CN102625380A - Relocation method and system - Google Patents

Abstract

Disclosed is a relocation method, comprising the following steps that: after a source signaling adapter (SA) receives a relocation request, a target SA is notified to prepare resources for to-be-relocated user equipment (UE) through a session initiation protocol (SIP) message; the target SA prepares resources for the to-be-relocated UE, establish a bearer between the target SA and the source SA and notifies the source SA that the preparation for the relocation is completed; and the source SA notifies the to-be-relocated UE to be relocated to a target network. Meanwhile, disclosed is a relocation system. According to the invention, a relocation message flow is simplified; compared with the prior art, the technology employed in the invention enables efficiency of the system relocation to be improved; and moreover, users will not notice any abnormity of service relocation and there is no relocation vibration, thereby improving the user experience effect of the service.

Description

Changing method and system

Technical field

The present invention relates to the handoff technique in IP Multimedia System (IMS, the IP Multimedia Subsystem) network architecture, relate in particular to a kind of changing method and switched system based on IMS centralized traffic (ICS, IMS Centralized Service).

Background technology

From the evolution and development of communication network, the development of the core net network architecture demonstrates two main trend: the one, and the IP of network (Internet Protocol) changes, and the 2nd, the fusion of diverse network.Therefore following core net will not be further divided into circuit switching (CS; Circuit Switched) territory, packet switching (PS; PacketSwitching) multiple core net such as territory and IMS; And will be an IP-based unified service control system, all business (comprising speech business, supplementary service and value-added service etc.) are all realized by this unified service control system.

IP-based unified service control system (back literary composition is called unified IP kernel heart net) has two characteristics, and the one, business realization such as voice adopt session initiation protocol (SIP, Session Initiation Protocol); The 2nd, this service control system and access technology are irrelevant, and promptly the user can insert also and can insert through CS through PS.The PS access way here refers to the user can be linked into core net through GPRS (GPRS, GeneralPacket Radio Service), WLAN packet networks such as (WLAN, Wireless Local Area Network).And referring to the user, the CS access way is linked into core net through circuit domain Radio Access Network such as base station sub-system (BSS, Base Station Subsystem) or RNS equipment such as (RNS, RadioNetwork Subsystem).No matter be to adopt which kind of access way, business is all provided by above-mentioned unified IP kernel heart net.

Fig. 1 is linked into the application scenarios sketch map of unified IP kernel heart net for adopting the CS access way; As shown in Figure 1; Subscriber equipment (UE; User Equipment) 101 be linked in the unified IP kernel heart net 104 through circuit domain access network (like BSS or RNS) 102 and signaling adaptation device 103, signaling adaptation device 103 plays necessary signaling transformation, and all business are provided by unified IP kernel heart net 104.

Fig. 2 is for the Organization Chart of the unified IP kernel heart net of CS access, and is as shown in Figure 2, and the framework that CS inserts unified IP kernel heart net comprises following network element: subscriber equipment (UE; User Equipment) 201, base station controller (BSC, Base Station Controller) or radio network controller (RNC; Radio NetworkController) 202, signaling adaptation device (SA, Signalling Adapter) 203; WMG (MGW; Media Gateway) 204, integrated service controlled function (ISCF, Integrated Service ControlFunction) 205; Wherein, BSC and RNC202 are used to realize that the user in CS territory inserts and functions such as the management of Radio Resource and control.Interface between BSC and the SA203 adopts Base Station Subsystem Application Part (BSSAP; Base Station System Application Part) signaling; Interface between RNC and the SA203 adopts Radio Access Network Application Part (RANAP; Radio Access Network ApplicationPart) signaling, BSSAP and RANAP signaling are referred to as the CS access signaling.Interface between SA203 and the equipment 202 adopts the CS access signaling, and the interface between the ISCF adopts Session Initiation Protocol, SA203 realize between CS access signaling and the sip message translation function and to the control of MGW204.MGW204 mainly realizes continuing of Media Stream and handles, sets up the functions such as carrying of medium face.ISCF 205 plays functions such as mobile management, professional route, calling control, professional control, storage.It can be realized by one or more functional entitys.

Concrete; UE 201 is linked into SA 203 through BSC or RNC; SA203 receives and is converted into the SIP signaling after the CS access signaling that BSC or RNC send and sends to ISCF205, and this moment, SA was equivalent to serve as the user agent, replaced subscriber equipment 201 to be linked into ISCF205; Carry out professional route and call out control by ISCF205, thus user UE201 can with the remote subscriber words that work of going forward side by side that connect.

In wireless communication system, when UE from a sub-district (coverage that refers to base station or base station) when moving to another sub-district, need carry out channel for not interrupt communication and switch.

Whether be in same RNC (or BSC) according to user before and after switching, switching can be divided into the inner switching of RNC (or BSC) and stride the switching of RNC (or BSC).The inner switching of RNC (or BSC) only need be accomplished by RNC (or BSC), and core net does not participate in handling, and the switching of striding RNC (or BSC) then needs core net also to carry out corresponding service switchover processing.What the present invention relates to is the service switchover of striding RNC or BSC.Stride RNC and the service switchover of striding BSC for all, difference only is that access signaling is RANAP or BSSAP, and the processing logic of the service switchover of core-network side is all identical.

