CN1406007A - Method for treatment of user's interface while optimizing soft switch-over - Google Patents

Abstract

With the switching decision being carried out for received the tested message reported from UE, the SRNC decides to execute the soft switching so that the new wireless link needs to be added. Thus, the signaling connection is built between the DRNC and the Node B. Then, the direct data carrier is built between SRNC and the Node B so as to shorten the path of the data transmission. The data reaches SRNC through the shortest route and the parameters such as the time delay in the line are optimized. Meanwhile, when the soft switching is carried out, the data in the wireless interface are sent to the SRNC without need of processing of the DRNC so as to simplify the processing flow and optimize the process of the user interface. The invention raises the utilization rate of the system resources and the handling efficiency.

Description

A kind of method that user's face is handled when optimizing soft handover

Technical field

The present invention relates to Wideband Code Division Multiple Access (WCDMA) (WCDMA) mobile communication system, the wireless access network that relates in particular to the WCDMA system is a kind of method that user's face is handled when optimizing soft handover when IP transmits.

Background technology

Universal mobile telecommunications system (UMTS:Universal Mobile TelecommunicationSystems) is to adopt the 3-G (Generation Three mobile communication system) of WCDMA air interface.Usually also the UMTS system is called the WCDMA communication system.The logical network unit of UMTS system can be divided into UMTS grounding wireless access network (UTRAN:UMTS Terrestrial Radio Access Network) and core net (CN:Core Network) on function.Wherein UTRAN is used to handle all and wireless function associated, and all voice calls in the UMTS system are connected with data and the exchange and the route of external network and CN handles.Above-mentioned two network element have constituted whole UMTS system with subscriber terminal equipment (UE:User Equipment), and its system configuration is referring to shown in Figure 1.

UTRAN comprises many RNSs (RNS) that are connected to CN by the Iu interface.A RNS comprises a radio network controller (RNC:Radio Network Control) and one or more wireless base station (Node B).Node B comprises one or more sub-districts, is connected to RNC by Iub interface.RNC is responsible for determining the switching of UE, has merging/separation function, in order to be supported in the grand diversity between the different N ode B.By Iur interactive interfacing information, the Iur interface can be the directly continuous of physics between the RNC or pass through suitable transmission network and realize between RNC.

Handoff procedure is that mobile communication is different from one of notable feature of fixed telecommunication.The switching that WCDMA supports comprises between soft handover, direct-cut operation, forward direction switching and system switches.Soft handover and direct-cut operation mainly are to be initiated by network side, and it mainly is to be initiated by UE that forward direction switches, and switches the situation that existing network side is initiated between system, the situation that has UE to initiate again.The reason that switches comprises moving of UE, resource distribute human intervention etc. rationally.

Soft handover is exactly that communication originally is unaffected, can realize from sub-district taking over seamlessly to another sub-district in the process of switching.In the WCDMA system, because neighbor cell exists with situation frequently, UE can carry out communication by multi wireless links and network, when multi wireless links merges, by relatively choosing one preferably of signal, thereby reach the purpose of optimizing communication quality, have only the FDD standard just can carry out soft handover.Merging that major issue is exactly a multi wireless links in the soft handover, use grand diversity (macro diversity) technology that Radio Link is merged among the WCDMA, according to the certain standard such as the error rate data from the different radio link are compared exactly, choose quality preferably data issue the upper strata.

Difference according to position between the sub-district, soft handover can be divided into following several situation: between the interior different districts of Node B, Radio Link can be in Node B in this case, also can arrive Serving RNC (SRNC:Serving RNC) and carry out grand diversity merging again, if just finished merging in Node B inside, promptly be referred to as More Soft Handoff; Between the different N ode B; Between the different RNCs.

The Iur interface is the interface between RNC, exchange and one or more Iur data flow of the signaling information when supporting between the different RNCs soft handover to take place.Wherein the user face data of Iur stream mainly is the customer traffic that carries out grand diversity when soft handover between RNC takes place UE.Referring to shown in Figure 2, in the present WCDMA system, new data flow when soft handover between RNC takes place UE is shown in the solid line among the figure, the upstream of UE is delivered to through the Node B that roams into and is delivered to SRNC by the Iur interface again behind the Drift Radio Network Controller (DRNC:DriftRNC) and handle, and SRNC delivers to Node B again after the downstream data flow of UE also needs to pass through DRNC by the Iur interface.

