CN100428840C

CN100428840C - Soft switching method of broadband CDMA network

Info

Publication number: CN100428840C
Application number: CNB2004100853369A
Authority: CN
Inventors: 高全中
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2004-10-11
Filing date: 2004-10-11
Publication date: 2008-10-22
Anticipated expiration: 2024-10-11
Also published as: CN1761358A

Abstract

The present invention provides a soft switching method of a wideband code division multiple access network, which is applicable to the situation that a DRNC adopts an IP transmission technique while an SRNC and a Node B adopt different transmission techniques. Compared with the prior art, the method in the present invention can overcome problems that the wideband utilization ratio of an IP network is affected because too many nodes are on the path of service flow when user devices intercommunicate with networks, and service is interrupted because of service delay. The soft switching method in the present invention comprises the following steps: an ATM SRNC sends a request for building wireless link to an IP DRNC; the IP DRNC sends a request for building wireless link to an IP Node B; the wireless link building response of the IP Node B is sent to the IP DRNC; the IP DRNC sends a response message of building wireless link to the ATM SRNC; the ATM SRNC and the IP Node B build wireless link bearing; the IP Node B and the ATM SRNC build a synchronization for the wireless link existed between the IP Node B and the ATM SRNC; the ATM DRNC sends a message for controlling wireless resource to a user device to update an active set; the user device sends a massage of completing the update of a district to the ATM 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 Radio network 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 R00 version wherein also comprise R4 and R5 version in the R00 version.The transmission technology of the R4 version wireless access network side in R99 version and the R00 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 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.

Because directly the major control functional unit of transmission is DRNC, and only version support after R5, so the situation when only considering here that DRNC is the IP transmission means.

The situation that SRNC-Node B in the cards directly transmits in the time of can telling intercommunication according to Fig. 1, and each self-corresponding transmission path.Wherein, be the IP node according to DRNC, DRNC is respectively that ATM and two kinds of situations of IP are considered.

Under the environment of IR SRNC and ATM Node B, needs successively pass through with lower node: IP SRNC, Edge Router, IP network, Edge Router, IP DRNC, Edge Router, IP network, atm network, and ATM Node B.

Under the environment of ATM SRNC and IP Node B, needs successively pass through with lower node: ATM SRNC, atm network, IWU, IP network, Edge Router, IP DRNC, Edge Router, IP network/EdgeRouter, and IP Node B.

This shows the transmission path more complicated of existing network.Total node number is 8 on the transmission path.

There is shortcoming in above-mentioned prior art:

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, is applicable to that DRNC adopts the IP transmission technology, and SRNC and Node B adopt the situation of different mutually transmission technologys.

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:IP SRNC sends Radio Link to IP DRNC and sets up request by SGW; Step 2:IP DRNC sets up the resource information that comprises in the request message to the Radio Link of IP SRNC and judges, determines whether availablely, if available, then IP DRNC sends Radio Link to ATM Node B and sets up request; Step 3:ATM Node B reports Radio Link to set up response message, and notice IP DRNC has set up success; Step 4:IP DRNC sends Radio Link to IP SRNC and sets up response; Step 5:IP SRNC and ATM NodeB set up the Radio Link carrying; Step 6 and step 7:ATM Node B and IP SRNC set up synchronously for the relevant link that has existed; Step 8:IP SRNC sends the active set updating message to subscriber equipment; Step 9: subscriber equipment sends cell update to IP SRNC and finishes message.

In such scheme, described Radio Link in the step 1 is set up request message and is comprised following resource information: 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, IP SRNC, and the local terminal udp port that distributes of IP SRNC number.

In such scheme, the described Radio Link request of setting up in the step 2 comprises following parameter: the transmission format set of sub-district ID, each DCH, the set of TFS Transport Format Set, frequency and uplink scrambling code.

In such scheme, described Radio Link in the step 3 is set up and is comprised following parameter in the response message: the transport layer address information that signaling link is ended, bearer context for data transmission is set up, comprise ATM Node B transport layer address in the described transport layer address information, and binding ID.

In such scheme, comprise the transport layer address information in the described response message in the step 4.

The present invention also provides the soft handover method in a kind of WCDMA network, comprises following steps: step 1:ATM SRNC sends Radio Link by SGW to IP DRNC and sets up request; Step 2:IP DRNC sets up the resource information that comprises in the request message to the Radio Link of ATM SRNC and judges, if determine it is available, then IP DRNC sends Radio Link to IP Node B and sets up request; Step 3:IP Node B Radio Link is set up response and is sent to IP DRNC; Step 4:IP DRNC sends Radio Link to ATM SRNC and sets up response message; Step 5:ATM SRNC and IP Node B set up the Radio Link carrying; Step 6 and 7:IP Node B and ATM SRNC set up synchronously for the Radio Link that has existed between them; Step 8:ATM SRNC sends radio resource control information to subscriber equipment and carries out the active set renewal; Step 9: subscriber equipment sends cell update to ATM SRNC and finishes message.

