whether there is an X2 interface between the DeNB and other eNBs. When the UE under the RN switches to a cell under the management of other eNBs, the RN cannot Determine whether to initiate X2 handover or S1 handover. the

Contents of the invention

Embodiments of the present invention provide a method for initiating handover and a relay node for improving the success rate of handover

The embodiment of the present invention proposes a method for initiating handover, including the following steps:

The relay node RN obtains the X2 interface indication information between the base station equipment where it is located and the adjacent cell of the RN;

When the user equipment under the RN is handed over, the RN judges whether there is an X2 interface between the base station equipment where it is located and the adjacent cell of the RN according to the X2 interface indication information, and if so, the RN initiates X2 handover; if it does not exist, the RN initiates an S1 handover. the

Preferably, the RN obtains the X2 interface indication information between the base station equipment where it is located and the adjacent cell of the RN, specifically including:

The RN receives and saves the X2 interface indication information from the base station device during the X2 establishment process or the X2 configuration update process. the

Preferably, during the establishment of X2, the RN receives and saves the X2 interface indication information from the base station equipment, specifically including:

The RN receives the X2 establishment response message from the base station device, and the neighbor information Neighbor Information IE in the X2 establishment response message carries the X2 interface indication information between the adjacent cells of the RN;

The RN compares whether there is a neighboring cell of the RN in the neighboring cell information of the base station equipment, if yes, saves the X2 interface indication information; if not, confirms that the base station equipment and the RN There is no X2 interface connection between adjacent cells. the

Preferably, during the X2 configuration update process, the RN receives and saves the X2 interface indication information from the base station equipment, specifically including:

The RN receives a Node B configuration update message from the base station device, and the Neighbor Information IE in the Node B configuration update message carries X2 interface indication information between the adjacent cells of the RN;

The RN compares whether there is a neighboring cell of the RN in the neighboring cell information of the base station equipment, if yes, saves the X2 interface indication information; if not, confirms that the base station equipment and the RN There is no X2 interface connection between adjacent cells. the

Preferably, before the RN receives and saves the X2 interface indication information from the base station equipment, it also includes:

The base station device transmits to the RN information about whether there is an X2 interface between the base station device and a neighboring cell of the RN, and according to the Neighbor Information IE acquires the neighbor cell information of the RN;

When the adjacent cell information of the RN changes, the base station device triggers an X2-AP procedure. the

Preferably, after the base station equipment obtains the neighbor cell information of the RN according to the Neighbor Information IE carried in the X2 establishment request message from the RN or the Node B configuration update message, it further includes:

If there is a neighboring cell of the RN in the cell connected to the base station device through an X2 interface, the base station device carries the RN's neighbor information in the Neighbor Information IE in the Node B configuration update message sent to the RN next time Adjacent cell information and X2 interface indication information. the

Preferably, after the base station equipment obtains the neighbor cell information of the RN according to the Neighbor Information IE carried in the X2 establishment request message from the RN or the Node B configuration update message, it further includes:

If there is no X2 interface connection between the base station device and the adjacent cell of the RN, the base station device obtains the transport layer address of the adjacent cell of the RN, and initiates the establishment of an X2 interface connection to the adjacent cell of the RN . the

The embodiment of the present invention also proposes an RN, including:

An acquisition module, configured to acquire the X2 interface indication information between the base station equipment where the RN is located and the adjacent cell of the RN;

A judging module, configured to judge whether there is an X2 interface between the base station equipment where the RN is located and a neighboring cell of the RN according to the X2 interface indication information acquired by the acquiring module when the user equipment under the RN is handed over ;

A handover module, configured to initiate an X2 handover when the judging module judges that there is an X2 interface between the base station equipment where the RN is located and a neighboring cell of the RN; when the judging module judges that the base station equipment where the RN is located When there is no X2 interface with the adjacent cell of the RN, an S1 handover is initiated. the

Preferably, the obtaining module is specifically configured to receive and save the X2 interface indication information from the base station device during the X2 establishment process or the X2 configuration update process. the