Node B1 belongs to active set among the figure, and so-called active set refers to the set of the current sub-district of using of UE, and the execution result of soft handover just shows the increase or the minimizing of sub-district in the active set.Node B2 and Node B3 belong to observe when UE roams into the sub-district of oneself and collect, and are added as active set through beginning after the measuring process by SRNC.Observing collection is the adjacent cell information that UE gives according to UTRAN, observing but the sub-district in active set not, UE measures observing concentrated sub-district, when measurement result meets certain condition, these sub-districts may be added into active set, so be also referred to as Candidate Set sometimes.Wherein the Node B in the active set of DRNC control has one or morely, and for simplicity's sake, the soft handoff procedure of only describing when a Node B is arranged under the DRNC is handled.When having a plurality of Node B under the DRNC in active set, need carry out grand diversity at DRNC and handle, and then deliver to SRNC and carry out grand diversity processing.

Soft switching process between RNC can be divided into following step:

1) the UE measuring control information of giving according to SRNC, to measuring with adjacent cell frequently, measurement result reports SRNC after treatment;

2) SRNC carries out switch decision to the measurement result that reports, and whether decision needs to carry out soft handover;

3) if there is new Radio Link to need to increase behind the switch decision, be ready to resource by DRNC notice NodeB earlier;

4) SRNC is after setting up signaling and connecting between DRNC and the Node B, sets up the Data-carrying of DRNC to the Data-carrying of Node B and DRNC to SRNC simultaneously.By the active set updating message, notice UE increases and/or the deletion Radio Link then;

5) after UE has successfully carried out the active set renewal, under new Node B, increase Radio Link.Delete the sub-district if desired, then notify Node B to discharge corresponding resource.

Referring to shown in Figure 3, SRNC is after receiving the metrical information MEHO that UE reports, and the detailed process that soft handover is initiated in decision is described as follows:

1. the SRNC decision increases a new Radio Link by DRNC, and SRNC sends RNS application protocol (RNSAP) message " Radio Link is set up request " (Radio LinkSetup Request) to DRNC.If article one Radio Link of this to be UE pass through this DRNC, this signaling has been set up a new Iur signaling and has been connected so, and all and this UE RNSAP signaling of being correlated with all will use this Iur signaling to be connected later on.RNSAP is the wireless network layer of Iur interface, is responsible for the Signalling exchange between two RNS.Message parameter comprises: Cellid (sub-district ID), Transport Format Set perDCH (transmission format set of each DCH), Transport Format Combination Set (set of TFS Transport Format Set), frequency (frequency), UL scrambling code (uplink scrambling code).

2. DRNC judges whether the resource of SRNC application can with available, if available, then DRNC sends " Radio Link is set up request " (Radio LinkSetup Request) by B node agreement (NBAP) to Node B.NBAP is the wireless network layer of Iub interface, is responsible for the RNC of RNS inside and the Signalling exchange between the Node B.Message parameter comprises: Cell id (sub-district ID), TransportFormat Set per DCH (transmission format set of each DCH), Transport FormatCombination Set (set of TFS Transport Format Set), frequency (frequency), UL scramblingcode (uplink scrambling code).

Node B begins UL (up link) reception after receiving message.

3. Node B assigns the DRNC requested resource, after the success result is reported DRNC by NBAP message RadioLink Setup Response (Radio Link is set up response).Message parameter comprises: Signailing link termination (signaling link termination), Transport layer addressinginformation (AAL2 address, AAL2 Binding Identitie (s)) for Data TransportBearer (s) (the transport layer address information that bearer context for data transmission is set up), wherein, AAL2 address is the address information of AAL2, and AAL2 Binding Identitie (s) is an AAL2 binding ID of distinguishing each bar link.

4. DRNC sends RNSAP message Radio Link Setup Response (Radio Link is set up response) and sets up message to SRNC response wireless connections.Message parameter comprises: Transport layeraddressing information (AAL2 address, AAL2 Binding Identity) for DataTransport Bearer (s) (the transport layer address information that bearer context for data transmission is set up), Neighbouringcell information (adjacent cells information).

