CN101415211B - Method, system and apparatus for processing switch - Google Patents

Abstract

The invention discloses a handover processing method, which includes the following steps: the TargetASN to which the MS is about to handover obtains the serial number SN' of the first data cached by the Anchor ASN and the serial number SN' of the last data not sent to the MS by the Serving ASN Serial number SN; the Target ASN acquires data between serial numbers SN to SN' from the Serving ASN; the Target ASN sends data starting from the serial number SN to the MS. Through the method provided by the embodiment of the present invention, regardless of whether the pre-registration process of the data path is completed in the handover preparation phase or the handover execution phase, the integrity of the data in the handover can be realized; at the same time, the Anchor ASN does not need to unicast to all Target ASNs data, and overcome the handover delay problem.

Description

Handover processing method, system and device

technical field

The present invention relates to the technical field of communications, and in particular to a handover processing method, system and device.

Background technique

WiMAX (Worldwide Interoperability for Microwave Access) is a wireless metropolitan area network technology based on the IEEE 802.16 standard. The WiMAX network is mainly composed of three parts: MSS/SS (client), ASN (Access Service Network, access service network), CSN (Connectivity Service Network, connection service network). Among them, ASN includes BS (Base Station, base station) and ASN-GW (ASN Gateway, access service network gateway), CSN includes logical entities such as AAA Server (Authentication Authorization Accounting, authentication, authorization and accounting server). The wireless side of the WiMAX network is a wireless metropolitan area network access technology based on the IEEE 802.16d/e standard, which mainly follows the IEEE 802.16-2004 (802.16d) standard formulated in July 2004. IEEE 802.16-2004 (802.16d) standard working frequency band is 2GHz to 11GHz, which is a mixed frequency band of licensed and unlicensed. WiMAX adopts the physical layer of OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) and OFDMA (Orthogonal Frequency Division Multiple Access, Orthogonal Frequency Division Multiple Access), which can effectively resist multipath fading and Under normal circumstances, the transmission rate can approach 75Mbps. The IEEE 802.16-2004 (802.16d) standard is used for non-line-of-sight point-to-multipoint technology in metropolitan area networks, mainly in the form of fixed and nomadic networks.

FIG. 1 shows a logical architecture diagram of a WiMAX network. The main components and functions of the WiMAX network are as follows: (1) Client (MSS/MS): used to access the WiMAX network. (2) Access Service Network (ASN): A set of network functions used to provide wireless access services for WiMAX terminals. The ASN includes BS and ASN-GW network elements. Mobile Station, mobile terminal) L2 connection, wireless resource management, etc.; the main functions of the ASN-GW network element are: providing client functions for MS authentication, authorization and billing functions, and providing L3 information relay (relay) for MS Functions (such as IP address allocation), intra-ASN switching, etc. (3) Connection service network (CSN): used to provide IP connection services for WiMAX terminals, specifically: MS IP address allocation, Internet access, AAA proxy or server (server), user-based authorization control, etc.

Logical entities in the WiMAX network communicate through interfaces R1 to R6, and the relationship between network elements and interfaces is shown in Figure 1.

The role of the ASN mainly includes the following aspects: ensuring the establishment of a layer 2 connection between WiMAX terminals and WiMAX base stations; radio resource management; network discovery and optimal selection of WiMAX user network service providers; The proxy server controls the authentication, authorization and billing messages of WiMAX users; it provides relays for the establishment of Layer 3 application connections of WiMAX terminals.

The role of the CSN mainly includes the following aspects: assigning IP addresses for WiMAX user sessions; providing Internet access; acting as an authentication, authorization, and accounting proxy server or authentication, authorization, and accounting server; performing policy and access control based on user subscription data; supporting ASN and The establishment of tunnels between CSNs; support the generation of WiMAX user bills and settlement of WiMAX services between operators; support the establishment of roaming tunnels between CSNs; support mobility between ASNs; support multiple WiMAX services, such as based on Location-based services, end-to-end services, multimedia broadcast and multicast services, etc.

In the existing WiMAX technology, a complete handover process is generally divided into two stages, the first stage is the handover preparation stage, and the second stage is the handover execution stage. The process of the two stages will be described in detail below in conjunction with the embodiments.

The process of the handover preparation phase (Handover Preparation) is shown in Figure 2, including the following steps:

In step S201, the MS sends a MOB_MSHO-REQ (handover request) message to the Serving ASN (Serving Access Service Network) to initiate a handover process.

In step S202, the ServingASN sends a HO_Req (handover request) message of the R4 interface to one or more TargetASNs (target access service networks). The Target ASNs are the ASNs where the potential handover TargetBSs (target base stations) are located.

Step S203, Target ASNs initiates the context request procedure (Context Request procedure), and requests the AK (Authorization Key, authorization key) context of the MS from the Authenticator ASN (authorized access service network). This step may also be done during handover execution.

Step S204, Target ASNs initiates a data path pre-establishment process to Anchor ASN (anchor access service network). If the AnchorASN does not support the data path pre-establishment process, it returns a Path_Prereg_Rsp (path pre-establishment response) message to the TargetASN(s) and carries an error indication in the message. At this time, this process needs to be performed in the handover execution phase. Therefore, the data path pre-establishment process step is optional in the handover preparation phase, and can be completed in the handover preparation phase or in the subsequent handover execution phase. However, in the prior art, if data integrity needs to be supported, this step must be performed in the handover preparation phase. At this time, the Anchor ASN needs to perform the following steps: Unicast data, and send the sequence number SN' (sequence number, sequence number) of the first unicast data to Target ASNs.

Step S205, the Target ASNs sends a HO_Rsp (handover response) message of the R4 interface to the Serving ASN to confirm the handover request.

Step S206, after the ServingASN receives the HO_Rsp message sent by the TargetASNs, it sends a MOB_BSHO-RSP (handover response) message to the MS, and the MOB_BSHO-RSP message includes one or more potential Target BSs selected by the network for the MS to switch over.