Preferably, during the establishment of X2,

The obtaining module is specifically configured to receive an X2 setup response message from the base station device, and the Neighbor Information IE in the X2 setup response message carries X2 interface indication information between the adjacent cells of the RN; compare the Whether there is a neighbor cell of the RN in the neighbor cell information of the base station equipment, if yes, the X2 interface indication information will be saved; if not, then confirm the connection between the base station equipment and the neighbor cell of the RN There is no X2 interface connection. the

Preferably, during the X2 configuration update process,

The acquisition module is specifically configured to receive a Node B configuration update message from the base station device, and the Neighbor Information IE in the Node B configuration update message carries X2 interface indication information between the adjacent cell of the RN ; Compare whether there is a neighboring cell of the RN in the neighboring cell information of the base station equipment, if yes, then save the X2 interface indication information; if not, confirm the relative relationship between the base station equipment and the RN There is no X2 interface connection between neighboring cells. the

The technical solution of the embodiment of the present invention has the following advantages, because when the UE is handed over, the RN determines how to initiate the handover process according to the X2 interface indication information between the base station equipment and the adjacent cell of the RN, which improves the success rate of the handover. the

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort. the

Figure 1 is a schematic diagram of the network architecture of the LTE-A system after the introduction of RN;

Figure 2 is a schematic diagram of the protocol stack architecture of RN, DeNB and other eNBs other than DeNB;

Fig. 3 is a flow chart of a method for initiating handover in Embodiment 1 of the present invention;

Fig. 4 is a flow chart of a method for initiating handover in Embodiment 2 of the present invention;

Fig. 5 is a flow chart of a method for initiating handover in Embodiment 3 of the present invention;

FIG. 6 is a schematic structural diagram of an RN in Embodiment 4 of the present invention. the

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention. the

As shown in Figure 3, it is a flow chart of a method for initiating handover in Embodiment 1 of the present invention, including the following steps:

In step 301, the RN obtains the indication information of the X2 interface between the base station equipment where it is located and a neighboring cell of the RN. the

Specifically, the RN receives and saves the X2 interface indication information from the base station device during the X2 establishment process or the X2 configuration update process. the

During the X2 establishment process, the RN receives and saves the X2 interface indication information from the base station equipment, specifically including: the RN receives the X2 establishment response message from the base station equipment, and the neighbor information Neighbor Information IE in the X2 establishment response message carries and the X2 interface indication information between the adjacent cells of the RN; the RN compares whether there are adjacent cells of the RN in the adjacent cell information of the base station equipment, and if so, will save the X2 interface indication information ; If not, confirm that there is no X2 interface connection between the base station equipment and the adjacent cell of the RN. the

During the X2 configuration update process, the RN receives and saves the X2 interface indication information from the base station device, specifically including: the RN receives the Node B configuration update message from the base station device, and the Neighbor Information in the Node B configuration update message The IE carries the X2 interface indication information between the adjacent cell of the RN; the RN compares whether there is a neighboring cell of the RN in the adjacent cell information of the base station equipment, and if so, will save the X2 Interface indication information; if not, confirm that there is no X2 interface connection between the base station equipment and the adjacent cell of the RN. the

Before the RN receives and saves the X2 interface indication information from the base station device, it also includes: the base station device transmits to the RN whether there is an X2 interface between the base station device and the adjacent cell of the RN, according to the information from the base station device The Neighbor Information IE carried in the X2 establishment request message of the RN or the Node B configuration update message obtains the neighbor cell information of the RN; when the neighbor cell information of the RN changes, the base station device triggers the X2-AP process . the

After the base station equipment obtains the neighbor cell information of the RN according to the Neighbor Information IE carried in the X2 establishment request message from the RN or the Node B configuration update message, it also includes: if there is a cell connected to the base station equipment through an X2 interface There are neighboring cells of the RN, and the base station device carries the neighboring cell information and X2 interface indication information of the RN in the Neighbor Information IE in the Node B configuration update message sent to the RN next time. the

