CN101909340B

CN101909340B - Method and system for switching mobile station (MS) in WiMAX (World Interoperability for Microwave Access) system

Info

Publication number: CN101909340B
Application number: CN200910146970.1A
Authority: CN
Inventors: 白玉超
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2009-06-05
Filing date: 2009-06-05
Publication date: 2014-04-30
Anticipated expiration: 2029-06-05
Also published as: CN101909340A

Abstract

The invention discloses a method for switching a mobile station (MS) in a WiMAX (World Interoperability for Microwave Access) system. The method comprises the following steps of: sending a switching request message to a plurality of neighboring BSs (Base Station) with idle resources after an initial business flow fails to be received; carrying out data channel pre-building of the initial business flow by the plurality of neighboring BSs with an access gateway and informing pre-building results; selecting successfully pre-built neighboring BSs by a service BS from the result; and determining a target switched BS by the MS. The invention also discloses a system for switching the MS in the WiMAX system, comprising the MS, the service BS, the plurality of neighboring BSs and the access gateway, wherein the MS is used for initiating a business flow access and selecting a switched target BS; the service BS is used for sending the switching request message after the initial business flow fails to be received; the plurality of neighboring BSs are used for pre-building the data channel of the initial business flow and returning the pre-building results; and the access gateway is used for pre-building the data channel of the initial business flow. The invention is used for guiding a currently accessed MS to switch to neighboring BSs with relatively idle resources to continue to finishing an initial access process.

Description

Mobile station handover method and system in WiMAX system

Technical field

The present invention relates to WiMAX (Worldwide Interoperability for Microwave Access, micro-wave access global inter communication) wireless communication system, relate in particular to mobile station handover method and switched system in a kind of WiMAX system.

Background technology

In WiMAX wireless communication system, travelling carriage (Mobile Station, MS) complete scanning, down-going synchronous, obtain, downlink parameter, initial ranging (Ranging), basic capability negotiating, pre-registration and single-wheel EAP (Extensible Authentication Protocol, Extensible Authentication Protocol) after subscription authentication and registration, IAD (ASN Gate Way, AGW) side can be initiated initial service flow (Initial Service Flow by data channel registration message, ISF) foundation of data channel, serving BS (Serving Base Station (BS)) is set up after request in the initial service flow data channel of receiving AGW, can receive and control judgement.

Existing serving BS is received to control and is judged there are two kinds of situations, a kind of situation is to receive to control to be judged as receivability, for example receive to control and think and can receive the initial service flow of MS, will reply the successful initial service flow data channel of AGW and set up response, and if there is other predefine Business Stream (PSF (Provisioned Service Flow, predefine Business Stream)), continue to wait for the foundation of PSF Business Stream; Another kind of situation is to receive to control to be judged as not receivability, for example receive and control the initial service flow of not receiving MS, existing processing mode has following two kinds: a kind of is the initial service flow data channel foundation response of replying AGW failure, this access of refusal MS; Another kind is to instruct other MS that accessed in current base station (BaseStation) to be switched to adjacent area BS above, thereby abdicate resource, for current MS, on current BS, completes access.

Summary of the invention

Technical problem to be solved by this invention is to provide mobile station handover method and system in a kind of WiMAX system, take to solve in prior art at serving BS and receive the problem of controlling while being judged as receivability initial service flow not, thereby realize this access of neither directly refusing travelling carriage, do not play away other travelling carriages that accessed in current base station, but directly instruct it to be switched on the relatively idle neighbor base station of resource, complete access yet.

In order to solve the problems of the technologies described above, the invention provides mobile station handover method in a kind of WiMAX system, the method comprises the following steps:

After serving BS determines that the initial service flow of travelling carriage is received unsuccessfully, to a plurality of neighbor base stations transmission handover request message of current resource free time;

According to described handover request message, described a plurality of neighbor base stations and IAD carry out the data channel of described initial service flow to be built in advance, and the result that described data channel is built is in advance notified described serving BS;

The result that described serving BS is built in advance from described data channel, select to build in advance successful neighbor base station, and recommend described travelling carriage; And

Described travelling carriage is determined its target BS switching from described build in advance successful neighbor base station.