Step S207, the Serving ASN sends the HO_Ack (handover acknowledgment) message of the R4 interface to the Target ASNs.

The process of switching the execution stage is shown in Figure 3, including the following steps:

Step S301, the MS sends a MOB_HO-IND (handover instruction) message to the Serving ASN, instructing the MS to handover to a Target BS selected by it in the handover preparation phase.

Step S302, the Serving ASN receives and sends the HO_Cnf (Handover Confirmation) message of the R4 interface to the Target ASN selected by the MS according to the MOB_HO-IND message. If data integrity needs to be supported, the ServingASN needs to stop sending downlink data to the source BS at this time, and cache the data sent by the AnchorASN, and carry the serial number SN of the last data not sent to the source BS in the HO_Cnf message sent to the Target ASN .

Step S303, after the Target ASN receives the HO_Cnf message, it sends the HO_Ack (handover response) message of the R4 interface to the Serving ASN.

Step S304, the Target ASN initiates a context request procedure (Context Request procedure), and requests the AK context of the MS from the Authenticator ASN. This step does not exist if the process has already been completed during the handover preparation process.

Step S305, if the data path pre-registration procedure (DataPath Pre-Reg Procedure) is not executed in the handover preparation phase, then execute the procedure in this step.

In step S306, the MS initiates a re-entry process to the Target ASN. After the MS successfully accesses the network, the TargetASN sends the stored data to the MS, and the sent data is: start sending from the received data with the serial number SN.

In step S307, the Target ASN initiates a data path registration procedure (Data Path Registration procedure) to the Anchor ASN, and establishes a data plane to the Anchor ASN. After the data plane is established, the Anchor ASN sends the downlink data to the Target ASN, and then the Target ASN sends it to the MS.

Step S308, the Target ASN initiates the CMAC Key Count Update process to update the CMAC Key Count value in the Authenticator ASN.

Step S309, the TargetASN sends a HO_Complete (handover complete) message of the R4 interface to the ServingASN, notifying the Serving ASN that the handover is complete; after receiving the HO_Complete message, the Serving ASN releases the context information of the MS.

Step S310, the Anchor ASN initiates a data path registration cancellation process (DataPath De-Registration) to the Serving ASN.

Step S311, the Anchor ASN cancels all pre-registered data paths of the Target ASNs that are not selected.

In the existing WiMAX technology, it is necessary to ensure the integrity of data during the handover process, so as to reduce packet loss during the handover process and realize a true lossless handover. At present, the schemes for ensuring data integrity in the switching process are divided into two types: the basic scheme and the scheme with ARQ (Automatic Repeat-reQuest, automatic repeat request) synchronization mechanism based on the basic scheme. The latter is a more fine-grained scheme. It needs to be built on the basis of the former.

In prior art 1, there is a data integrity method for unicasting along multiple path trees. The basic principle of this method has been embodied in the handover process of the above embodiment, that is, during the handover preparation process, the data path pre-registers the message ( Data Path Pre-Reg Request) triggers service flow data from the root node Anchor ASN of the data path tree to all Target ASNs along the branches of the data path tree, and sends the data unicast along all branches and Anchor ASN to Serving ASN The service data flow is consistent, and the Target ASN saves the unicast data until the MS switches over or the switch is canceled. In the handover preparation phase, when the Target ASN performs data path pre-registration (Data Path Pre-Reg Procedure) with the Anchor ASN, the Anchor ASN starts to unicast data (as shown in step S204 in Figure 1), and the Anchor ASN sends data to the Target ASN The response message of the path pre-registration carries the sequence number SN' of the first unicast data, and the TargetASN receives the sequence number SN' and notifies the ServingASN, so that the ServingASN grasps the data content cached by each Target ASN, so that the Serving ASN notifies the MS Before switching, it is necessary to send all the data that is not cached in the Target ASNs to the MS, that is, the Serving ASN needs to send at least all the data before the serial number SN' to the MS before notifying the MS of switching. Since the messages sent by each TargetASN may not arrive at the same time when pre-registering with the Anchor ASN for the data path, it may be necessary to maintain a sequence number for each Target ASN. In this case, the ServingASN must at least It is necessary to send all the data before the SN' with the largest serial number to the MS.

While the Anchor ASN unicasts data to each branch of the path tree, the Serving ASN still sends data to the MS. When the MS sends a MOB_HO-IND message to the Serving ASN to notify the Serving ASN that it will switch (as shown in step S301 in Figure 2), the Serving ASN stops sending data to the source BS (and MS), and caches the data sent by the Anchor ASN at the same time , and notify the TargetASN by the HO_Conf message of the last serial number SN of the data that is not sent to the source BS (as shown in step S302 in Figure 2), as mentioned above, after the MS switches to the target network, the Target ASN of the target network It will send all the data starting from the serial number SN to MS.

Prior art 1 has the following disadvantages: (1) The data path pre-registration process may be completed in the handover preparation phase, and may also be completed in the handover execution phase, which is an optional step. If the process is completed in the handover preparation phase, it can be guaranteed The integrity of the data in the handover, if the process is completed during the handover execution phase, the integrity of the data in the handover cannot be guaranteed. (2) After the data path is established, AnchorASN needs to unicast data to all Target ASNs along the branches of the data path tree. Therefore, this will require high caching capabilities of TargetASN, and also greatly waste resources such as system bandwidth. (3) In this method, it is required that the Serving BS (serving base station) must forward all the data that the Anchor ASN has not cached to the MS before it can initiate MOB_BS_RSP/REQ to the MS, so the handover needs to wait for a period of time, which affects the handover delay and The efficiency of data forwarding.

There is a data integrity method for request forwarding in prior art 2, and some improvements have been made to prior art 1, specifically: Anchor ASN is not sent to all path trees during data path pre-registration (Data Path Pre-Registration). Instead of forwarding data, the data is cached until the Target ASN sends a Data Path Registration Request message (Data Path Registration Request) to it, and the Anchor ASN forwards the data to the Target ASN.