After the base station equipment obtains the neighbor cell information of the RN according to the Neighbor Information IE carried in the X2 establishment request message from the RN or the Node B configuration update message, it also includes: if the base station equipment and the neighbor cell of the RN If there is no X2 interface connection between them, the base station device obtains the transport layer address of the adjacent cell of the RN, and initiates the establishment of an X2 interface connection to the adjacent cell of the RN. the

Step 302, when the user equipment under the RN is handed over, the RN judges according to the X2 interface indication information whether there is an X2 interface between the base station equipment where it is located and the adjacent cell of the RN, and if it exists, perform step 303; if not, Then step 304 is executed. the

In step 303, the RN initiates an X2 handover. the

In step 304, the RN initiates an S1 handover. the

The technical solution of the embodiment of the present invention has the following advantages, because when the UE is handed over, the RN determines how to initiate the handover process according to the X2 interface indication information between the base station equipment and the adjacent cell of the RN, which improves the success rate of the handover. the

As shown in Figure 4, it is a flow chart of a method for initiating handover in Embodiment 2 of the present invention, including the following steps:

In step 401, the RN sends an X2SETUP REQUEST (X2 setup request) message to the DeNB. the

In step 402, the DeNB returns an X2SETUP RESPONSE (X2 Setup Response) message to the RN. the

Among them, the format of the X2SETUP RESPONSE message is shown in Table 1, and the DeNB carries the X2 interface indication information with the neighboring cell of the RN in the Neighbor Information IE in the X2SETUP RESPONSE message. the

Table 1X2SETUP RESPONSE message format table

In step 403, the RN receives the X2SETUP RESPONSE message, checks whether there is a neighboring cell of the RN in the neighboring cell information of the DeNB, and if yes, executes step 404; if not, executes step 405. the

In step 404, the RN saves the X2 interface indication information. the

In step 405, the RN confirms that there is no X2 interface connection between the DeNB and the neighboring cell of the RN. the

Step 406, when the user equipment under the RN is handed over, the RN judges according to the X2 interface indication information whether there is an X2 interface between the base station equipment where it is located and the adjacent cell of the RN, and if it exists, perform step 407; if not, Then execute step 408 . the

In step 407, the RN initiates an X2 handover. the

In step 408, the RN initiates an S1 handover. the

It should be noted that, in the method of the present invention, the order of each step can be adjusted according to actual needs. the

The technical solution of the embodiment of the present invention has the following advantages, because when the UE is handed over, the RN determines how to initiate the handover process according to the X2 interface indication information between the DeNB and the adjacent cell of the RN, which improves the success rate of the handover. the

As shown in Figure 5, it is a flow chart of a method for initiating handover in Embodiment 3 of the present invention, including the following steps:

In step 501, the DeNB sends an ENB CONFIGURATION UPDATE (eNB configuration update) message to the RN to initiate an X2 interface configuration update process. the

Specifically, the format of the ENB CONFIGURATION UPDATE message is shown in Table 2. The DeNB exchanges all added or modified serving cell information, and the Neighbor Information IE in the ENB CONFIGURATIONUPDATE message carries the X2 interface indication information with the adjacent cell. the

Table 2 ENB CONFIGURATION UPDATE message format table

In step 502, the RN receives the ENB CONFIGURATION UPDATE message, compares whether there is a neighboring cell of the RN in the neighboring cell information of the DeNB, and if yes, executes step 503; if not, executes step 504. the

In step 503, the RN saves the X2 interface indication information. the

In step 504, the RN confirms that there is no X2 interface connection between the DeNB and a neighboring cell of the RN. the

It should be noted that when the information of the serving cell changes, the RN will also send an X2 configuration update message to the DeNB, and the DeNB can determine the ENB CONFIGURATION UPDATE message in the next ENB CONFIGURATION UPDATE message initiated by the DeNB according to the NeighborInformation IE carried by the RN in the X2 configuration update message. The carried Neighbor Information IE obtains the information of the neighboring cell of the RN. If there is a neighboring cell of the RN in the cells of other eNBs connected to the X2 interface with the DeNB, the DeNB can send the NeighborInformation IE in the ENB CONFIGURATION UPDATE message to the RN next time contains the information of the neighboring cell of the RN, and carries the indication information of the X2 interface. the