Fig. 3 is the flow chart of switching of the prior art, and is as shown in Figure 3, and UE1 is the user terminal that switches; UE2 is the user terminal of conversing with UE1; Source RNC is the RNC that the user inserts before switching, and Target RNC is the RNC that the user will switch to, and source SA is the SA of the source network before the user is switched; Target SA is the SA of user's objective network that will switch to, and ISCF is the ISCF of source network.Business scenario be in UE1 and UE2 communication process UE1 RNC switches to Target RNC from the source.

ICS strengthens registration process and may further comprise the steps:

Step 301:UE sends measurement report (Measurement Report) to source RNC.

Step 302: source RNC judges that according to measurement report UE1 need switch.

Step 303: source RNC sends handoff request (RELOCATION REQUIRED) to source SA;

Step 304: source SA converts handoff request to call transfer request (REFER) and sends to ISCF.The address parameter that requires in this call transfer request message to carry in destination address (Refer-To) header field of contact is the target location district sign (Target LAI) that will switch to; Method (method) parameter is HANDOVER; Because HANDOVER does not belong to the standard method title that defines among the method, therefore need expand the method parameter.In addition, carried in the handoff request that source SA receives and switched necessary parameter, comprised but be not limited to: switch reasons, switching type, cell-of-origin, Target cell etc.Above-mentioned handoff parameter is also placed in the REFER message and sends to ISCF; These parameters are placed on the Session Description Protocol (SDP of REFER; Session Description Protocol) carries through extend markup language (XML, Extensible Markup Language) expansion in.

Step 305:ISCF accepts message (202Accepted) to source SA callback transfer request after receiving REFER.ISCF is handoff request according to this message of HANDOVER value decidable in the method parameter in the REFER message, further, can also confirm the address of target SA according to operator's configuration and parameter.

Step 306:ISCF is transmitted to target SA with REFER message with it.

Step 307: target SA accepts message (202Accepted) to the ISCF callback transfer request after receiving REFER.

Step 308: target SA is the switching terminal reserved resource, sends handoff request (RELOCATION REQUEST) to Target RNC afterwards.

Step 309: Target RNC carries out the access network resource reservation procedure, distributes corresponding radio resource for UE1 inserts 3G network from Target RNC.Target RNC sends switching request response (RELOCATION REQUEST ACK) to target SA afterwards.

Step 310: target SA sends a notification message (NOTIFY) to ISCF, and notice ISCF switching is ready to complete.

Step 311:ISCF returns acknowledge message (200OK) after receiving notice.

Step 312:ISCF carries the media information of UE2 to the target SA invitation (INVITE) that makes a call in SDP.

Step 313: target SA is updated to the media information of UE2 with the distant end media surface information, sends response message (200OK) to ISCF afterwards, carries local terminal media information SDP1 in the message.

Step 314:ISCF sends to target SA and replys acknowledge message (ACK).

Step 315:ISCF carries out the session description information negotiations process with UE2, and UE2 is the media information among the SDP1 of target SA with self distant end media information updating.

Step 316:ISCF sends a notification message (NOTIFY) to source SA, and notification source SA switching is ready to complete.

Step 317: source SA returns acknowledge message (200OK) after receiving notice.

Step 318: source SA sends switching command (Relocation Command) to source RNC.

Step 319: source RNC sends switching command to UE1.

Step 320:UE1 switches to Target RNC, and UE1 begins the Radio Resource of access destination RNC.

Step 321: Target RNC detects after the UE1, sends to target SA and switches probe message (Relocation Detect).

Step 322: Target RNC receives after the handover success message of UE1 transmission, sends handoff completion message (Relocation Complete) to target SA.

Step 323: target SA sends a notification message (NOTIFY) to ISCF, and notice ISCF switching is accomplished.

After step 324:ISCF receives notification message, return acknowledge message (200OK) to target SA.

Step 325:ISCF transmits notification message (NOTIFY) to source SA, and notification source SA switching is accomplished.

Step 326: after source SA receives notification message, return acknowledge message (200OK) to ISCF.

Step 327: link of source SA notification source RNC release signaling and bearing resource.

Though prior art can be accomplished basic service switchover, also there is following problem:

1, the flow process message count is too much, and flow process is complicated alternately.In the prior art, switching controls is accomplished by ISCF, after ISCF receives the handoff request that source SA sends, next two processing is arranged, the one, notification target SA carries out hand-off process, the 2nd and target SA carry out medium face SDP negotiation.In the prior art; These two processing procedures are to realize through two separate message interaction processes respectively; Be that ISCF earlier carries out hand-off process (step 306～step 311) through call transfer request notification target SA, follow-uply carry out SDP negotiation (step 312～step 314) through calling invitation request and target SA again.This implementation method makes that the interacting message between ISCF and the target SA is too much and flow process is complicated, thereby influences system handles efficient.

2, the SDP renewal process of ISCF and target SA may cause switching the concussion problem.Be that ISCF consults to be the SDP of UE2 (step 306～step 307) with the distant end media surface information of target SA earlier in the prior art, again UE2 carried out the distant end media face and upgrade.UE2 is carried out the medium face upgrade the SDP be to use target SA and UE2 hold consultation (step 315); This may cause UE2 to apply for that again a new port is used for communicating by letter with switching terminal; The medium surface information of UE2 will change this moment; The SDP of the UE2 that this will cause consulting before the target SA is invalid, follow-uply also needs to carry out the medium face with target SA again with the new medium surface information of UE2 again and consults, and has promptly caused switching concussion problem.