Described according to described handover request message, described a plurality of neighbor base stations and IAD carry out the data channel of described initial service flow to be built in advance, and the result that described data channel is built in advance notifies described serving BS, comprising:

According to described handover request, the data channel that described a plurality of neighbor base stations are initiated described initial service flow to IAD is built request message in advance; Described IAD responds described data channel and builds in advance the result that request message is built in advance to described a plurality of neighbor base station return data passages; And the result that described a plurality of neighbor base station is built described data channel is in advance notified described serving BS.

The result that described serving BS is built described data channel in advance, for building in advance successful neighbor base station, is recommended described travelling carriage and is comprised as switching target:

Described serving BS is built in advance result from described data channel and is selected to build in advance successful neighbor base station and recommend described travelling carriage and scan; According to the scanning result of described travelling carriage, good described of signal conditioning built to successful neighbor base station in advance and recommend described travelling carriage as switching target.

Described travelling carriage determines that from described building in advance successful neighbor base station its target BS switching also comprises afterwards:

Described serving BS is notified described a plurality of neighbor base station, the target BS switching that described mobile radio station is determined; The neighbor base station and the described IAD that in described a plurality of neighbor base station, are not confirmed as switched target BS carry out the cancellation of the described data channel of described initial service data flow, and the described Mobile Originated ranging process of neighbor base station reception that is defined as switched target BS.

After described serving BS determines that the initial service flow of travelling carriage is received unsuccessfully, to a plurality of neighbor base stations transmission handover request message of current resource free time; With according to described handover request message, the data channel that described a plurality of neighbor base stations are initiated described initial service flow to IAD is built between request message and is also comprised in advance:

According to described handover request message, described a plurality of neighbor base stations obtain the authentication information of described mobile radio station to authentication gateway.

After described ranging process success, also comprise:

The described neighbor base station that is defined as switched target BS receives described travelling carriage distance measurement request message, according to the described described authentication information obtaining, described distance measurement request message is carried out to verification; After described verification is passed through, to described IAD update notifications message; The information that described IAD switches according to the described travelling carriage carrying in described updating message, replys the neighbor base station that response message is defined as switched target BS described in giving, and waits for initial service flow data channel acknowledge message; And described in be defined as switched target BS neighbor base station to described IAD, send described initial service flow data channel acknowledge message.

The described neighbor base station that is defined as switched target BS sends described initial service flow data channel acknowledge message to described IAD after, also comprise:

Described IAD is confirmed the validity of described initial service flow data channel, carries out the process of establishing of predefine business datum circulation road with the described neighbor base station that is defined as switched target BS.

In described WiMAX system, mobile station handover method also comprises:

Described a plurality of neighbor base station and serving BS are notified its current resource utilization each other mutually by IAD.

The present invention also provides travelling carriage switched system in a kind of WiMAX system, and this system comprises:

Travelling carriage, for initiating the access of initial service flow, and the result of building in advance according to the data channel of initial service flow is selected the target BS that will switch;

Serving BS, is connected with described travelling carriage, after determining that the initial service flow of described travelling carriage is received unsuccessfully, sends handover request message; The data channel result of building in advance with the described initial service flow of statistics;

A plurality of neighbor base stations, are connected with described serving BS, for according to described handover request message, carry out the data channel of described initial service flow and build in advance, and the result that data channel is built in advance returns to described serving BS; With

IAD, is connected with described a plurality of neighbor base stations, for carrying out the data channel of described initial service flow, builds in advance.

Described neighbor base station is further used for: the authentication information that obtains described mobile radio station to IAD; The described neighbor base station that is defined as switched target BS, for receiving described travelling carriage distance measurement request message, carries out verification according to the described described authentication information obtaining to described distance measurement request message; After described verification is passed through, to described IAD update notifications message.

