CN1223122C

CN1223122C - Method of soft switching in WCDMA network

Info

Publication number: CN1223122C
Application number: CNB021317747A
Authority: CN
Inventors: 高全中
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2002-09-23
Filing date: 2002-09-23
Publication date: 2005-10-12
Anticipated expiration: 2022-09-23
Also published as: CN1486003A

Abstract

The present invention provides a soft switch method in a wideband code division multiple access network, which is suitable for the conditions that DRNC uses an ATM transmission technique, and SRNC and Node B both use an IP transmission techniques. The method of the present invention can overcome the problems that excessive nodes on a path of a service flow influences the utilization rate of bandwidth of an IP network when user equipment is mutually communicated with a network, and service is interrupted because of service delay in the prior art. The soft switch method of the present invention comprises the following steps that IP SRNC transmits a wireless link establishment request to ATM DRNC; the ATM DRNC transmits a wireless link establishment request to IP Node B which transmits a wireless link establishment response to the IP DRNC; the ATM DRNC transmits a wireless link establishment response to the IP SRNC; the IP SRNC and the IP Node B establish direct transmission load bearing; the IP SRNC transmits update messages of an active set to user equipment which transmits the update messages of the active set to the IP SRNC.

Description

Soft handover method in the WCDMA network

Technical field

The present invention relates to the soft handover method in the communication system, relate in particular to WCDMA (Wideband CodeDivision Multiple Access, Wideband Code Division Multiple Access (WCDMA)) in the wireless access network, DRNC (Drift Radio network Controller based on different editions, floating radio network controller), the soft handover between SRNC (Serving Radionetwork Controller, service wireless network controller) and the Node B (wireless base station of WCDMA network).

Background technology

At present, 3GPP (The 3rd Generation Partnership Project, third generation partnership project) has two class versions: R99 version and ROO version wherein also comprise R4 and R5 version in the ROO version.The transmission technology of the R4 version wireless access network side in R99 version and the ROO version is based on ATM's, and the transmission technology of R5 version wireless access network side is then based on IP.Because some advantages of IP transmission technology will more and more substitute the ATM transmission technology after estimating.Therefore produced a new problem, that is, the how intercommunication of ATM node and IP node.

Simultaneously, because it is more frequent that soft handover takes place between RNC (Radio Network Controller, radio network controller) in the 3G network, each RNC has reserved more resource for the soft handover service.The soft handover number of times is more, causes the decline of communication quality easily, and especially in the edge zone that RNC covers, frequent the moving of subscriber equipment often causes frequent switching between two RNC.Compare with soft handover in the RNC, need SRNC, Node B and DRNC to handle jointly during soft handover between RNC, cause expense huge.Therefore press for now and can promptly under the environment that IP and ATM transmission technology are used with, carry out the solution of the soft handover between RNC well in different transmission technologys.

Introduce in the prior art related content and method below based on soft handover between the RNC of different transmission technologys.Introduce in the soft handover Same of Important earlier about adjacent cell:

Active set refers to the set of the current sub-district of using of subscriber equipment, and the execution result of soft handover just shows that the sub-district increases or reduces in the active set.

Observe collection, subscriber equipment is according to UTRAN (Universal Mobile telecommunicationsSystem, the adjacent cell information of universal mobile telecommunications system) giving, observing but the sub-district in active set not, subscriber equipment is measured observing concentrated sub-district, when measurement result met certain condition, these sub-districts may be added into active set, so be also referred to as Candidate Set sometimes.

Detected set, subscriber equipment detects, does not also belong to the sub-district of observing collection but neither belong to active set, and UTRAN can require subscriber equipment to report the measurement result of detected set; Because they do not belong to neighbor cell list, so be referred to as unlisted collection sometimes yet.

In the prior art, the soft switching process between the RNC can be divided into several steps:

1) the subscriber equipment 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, SRNC passes through SGW, send RNSAP (Radio Network Subsystem Application Part, Radio Network Subsystem Application Part) message to DRNC, notify Node B to be ready to resource thus;

4) set up signaling between DRNC and the Node B and connect after, SRNC sets up Data-carrying with DRNC earlier, sets up Data-carrying with Node B then.By the active set updating message, notifying user equipment increases and/or the deletion Radio Link then;

5) after subscriber equipment 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.