Summary of the invention

In view of this, main purpose of the present invention is to provide a kind of changing method and switched system, and it is compatible to the communication service of other mobile network users to realize that ICS strengthens network.

For achieving the above object, technical scheme of the present invention is achieved in that

A kind of changing method comprises:

After source SA receives handoff request, be that to be switched user equipment (UE) is prepared resource through sip message notification target SA;

Said target SA is that said to be switched UE prepares resource, the carrying between foundation and the said source SA, and notify said source SA switching to be ready to complete;

Said source SA notifies said to be switched UE to switch to objective network.

Preferably, carry the relevant parameter and/or the switching sign of switching in the said sip message.

Preferably, carry the relevant parameter of switching and/or switch sign and be specially in the said sip message:

Carry the relevant parameter that switches in the message body of said sip message and/or switch sign.

Preferably, the relevant parameter of said switching comprises the medium coding/decoding information of the information of switching target small area and target radio network controller RNC, said source SA support and the coding/decoding information that current business adopts.

Preferably, carry the relevant parameter of switching and/or switch sign and be specially in the said sip message:

Carry in the message header of said sip message and switch sign.

Preferably, said sip message is a transfer request REFER message, and/or, the calling invitation INVITE.

Preferably, carrying the switching sign in the message header of said sip message is specially:

For said REFER message, said switching sign is carried in the Route header field or Request-URI header field of said REFER message.

Preferably, source SA is that to be switched UE preparation resource is specially through sip message notification target SA:

It is that to be switched UE prepares resource that said source SA directly notifies said target SA through sip message;

Perhaps, said source SA is through sip message and to notify said target SA through integrated service controlled function entity ISCF be that to be switched UE prepares resource.

Preferably, said source SA is through sip message and to notify said target SA through ISCF be that to be switched UE prepares resource and is specially:

After said source SA receives handoff request, through the said ISCF of REFER message informing; Said ISCF judges and need switch according to the switching in REFER message sign, obtains said target SA address, and to notify said target SA through SIP session invitation INVITE be that to be switched UE prepares resource.

Preferably; Said source SA is through the said ISCF of REFER message informing; And to notify said target SA by said ISCF through the SIP INVITE be to be switched UE when preparing resource, do not carry the conversation media information with the opposite end UE of said to be switched UE session in the said INVITE.

Preferably, said ISCF obtains said target SA address and is specially:

Said ISCF selects said target SA according to Target cell and operator's collocation strategy;

Perhaps, be carried in the REFER message that sends to said ISCF, notify said ISCF by said source SA select target SA and with the address of said target SA.

Preferably, said method also comprises:

After said target SA receives the switching sip message of said source SA transmission, confirm that according to the sign of the switching in the sip message needs switch, and send handoff request to said Target RNC; After receiving the switching request response of said Target RNC transmission, be current session reserved media face resource, and notify said ISCF;

Said ISCF carries the medium face resource information of said target SA and carries out the negotiation of medium face with the opposite end UE with said to be switched UE session through sip message, making this opposite end UE is the medium face resource of said target SA with the distant end media face resource updates of self.

Preferably, said source SA is through the said ISCF of REFER message informing, and to notify said target SA by said ISCF through the SIP INVITE be to be switched user equipment (UE) when preparing resource, and said target SA notifies said ISCF through call progress message 183;

Said source SA is to be switched UE when preparing resource through sip message directly or through said ISCF notification target SA, and said target SA notifies said ISCF through INVITE.

Preferably, said source SA is through sip message and to notify said target SA through ISCF be to be switched UE when preparing resource, and said method also comprises:

After the opposite end UE that accomplishes said target SA and said to be switched UE session accomplished IP carrying foundation, said source SA received to switch and is ready to complete notice, notified said source SA to switch by said ISCF through sip message and was ready to complete.

It is to be switched UE when preparing resource that said source SA directly notifies said target SA through sip message, and said method also comprises:

After the opposite end UE that accomplishes said target SA and said to be switched UE session accomplished IP carrying foundation, said source SA received to switch and is ready to complete notice, notified said source SA to switch by said target SA through sip message and was ready to complete.

Preferably, said method also comprises:

After said target SA receives the handoff completion message of said Target RNC, switch completion through sip message notification source SA.

Preferably; Said source SA is through sip message and to notify said target SA through ISCF be that to be switched UE is when preparing resource; Said target SA notifies said source SA to switch to accomplish through sip message and is specially: said target SA sends response message 200OK to said ISCF and notifies said ISCF to switch to accomplish, and said ISCF receives after the said 200OK message to the said source SA NOTIFY that sends a notification message and notifies said ISCF to switch to accomplish;

It is to be switched UE when preparing resource that said source SA directly notifies said target SA through sip message, and said target SA notifies said source SA to switch to accomplish through sip message and is specially: said target SA directly sends NOTIFY to said source SA and notifies said source SA to switch to accomplish.