Described IAD is further used for the cancellation of the described data channel of described initial service data flow.

Therefore, by mobile station handover method provided by the invention and system, unsuccessfully rear serving BS and the concrete processing policy of IAD are controlled in the initial service flow receiving that has proposed travelling carriage, instruct the current MS accessing to be switched on the relatively idle adjacent area BS of resource and continued initial access process, and save MS authorizing procedure during initial access on the BS of adjacent area.

Accompanying drawing explanation

Fig. 1 is RRM schematic diagram between neighbor base station of the present invention.

Fig. 2 is the schematic flow sheet of the first process in mobile station handover method in WiMAX system of the present invention.

Fig. 3 is the schematic flow sheet of the second process in mobile station handover method in WiMAX system of the present invention.

Fig. 4 is the signalling diagram of mobile station handover method in WiMAX system of the present invention.

Embodiment

Unsuccessfully rear serving BS and the concrete processing policy of IAD are controlled in the initial service flow receiving that the present invention proposes travelling carriage, thereby realized after travelling carriage initial service flow is received unsuccessfully, the current travelling carriage accessing can be switched on the neighbor base station of resource free time.

As shown in Figure 1, be RRM schematic diagram between neighbor base station of the present invention.As shown in fig. 1, between serving BS (being base station under current mobile station), a plurality of neighbor base station, by timer, periodically report mutually current utilization of resources situation.

Same IAD (ASN Gate Way, AGW) each BS under management, resource reporting timer of internal maintenance, when this timer expiry, BS just passes through RRM module (Radio Resource Management by current resource utilization, RRM) related news, for example R6 adjacent area BS reporting resource state message (Neighbor_BS_Resource_Status_Update) reports current resource utilization to AGW, in AGW, be given to other adjacent areas BS (as shown situation and the overtime situation of adjacent area BS1 of BS timer expiry on figure), the utilization of resources situation of learning its adjacent area BS that each BS can be real-time like this, when the initial service flow of certain travelling carriage is received unsuccessfully, the utilization of resources situation of these adjacent areas BS just can be used as the part foundation that instructs MS to switch by serviced BS.

Flow process shown in Fig. 1 is the basis of mobile station handover method of the present invention, and serving BS broadcasts must be known the utilization of resources situation of adjacent area BS.

For the ease of understanding, now the whole process of mobile station handover method in WiMAX system of the present invention is divided into two processes, the first process relates to after initial service flow is received unsuccessfully, and MS determines the target neighbor base station of the resource free time that it will switch; The second process relates to be determined after target neighbor base station, carries out follow-up flow process, as the confirmation of the initial service flow data channel of the dismounting of the initial service flow data channel of neighbor base station, target BS, and the follow-up process of setting up predefine business datum circulation road.

As shown in Figure 2, schematic flow sheet for the first process in mobile station handover method in WiMAX system of the present invention, as shown in Figure 4, signalling diagram for mobile station handover method in WiMAX system of the present invention, Fig. 4 acceptance of the bid shows 2 neighbor base stations, i.e. target (target) BS1 and target (target) BS2.As shown in Figure 2 after travelling carriage initial service flow is received unsuccessfully, under serving BS is controlled, travelling carriage is switched to neighbor base station, and this mobile station handover method embodiment 1 comprises the following steps as shown in the figure:

Step 21, after serving BS determines that the initial service flow of travelling carriage is received unsuccessfully, to a plurality of neighbor base stations transmission handover request message of current resource free time;

This step is that the

signaling step

31,32 and 33 in signalling diagram is as shown in Figure 4 carried out afterwards, serving BS initially accesses range finding, capability negotiation pre-registration (31), MS completes initial access process single-wheel EAP authentication and sends after registration request (32), and AGW initiates the data channel process of establishing (33) of initial service flow (ISF) by Path_Reg_Req message.