In the preparation stage of switching, once the Anchor ASN receives the Data Path Pre-Registration Request message sent by any Target ASN, it starts to cache data, and the Anchor ASN passes the serial number SN' of the first cached data through Data Path Pre-Registration The Response is sent to the Target ASN, and the Target ASN forwards the serial number SN' to the ServingASN through the HO_Response message, so that the Serving ASN can learn what data can be obtained from the Target ASN, and the ServingASN needs to send the data that the Target ASNs cannot obtain before notifying the MS to switch Both are sent to MS.

At the same time, Serving ASN still sends data to MS. When the MS sends a MOB_HO-IND message to the Serving ASN to notify that it will switch, the Serving ASN notifies the TargetASN of the last serial number SN that has not been sent out through the HO_Conf message, so that when the MS switches to the target network, the Target ASN of the target network will be All data starting from this serial number SN are sent to MS.

In prior art 2, Anchor ASN no longer forwards data to all path trees when the data path is pre-registered, which saves resources such as system bandwidth, but other disadvantages of prior art 1 still exist in prior art 2.

Contents of the invention

Embodiments of the present invention provide a handover processing method, system, and device to solve the problem that the data path pre-registration process must be completed in the handover preparation stage when data integrity is achieved during handover, Anchor ASN unicasts data along multiple paths, and handover notification messages The problem of sending timing constraints.

To achieve the above purpose, an embodiment of the present invention provides a handover processing method, including the following steps:

The target service access network Target ASN that the mobile terminal MS is about to switch to obtains the serial number SN' of the first data cached by the anchor access service network Anchor ASN and the last data not sent to the MS by the serving service access network ServingASN The serial number SN of the data;

The Target ASN establishes a data plane to the Anchor ASN, and the AnchorASN sends its buffered downlink data to the Target ASN;

The Target ASN obtains data between the serial number SN and SN'-1 from the Serving ASN;

The Anchor ASN initiates a process of canceling the data path registration to the Serving ASN;

The Target ASN sends data starting from the sequence number SN to the MS.

An embodiment of the present invention also provides a switching processing system, including:

The mobile terminal MS is used to send a handover request to the Serving ASN during handover;

The Serving ASN is configured to receive and send the MS handover request to one or more target service access networks Target ASN according to the handover request sent by the MS; after receiving the handover instruction sent by the MS, it will not The sequence number SN of the last data sent to the MS is sent to the Target ASN to which the MS is about to switch; and the sequence number SN to the first data sequence number SN' is sent to the Target ASN- Data between 1;

The Target ASN is used to initiate a data path pre-establishment process to the anchor point access service network Anchor ASN after receiving the switching request sent by the Serving ASN; obtain the serial number SN of the first data cached by the AnchorASN 'and the serial number SN of the last data that the Serving ASN has not sent to the MS; receive the data between the serial numbers SN and SN'-1 sent by the Serving ASN; when the MS switches to the device, send The MS sends data starting from the sequence number SN;

The Anchor ASN is used to cache data received from other entities during the pre-establishment process of the data path, and send the serial number SN' of the first cached data to the Target ASN; after the data path is established, the The cached data is sent to the Target ASN.

A target service access network Target ASN, comprising: a data path pre-establishment unit, used to initiate the data path pre-establishment process to the AnchorASN after receiving the switching request sent by the serving service access network Serving ASN; forwarding unit , used to forward all the received data to the MS after the MS is handed over to the device.

Compared with the prior art, the embodiments of the present invention have the following advantages:

Through the method provided by the embodiment of the present invention, regardless of whether the pre-registration process of the data path is completed in the handover preparation phase or in the handover execution phase, the integrity of the data in the handover can be realized; at the same time, the Anchor ASN does not need to unicast to all Target ASNs data, and overcome the handover delay problem.

Description of drawings

FIG. 1 is a schematic diagram of a logical architecture of a WiMAX network in the prior art;

Fig. 2 is a flow chart of the handover preparation stage in the prior art;

Fig. 3 is a flow chart of the handover execution stage in the prior art;

Fig. 4 is a schematic diagram of a data path tree of a service flow in the prior art;

FIG. 5 is a flowchart of a handover processing method according to Embodiment 1 of the present invention;

FIG. 6 is a flowchart of a handover processing method according to Embodiment 2 of the present invention;

FIG. 7 is a schematic diagram of a handover processing method according to Embodiment 3 of the present invention;

FIG. 8 is a schematic diagram of a handover processing method according to Embodiment 3 of the present invention;

FIG. 9 is a schematic diagram of a handover processing method according to Embodiment 4 of the present invention;

FIG. 10 is a schematic diagram of a handover processing method according to Embodiment 5 of the present invention;

FIG. 11 is a schematic diagram of a handover processing method according to Embodiment 6 of the present invention;

FIG. 12 is a schematic diagram of a switching processing system according to Embodiment 7 of the present invention;

Fig. 13 is a schematic diagram of a Target ASN in Embodiment 8 of the present invention;

Fig. 14 is a schematic diagram of a Serving ASN according to Embodiment 9 of the present invention.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

In Embodiment 1 of the present invention, a handover processing method is shown in FIG. 5, and the specific steps are as follows:

Step S501, the Serving ASN sends a handover request to one or more TargetASNs according to the handover request sent by the MS.

In step S502, the Target ASN initiates a data path pre-establishment process to the Anchor ASN after receiving the switching request sent by the Serving ASN.

Step S503, after the Anchor ASN receives the data path pre-establishment request sent by the Target ASN, it stops sending data to the Serving ASN, caches the data received from the HA (Home Agent, home agent), and caches the first cached data The serial number SN' is sent to the Target ASN, and the TargetASN can send the SN' to the Serving ASN through the switching request response.

Step S504, after the Serving ASN receives the switching instruction sent by the MS, it stops sending data to the MS, buffers the data sent from the Anchor ASN, and notifies the Target ASN of the serial number SN of the last data not sent to the MS.