In step 505, the RN returns an ENB CONFIGURATION ACKNOWLEDGE (eNB configuration response) message to the DeNB. the

Step 506, when the user equipment under the RN is handed over, the RN judges according to the X2 interface indication information whether there is an X2 interface between the base station equipment where it is located and the adjacent cell of the RN, and if it exists, perform step 507; if not, Then step 508 is executed. the

In step 507, the RN initiates an X2 handover. the

In step 508, the RN initiates an S1 handover. the

It should be noted that, in the method of the present invention, the order of each step can be adjusted according to actual needs. the

The technical solution of the embodiment of the present invention has the following advantages, because when the UE is handed over, the RN determines how to initiate the handover process according to the X2 interface indication information between the DeNB and the adjacent cell of the RN, which improves the success rate of the handover and reduces the The number of cells carried by the Neighbor Information IE. the

As shown in Figure 6, it is a schematic structural diagram of an RN in Embodiment 4 of the present invention, including:

An obtaining module 610, configured to obtain X2 interface indication information between the base station equipment where the RN is located and a neighboring cell of the RN. the

A judging module 620, configured to judge, according to the X2 interface indication information acquired by the acquiring module 610, whether there is a network between the base station equipment where the RN is located and a neighboring cell of the RN when the user equipment under the RN is handed over. X2 interface. the

A switching module 630, configured to initiate an X2 handover when the judging module 620 judges that there is an X2 interface between the base station equipment where the RN is located and a neighboring cell of the RN; when the judging module 620 judges that the RN is located When there is no X2 interface between the base station equipment of the RN and the adjacent cell of the RN, an S1 handover is initiated. the

The acquisition module 610 is specifically configured to receive and save the X2 interface indication information from the base station device during the X2 establishment process or the X2 configuration update process. the

During the X2 establishment process, the acquisition module 610 is specifically configured to receive the X2 establishment response message from the base station device, and the Neighbor Information IE in the X2 establishment response message carries the X2 interface between the adjacent cell of the RN Indication information; compare whether there is a neighboring cell of the RN in the adjacent cell information of the base station equipment, if yes, save the X2 interface indication information; if not, confirm the base station equipment and the RN There is no X2 interface connection between adjacent cells. the

During the X2 configuration update process, the acquisition module 610 is specifically configured to receive a Node B configuration update message from the base station device, and the NeighborInformation IE in the Node B configuration update message carries the The X2 interface indication information among them; compare whether there is a neighboring cell of the RN in the adjacent cell information of the base station equipment, if yes, then save the X2 interface indication information; if not, confirm the base station equipment There is no X2 interface connection with the adjacent cell of the RN. the

The technical solution of the embodiment of the present invention has the following advantages, because when the UE is handed over, the RN determines how to initiate the handover process according to the X2 interface indication information between the base station equipment and the adjacent cell of the RN, which improves the success rate of the handover. the

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus a necessary general-purpose hardware platform, and of course also by hardware, but in many cases the former is a better implementation Way. Based on this understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions to make a A terminal device (which may be a mobile phone, a personal computer, a server, or a network device, etc.) executes the methods described in various embodiments of the present invention. the

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention. the

Those skilled in the art can understand that the modules in the device in the embodiment can be distributed in the device of the embodiment according to the description of the embodiment, and can also be correspondingly changed and located in one or more devices different from the embodiment. The modules in the above embodiments can be integrated, deployed separately, merged into one module, or further divided into multiple sub-modules. the

The serial numbers of the above embodiments of the present invention are for description only, and do not represent the advantages and disadvantages of the embodiments. the

The above disclosures are only a few specific embodiments of the present invention, however, the present invention is not limited thereto, and any changes conceivable by those skilled in the art shall fall within the protection scope of the present invention. the

Claims (9)