5. SRNC initiates the foundation of Iur/Iub bearer context for data transmission by Access Link Control Application Protocol (ALCAP).This is crossed, and range request comprises the AAL2 binding ID so that bind with the DCH bearer context for data transmission of Iub interface.The foundation of the Data-carrying of each Iur/Iub all will repeat this process.ALCAP (Access Link Control Application Protocol) is the agreement that is used for setting up the data link of ATM.

6./7. Node B sets up synchronously for the relevant Radio Link that has existed with Uplink Synchronisation (uplink synchronisation) by suitable DCH (dedicated channel) the protocol frame Downlink Synchronisation (downlink synchronization) of exchange with SRNC.Node B begins DL (down link) emission then.

8. SRNC carries out active set renewal (increasing by a wireless links) to UE by Dedicated Control Channel (DCCH) transmission Radio Resource control (RRC) message Active Set Update (Radio Link Addition).Message parameter comprises: Update type (updating type), Cell id (sub-district ID), DL scrambling code (descending scrambler), Power control information (power control information), Ncell information (adjacent cells information).

9. UE responds successful information with RRC message Active Set Update Complete (active set upgrades and finishes).

When existing a plurality of Node B to be added into the active set of UE under the DRNC, will repeat above process.

Every of DRNC relevant link carries out delivering to after diversity merges SRNC again and goes to carry out diversity and merge after the link establishment.After switching is finished, when the SRNC decision is moved, send migration request message Relocation Required (migration request) to CN, CN begins to initiate the foundation of the RAB (RAB) between CN and DRNC after receiving migration request, discharge the RAB carrying between CN and SRNC after finishing, DRNC is become SRNC, finish transition process.

By above explanation as seen, because in the existing WCDMA system, terrestrial interface Iu among the UTRAN and Iur/Iub are based on the ATM transmission, be the connection of tight lotus root mould assembly between RNC and the Node B, when causing taking place the switching between RNC, simple without comparison connected mode between SRNC and the new Node B, data transfer path is subjected to the restriction of network actual conditions, than difficulty directly from Node B to SRNC, transfer of data between SRNC and the Node B needs DRNC to participate in handling, and has increased the time delay that data transmit between SRNC and Node B.Simultaneously, the Frame of wave point can only be delivered to SRNC and carry out processing such as grand diversity again after DRNC is through processing and grand diversity, and DRNC and SRNC have part work to repeat, and system resource is not utilized effectively.

Summary of the invention

Because the plurality of advantages of IP and the impact of global ip tide will be introduced the IP network transmission among the UTRAN of WCDMA system.After introducing the IP network transmission, network configuration originally will have greatly changed, and will be the connection of an IP transmission network between RNC and the Node B, and the physical connection mode of Iur interface will be than flexible more and convenient originally.Fig. 4 has shown the network configuration of the UTRAN behind the introducing IP transmission network.

The method that user's face was handled when purpose of the present invention was based on soft handover between the optimization RNC of IP transmission with regard to the wireless access network that is to provide a kind of WCDMA system.

A kind of method that user's face is handled when being applied to wireless access network based on the optimization soft handover of the WCDMA system of IP transmission provided by the invention may further comprise the steps at least:

When SRNC carries out switch decision to the measurement message that the UE that receives reports, determine to carry out soft handover, when needing to increase new Radio Link, at first the signaling between foundation and DRNC and the Node B connects;

After signaling connects foundation, set up the immediate data carrying of SRNC to Node B.