Step S505, Target ASN acquires data between serial numbers SN to SN' from Serving ASN. This step can adopt the method of data forwarding (Data forwarding), that is, the Serving ASN actively forwards the data between the serial number SN to SN' to the Target ASN, or the method of data retrieval (Data Retrieval), that is, the Target ASN triggers the Serving ASN Data between sequence numbers SN to SN' are forwarded.

In step S506, the Anchor ASN and the Target ASN establish a data path, and the Anchor ASN sends the cached data to the Target ASN.

Step S507, when the MS switches to the Target ASN, the Target ASN forwards the received data beginning with the serial number SN to the MS, and discards the data before the serial number SN is received.

Further, Embodiment 2 of the present invention is an improvement on the basis of Embodiment 1 of the present invention. A handover processing method is shown in FIG. 6 , and the specific steps are as follows:

Step S601, the Serving ASN sends a handover request to one or more TargetASNs according to the handover request sent by the MS.

Step S602, after the Target ASN receives the switching request sent by the Serving ASN, it initiates a data path pre-establishment process to the AnchorASN.

Step S603: After receiving the data path pre-establishment request sent by the Target ASN, the Anchor ASN caches the data received from the HA, and sends the serial number SN' of the first cached data to the TargetASN, and at the same time continues to send data to the Serving ASN , Target ASN can send SN' to Serving ASN by switching request response. .

Step S604, after the Serving ASN receives the handover instruction from the MS, it stops sending data to the MS, buffers the data sent from the Anhor ASN, and notifies the Target ASN of the serial number SN of the last data not sent to the MS.

Step S605, Target ASN compares the size of the serial number SN and SN', if the serial number is not reversed and SN is not greater than SN', go to step S606, otherwise there is no need to request forwarding data from the Serving ASN; or the Serving ASN compares the serial number SN and SN', if the serial number does not reverse and SN is not greater than SN', go to step S606, otherwise Serving ASN does not need to actively forward data to Target ASN.

Step S606, Target ASN acquires data between serial numbers SN to SN' from Serving ASN. This step can adopt the method of data forwarding (Data forwarding), that is, the Serving ASN actively forwards the data between the serial number SN to SN' to the Target ASN, or the method of data retrieval (Data Retrieval), that is, the Target ASN triggers the Serving ASN Data between sequence numbers SN to SN' are forwarded.

In step S607, the Anchor ASN and the Target ASN establish a data path, and the Anchor ASN sends the cached data to the Target ASN.

Step S608, after the MS switches to the Target ASN, the Target ASN forwards the received data beginning with the serial number SN to the MS, and discards the data before the serial number SN is received.

In the third embodiment of the present invention, the present invention is described by taking the pre-registration process of the data path in the handover preparation stage as an example. A complete handover process in WiMAX is generally divided into two stages. The first stage is the handover preparation stage, and the second stage is the handover preparation stage. The second stage is the handover execution stage, and a handover processing method is shown in FIGS. 7 to 8 .

The flow of the switching preparation phase in this embodiment is shown in Figure 7, and the specific steps are as follows:

In step S701, the MS initiates a handover by sending a MOB_MSHO-REQ (handover request) message to the Serving ASN.

Step S702, the Serving ASN sends the HO_Req message of the R4 interface to one or more Target ASNs. The Target ASNs are the ASNs where the Target BSs for potential switching are located.

In step S703, the Target ASN(s) initiates a context request procedure (Context Request procedure) to request the AK context of the MS from the Authenticator ASN. This step may also be done during the handover execution phase.

In step S704, the Target ASN(s) initiates a data path pre-establishment process to the Anchor ASN. If the Anchor ASN does not support the data path pre-establishment process, the Anchor ASN returns the Path_Prereg_Rsp message to the Target ASN(s) and carries an error indication in the message. At this time, the data path pre-establishment process needs to be executed during the handover execution phase. Assuming that the Anchor ASN supports this process, the Anchor ASN needs to perform the following steps:

a) Anchor ASN stops sending downlink data to Serving ASN, and caches the data sent by HA;

b) Anchor ASN sends the sequence number SN' of the first data unit it caches to TargetASN.

In step S705, a data path pre-registration (R4-DP-PreReg) process is initiated between the Serving ASN and the Target ASN(s), for establishing a data path to forward data between the two. This process may also be done during the handover execution phase.

Step S706, the Target ASN(s) sends the HO_Rsp message of the R4 interface to the Serving ASN to confirm the handover request, and the message carries the information of the serial number SN'.

Step S707, the Serving ASN sends a MOB_BSHO-RSP message to the MS, and the message includes one or more potential Target BSs selected by the network to hand over to the MS.

Step S708, the Serving ASN sends the HO_Ack message of the R4 interface to the Target ASN(s).

The process of switching the execution stage in this embodiment is shown in Figure 8, and the specific steps are as follows:

Step S801, the MS sends a MOB_HO-IND message to the Serving ASN, instructing the MS to handover to a Target BS selected by it in the handover preparation phase.

Step S802: After receiving the MOB_HO-IND message, the Serving ASN stops sending downlink data to the source BS, and buffers the data sent from the Anchor ASN. The Serving ASN sends the HO_Cnf message of the R4 interface to the Target ASN selected by the MS, in which the sequence number SN of the last data not sent to the source BS is carried.

Step S803: After receiving the HO_Cnf message, the Target ASN sends the HO_Ack message of the R4 interface to the Serving ASN.

Step S804, the Target ASN initiates a context request procedure (Context Request procedure), and requests the AK context of the MS from the Authenticator ASN. This step does not exist if the process has already been completed during the handover preparation process.

In step S805, a data path pre-registration procedure (R4-DP-PreReg Procedure) is initiated between the Serving ASN and the Target ASN to establish a data path to forward data between the two. If the data path pre-registration process has been completed in the handover preparation phase, this step does not exist.

In step S806, the MS initiates a re-entry process to the Target ASN.