This step 21, signaling step in Fig. 4 is

step

34,35,36 and 37, Serving BS receives and controls judgement, find because the initial service flow of resource limitation MS can not be accepted, so the data channel that reply failure cause is 51 (No Resources) is set up response message Path_Reg_Rsp to AGW; AGW receives after response, learn that failure cause is that Serving BS receiving is controlled unsuccessfully, start timer and wait for CMAC_Key_Count_Update renewal process, with reply MS, be switched to the possibility of other BS, AGW returns to Path_Reg_Ack response message to serving BS, Serving BS selects the relatively idle adjacent area BS of current resource by RRM module, to it, send HO_Req message (handover request message), the initial service stream information, authentication (Authenticator) ID, the Anchor GW ID etc. that carry MS, notify it to carry out switching preparation.

Step 22, according to described handover request message, described a plurality of neighbor base stations and IAD carry out the data channel of described initial service flow to be built in advance, and the result that described data channel is built is in advance notified described serving BS; In this embodiment 1, this step 22 specifically comprises:

Step 221, according to described handover request message, the data channel that described a plurality of neighbor base stations are initiated described initial service flow to IAD is built request message in advance;

Step 222, described IAD responds described data channel and builds in advance the result that request message is built in advance to described a plurality of neighbor base station return data passages; And

Step 223, the result that described a plurality of neighbor base stations are built described data channel is in advance notified described serving BS.

This step 22, signaling step in Fig. 4 is

step

391 and 401,

step

392 and 402, adjacent area BS receives handover request message (HO_Req message), the data channel of initiating initial service flow to AGW by Path_Prereg_Req message is built process in advance, and the result that data channel is built is in advance informed Serving BS by HO_Rsp message.

Step 23, selects the result that described serving BS is built in advance from described data channel to build in advance successful neighbor base station, recommends described travelling carriage as switching target; In this embodiment 1, this step 23 specifically comprises:

Step 231, described serving BS is built in advance result by described data channel and is recommended described travelling carriage and scan for building in advance successful neighbor base station;

Step 232, according to the scanning result of described travelling carriage, builds in advance successful neighbor base station using good described of signal conditioning and recommends described travelling carriage as switching target.

This step 23, signaling step in Fig. 4 is

step

41,42 and 43, Serving BS receives after the HO_Rsp message of adjacent area BS in succession, the result of data channel being built in advance by the Result Code in this message is added up, select data channel to build in advance successful adjacent area BS, by MOB_SCN-RSP message (response message of eating dishes without rice or wine to scan), recommend MS and do the scanning before switching; MS is according to the recommendation scanning adjacent area BS of Serving BS, and by scanning result (as the average CINR of adjacent area BS (Carrier toInterference and Noise Ratio, carrier wave and interference-to-noise ratio), average RSSI (Received SignalStrength Indication, received signal strength)) by MOB_SCN-REP message (the scanning result report message of eating dishes without rice or wine), report to Serving BS.Serving BS is according to the scanning result of MS, and good adjacent area BS recommends MS as switching target by MOB_BSHO-REQ (the handover request message that BS initiates), to carry signal conditioning.

Step 24, described travelling carriage is determined its target BS switching from described building in advance successful neighbor base station, the target BS switching is selected in the BS list of carrying from MOB_BSHO-REQ message.

In this embodiment, completed travelling carriage when initial service accesses, when serving BS can not be received, select the process of other idle neighbor base stations, in the process (step 23) of above-mentioned definite target BS, adopted serving BS that data channel is built to successful adjacent area BS in advance and recommended travelling carriage scanning, to select the idle base station of resource that signal quality is good as target BS.

But in the optional embodiment of mobile station handover method of the present invention, in embodiment 2, scanning process can be omitted, on signaling diagram as shown in Figure 4, can omit

signaling step

41,42, any signaling that correspondingly signaling in signaling step 41 can be carried the adjacent area BS information of resource free time by serving BS replaces, so as notice travelling carriage its can from the adjacent area BS of these resource free time, select a base station as its target BS.