1. A method for initiating handover, comprising the following steps: The relay node RN receives and saves the X2 interface indication information from the base station device during the X2 establishment process or the X2 configuration update process; When the user equipment under the RN is handed over, the RN judges whether there is an X2 interface between the base station equipment where it is located and the adjacent cell of the RN according to the X2 interface indication information, and if so, the RN initiates X2 handover; if it does not exist, the RN initiates an S1 handover. 2. The method according to claim 1, wherein, during the establishment of X2, the RN receives and saves the X2 interface indication information from the base station equipment, which specifically includes: The RN receives the X2 setup response message from the base station device, and the neighbor information Neighbor Information IE in the X2 setup response message carries the X2 interface indication information between the adjacent cells of the RN; The RN compares whether there is a neighboring cell of the RN in the neighboring cell information of the base station equipment, and if yes, saves the X2 interface indication information; if not, confirms that the base station equipment and the RN There is no X2 interface connection between adjacent cells. 3. The method according to claim 1, wherein, during the X2 configuration update process, the RN receives and saves the X2 interface indication information from the base station device, specifically comprising: The RN receives a Node B configuration update message from the base station device, and the Neighbor Information IE in the Node B configuration update message carries X2 interface indication information with the neighboring cell of the RN; The RN compares whether there is a neighboring cell of the RN in the neighboring cell information of the base station equipment, and if yes, saves the X2 interface indication information; if not, confirms that the base station equipment and the RN There is no X2 interface connection between adjacent cells. 4. The method according to claim 1, wherein before the RN receives and saves the X2 interface indication information from the base station equipment, it further comprises: The base station device transmits to the RN information about whether there is an X2 interface between the base station device and a neighboring cell of the RN, and according to the Neighbor Information IE acquires the neighbor cell information of the RN; When the adjacent cell information of the RN changes, the base station device triggers an X2-AP procedure. 5. The method according to claim 4, wherein after the base station equipment obtains the neighbor cell information of the RN according to the NeighborInformation IE carried in the X2 establishment request message from the RN or the Node B configuration update message, Also includes: If there is a neighboring cell of the RN in the cell connected to the base station device through an X2 interface, the base station device carries the RN's neighbor information in the Neighbor Information IE in the Node B configuration update message sent to the RN next time Adjacent cell information and X2 interface indication information. 6. The method according to claim 4, wherein after the base station equipment obtains the neighbor cell information of the RN according to the NeighborInformation IE carried in the X2 setup request message from the RN or the Node B configuration update message, Also includes: If there is no X2 interface connection between the base station device and the adjacent cell of the RN, the base station device obtains the transport layer address of the adjacent cell of the RN, and initiates the establishment of an X2 interface connection to the adjacent cell of the RN . 7. A RN, characterized in that, comprising: An acquisition module, configured to receive and save the X2 interface indication information from the base station device during the X2 establishment process or the X2 configuration update process; A judging module, configured to judge whether there is an X2 interface between the base station equipment where the RN is located and a neighboring cell of the RN according to the X2 interface indication information acquired by the acquiring module when the user equipment under the RN is handed over ; A switching module, configured to initiate an X2 handover when the judging module judges that there is an X2 interface between the base station equipment where the RN is located and a neighboring cell of the RN; when the judging module judges that the base station equipment where the RN is located When there is no X2 interface with the adjacent cell of the RN, an S1 handover is initiated. 8. The RN according to claim 7, characterized in that, during the establishment of X2, The acquisition module is specifically configured to receive an X2 setup response message from the base station device, and the Neighbor Information IE in the X2 setup response message carries X2 interface indication information between the adjacent cells of the RN; compare the Whether there is a neighboring cell of the RN in the neighboring cell information of the base station equipment, if yes, the X2 interface indication information will be saved; if not, confirm the connection between the base station equipment and the neighboring cell of the RN There is no X2 interface connection. 9. The RN according to claim 7, characterized in that, during the X2 configuration update process, The acquisition module is specifically configured to receive a Node B configuration update message from the base station device, and the Neighbor Information IE in the Node B configuration update message carries X2 interface indication information between the adjacent cell of the RN ; Compare whether there is a neighboring cell of the RN in the neighboring cell information of the base station equipment, if yes, then save the X2 interface indication information; if not, confirm the relative relationship between the base station equipment and the RN There is no X2 interface connection between neighboring cells.

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