In step S807, the Target ASN initiates a data path registration procedure (DataPath Registration procedure) to the Anchor ASN, and establishes a data plane to the Anchor ASN. Anchor ASN sends its cached downlink data to Target ASN.

In step S808, a data path registration (R4-DP-Reg) is initiated between the Serving ASN and the Target ASN. After establishing the data path between the Serving ASN and the Target ASN, the Serving ASN forwards all the cached data to the Target ASN.

In step S809, the Target ASN initiates a CMAC Key Count Update process to update the CMAC Key Count value of the Authenticator ASN.

In step S810, the Target ASN sends an R4HO_Complete message to the Serving ASN, notifying the Serving ASN that switching is complete. After receiving the HO_Complete message, the Serving ASN releases the context information of the MS.

In step S811, the Anchor ASN initiates a data path de-registration process (Data Path De-Registration) to the Serving ASN. The Anchor ASN cancels all pre-registered data paths for Target ASNs that are not selected.

In step S812, a data path deregistration (R4-DP-DeReg) process is initiated between the Serving ASN and the Target ASN.

Step S813, after the MS switches to the Target ASN, the Target ASN forwards the received data starting from the serial number SN to the MS, and discards if the data before the serial number SN is received. This step can start after the Target ASN receives the data with the sequence number SN.

In Embodiment 4 of the present invention, the data path pre-registration process is not performed in the preparation phase of the handover, but is performed in the execution phase of the handover. The complete handover process is generally divided into two stages, and the process of the handover preparation stage in this embodiment does not exist except step S704 in Figure 7 (that is, the data path pre-establishment process initiated by Target ASN(s) to Anchor ASN , other steps are consistent with those described in the above-mentioned implementation three, and the process of the handover preparation phase will not be repeated here, and only the process of the handover execution phase will be described. A handover processing method is shown in Figure 9, and the specific steps are as follows:

Step S901, the MS sends a MOB_HO-IND message to the Serving ASN, instructing it to switch to a Target BS selected in the handover preparation stage.

Step S902: After receiving the MOB_HO-IND message, the Serving ASN stops sending downlink data to the source BS, and buffers the data sent from the Anchor ASN. The Serving ASN sends the HO_Cnf message of the R4 interface to the TargetASN, and the message carries the serial number SN of the last data not sent to the source BS.

Step S903, after receiving the HO_Cnf message, the Target ASN sends the HO_Ack message of the R4 interface to the Serving ASN.

Step S904, the Target ASN initiates a context request procedure (Context Request procedure), and requests the AK context of the MS from the Authenticator ASN.

In step S905, the Target ASN initiates a data path pre-establishment process to the Anchor ASN. Anchor ASN performs the following steps after receiving the data path pre-registration message sent by Target ASN:

a) Anchor ASN stops sending downlink data to Serving ASN, and caches the data sent from HA;

b) Anchor ASN sends the sequence number SN' of the first cached data unit to TargetASN.

In step S906, a data path pre-registration procedure (R4-DP-PreReg Procedure) is initiated between the Serving ASN and the Target ASN to establish a data path to forward data between the two. If the data path pre-registration process has been completed in the handover preparation phase, this step does not exist.

Step S907, the MS initiates a re-entry process to the Target ASN.

In step S908, the Target ASN initiates a data path registration procedure (DataPath Registration procedure) to the Anchor ASN, and establishes a data plane to the Anchor ASN. Anchor ASN sends its cached downlink data to Target ASN.

In step S909, a data path registration (R4-DP-Reg) is initiated between the Serving ASN and the Target ASN. After establishing the data path between the Serving ASN and the Target ASN, the Serving ASN forwards all the cached data to the Target ASN.

In step S910, the Target ASN initiates a CMAC Key Count Update process to update the CMAC Key Count value of the Authenticator ASN.

Step S911, the Target ASN sends the HO_Complete message of the R4 interface to the Serving ASN, notifying the Serving ASN that the switching is completed. After receiving the HO_Complete message, the Serving ASN releases the context information of the MS.

In step S912, the Anchor ASN initiates a deregistration process (Data Path De-Registration) to the Serving ASN. The Anchor ASN cancels all pre-registered data paths for Target ASNs that are not selected.

Step S913, if all the data has been forwarded, a data path deregistration (R4-DP-DeReg) process is initiated between the Serving ASN and the Target ASN.

Step S914, after the MS switches to the Target ASN, the Target ASN forwards the received data starting from the serial number SN to the MS, and discards if the data before the serial number SN is received. This step can start after the Target ASN receives the data with the sequence number SN.

In the third and fourth embodiments above, no matter whether the data path pre-registration process is executed in the handover preparation phase or in the handover execution phase, the Anchor ASN will perform the following steps in the data path pre-registration process: a) stop sending data to the Serving ASN sends data and caches the data sent from HA; b) sends the sequence number SN' of the first cached data to Target ASN.

After the MS sends MO_HO_IND to the Serving ASN, the Serving ASN will stop sending data to the MS, and cache the data from the Anchor ASN, and at the same time send the serial number SN of the last data not sent to the MS to the Targrt ASN through the HO_Cnf message. After the above steps are completed, the Serving ASN forwards all the data from the serial number SN to SN’-1 to the Target ASN; after the MS enters the target network, the Target ASN sends the unsent data starting from the serial number SN to the MS.

In the above method, the Target ASN needs to tell the Serving ASN the serial number SN'. There are two ways. One is that the Target ASN can send the serial number SN' to the Serving ASN through the handover response message (HO_Rsp) to let it know which data can be obtained , or the Target ASN can notify the Serving ASN of the serial number SN' through the context delivery message, and the Serving ASN will forward all the data from the serial number SN to SN'-1 to the Target ASN.