Further, the described signaling of setting up between DRNC and Node B connects and may further comprise the steps at least:

SRNC sends RNSAP message " Radio Link is set up request " to DRNC, message parameter increases message parameter " the IP address of SRNC ", " the local terminal udp port that SRNC distributes number " and " qos parameter of this link " except that comprising " sub-district ID ", " transmission format set of each DCH ", " set of TFS Transport Format Set ", " frequency ", " uplink scrambling code ";

DRNC judges whether the resource of SRNC application is available, as available, then send NBAP message " Radio Link is set up request " to Node B, message parameter increases message parameter " the IP address of SRNC ", " the local terminal udp port that SRNC distributes number " and " qos parameter of this link " except that comprising " sub-district ID ", " transmission format set of each DCH ", " set of TFS Transport Format Set ", " frequency ", " uplink scrambling code ";

The beginning up link received after Node B received message, and appointment DRNC requested resource, after the success result is reported DRNC by NBAP message " Radio Link is set up response ", message parameter comprises " signaling link termination ", " bearer context for data transmission set up transport layer address information ", and wherein " the transport layer address information that bearer context for data transmission is set up " comprises " the IP address of Node B " and be the sign ID that distinguishes each bar link " the local terminal udp port that Node B distributes number ";

DRNC sends RNSAP message " Radio Link is set up response ", set up request message to SRNC response Radio Link, message parameter comprises " bearer context for data transmission set up transport layer address information ", " adjacent cells information ", and wherein " the transport layer address information that bearer context for data transmission is set up " comprises " the IP address of NodeB " and be the sign ID that distinguishes each bar link " the local terminal udp port that Node B distributes number ".

Further, described signaling connects and directly sets up SRNC after setting up and comprise step at least to the Data-carrying of Node B:

After SRNC receives the RNSAP message " Radio Link is set up response " of the response Radio Link foundation request that DRNC sends, set up corresponding data wireless links carrying, its parameter and Node B submitted IP address and udp port number are associated, and comprising: destination address is the port numbers that the udp port number of Node B submitted IP address, data wireless links reports for Node B.

Owing to introduced the IP network transmission at the UTRAN of WCDMA system, be that a dynamic IP network connects between RNC and the Node B, addressing system is simple, therefore, the present invention adopts the stretch footpath, and the data that wave point sends and receives during with soft handover are directly delivered to SRNC from the Node B that roams into, and satisfy the shortest principle in path, improve the parameters such as time delay index of grand diversity data, optimized network performance.

Description of drawings

Fig. 1 is the system configuration signal of UMTS.

Fig. 2 is the path signal during soft handover between the RNC of prior art.

Fig. 3 is the flow process signal of soft handover between the RNC of prior art.

Fig. 4 is the network configuration signal of the UTRAN of the WCDMA of introducing IP transmission network.

Fig. 5 is the signal of the path during soft handover between RNC of the present invention.

Fig. 6 is the flow process signal of soft handover between RNC of the present invention.

Embodiment

Below in conjunction with drawings and the specific embodiments the present invention is described in more detail.

The present invention utilizes the IP technology, when the soft handover between generation RNC need be set up new data wireless links carrying, by RNSAP Signalling exchange between SRNC and DRNC and the NBAP Signalling exchange between DRNC and NodeB, between SRNC and new Node B, set up data link, send or receive the air interface radio frames.Wherein DRNC still participates in the signaling connection, and plays function served as bridge between Node B and SRNC, tells the other side with both IP addresses.Compared with prior art, the original data channel by the transmission of Iur interface is become newly-increased direct data channel between Node B and SRNC.Signalling exchange is still at original Iur interface.The conversion in the path that relates among the present invention, the UTRAN network for having introduced after the IP transmission only means the change of route table items, the difficulty of realization is very little.

Referring to shown in Figure 5, shown under the IP transmission situation, the path signal when soft handover between different RNCs takes place, wherein dotted line is represented existing path (already present path before switching), path from the Node B that roams into to SRNC when solid line is represented to switch, chain-dotted line represents to have only signalling path.The process of soft handover can be divided into following step between the RNC after application the inventive method:

1) the UE measuring control information of giving according to SRNC, to measuring with adjacent cell frequently, measurement result reports SRNC after treatment;

2) SRNC carries out switch decision to the measurement result that reports, and whether decision needs to carry out soft handover;

3) if there is new Radio Link to need to increase behind the switch decision, be ready to resource by DRNC notice NodeB earlier;

4) SRNC sets up the immediate data carrying of SRNC to NodeB after setting up the signaling connection between DRNC and the Node B.By the active set updating message, notice UE increases and/or the deletion Radio Link then;

5) after UE has successfully carried out the active set renewal, under new Node B, increase Radio Link.Delete the sub-district if desired, then notify NODEB to discharge corresponding resource.