A kind of switched system is applied in the wireless communication system, said switched system comprise source SA, source RNC, Target RNC, target SA, to be switched UE and with the UE of to be switched UE session, wherein,

Source SA is used for after receiving handoff request, is that to be switched UE prepares resource through sip message notification target SA; And, be after said to be switched UE prepares resource, to notify said to be switched UE to switch to objective network at target SA;

Target SA is used to said to be switched UE and prepares resource, the carrying between foundation and the said source SA, and notify said source SA switching to be ready to complete;

Preferably, carry the relevant parameter and/or the switching sign of switching in the said sip message.

Preferably; Carry the relevant parameter that switches in the message body of said sip message and/or switch sign; Wherein, the relevant parameter of said switching comprises the medium coding/decoding information of the information of switching target small area and Target RNC, said source AG support and the coding/decoding information that current business adopts.

Preferably, carry the switching sign in the message header of said sip message.

Preferably, said sip message is a transfer request REFER message, or the calling invitation INVITE; Wherein, carry the switching sign in the message header of said sip message and be specially: for said REFER message, said switching sign is carried in the Route header field or Request-URI header field of said REFER message.

Preferably, to be further used for directly notifying said target SA through sip message be that to be switched UE prepares resource to said source SA;

Perhaps, said source SA is further used for through sip message and to notify said target SA through ISCF be that to be switched UE prepares resource.

Preferably, said source SA is further used for through sip message and to notify said target SA through ISCF be that to be switched UE prepares resource and is specially:

Said source SA is further after receiving handoff request, through the said ISCF of REFER message informing; Said ISCF judges and need switch according to the switching in REFER message sign, obtains said target SA address, and to notify said target SA through SIP session invitation INVITE be that to be switched user equipment (UE) is prepared resource.

Preferably; Said source SA is further through the said ISCF of REFER message informing; And to notify said target SA by said ISCF through the SIP INVITE be to be switched user equipment (UE) when preparing resource, do not carry the conversation media information with the opposite end UE of said to be switched UE session in the said INVITE.

Preferably, said ISCF further selects said target SA according to Target cell and operator's collocation strategy;

Perhaps, said source SA select target SA, and the address of said target SA is carried in the REFER message that sends to said ISCF, notify said ISCF.

Among the present invention, receive the handoff request of source RNC as source SA after, be that to be switched UE prepares resource through sip message notification target SA; After receiving sip message, target SA is that to be switched UE prepares resource, and the carrying between foundation and the source SA, and notification source SA switching afterwards is ready to complete; Source SA notifies to be switched UE to switch to objective network.With respect to prior art, the present invention has simplified the switching message flow, with respect to prior art, has improved the efficient that system is switched, and the user can not feel can not exist professional switch unusual and switch the concussion problem, has promoted professional user experience effect.

Description of drawings

Fig. 1 is linked into the application scenarios sketch map of unified IP kernel heart net for adopting the CS access way;

Fig. 2 inserts the Organization Chart of unified IP kernel heart net for CS;

Fig. 3 is the flow chart of switching of the prior art;

Fig. 4 is the flow chart of the changing method of the embodiment of the invention one;

Fig. 5 is the flow chart of the changing method of the embodiment of the invention two.

Embodiment

Basic thought of the present invention is, receive the handoff request of source RNC as source SA after, be that to be switched UE prepares resource through sip message notification target SA; After receiving sip message, target SA is that to be switched UE prepares resource, and the carrying between foundation and the source SA, and notification source SA switching afterwards is ready to complete; Source SA notifies to be switched UE to switch to objective network.

For making the object of the invention, technical scheme and advantage clearer, below lift embodiment and with reference to accompanying drawing, to further explain of the present invention.

Switched system of the present invention; Be applied in the wireless communication system; Specifically comprise source SA, source RNC, Target RNC, target SA, to be switched UE (UE1) and with the UE (UE2) of to be switched UE session; Wherein, after source SA receives the handoff request message of source RNC, prepare resource through sip message notification target SA; Target SA prepare resource and and user equipment (UE) 2 between set up IP and carry; Source SA informing user terminal UE1 switches to objective network.In the switched system of the present invention; Network configuration is compared with existing network configuration and is not changed; Just, the function that each network element is realized is no longer identical, and the information of carrying in institute's interactive messages and the message between each network element is no longer identical; After network element received these message, performed function was also different with prior art.Function that the present invention mainly realizes network element and the interactive mode between each network element are described in detail.

Above-mentioned source SA prepares resource through conversation initiating protocol message sip message notification target SA, is specially, and source SA passes through sip message via ISCF notification target SA through direct notification target SA of sip message or source SA.

Source SA passes through sip message via source integrated service controlled function ISCF notification target SA; Be specially; Source SA is through REFER message informing ISCF; ISCF obtains target SA address after switching according to the sign of the switching in REFER message judgement needs, and through SIP session invitation message INVITE notification target SA.

Carry the relevant parameter of switching in the above-mentioned sip message and/or switch sign.

Perhaps; Carry the relevant parameter that switches in the message body of sip message and/or switch sign; Wherein, the relevant parameter of switching comprises the information of switching target small area and Target RNC, the medium coding/decoding information of source AG support and the coding/decoding information that current business adopts.

Particularly, carry the switching sign in the message header of sip message.

Above-mentioned sip message is a transfer request REFER message, or the calling invitation INVITE; Wherein, carry the switching sign in the message header of sip message and be specially:, switch sign and be carried in the Route header field or Request-URI header field of REFER message for REFER message.