In the fifth embodiment of the present invention, the present invention is described by taking the pre-registration process of the data path in the handover preparation stage as an example. As described in the third embodiment, a complete handover process in WiMAX is generally divided into two stages. The first The first stage is the handover preparation stage, and the second stage is the handover execution stage. In this embodiment, the process of the handover preparation phase is consistent with that described in the second implementation, except that the Anchor ASN continues to send downlink data to the Serving ASN while buffering data during the data path pre-registration process. For details, only the process of the handover execution phase is described. A handover processing method is shown in Figure 10, and the specific steps are as follows:

Step S1001, the MS sends a MOB_HO-IND message to the Serving ASN, instructing it to switch to a Target BS selected in the handover preparation phase.

Step S1002: After receiving the MOB_HO-IND message, the Serving ASN stops sending downlink data to the source BS, and buffers the data sent from the Anchor ASN. The Serving ASN sends the HO_Cnf message of the R4 interface to the Target ASN, which carries the serial number SN of the last data not sent to the source BS.

Step S1003: After receiving the HO_Cnf message, the Target ASN sends the HO_Ack message of the R4 interface to the Serving ASN.

In step S1004, the Target ASN initiates a context request procedure (Context Request procedure) to request the AK context of the MS from the Authenticator ASN.

In step S1005, a data path pre-registration process (R4-DP-PreReg Procedure) is initiated between the Serving ASN and the Target ASN to establish a data path to forward data between the two. If the data path pre-registration process has been completed in the handover preparation phase, this step does not exist.

Step S1006, the MS initiates a re-entry process to the Target ASN.

In step S1007, the Target ASN initiates a data path registration procedure (DataPath Registration procedure) to the Anchor ASN, and establishes a data plane to the Anchor ASN. When the data plane is established, the Anchor ASN can start forwarding the cached data to the Target ASN.

In step S1008, a data path registration (R4-DP-Reg) is initiated between the Serving ASN and the Target ASN. After establishing the data path between the Serving ASN and the Target ASN, the Serving ASN compares the serial number SN' and the size of SN, and if the serial number does not reverse and SN is greater than SN', the Serving ASN does not need to forward any data To Target ASN; if SN is smaller than SN', Serving ASN needs to forward all the data between serial number SN to SN'-1 to Target ASN.

In step S1009, the Target ASN initiates the CMAC Key Count Update process to update the CMAC Key Count value of the Authenticator.

Step S1010, the Target sends an R4 HO_Complete message to the Serving ASN to notify the Serving ASN that the switching is complete, and the Serving ASN releases the context information of the MS after receiving the HO_Complete message.

Step S1011, the Anchor ASN initiates the deregistration process (Data Path De-Registration) to the Serving ASN. The Anchor ASN cancels all pre-registered data paths for Target ASNs that are not selected.

In step S1012, a data path deregistration (R4-DP-DeReg) process is initiated between the Serving ASN and the Target ASN.

Step S1013, when the MS switches to the Target ASN, the Target ASN forwards the received data beginning with the serial number SN to the MS, and discards the data before the serial number SN is received. This step can start after the Target ASN receives the data with the sequence number SN. The data whose serial number is SN can be forwarded from Serving ASN (SN is less than SN’), or sent from Anchor ASN (SN is greater than SN’).

In Embodiment 6 of the present invention, the data path pre-registration process is not performed in the preparation phase of the handover, but is performed in the execution phase of the handover. The complete handover process is generally divided into two stages. The process of the handover preparation stage in this embodiment is consistent with that described in the second implementation above, and will not be repeated here. Only the process of the handover execution stage is described. A handover processing method is shown in the figure 11, the specific steps are as follows:

Step S1101, the MS sends a MOB_HO-IND message to the Serving ASN, instructing it to switch to a Target BS selected in the handover preparation stage.

Step S1102: After receiving the MOB_HO-IND message, the Serving ASN stops sending downlink data to the source BS, and buffers the data sent from the Anchor ASN. The Serving ASN sends the HO_Cnf message of the R4 interface to the Target ASN, which carries the serial number SN of the last data not sent to the source BS.

Step S1103: After receiving the HO_Cnf message, the Target ASN sends the HO_Ack message of the R4 interface to the Serving ASN.

In step S1104, the Target ASN initiates a context request procedure (Context Request procedure), and requests the AK context of the MS from the Authenticator ASN.

In step S1105, the Target ASN initiates a data path pre-establishment process to the Anchor ASN. Anchor ASN performs the following steps after receiving the data path pre-registration message sent by Target ASN:

a) Different from what is described in Embodiment 2 and Embodiment 3, the Anchor ASN still continues to send downlink data to the ServingASN, and caches the data sent from the HA;

b) Anchor ASN sends the sequence number SN' of the first cached data unit to TargetASN.

In step S1106, a data path pre-registration process (R4-DP-PreReg Procedure) is initiated between the Serving ASN and the Target ASN to establish a data path to forward data between the two. If the data path pre-registration process has been completed in the handover preparation phase, this step does not exist.

Step S1107, the MS initiates a re-entry process to the Target ASN.

In step S1108, the Target ASN initiates a data path registration procedure (DataPath Registration procedure) to the Anchor ASN, and establishes a data plane to the Anchor ASN. When the data plane is established, the Anchor ASN can start forwarding the cached data to the Target ASN.

In step S1109, a data path registration (R4-DP-Reg) is initiated between the Serving ASN and the Target ASN. After establishing the data path between the Serving ASN and the Target ASN, the Serving ASN compares the serial number SN' and the size of SN, and if the serial number does not reverse and SN is greater than SN', the Serving ASN does not need to forward any data To Target ASN; if SN is smaller than SN', Serving ASN needs to forward all the data between serial number SN to SN'-1 to Target ASN.

In step S1110, the Target ASN initiates the CMAC Key Count Update process to update the CMAC Key Count value of the Authenticator.

Step S1111, the Target sends a HO_Complete message of the R4 interface to the Serving ASN to notify the Serving ASN that the handover is complete, and the Serving ASN releases the context information of the MS after receiving the HO_Complete message.

Step S1112, the Anchor ASN initiates the deregistration process (Data Path De-Registration) to the Serving ASN. The Anchor ASN cancels all pre-registered data paths for Target ASNs that are not selected.