Referring to shown in Figure 6, SRNC is after receiving the metrical information MEHO that UE reports, and the detailed process that soft handover is initiated in decision is described as follows:

1. the SRNC decision increases a new Radio Link by DRNC, and SRNC sends RNSAP message Radio Link Setup Request (Radio Link is set up request) to DRNC.If article one Radio Link of this to be UE pass through this DRNC, this message has been set up a new Iur signaling and has been connected so, and all and this UE RNSAP message of being correlated with all will use this Iur signaling to be connected later on.Message parameter is except that comprising: Cell id (sub-district ID), Transport Format Set per DCH (transmission format set of each DCH), Transport Format Combination Set (set of TFS Transport Format Set), frequency (frequency), the UL scrambling code (uplink scrambling code), increase SRNC IP Address (the IP address of SRNC), UDP Port Number (s) (the local terminal udp port that SRNC distributes number) and QoS parameter (qos parameter of this link).

2. DRNC judges whether the resource of SRNC application can be used, if available, then DRNC sends Radio Link Setup Request (Radio Link is set up request) by NBAP to Node B.Message parameter is except that comprising: Cell id (sub-district ID), Transport Format Set per DCH (transmission format set of each DCH), Transport Format Combination Set (set of TFS Transport Format Set), frequency (frequency), the UL scrambling code (uplink scrambling code), increase SRNC IP Address (the IP address of SRNC), UDP Port Number (s) (the local terminal udp port that SRNC distributes number) and QoS parameter (qos parameter of this link).

Beginning UL received after Node B received message.

3. Node B assigns the DRNC requested resource, and the destination slogan that the destination address of this link is IP address, this link of SRNC is udp port that SRNC distributes number, and the QoS grade is the qos parameter that SRNC transmits.After setting up successfully the result is reported DRNC by NBAP message Radio Link SetupResponse (Radio Link is set up response).Message parameter comprises: Signalling linktermination (signaling link termination), Transport layer addressing information (Node BIP Address, UDP Port Number (s)) for Data Transport Bearer (s) (the transport layer address information that bearer context for data transmission is set up).Wherein, Node B IP Address is the IP address of Node B, and UDP Port Number (s) is the sign ID that distinguishes each bar link.

4. DRNC sends RNSAP message Radio Link Setup Response (Radio Link is set up response) and sets up message to SRNC response wireless connections.Message parameter comprises: Transport layeraddressing information (Node B IP Address, UDP Port Number (s)) for DataTransport Bearer (s) (the transport layer address information that bearer context for data transmission is set up), Neighbouringcell information (adjacent cells information).

5. SRNC sets up corresponding Radio Link carrying after receiving response, its parameter and Node B submitted IP address and udp port number are associated: destination address is a Node B submitted IP address, the port numbers that the udp port of data wireless links number reports for Node B.This is crossed range request and comprises udp port number so that bind with the DCH bearer context for data transmission of Iub interface.Each port numbers is corresponding to each Radio Link.

6./7. Node B sets up synchronously for the relevant Radio Link that has existed with Uplink Synchronisation (uplink synchronisation) by suitable DCH (dedicated channel) the protocol frame Downlink Synchronisation (downlink synchronization) of exchange with SRNC.Node B begins DL (down link) emission then.

8. SRNC carries out active set renewal (increasing by a wireless links) to UE by DCCH transmission RRC message Active Set Update (Radio LinkAddition).Message parameter comprises: Update type (updating type), Cellid (sub-district ID), DL scrambling code (descending scrambler), Power control information (power control information), Ncell information (adjacent cells information).

9. UE responds successful information with RRC message Active Set Update Complete (cell update is finished).

When existing a plurality of Node B to be added into the active set of UE under the DRNC, will repeat above process.

After the link establishment, every relevant link of DRNC carries out delivering to after diversity merges SRNC again and goes to carry out the diversity merging.After switching is finished, when the SRNC decision is moved, send migration request message Relocation Required (migration request) to CN, CN begins to initiate the foundation of the RAB (RAB) between CN and DRNC after receiving migration request, discharge the RAB carrying between CN and SRNC after finishing, DRNC is become SRNC, finish transition process.