At this moment, if SRNC is different with Node B transmission means, wherein, DRNC is the IP transmission means, then as shown in Figure 1, needs on the transmission path to carry out the conversion of user's face, flow process more complicated through intercommunication IWU (Interworking Unit, interworking unit) and DRNC.Therefore there is following shortcoming:

1. the node on the path of Business Stream is too much during intercommunication, influences the bandwidth availability ratio of IP network;

2. increase traffic delay may cause service disconnection, for operator brings adverse effect.

Summary of the invention

The object of the invention is at the problems referred to above, proposes a kind of new soft handover method, be applicable to that DRNC adopts the ATM transmission technology, and SRNC and Node B adopts the situation of IP transmission technology.

In addition, it is not high that this method can overcome the bandwidth availability ratio that too much causes owing to the node on the transmission path in the prior art, and because traffic delay might cause the problem of service disconnection.

Soft handover method in the WCDMA network provided by the invention comprises following steps: step 1:IPSRNC (service wireless network controller) sends Radio Link by IWU to ATM DRNC and sets up request; The resource information that comprises in the described request message of step 2:ATM DRNC to IP SRNC is judged, but when the time spent, ATM DRNC is by NBAP (Node B Application Part, Node B applying portion) sends Radio Link to IP NodeB and set up request, comprise following parameter: the IP address of IP service wireless network controller, the udp port of IP service wireless network controller number; Step 3:IP Node B assigns ATM DRNC to set up resource needed in the request at above-mentioned Radio Link, sends Radio Link to IP DRNC after finishing and sets up response; Step 4:ATM DRNC sends Radio Link to IP SRNC and sets up response, comprises following parameter: the IP address of IP wireless base station and udp port number; Step 5:IP SRNC and IP Node B set up direct transmission bearer without atm network; Step 6 and step 7:IP Node B and IP SRNC set up synchronously for the Radio Link of being set up in above-mentioned steps; Step 8:IP SRNC sends the message that active set upgrades to subscriber equipment; Step 9: subscriber equipment sends active set to IP SRNC and upgrades the message of finishing.

In the present invention, the described Radio Link in the step 1 is set up and is comprised following resource information in the request message: the local terminal udp port that the IP address of the transmission format set of sub-district ID, each DCH, the set of TFS Transport Format Set, frequency, uplink scrambling code, SRNC, SRNC are distributed number.

In the present invention, the described Radio Link in the step 3 is set up and is comprised following parameter in the response message: the IP address of IPNode B and udp port number.

According to soft handover method of the present invention,, guaranteed the broadband utilance of IP network owing to the node on the path of having reduced interworking service stream.Simultaneously, because path contraction has reduced traffic delay, thereby has avoided causing the factor of service disconnection.

Summary of drawings

Fig. 1 is the soft handover path schematic diagram under IP SRNC and the IP Node B condition in the prior art;

Fig. 2 is the soft handover path schematic diagram under IP SRNC and the IP Node B condition among the present invention;

Fig. 3 is the soft handoff procedure figure under IP SRNC and the IP Node B condition among the present invention.

Specific embodiment

Fig. 2 illustrates among the present invention to be proposed, the direct transmission bearer path under ATM DRNC, IP SRNC and IP Node B condition.

According to the transmission path shown in Fig. 2, as can be seen, the present invention is after realizing directly transmission, transmission path obtains very big optimization, the intermediate node number reduces over half, adds the processing delay of low speed chain circuit processing and IWU, also should be considerable to the optimization of time delay.

Specify the process of the direct transmission method of the present invention's proposition below.

Step 1:IP SRNC sends Radio Link by IWU to ATM DRNC and sets up request, has for example comprised in this message: parameters such as the local terminal udp port that the IP address of the transmission format set of sub-district ID, each DCH, the set of TFS Transport Format Set, frequency, uplink scrambling code, SRNC, SRNC distribute number.

Between subscriber equipment and ATM DRNC, increase by a new Radio Link thus.If this is article one Radio Link of setting up between the two, a new Iur signaling connection has been set up in the request of setting up of this Radio Link so, and all will use this Iur signaling to be connected with the relevant RNSAP signalings of this subscriber equipment later on.

The resource information that comprises in the request message of step 2:ATM DRNC to IP SRNC is judged, determines whether it is available.If available, then ATM DRNC sends Radio Link by NBAP (Node B Application Part, Node B applying portion) to IP Node B and sets up request.In this request, for example comprise: parameters such as the local terminal udp port that the IP address of the transmission format set of sub-district ID, each DCH, the set of TFS Transport Format Set, frequency, uplink scrambling code, SRNC, SRNC are distributed number.