Above-mentioned INVITE body adopts the XML form.

It is that to be switched UE prepares resource that source SA is further used for through the direct notification target SA of sip message;

Perhaps, source SA is further used for that integrated service controlled function entity ISCF notification target SA is that to be switched UE prepares resource through sip message and through the source; Concrete, source SA is after receiving handoff request, through REFER message informing ISCF; ISCF judges and need switch according to the switching in REFER message sign, obtains target SA address, and is that to be switched user equipment (UE) is prepared resource through SIP session invitation INVITE notification target SA.

Above-mentioned source SA is further through REFER message informing ISCF, and is to be switched user equipment (UE) when preparing resource by ISCF through SIP INVITE notification target SA, do not carry the conversation media information with the opposite end UE of to be switched UE session in the INVITE.

Above-mentioned ISCF is further according to Target cell and the collocation strategy select target SA of operator;

Perhaps, source SA select target SA, and the address of target SA is carried in the REFER message that sends to ISCF notice ISCF.

Target SA is that to be switched UE prepares resource; Be specially; After target SA receives above-mentioned INVITE or REFER (source SA receives after the handoff request handoff notification message to target SA sends) message; After switching according to the switching in message sign judgements needs, to Target RNC transmission handoff request.After target SA received the switching request response of Target RNC transmission, target SA carried through setting up IP between ISCF and the user equipment (UE) 2.

ISCF carries the medium face resource information of target SA and carries out the negotiation of medium face with the opposite end UE with to be switched UE session through sip message, making this opposite end UE is the medium face resource of target SA with the distant end media face resource updates of self.

Source SA is through REFER message informing ISCF, and is to be switched user equipment (UE) when preparing resource by ISCF through SIP INVITE notification target SA, and target SA is through call progress message 183 notice ISCF; Source SA is to be switched UE when preparing resource through sip message directly or through ISCF notification target SA, and target SA is through INVITE notice ISCF.All carry the medium face resource that target SA reserves among the SDP of above-mentioned 183 message and INVITE, and carry the switching sign.After ISCF receives 183 message or above-mentioned INVITE; ISCF carries target SA through sip message media information carries out the negotiation of medium face with UE2; UE2 is updated to oneself distant end media surface information the medium surface information of target SA; And bringing ISCF through sip message with oneself medium surface information, ISCF sends the medium surface information that sip message carries the UE2 that gets access to target SA.

ISCF sends the medium surface information that sip message carries the UE2 that gets access to target SA, is specially, and sip message is meant Temporary Response message PRACK or response message 200OK.

Source SA sends switching command to source RNC after receiving that switching is ready to complete notice.

If source SA utilizes REFER message and INVITE notification target SA to switch before; To be ready to complete notice be after accomplishing target SA and accomplishing the IP loading establishing process with UE2 in the source SA switching of receiving so, is ready to complete through sip message notification source SA switching by ISCF.If source SA directly switches through ISCF notification target SA through sip message or through sip message before; To be ready to complete notice be after accomplishing target SA and accomplishing the IP loading establishing process with UE2, to be ready to complete through sip message notification source SA switching by target SA in the source SA switching of receiving so.The sip message here all is meant notification message NOTIFY.

If source SA utilizes REFER message and INVITE notification target SA to switch before; Target SA accomplishes through sip message notification source SA switching and is meant so; Target SA sends response message 200OK notice ISCF to ISCF and switches and accomplish, and ISCF receives after the 200OK message to the source SA NOTIFY notice ISCF that sends a notification message and switches and accomplish.If source SA directly switches through ISCF notification target SA through sip message or through sip message before, target SA switch to accomplish through sip message notification source SA and is meant so, and target SA directly switches and accomplishes to the source SA NOTIFY notification source SA that sends a notification message.

Fig. 4 is the flow chart of the changing method of the embodiment of the invention one, has described in UE1 and the UE2 communication process, and is as shown in Figure 4, and the UE1 switching that RNC switches to Target RNC from the source specifically may further comprise the steps:

Step 401, UE sends measurement report (Measurement Report) to source RNC.

Step 402, source RNC judges that according to measurement report UE1 need switch.

Step 403, source RNC sends handoff request (RELOCATION REQUIRED) to source SA.

Step 404; Source SA converts this request to call transfer request (REFER) and sends to ISCF; The address parameter that requires in this call transfer request message to carry in destination address (Refer-To) header field of contact is the target location district sign (target LAI) that will switch to, and method (method) parameter is that HANDOVER is as switching sign.Because HANDOVER does not belong to the standard method title that defines among the method, therefore need expand the method parameter.In addition, the necessary parameter of some other switching of carrying in the handoff request that source SA receives is also placed in the REFER message and sends to ISCF, and these parameters can be placed among the SDP of REFER and carry through XML, also can adopt other suitable methods.

Step 405, ISCF accepts message (202Accepted) to source SA callback transfer request after receiving REFER.ISCF is a handoff request according to this message of HANDOVER value decidable in the method parameter in the REFER message.The method of ISCF select target SA can be the collocation strategy according to Target cell and operator; Also can be to select to bring ISCF through REFER message afterwards by source SA; For example can bring ISCF, also can carry through the XML expansion through the route header field in the REFER message.