Obviously, the signal conditioning of the target BS of choosing after embodiment 1 scanning process is better than the signal conditioning of the target BS of embodiment 2, but embodiment 2 can realize the target BS that mobile station in selecting initial service flow accesses required switching equally.In WiMAX system of the present invention, other flow processs of mobile station handover method embodiment 2, with embodiment 1, do not repeat them here.

Referring to Fig. 3, the schematic flow sheet of mobile station handover method the second process in WiMAX system of the present invention, simultaneously referring to Fig. 4, mobile station handover method embodiment 1 in WiMAX system of the present invention also comprises after step 24:

Step 25, described serving BS is notified described a plurality of neighbor base station, the target BS switching that described mobile radio station is determined;

This step 25, the signaling step in Fig. 4 be step 44,451 and 452, MS by the switching target BS of its selection of MOB_HO-IND (switch indicating information of eating dishes without rice or wine) message informing Serving BS; Serving BS sends to switch to the adjacent area BS that once sent HO_Req message and confirms HO_Cnf message, and the switching of notice MS is selected; This HO_Cnf message comprises whether this adjacent area BS is confirmed to be the HO Confirm Type that switches target;

Step 26, the neighbor base station and the described IAD that in described a plurality of neighbor base station, are not confirmed as switched target BS carry out the cancellation of the described data channel of described initial service data flow, and the neighbor base station reception described Mobile Originated ranging process (ranging) that is defined as switched target BS.

, the adjacent area BS that is defined as switched target BS starts timer and waits for that MS carries out Ranging, if timer expiry MS does not have Ranging successfully to talk about, adjacent area BS completes the delete procedure of pre-established initial service flow data channel and nullifies together with AGW, if MS is in the Ranging process success of this adjacent area BS before timer expiry, adjacent area BS initiates CMAC_Key_Count_Update flow process to AGW, variation by BSID in CMAC_Key_Count_Update message allows AGW perceive the generation that MS switches, and initiate the confirmation flow process (this flow process specific as follows described) of pre-established initial service flow data channel simultaneously.

This step 26, signaling step in Fig. 4 is step 46 and 47, adjacent area BS is according to the choice situation of HO Confirm Type judgement MS in HO_Cnf message, if do not select self as switching target (HO Confirm Type=Reject), adjacent area BS initiates to switch the logout flow path of initial service flow data channel pre-established in set-up procedure to AGW by Path_Dereg_Req message.MS initiates Ranging process to the switching target BS of choosing.

In WiMAX system of the present invention, mobile station handover method embodiment 2 also can the same manner as in Example 1ly have above-mentioned steps 25 and step 26, therefore embodiment 2 does not repeat them here.

In above-described embodiment 1 and embodiment 2, at initial access ranging (step 26) afterwards, can carry out the follow-up flow processs such as normal EAP subscription authentication, registration, and these follow-up flow process co-occurrences there is technology identical.But can re-start like this authentication process of a travelling carriage.

Before the present invention considers that initial service flow receiving is controlled unsuccessfully, MS has successfully passed through authentication, relevant information is (as KI Authentication Key, AK) be retained in AGW side, and these information can be used by adjacent area BS completely, thereby the process of authentication when saving MS and again initially accessing on the BS of adjacent area, therefore the present invention proposes the initial service flow data channel of MS while setting up unsuccessfully, the information such as the adjacent area BS resource utilization that Serving BS provides by RRM module RRM, instruct the current MS accessing to be switched on the relatively idle adjacent area BS of resource and continued initial access process, save MS authorizing procedure during initial access on the BS of adjacent area.

To achieve these goals, the flow process of a kind of mobile station handover method embodiment 3 of the present invention is basic identical with embodiment 1 or 2, difference is also to comprise between step 21 and step 22: step 20, according to handover request message, described a plurality of neighbor base stations obtain the authentication information of described mobile radio station to IAD.As shown in Figure 2, between

step

21 and 22 also in steps 20.