In the present embodiment, because ATM DRNC knows that IP Node B is the IP node, so when transmission message, carry the IP address of IP SRNC and udp port number.

Step 3:IP Node B assigns ATM DRNC to set up resource needed in the request at above-mentioned Radio Link, sends Radio Link to IP DRNC after finishing and sets up response.Except the IP address that comprises IP Node B oneself and the udp port number, also comprise parameters such as for example signaling link termination in this message.

Step 4:ATM DRNC sends Radio Link to IP SRNC and sets up response.The IP address that has comprised Node B in this message, and its udp port number also have adjacent cell information etc. in addition.

After step 5:IP SRNC receives that Radio Link is set up response,, obtain the IP address of IP Node B and udp port thereof number, set up the Radio Link carrying with IP Node B by RNSAP message.Thereby between IP SRNC and IPNode B, set up direct transmission bearer.

Step 6 and step 7:IP Node B and IP SRNC are by exchange suitable dedicated channel protocol frame " downlink synchronization " and " uplink synchronisation ", for the Radio Link of being set up in above-mentioned steps is set up synchronously.Begin downlink transmission by IP Node B immediately.Need to prove, if can't set up above-mentioned synchronously, the expression purpose is unreachable to.In this case, SRNC can select to resend with the carrying of DRNC and set up.

Because in the present embodiment, SRNC knows that DRNC is the ATM node, sets up in the request not IP address and udp port number with oneself so can be chosen in Radio Link, to adapt to the ATM mode.

In above-mentioned situation, DRNC can't adopt direct transmission bearer to set up, will be by the mode of using at present, and the transmission bearer of Iur interface and Iub interface is set up in segmentation.Because this belongs to the prior art part, in this specification

Step 8:IP SRNC and IP Node B send the message that active set upgrades to subscriber equipment after having set up synchronously, promptly require to increase a wireless links to subscriber equipment.

Step 9: subscriber equipment sends active set to SRNC and upgrades the message of finishing.

Need to prove,, will repeat above process if when ATM DRNC down exists a plurality of IP Node B to be added into the active set of subscriber equipment.

When IP SRNC decision migration, send migration request message to core net (CN).After CN receives this message, initiate the foundation of the RAB between CN and the ATM DRNC, the transmission bearer between IP DRNC initiation simultaneously and the IP NodeB.After finishing above-mentioned two carryings, original core net and IP SRNC, and the radio bearer between IP SRNC and the IP Node B will be released.Thereby ATM DRNC becomes ATM SRNC, finishes transition process.

Processing and signaling process that the present invention has optimized existing DRNC come, and have realized that DRNC and SRNC and Node B set up direct transmission bearer when not being the identical traffic mode.

Claims

1. the soft handover method in the WCDMA network is characterized in that comprising following steps:

Step 1:IP service wireless network controller sends Radio Link by interworking unit to the ATM floating radio network controller and sets up request;

The resource information that comprises in the described request message of step 2:ATM floating radio network controller to the IP service wireless network controller is judged, but when the time spent, the ATM floating radio network controller sends Radio Link by wireless base station applications part to the IP wireless base station and sets up request, comprises following parameter: the IP address of IP service wireless network controller, the udp port of IP service wireless network controller number;

Step 3:IP wireless base station assigns the ATM floating radio network controller to set up resource needed in the request at above-mentioned Radio Link, sends Radio Link to the IP floating radio network controller after finishing and sets up response;

Step 4:ATM floating radio network controller sends Radio Link to the IP service wireless network controller and sets up response, comprises following parameter: the IP address of IP wireless base station and udp port number;

Direct transmission bearer is set up without atm network in step 5:IP service wireless network controller and IP wireless base station;

Step 6 and step 7:IP wireless base station and IP service wireless network controller are set up synchronously for the Radio Link of being set up in above-mentioned steps;

Step 8:IP service wireless network controller sends the message that active set upgrades to subscriber equipment;

Step 9: subscriber equipment sends active set to the IP service wireless network controller and upgrades the message of finishing.

2. the changing method in the WCDMA network as claimed in claim 1, it is characterized in that the described Radio Link in step 1 is set up and comprised following resource information in the request message: the local terminal udp port that the IP address of the transmission format set of sub-district ID, each designated lane, the set of TFS Transport Format Set, frequency, uplink scrambling code, service wireless network controller, service wireless network controller are distributed number.

3. the changing method in the WCDMA network as claimed in claim 1 is characterized in that, the described Radio Link in step 3 is set up and comprised following parameter in the response message: the IP address of IP wireless base station and udp port number.