Step 406, ISCF sends calling invitation request (INVITE) to target SA.Carry in the INVITE and switch sign.It can be to realize through the method that method parameter in the route header field is expanded that INVITE carries the method for switching sign, for example can adopt following form, route: destination address; Method=handover.It can also be to realize through the method to the parameter expansion in the Request-URI header field that INVITE carries the method for switching sign, for example can adopt following form: destination address; Method=handover.In addition; The necessary parameter of switching that ISCF carries from the REFER request that source SA receives is also placed in and sends to target SA in the INVITE; The mode that these parameters are carried adopts method of the prior art, can expand among the SDP that also can be placed on REFER the XML expansion to the refer header field and carry.The medium surface information of carried terminal not in this request message.

Step 407, target SA is the switching terminal reserved resource.Send handoff request (RELOCATION REQUEST) to Target RNC afterwards, carry switching-related parameters in the message.

Step 408, Target RNC carries out the access network resource reservation procedure, distributes corresponding resource for UE1 inserts 3G network from Target RNC in the future.Target RNC sends switching request response (RELOCATION REQUEST ACK) to target SA afterwards.

Step 409, target SA sends call progress message (183 call progressing) to ISCF, carries the medium surface information of target SA among the SDP.

Step 410; ISCF carries target SA through sip message medium surface information carries out the session negotiation of medium face with UE2; UE2 is updated to the medium surface information of target SA with self distant end media surface information, and self medium surface information is sent to ISCF through sip message.ISCF can obtain the terminal media surface information after the possible renewal of UE2 thus, and follow-up ISCF promptly uses the terminal media surface information of the UE2 after the renewal and target SA to carry out SDP negotiation.

Step 411, ISCF sends call progress message (PRACK) to target SA, carries the medium surface information of the UE2 that gets access in the step 410.

Step 412 after target SA receives PRACK, is updated to the medium surface information of UE2 with self distant end media surface information, sends Temporary Response acknowledge message (200OK) to ISCF afterwards.

Step 413, ISCF can judge source SA switching and be ready to complete after the Temporary Response acknowledge message that receives target SA transmission, and ISCF sends a notification message (NOTIFY) to source SA, and notification source SA switching is ready to complete.

Step 414, source SA returns acknowledge message (200OK) after receiving notice.

Step 415, source SA sends switching command (Relocation Command) to source RNC.

Step 416, source RNC sends switching command to UE1.

Step 417, UE1 switches to Target RNC, and UE1 begins the Radio Resource of access destination RNC.

Step 418, Target RNC detect after the UE1, send to target SA and switch probe message (Relocation Detect).

Step 419, Target RNC receive after the handover success message of UE1 transmission, send handoff completion message (Relocation Complete) to target SA.

Step 420, target SA sends to ISCF and replys (200OK).

Step 421 after ISCF receives response message, can be judged switching and accomplish, and ISCF responds to target SA and answers acknowledge message (ACK).

Step 422, ISCF sends a notification message (NOTIFY) to source SA, and notification source SA switching is accomplished.

Step 423 after source SA receives notification message, is returned acknowledge message (200OK) to ISCF.

Step 424, link of source SA notification source RNC release signaling and bearing resource.

Can find out that from above-mentioned flow process present embodiment one has solved two problems that exist in the prior art:

1, present embodiment carries out the notification target SA that separately implements in the prior art switching processing and carries out the processing of medium face SDP negotiation with target SA, merges in the INVITE flow process (step 406) to realize, thereby makes switching flow more simplify.

2, the present invention carries out the method that far-end SDP upgrades (step 411) to target SA again through obtaining the SDP (step 410) of UE2 earlier, has evaded the switching concussion problem that exists in the prior art.

Fig. 5 is the flow chart of the changing method of the embodiment of the invention one, has described in UE1 and the UE2 communication process, and is as shown in Figure 5, and the UE1 switching that RNC switches to Target RNC from the source specifically may further comprise the steps:

Step 501, UE sends measurement report (Measurement Report) to source RNC.

Step 502, source RNC judges that according to measurement report UE1 need switch.

Step 503, source RNC sends handoff request (RELOCATION REQUIRED) to source SA.

Step 504, the handoff request that source SA will receive convert call transfer request (REFER) to and send to target SA.The selection of target SA can be according to Target cell and operator's collocation strategy.The address parameter that requires in this request to carry in destination address (Refer-To) header field of contact is the target location district sign (target LAI) that will switch to, and method (method) parameter is HANDOVER.Because HANDOVER does not belong to the standard method title that defines among the method, therefore need expand the method parameter.In addition; The necessary parameter of some other switching of carrying in the handoff request that source SA receives is also placed in and sends to target SA in the REFER message; The mode that these parameters are carried adopts method of the prior art, can expand among the SDP that also can be placed on REFER the XML expansion to the REFER header field and carry.In addition, source SA also is placed on the address of ISCF and sends to target SA among the REFER, and succeeding target SA can find ISCF in view of the above.The address mode of carrying of ISCF can be carried through XML expansion among the SDP of REFER message.

Step 505, target SA accepts message (202Accepted) to source SA callback transfer request after receiving REFER.

Step 506, it is a handoff request that target SA judges this according to the HANDOVER value in the method parameter in the REFER message, so be the switching terminal reserved resource, sends handoff request (RELOCATION REQUEST) to Target RNC afterwards.