In the signaling diagram shown in Fig. 4, before signaling

step

391 and 392, comprise that

step

381 and 382 asks for the authentication informations such as AK of MS to AGW by Context_Req/Context_Rpt process.This signaling

step

381 and 382 be not limited to one fix on signaling

step

391 and 392 and step 37 between, after this

step

381 and 382 also can be arranged on signaling

step

391 and 392.

Continuation, referring to Fig. 4 and Fig. 3, also comprises after step 26

Step 27, described in be defined as switched target BS neighbor base station receive described travelling carriage distance measurement request (RNG_REQ) message, according to the described described authentication information obtaining, described distance measurement request message is carried out to verification;

This step 27, in the signaling diagram of Fig. 4, it is step 48, after Ranging success, MS is to the switching target BS of choosing, transmission is carried the RNG_REQ message of HMAC/CMAC Tuple (Hashed Message AuthenticationCode/Cipher-based Message Authentication Code Tuple, ashed information identifying code/cipher-text message authentication code tuple) to target BS.

Step 28, after described verification is passed through, to described IAD update notifications message;

This step 28, in the signaling diagram of Fig. 4, it is step 49, target BS is done verification according to the AK information of switching the MS obtaining in set-up procedure to the RNG_REQ message of receiving, verification notifies it to upgrade CMAC by sending CMAC_Key_Count_Update (CMAC updating message) message to AGW.

Step 29, the information that described IAD switches according to the described travelling carriage carrying in described updating message, replys the neighbor base station that response message is defined as switched target BS described in giving, and waits for initial service flow data channel acknowledge message;

This step 29, in the signaling diagram of Fig. 4, it is step 50, AGW receives the CMAC_Key_Count_Update message of target BS, according to the variation of the BS ID carrying in this message, perceive the generation that MS switches, reply CMAC_Key_Count_Update_Ack message to target BS, and wait for the initial service flow data channel acknowledge message of target BS, target BS is returned to RNG_RSP response message to travelling carriage simultaneously;

Step 30, described in be defined as switched target BS neighbor base station to described IAD, send described initial service flow data channel acknowledge message.This step 30 is step 51 in the signaling diagram of Fig. 4.

In this embodiment, be authentication when carrying out initial access, the authentication information obtaining according to the existing authentication process carrying out before carries out verification to described distance measurement request message, if do not adopt the present embodiment, need to re-start once initial access authentication.

Continuation, referring to shown in Fig. 3 and Fig. 4, the neighbor base station that is defined as switched target BS described in step 30 sends described initial service flow data channel acknowledge message to described IAD after, also comprises:

Step 300, described IAD is confirmed the validity of described initial service flow data channel, carries out the process of establishing of predefine business datum circulation road with the described neighbor base station that is defined as switched target BS.It is the signaling step 52 in Fig. 4.

Correspondingly, the present invention also provides travelling carriage switched system in a kind of WiMAX system, and this system comprises:

A plurality of neighbor base stations, are connected with described serving BS, for according to described handover request message, carry out the data channel of described initial service flow and build in advance, and the result that data channel is built in advance returns to described serving BS;

Described neighbor base station is further used for: the authentication information that obtains described mobile radio station to IAD; The described neighbor base station that is defined as switched target BS, for receiving described travelling carriage distance measurement request message, carries out verification according to the described described authentication information obtaining to described distance measurement request message; After described verification is passed through, to described IAD update notifications message.Described anchor ASN-GW is further used for the cancellation of the described data channel of described initial service data flow.

Generally speaking, in the switched system of this travelling carriage, Serving BS needs the support of RRM module (RRM), when receiving control not receive the initial service flow of MS, Serving BS inquiry RRM module, therefrom determine the relatively idle adjacent area BS of resource, and (carry the initial service stream information of MS to the relatively idle adjacent area BS transmission HO_Req message of these resources, Anchor GWID, Authenticator ID etc.), the switching that notice adjacent area BS may arrive, after receiving the HO_Rsp message that adjacent area BS replys, the pre-established situation of initial service flow data channel between Serving BS statistics adjacent area BS and Anchor AGW, selecting the pre-established successful adjacent area BS of data channel to recommend MS scans.