In such scheme, comprise following resource information in the request message in the step 1: parameters such as the transmission format set of sub-district ID, each DCH, the set of TFS Transport Format Set, frequency and uplink scrambling code.

In such scheme, comprise following parameter in the described request message in the step 2: parameters such as the transmission format set of sub-district ID, each DCH, the set of TFS Transport Format Set, frequency, uplink scrambling code.

In such scheme, the described Radio Link in the step 3 is set up and is comprised following parameter in the response message: transport layer address and binding ID on IP Node B correspondence and the IWU.

In such scheme, described Radio Link in the step 4 is set up and is comprised following parameter in the response message: parameters such as transport layer address information, adjacent cell message, wherein, the transport layer address information comprises the AAL2 address that IP NodeB reports, and data link carrying AAL2 binding ID.

Description of drawings

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

Fig. 2 is SRNC of the present invention and Node B soft handover path schematic diagram;

Fig. 3 is IP SRNC of the present invention and the soft handoff procedure figure of ATM Node B under IP DRNC condition;

Embodiment

Fig. 2 illustrates among the present invention, adopts the direct transmission bearer path of the SRNC and the Node B of different transmission technologys.Wherein, solid line and the respectively corresponding two kinds of different situations of dotted line, the path when wherein solid line is IP SRNC and ATM Node B, the path when dotted line is ATM SRNC and IP Node B.

According to the transmission path shown in Fig. 2, as can be seen, the present invention is after realizing directly transmission, and transmission path obtains very big optimization.Be embodied in, under the condition of IP DRNC, when SRNC is the IP transmission mode, and Node B is when being the ATM transmission mode, on the transmission path successively through with lower node: IP SRNC, Edge Router, IP network, IWU, atm network, and ATM Node B; When SRNC is the ATM transmission mode, and Node B is when being the IP transmission mode, on the transmission path successively through with lower node: ATM SRNC, atm network/IWU, IP network, Edge Router, and IP Node B.

This shows that behind the direct transmission method that carries out the present invention's proposition, the path has been optimized than originally a lot, 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.

Below again under the IP DRNC condition, IP SRNC and ATM Node B, and the soft switching process of ATM SRNC and two kinds of situations of IP Node B is described.

1.IP SRNC and ATM Node B

Fig. 3 has described IP SRNC after receiving the metrical information MEHO at ATM Node B of user equipment to report (Mobile evaluated handover, the travelling carriage estimated value is switched), initiates the flow process of soft handover.

Step 1:IP SRNC sends Radio Link to IP DRNC and sets up request by SGW, increases a new Radio Link.Set up in the request at this Radio Link, comprise for example sub-district ID, each DCH (Dedicated Channel, designated lane) the IP address of transmission format set, the set of TFS Transport Format Set, frequency, uplink scrambling code, IP SRNC, and parameter such as the local terminal udp port that distributes of IP SRNC number.

Step 2:IP DRNC sets up the resource information that comprises in the request message to the Radio Link of IP SRNC and judges, determine whether available, if it is available, then IP DRNC sends Radio Link by NBAP (Radio NetworkSubsystem Application Part, Radio Network Subsystem Application Part) to ATM Node B and sets up request.For example comprise in this request: parameters such as the transmission format set of sub-district ID, each DCH, the set of TFS Transport Format Set, frequency and uplink scrambling code.

Need to prove, the IP address of IP SRNC herein and udp port number are not forwarded to ATM Node B by DRNC, need IP SRNC to give IWU together with the E.164 address of ATM Node B and binding ID by the ERQ (Establish Request sets up request) of SRNC by IP ALCAP when setting up at the IP of back ALCAP (Access Link Control Application Protocol).

Step 3:ATM Node B assigns the resource that comprises in the IP DRNC request, reports Radio Link to set up response message to IP DRNC after finishing, and notice IP DRNC has set up success.Wherein, Radio Link is set up and is for example comprised in the response message: the parameters such as transport layer address information that signaling link is ended, bearer context for data transmission is set up.Need illustrate, in the transport layer address information, comprise for example ATM Node B transport layer address, i.e. the sign ID of each bar link is promptly distinguished in the AAL2 address of ATM Node B, and binding ID.