Step 507, Target RNC carries out the access network resource reservation procedure, distributes corresponding resource for UE1 inserts 3G network from Target RNC in the future.Target RNC sends switching request response (RELOCATION REQUEST ACK) to target SA afterwards.

Step 508, target SA sends session invitation (INVITE) according to the ISCF address in the REFER message that receives to ISCF, carries the medium surface information of target SA.Also carry among the INVITE simultaneously and switch sign, the method for carrying of switching sign is with step 406.

Step 509; ISCF receives behind the INVITE according to switching sign wherein can know the needs hand-off process of being correlated with; ISCF carries target SA through sip message medium surface information carries out the session negotiation of medium face with UE2; UE2 is updated to the medium surface information of target SA with self distant end media surface information, and self medium surface information is sent to ISCF through sip message.ISCF can obtain the terminal media surface information after the possible renewal of UE2 thus, and follow-up ISCF promptly uses the terminal media surface information of the UE2 after the renewal and target SA to carry out SDP negotiation.

Step 510, ISCF sends response message (200OK) to target SA, carries the terminal media surface information of the UE2 that gets access in the step 509.

Step 511, target SA receives after the response message, and self distant end media surface information is updated to the medium surface information of UE2, responds afterwards and answers acknowledge message (ACK).

Step 512, target SA sends a notification message (NOTIFY) to source SA, and notification source SA switching is ready to complete.

Step 513, source SA returns acknowledge message (200OK) after receiving notice.

Step 514, source SA sends switching command (Relocation Command) to source RNC.

Step 515, source RNC sends switching command to UE1.

Step 516, UE1 switches to Target RNC, and UE1 begins the Radio Resource of access destination RNC.

Step 517, Target RNC detect after the UE1, send to target SA and switch probe message (Relocation Detect).

Step 518, Target RNC receive after the handover success message of UE1 transmission, send handoff completion message (Relocation Complete) to target SA.

Step 519, target SA sends a notification message (NOTIFY) to source SA, and notification source SA switching is accomplished.

Step 520 after source SA receives notification message, is returned acknowledge message (200OK) to target SA.

Step 521, link of source SA notification source RNC release signaling and bearing resource.

Can find out that from above-mentioned flow process present embodiment two has solved two problems that exist in the prior art equally:

1, present embodiment is through directly switching the mode of (step 504) by source SA to target SA notice, omitted in the prior art and to have transmitted the step of switching notice via ISCF, thereby made switching flow more simplify, and reduced the complexity of prior art flow process.

2, present embodiment carries out the method that far-end SDP upgrades (step 510) to target SA again through obtaining the SDP (step 509) of UE2 earlier, has evaded the switching concussion problem that exists in the prior art.

More than, be merely preferred embodiment of the present invention, be not to be used to limit protection scope of the present invention.

Claims (25)

1. a changing method is characterized in that, said method comprises:

After source signaling adaptation device SA receives handoff request, be that to be switched user equipment (UE) is prepared resource through session initiation protocol sip message notification target SA;

Said target SA is that said to be switched UE prepares resource, the carrying between foundation and the said source SA, and notify said source SA switching to be ready to complete;

Said source SA notifies said to be switched UE to switch to objective network.

2. method according to claim 1 is characterized in that, carries the relevant parameter of switching in the said sip message and/or switches sign.

3. method according to claim 2 is characterized in that, carries the relevant parameter of switching in the said sip message and/or switch sign to be specially:

Carry the relevant parameter that switches in the message body of said sip message and/or switch sign.

4. according to claim 2 or 3 described methods; It is characterized in that the relevant parameter of said switching comprises the medium coding/decoding information of the information of switching target small area and target radio network controller RNC, said source SA support and the coding/decoding information that current business adopts.

5. method according to claim 2 is characterized in that, carries the relevant parameter of switching in the said sip message and/or switch sign to be specially:

Carry in the message header of said sip message and switch sign.

6. according to claim 1,2,3 or 5 described methods, it is characterized in that said sip message is a transfer request REFER message, and/or, the calling invitation INVITE.

7. method according to claim 6 is characterized in that, carries in the message header of said sip message to switch to identify to be specially:

For said REFER message, said switching sign is carried in the Route header field or Request-URI header field of said REFER message.

8. method according to claim 6 is characterized in that, source SA is that to be switched UE preparation resource is specially through sip message notification target SA:

It is that to be switched UE prepares resource that said source SA directly notifies said target SA through sip message;

Perhaps, said source SA is through sip message and to notify said target SA through integrated service controlled function entity ISCF be that to be switched UE prepares resource.

9. method according to claim 8 is characterized in that, said source SA is through sip message and to notify said target SA through ISCF be that to be switched UE prepares resource and is specially:

After said source SA receives handoff request, through the said ISCF of REFER message informing; Said ISCF judges and need switch according to the switching in REFER message sign, obtains said target SA address, and to notify said target SA through SIP session invitation INVITE be that to be switched UE prepares resource.

10. method according to claim 8; It is characterized in that; Said source SA is through the said ISCF of REFER message informing; And to notify said target SA by said ISCF through the SIP INVITE be to be switched UE when preparing resource, do not carry the conversation media information with the opposite end UE of said to be switched UE session in the said INVITE.