In the transition process after switching is finished, consider that Node B need rebulid to the link of DRNC, compare, increased the Signalling exchange of Node B with original transition process.But consider that from the main-process stream that switches and move this part work just changes its switching from prior art into migration in earlier stage to be carried out early stage, the workload of whole flow process does not have to be increased.When using migration of the present invention simultaneously, be the foundation of carrying out the RAB carrying between the Node B of CN-DRNC-roaming earlier, discharge the RAB carrying between the Node B of CN-SRNC-roaming after finishing again, indexs such as stability when having guaranteed effectively to switch are so that advantage of the present invention remains is very significant.Moreover, transition process compared with prior art, though increased the Signalling exchange of Node B, considering has just increased several signalings, and optimized the processing of user's face mass data stream, beneficial effect still is a highly significant.

In sum, adopt the inventive method, when soft handover takes place in the WCDMA wireless access network between RNC when, between Node B that roams into and SRNC, set up a direct channel, be that Node B--DRNC--SRNC is two sections paths altogether from the path that the Node B that roams into delivers to SRNC compared to existing technology, shortened the path of transfer of data, thereby can allow data arrive SRNC, optimized the parameters such as time delay on the circuit with the shortest path.Simultaneously, the data of wave point not be used in when soft handover delivers to SRNC after DRNC handles again, the handling processes such as grand diversity of DRNC have been simplified, give SRNC with all grand diversity operation unifications, the processing of user's face when having optimized soft handover between RNC has improved the resource utilization and the treatment effeciency of system effectively.

Claims (3)

1, a kind of method that user's face is handled when being applied to wireless access network based on the optimization soft handover of the WCDMA system of IP transmission is characterized in that this method may further comprise the steps at least:

When SRNC carries out switch decision to the measurement message that the UE that receives reports, determine to carry out soft handover, when needing to increase new Radio Link, at first the signaling between foundation and DRNC and the Node B connects;

After signaling connects foundation, set up the immediate data carrying of SRNC to Node B.

2, the method that user's face is handled during optimization soft handover according to claim 1 is characterized in that the described signaling of setting up connects and may further comprise the steps at least between DRNC and Node B:

SRNC sends RNSAP message " Radio Link is set up request " to DRNC, message parameter increases message parameter " the IP address of SRNC ", " the local terminal udp port that SRNC distributes number " and " qos parameter of this link " except that comprising " sub-district ID ", " transmission format set of each DCH ", " set of TFS Transport Format Set ", " frequency ", " uplink scrambling code ";

DRNC judges whether the resource of SRNC application is available, as available, then send NBAP message " Radio Link is set up request " to Node B, message parameter increases message parameter " the IP address of SRNC ", " the local terminal udp port that SRNC distributes number " and " qos parameter of this link " except that comprising " sub-district ID ", " transmission format set of each DCH ", " set of TFS Transport Format Set ", " frequency ", " uplink scrambling code ";

The beginning up link received after Node B received message, and appointment DRNC requested resource, after the success result is reported DRNC by NBAP message " Radio Link is set up response ", message parameter comprises " signaling link termination ", " bearer context for data transmission set up transport layer address information ", and wherein " the transport layer address information that bearer context for data transmission is set up " comprises " the IP address of Node B " and " the local terminal udp port of Node B distribution number ";

DRNC sends RNSAP message " Radio Link is set up response ", set up request message to SRNC response Radio Link, message parameter comprises " bearer context for data transmission set up transport layer address information ", " adjacent cells information ", and wherein " the transport layer address information that bearer context for data transmission is set up " comprises " the IP address of NodeB " and " the local terminal udp port of Node B distribution number ".

3, the method that user's face is handled during optimization soft handover according to claim 2 is characterized in that described signaling connects directly to set up SRNC after setting up and comprise step at least to the Data-carrying of Node B:

After SRNC receives the RNSAP message " Radio Link is set up response " of the response Radio Link foundation request that DRNC sends, set up corresponding data wireless links carrying, its parameter and Node B submitted IP address and udp port number are associated, and comprising: destination address is the port numbers that the udp port number of Node B submitted IP address, data wireless links reports for Node B.

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