Adjacent area BS is after receiving the HO_Req message of Serving BS, by the Authenticator id information carrying in this message, to Authenticator Gate Way, ask for the authentication information (as AK) of MS, and/or initiate the pre-established process of initial service flow data channel with Anchor GW by the initial service flow parameter of carrying in this message.No matter data channel is pre-established successful or failed, and adjacent area BS can inform the pre-established result of BS initial service flow data channel by HO_Rsp message.After MS finally selects this adjacent area BS as the target BS of switching (whether Serving BS can be switched on the BS of this adjacent area by the current MS of HO_Cnf message informing adjacent area BS), adjacent area BS starts timer and waits for that MS carries out Ranging, if timer expiry MS does not have Ranging successfully to talk about, adjacent area BS completes the delete procedure of pre-established initial service flow data channel together with AGW; If MS is in the Ranging process success of this adjacent area BS before timer expiry, adjacent area BS initiates CMAC_Key_Count_Update flow process to AGW, variation by BSID in CMAC_Key_Count_Update message allows AGW perceive the generation that MS switches, and initiates the confirmation flow process of pre-established initial service flow data channel simultaneously.

AGW sets up after message in the initial service flow data channel of receiving the failure that BS sends, it not the authentication information of deleting at once MS, but start timer, wait for CMAC_Key_Count_Update message, with defence MS, be switched to the possibility of adjacent area BS, when timer expiry is not still received the CMAC_Key_Count_Update message that MS is relevant, AGW think MS this access utter failure, the local authentication information of deleting MS, and pre-established initial service flow data channel (if having pre-established data channel) between dismounting and adjacent area BS; When the CMAC_Key_Count_Update message of receiving that before timer expiry MS is relevant, AGW can be by the variation of the BS ID that carries in this message so, perceive MS and be switched to adjacent area BS, the adjacent area BS after at this moment AGW cooperation is switched has continued the foundation of the PSF traffic data passage of MS.

MS is after receiving the scan request of eating dishes without rice or wine (MOB_SCN-RSP) that Serving BS sends, can scan one by one the adjacent area BS recommending in the scan request of eating dishes without rice or wine, and notify scanning result at once to Serving BS, so that selecting suitable adjacent area BS to recommend MS according to scanning result, Serving BS switches.When MS receives after the handover request of Serving BS initiation, in the target BS list that can recommend from this request, select a suitable adjacent area BS as switching target, and selection result is informed to Serving BS by MOB_HO-IND message, MS just starts initially to access Ranging with selected switching target BS subsequently, initially, after access Ranging success, MS, switching target BS and AGW complete the foundation that initial access process is switched rear PSF traffic data passage jointly.

Therefore, by mobile station handover method and switched system in a kind of WiMAX system provided by the invention, having realized the current travelling carriage accessing does not receive after its initial service flow at serving BS, can switch to other neighbor base stations of resource free time, thereby do not hinder the activity of the travelling carriage of original access on serving BS, without the former travelling carriage having accessed, be switched on neighbor base station; And before initial service flow receiving is controlled unsuccessfully, travelling carriage has successfully passed through authentication, relevant information (as AK/ traffic flow parameters etc.) has been retained in AGW side, therefore these authentication informations are directly neighbor base station use, thereby have save the process of authentication when travelling carriage again initially accesses on neighbor base station.

Finally should be noted that, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, although the present invention is had been described in detail with reference to preferred embodiment, those of ordinary skill in the art is to be understood that, can to the present invention, modify, change or be equal to replacement, and not depart from the spirit and scope of the present invention and claim.