In step S1113, a data path deregistration (R4-DP-DeReg) process is initiated between the Serving ASN and the Target ASN.

Step S1114, when the MS switches to the Target ASN, the Target ASN forwards the received data starting from the serial number SN to the MS, and discards if the data before the serial number SN is received. This step can start after the Target ASN receives the data with the sequence number SN. The data whose serial number is SN can be forwarded from Serving ASN (SN is less than SN’), or sent from Anchor ASN (SN is greater than SN’).

In the above-mentioned fifth and sixth embodiments, regardless of whether the data path pre-registration process is performed in the handover preparation phase or in the handover execution phase, the Anchor ASN will perform the following steps in the process: The four described methods are different. The downlink data sent from the HA is cached, but it still continues to send downlink data to the Serving ASN; b) Send the serial number SN' of the first cached data to the Target ASN.

After the MS sends a handover instruction message (MO_HO_IND) to the Serving ASN, the Serving ASN will stop sending data to the MS, and cache the data sent from the Anchor ASN, and at the same time send the serial number SN of the last data not sent to the MS through the HO_Cnf message Give the Targrt ASN. After the data path between Anchor ASN and Target ASN is established, Anchor ASN can start sending cached data to Target ASN. After the data path between Serving ASN and Target ASN is established, Serving ASN compares the size of the serial number SN and SN'. If the serial number has not been reversed and SN is greater than SN', Serving ASN does not need to forward any data to Target ASN,; if the serial number has not been reversed and SN' is greater than SN, Serving ASN will forward all the data between serial number SN to SN'-1 to Target ASN. After the MS enters the target network, the Target ASN sends the unsent data starting from the serial number SN to the MS. If the Target ASN receives data with a serial number smaller than the SN, it discards it. The data whose serial number is SN can be forwarded from Serving ASN (SN is less than SN’), or sent from Anchor ASN (SN is greater than SN’).

The methods described in Embodiment 5 and Embodiment 6 of the present invention are further improvements of the methods described in Embodiment 3 and Embodiment 4 of the present invention, especially the method described in Embodiment 5, which can further improve the efficiency of data forwarding efficiency and reduce switching delay.

In the above-described embodiments, the Target ASN obtains data from the Serving ASN through data forwarding, or data retrieval can be adopted, that is, the Target ASN triggers the Serving ASN to forward data, specifically: the Target ASN sends Data Retrival to the Serving ASN The Request (Data Retrieval Request) message requests the Serving ASN to forward data; after receiving the Data Retrival Request message sent by the Target ASN, the Serving ASN sends a Data Retrival Response (Data Retrieval Response) message to the Target ASN, which carries the data to be forwarded . When the data retrieval method is used, no data path needs to be established between the Serving ASN and the Target ASN, and the size of SN and SN' can be compared by the Target ASN; a data path can also be established, that is, the Target ASN requests the Serving ASN through the Data Retrival Request message When forwarding data, the Serving ASN forwards the data through the established data path with the Target ASN. After the data is forwarded, the Serving ASN sends a DataRetrival Response message to the Target ASN for confirmation. Other implementation processes are similar to the way of data forwarding, and will not be repeated here.

In the embodiment described above, if data forwarding is adopted between Target ASN and Serving ASN, Target ASN needs to notify Serving ASN of SN'; if data retrieval is used to forward data, Target ASN does not need to forward SN ' Notify Serving ASN.

Through the method provided by the above embodiment, regardless of whether the pre-registration process of the data path is completed in the handover preparation phase or in the handover execution phase, the integrity of the data in the handover can be realized; at the same time, the AnchorASN does not need to unicast data to all Target ASNs, And it overcomes the delay problem of handover.

In Embodiment 7 of the present invention, a handover processing system is shown in FIG. 12, including:

MS10 is used to send a switching request to Serving ASN20 during switching. Serving ASN20 is used to receive and send MS10 switching request to one or more Target ASN30 according to the switching request sent by MS10; after receiving the switching instruction sent by MS10, send the sequence number SN of the last data not sent to MS10 to MS10 is about to switch to Target ASN30; and send data to TargetASN30. Target ASN30 is used to initiate the data path pre-establishment process to Anchor ASN40 after receiving the switching request sent by Serving ASN20; obtain the serial number SN' of the first data cached by Anchor ASN40 and the last one not sent to MS10 by Serving ASN20 The serial number SN of the data; receive the data sent by Serving ASN20; when MS10 switches to the device, send the data starting from the serial number SN to MS10. Anchor ASN40 is used to cache the data received from other entities during the pre-establishment of the data path, and send the serial number SN' of the first cached data to Target ASN30; after the data path is established, the cached data Send to Target ASN30.

In the eighth embodiment of the present invention, a Target ASN30 as shown in Figure 13 includes:

The data path pre-establishment unit 31 is configured to initiate a data path pre-establishment process to the Anchor ASN40 after receiving the switching request sent by the Serving ASN20. The forwarding unit 32 is configured to forward all the received data to the MS10 after the MS10 switches to the device.

Also includes: a comparison unit 33, used to compare the size of SN' and SN when Target ASN30 triggers Serving ASN20 to send data to it by means of data retrieval, and if SN' is greater than SN, trigger Serving ASN20 to send SN to SN ', otherwise ServingASN20 will not be triggered to send data to it.

In Embodiment 9 of the present invention, a Serving ASN20 is shown in Figure 14, including:

The transceiver unit 21 is configured to receive and send a switching request to one or more TargetASN30 according to the switching request sent by the MS10. The processing unit 22 is configured to stop sending data to the MS10 after receiving the handover instruction sent by the MS10, buffer the data sent from the Anchor ASN40, and send the serial number SN of the last data that is not sent to the MS10 to the MS10 that is about to be handed over to Target ASN30.

Also include: comparison unit 23, for when Serving ASN20 adopts the mode of data forwarding to send data to Target ASN30, compare the size of SN' and SN, if SN' is greater than SN, forward the data between SN to SN' to TargetASN30, Otherwise, do not forward data to Target ASN30. Data path establishment unit 24, is used for establishing the data path between Serving ASN20 and Target ASN30.