11. method according to claim 8 is characterized in that, said ISCF obtains said target SA address and is specially:

Said ISCF selects said target SA according to Target cell and operator's collocation strategy;

Perhaps, be carried in the REFER message that sends to said ISCF, notify said ISCF by said source SA select target SA and with the address of said target SA.

12. method according to claim 8 is characterized in that, said method also comprises:

After said target SA receives the switching sip message of said source SA transmission, confirm that according to the sign of the switching in the sip message needs switch, and send handoff request to said Target RNC; After receiving the switching request response of said Target RNC transmission, be current session reserved media face resource, and notify said ISCF;

Said ISCF carries the medium face resource information of said target SA and carries out the negotiation of medium face with the opposite end UE with said to be switched UE session through sip message, making this opposite end UE is the medium face resource of said target SA with the distant end media face resource updates of self.

13. method according to claim 12; It is characterized in that; Said source SA is through the said ISCF of REFER message informing; And to notify said target SA by said ISCF through the SIP INVITE be to be switched user equipment (UE) when preparing resource, and said target SA notifies said ISCF through call progress message 183;

Said source SA is to be switched UE when preparing resource through sip message directly or through said ISCF notification target SA, and said target SA notifies said ISCF through INVITE.

14. method according to claim 8 is characterized in that, said source SA is through sip message and to notify said target SA through ISCF be to be switched UE when preparing resource, and said method also comprises:

After the opposite end UE that accomplishes said target SA and said to be switched UE session accomplished IP carrying foundation, said source SA received to switch and is ready to complete notice, notified said source SA to switch by said ISCF through sip message and was ready to complete.

It is to be switched UE when preparing resource that said source SA directly notifies said target SA through sip message, and said method also comprises:

After the opposite end UE that accomplishes said target SA and said to be switched UE session accomplished IP carrying foundation, said source SA received to switch and is ready to complete notice, notified said source SA to switch by said target SA through sip message and was ready to complete.

15. method according to claim 14 is characterized in that, said method also comprises:

After said target SA receives the handoff completion message of said Target RNC, switch completion through sip message notification source SA.

16. method according to claim 15; It is characterized in that; Said source SA is through sip message and to notify said target SA through ISCF be that to be switched UE is when preparing resource; Said target SA notifies said source SA to switch to accomplish through sip message and is specially: said target SA sends response message 200OK to said ISCF and notifies said ISCF to switch to accomplish, and said ISCF receives after the said 200OK message to the said source SA NOTIFY that sends a notification message and notifies said ISCF to switch to accomplish;

It is to be switched UE when preparing resource that said source SA directly notifies said target SA through sip message, and said target SA notifies said source SA to switch to accomplish through sip message and is specially: said target SA directly sends NOTIFY to said source SA and notifies said source SA to switch to accomplish.

17. a switched system is applied in the wireless communication system, said switched system comprise source SA, source RNC, Target RNC, target SA, to be switched UE and with the UE of to be switched UE session, it is characterized in that:

Source SA is used for after receiving handoff request, is that to be switched UE prepares resource through sip message notification target SA; And, be after said to be switched UE prepares resource, to notify said to be switched UE to switch to objective network at target SA;

Target SA is used to said to be switched UE and prepares resource, the carrying between foundation and the said source SA, and notify said source SA switching to be ready to complete;

18. system according to claim 17 is characterized in that, carries the relevant parameter of switching in the said sip message and/or switches sign.

19. system according to claim 18; It is characterized in that; Carry the relevant parameter that switches in the message body of said sip message and/or switch sign; Wherein, the relevant parameter of said switching comprises the medium coding/decoding information of the information of switching target small area and Target RNC, said source AG support and the coding/decoding information that current business adopts.

20. system according to claim 18 is characterized in that, carries in the message header of said sip message to switch sign.

21., it is characterized in that said sip message is a transfer request REFER message, or the calling invitation INVITE according to each described system of claim 17 to 20; Wherein, carry the switching sign in the message header of said sip message and be specially: for said REFER message, said switching sign is carried in the Route header field or Request-URI header field of said REFER message.

22. system according to claim 17 is characterized in that, it is that to be switched UE prepares resource that said source SA is further used for directly notifying said target SA through sip message;

Perhaps, said source SA is further used for through sip message and to notify said target SA through ISCF be that to be switched UE prepares resource.

23. system according to claim 22 is characterized in that, said source SA is further used for through sip message and to notify said target SA through ISCF be that to be switched UE prepares resource and is specially:

Said source SA is further after receiving handoff request, through the said ISCF of REFER message informing; Said ISCF judges and need switch according to the switching in REFER message sign, obtains said target SA address, and to notify said target SA through SIP session invitation INVITE be that to be switched user equipment (UE) is prepared resource.

24. system according to claim 17; It is characterized in that; Said source SA is further through the said ISCF of REFER message informing; And to notify said target SA by said ISCF through the SIP INVITE be to be switched user equipment (UE) when preparing resource, do not carry the conversation media information with the opposite end UE of said to be switched UE session in the said INVITE.

25. system according to claim 22 is characterized in that, said ISCF further selects said target SA according to Target cell and operator's collocation strategy;

Perhaps, said source SA select target SA, and the address of said target SA is carried in the REFER message that sends to said ISCF, notify said ISCF.

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