Claims

1. a mobile station handover method in WiMAX system, is characterized in that comprising:

2. mobile station handover method in WiMAX system as claimed in claim 1, it is characterized in that according to described handover request message, described a plurality of neighbor base station and IAD carry out the data channel of described initial service flow and build in advance, and the result that described data channel is built in advance notifies described serving BS, comprising:

According to described handover request, the data channel that described a plurality of neighbor base stations are initiated described initial service flow to IAD is built request message in advance;

Described IAD responds described data channel and builds in advance the result that request message is built in advance to described a plurality of neighbor base station return data passages; And

The result that described a plurality of neighbor base station is built described data channel is in advance notified described serving BS.

3. mobile station handover method in WiMAX system as claimed in claim 2, is characterized in that result that described serving BS builds described data channel in advance, for building in advance successful neighbor base station, recommends described travelling carriage and comprise as switching target:

Described serving BS is built in advance result from described data channel and is selected to build in advance successful neighbor base station and recommend described travelling carriage and scan;

According to the scanning result of described travelling carriage, good described of signal conditioning built to successful neighbor base station in advance and recommend described travelling carriage as switching target.

4. mobile station handover method in the WiMAX system as described in as arbitrary in claim 1-3, is characterized in that described travelling carriage also comprises from described building in advance after determining its target BS switching successful neighbor base station:

Described serving BS is notified described a plurality of neighbor base station, the target BS switching that described travelling carriage is determined;

The neighbor base station and the described IAD that in described a plurality of neighbor base station, are not confirmed as switched target BS carry out the cancellation of the described data channel of described initial service data flow, and the described Mobile Originated ranging process of neighbor base station reception that is defined as switched target BS.

5. mobile station handover method in WiMAX system as claimed in claim 4, is characterized in that after described serving BS determines that the initial service flow of travelling carriage is received unsuccessfully, to a plurality of neighbor base stations transmission handover request message of current resource free time; With according to described handover request message, the data channel that described a plurality of neighbor base stations are initiated described initial service flow to IAD is built between request message and is also comprised in advance:

6. mobile station handover method in WiMAX system as claimed in claim 5, is characterized in that, after described ranging process success, also comprising:

The described neighbor base station that is defined as switched target BS receives described travelling carriage distance measurement request message, according to the described described authentication information obtaining, described distance measurement request message is carried out to verification;

After described verification is passed through, to described IAD update notifications message;

The information that described IAD switches according to the described travelling carriage carrying in described updating message, replys the neighbor base station that response message is defined as switched target BS described in giving, and waits for initial service flow data channel acknowledge message;

The described neighbor base station that is defined as switched target BS sends described initial service flow data channel acknowledge message to described IAD.

7. mobile station handover method in WiMAX system as claimed in claim 6, is characterized in that, the described neighbor base station that is defined as switched target BS sends described initial service flow data channel acknowledge message to described IAD after, also comprising:

8. mobile station handover method in WiMAX system as claimed in claim 4, characterized by further comprising:

9. a travelling carriage switched system in WiMAX system, is characterized in that comprising:

Serving BS, is connected with described travelling carriage, after determining that the initial service flow of described travelling carriage is received unsuccessfully, to a plurality of neighbor base stations transmission handover request message of current resource free time; The data channel result of building in advance with the described initial service flow of statistics;

A plurality of neighbor base stations, are connected with described serving BS, for according to described handover request message, carry out building in advance with the data channel of the described initial service flow of IAD, and the result that data channel is built in advance return to described serving BS; With

10. travelling carriage switched system in WiMAX system as claimed in claim 9, is characterized in that described neighbor base station is further used for: the authentication information that obtains described travelling carriage to IAD; The described neighbor base station that is chosen as switched target BS, for receiving described travelling carriage distance measurement request message, carries out verification according to the described described authentication information obtaining to described distance measurement request message; After described verification is passed through, to described IAD update notifications message.

Travelling carriage switched system in 11. WiMAX systems as claimed in claim 9, is characterized in that described IAD is further used for the cancellation of the described data channel of described initial service data flow.