Through the system provided by the above embodiments, regardless of whether the data path pre-registration process is completed in the handover preparation phase or in the handover execution phase, the integrity of the data in the handover can be realized; at the same time, the Anchor ASN does not need to unicast data to all Target ASNs , and overcome the handover delay problem.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be realized 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, and the software product of the acquisition machine is stored in a storage medium, including several instructions for making A terminal device executes the methods of various embodiments of the present invention.

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.

Claims (11)

1. A handover processing method, characterized in that, comprising the following steps: The target service access network Target ASN that the mobile terminal MS is about to switch to obtains the serial number SN' of the first data cached by the anchor access service network Anchor ASN and the last data not sent to the MS by the serving service access network ServingASN The serial number SN of the data; The Target ASN establishes a data plane to the Anchor ASN, and the Anchor ASN sends its buffered downlink data to the Target ASN; The Target ASN acquires data between the serial numbers SN and SN′-1 from the Serving ASN; The Anchor ASN initiates a process of canceling the data path registration to the Serving ASN; The Target ASN sends data starting from the sequence number SN to the MS. 2. handover processing method as claimed in claim 1, is characterized in that, before described Target ASN obtains the serial number SN ' of the first data of Anchor ASN cache, also comprises: The Target ASN sends a data path pre-establishment request to the Anchor ASN. 3. The handover processing method according to claim 2, wherein, after the Target ASN sends the data path pre-establishment request to the Anchor ASN, it also includes: After the Anchor ASN receives the data path pre-establishment request sent by the Target ASN, it continues to send data to the Serving ASN, caches the data sent from the home agent HA, and assigns the serial number SN of the first cached data to ' sent to the Target ASN; or After the Anchor ASN receives the data path pre-establishment request sent by the Target ASN, it stops sending data to the Serving ASN, caches the data sent from the HA, and sends the serial number SN' of the first cached data to The Target ASN. 4. The handover processing method as claimed in claim 1, wherein the Target ASN acquires the serial number SN of the last data that the Serving ASN does not send to the MS is specifically: The Target ASN receives the handover confirmation message sent by the Serving ASN, and the handover confirmation message carries the sequence number SN of the last data not sent to the MS. 5. The handover processing method as claimed in claim 1, wherein the Target ASN obtains the data between the serial number SN and SN′-1 from the Serving ASN as follows: The Serving ASN actively sends the data between the serial number SN to SN′-1 to the Target ASN through data forwarding; or The Target ASN triggers the Serving ASN to send the data between the serial numbers SN to SN'-1 to it by means of data retrieval. 6. The switching processing method according to claim 5, wherein the Serving ASN actively sends the data between the serial number SN to SN′-1 to the Target ASN by means of data forwarding, specifically: The Serving ASN compares the size of the SN' and SN, if the SN' is greater than SN, the Serving ASN sends the data between the serial number SN to SN'-1 to the Target ASN, otherwise the The Serving ASN does not forward data to the Target ASN. 7. The handover processing method according to claim 6, wherein, before the Serving ASN sends the data between the serial numbers SN to SN′-1 to the Target ASN, it also includes: The Serving ASN establishes a data path with the Target ASN. 8. The handover processing method according to claim 5, wherein the Target ASN triggers the Serving ASN to send data between the serial numbers SN to SN′-1 by the Target ASN in a data retrieval manner. for: The Target ASN compares the size of the SN' and SN, if the SN' is greater than SN, the Serving ASN sends the data between the serial number SN to SN'-1 to the Target ASN, otherwise the The Serving ASN does not forward data to the Target ASN. 9. A handover processing system, comprising: The mobile terminal MS is used to send a handover request to the Serving ASN during handover; The Serving ASN is configured to receive and send the MS handover request to one or more target service access networks Target ASN according to the handover request sent by the MS; after receiving the handover instruction sent by the MS, it will not The sequence number SN of the last data sent to the MS is sent to the Target ASN to which the MS is about to switch; and the sequence number SN to the first data sequence number SN' is sent to the Target ASN- Data between 1; The Target ASN is used to initiate a data path pre-establishment process to the anchor point access service network Anchor ASN after receiving the switching request sent by the Serving ASN; obtain the serial number of the first data cached by the Anchor ASN SN' and the serial number SN of the last data that the Serving ASN has not sent to the MS; receive the data between the serial number SN and SN'-1 sent by the Serving ASN; when the MS switches to the device, Send data starting from the serial number SN to the MS; The Anchor ASN is used to cache data received from other entities during the pre-establishment process of the data path, and send the serial number SN' of the first cached data to the Target ASN; when the Target ASN is established After reaching the data plane of the Anchor ASN, the Anchor ASN sends the buffered downlink data to the Target ASN; the Anchor ASN cancels the data plane to the Serving ASN. 10. A target service access network Target ASN, characterized in that, comprising: The data path pre-establishment unit is used to initiate the data path pre-establishment process to the anchor point access service network Anchor ASN after receiving the switching request sent by the serving service access network Serving ASN; The forwarding unit is used for receiving the cached downlink data sent by the Anchor ASN by the Target ASN after the Target ASN establishes the data plane to the Anchor ASN; and for switching the mobile terminal MS to the device after , the Target ASN transfers the serial number SN of the last data received from the Serving ASN to the Target ASN to obtain the anchor access service The data between the sequence number SN′-1 of the first data cached by the network Anchor ASN is forwarded to the MS. 11. Target ASN as claimed in claim 10, is characterized in that, also comprises: The comparison unit is used to compare the serial number SN' of the first data cached by the Anchor ASN with the Serving ASN not sent to when the Target ASN triggers the ServingASN to send data to it by means of data retrieval. The size of the serial number SN of the last data of the MS, if the SN' is greater than SN, trigger the Serving ASN to send data between the SN and SN'-1, otherwise the Serving ASN is not triggered Send data to it. the

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