Step 4:IP DRNC sends Radio Link to IP SRNC and sets up response.Comprise the transport layer address information in this response message, i.e. the AAL2 address that reports of ATM Node B, the carrying of AAL2 B data link, adjacent cell information etc.

Step 5:IP SRNC and ATM Node B set up the Radio Link carrying.Specifically, SRNC finds that its parameter is transport layer address and the binding ID that Node B reports, and then initiates IP ALCAP by IP ALCAP to IWU and sets up flow process, the IP address of SRNC, udp port number is reported IWU in IP ALCAP.

Need to prove, in the present embodiment, IP SRNC needs that still the IP address of oneself, udp port number are sent out one time again and gives IWU, though sent to IP DRNC in the first step, but after detecting address that IP DRNC returns and being atm address, need send out one time again and give IWU.

In this flow process, IWU is mapped transport layer address and the binding ID of the IP address of IP SRNC and udp port number and ATM Node B one by one.

Step 6 and step 7:ATM Node B and IP SRNC are by the suitable dedicated channel protocol frame of exchange, and promptly downlink synchronization and uplink synchronisation are the relevant link that has existed, and promptly the link establishment between ATM Node B and the IP SRNC is synchronous.

Need to prove that if set up synchronization failure, the expression purpose is unreachable, but because IP SRNC and ATM DRNC are all the IP transmission manner, initiating to set up with IP DRNC too can be unreachable.Think that then this sets up failure.

Step 8:IP SRNC sends the active set updating message to subscriber equipment, promptly increases by a wireless links.Wherein, comprise for example parameters such as updating type, sub-district ID, descending scrambler, power control information, adjacent cell information of message in this message.

Step 9: subscriber equipment sends cell update to IP SRNC and finishes message.

2.ATM SRNC and IP Node B

ATM SRNC is described below after receiving the metrical information MEHO at IP Node B of user equipment to report (Mobile evaluated handover, the travelling carriage estimated value is switched), initiates the flow process of soft handover.

Step 1:ATM SRNC sends Radio Link by SGW to IP DRNC and sets up request, increases a new Radio Link.Comprise the transmission format set of for example sub-district ID, each DCH, the parameters such as set, frequency and uplink scrambling code of TFS Transport Format Set in this request message.

Step 2:IP DRNC sets up the resource information that comprises in the request message to the Radio Link of ATM SRNC and judges, if determine it is available, then IP DRNC sends Radio Link by NBAP (Radio Network SubsystemApplication Part, Radio Network Subsystem Application Part) to IP Node B and sets up request.For example comprise in this request: parameters such as the transmission format set of sub-district ID, each DCH, the set of TFS Transport Format Set, frequency, uplink scrambling code.

Need to prove that IP DRNC knows that this IP Node B is the IP transmission means.Simultaneously, IP DRNC sets up the parameter that comprises in the request by the Radio Link that ATM SRNC sends, can know that ATM SRNC is not the IP transmission means, in order not change the message of wireless network layer, IP DRNC regards oneself as the ATM transmission means herein and handles, and does not promptly carry IP address and the udp port number of oneself in this message.

Step 3:IP Node B assigns IP DRNC requested resource, after finishing Radio Link and connecting, Radio Link is set up response send to IP DRNC.Need to prove, because setting up, the Radio Link that IP Node B receives do not have IP address and port numbers in the request message, event makes IP Node B think that IP DRNC is the ATM transmission means, sets up at Radio Link to comprise own corresponding transport layer address and binding ID on IWU in the response message.

Wherein, Radio Link is set up the parameters such as transport layer address information that response message comprises for example signaling link termination, bearer context for data transmission foundation.Have in the transport layer address information and corresponding AAL2 address, the transport layer address of IP Node B on IWU, and the AAL2 binding ID of distinguishing the sign ID of each bar link.

Step 4:IP DRNC sends Radio Link to ATM SRNC and sets up response message.Comprise for example transport layer address information in this message, and parameter such as adjacent cell message.Wherein, the transport layer address information comprises the AAL2 address that IP Node B reports, and data link carrying AAL2 binding ID.

Step 5:ATM SRNC and IP Node B set up the Radio Link carrying.ATM SRNC finds that the parameter of IP NodeB is transport layer address and binding ID, then uses ALCAP, initiates IP ALCAP by IWU to IP Node B, sets up flow process, and in ALCAP transport layer address, the binding ID of ATM SRNC is reported IWU.

In this flow process, IWU is transport layer address and the binding ID of ATM SRNC, number is mapped mutually with the IP address of IP Node B and udp port.The udp port of IP Node B number is bound with the dedicated channel data transmission bearer of Iub interface.The all corresponding Radio Link of each port numbers.

Step 6 and 7:IP Node B and ATM SRNC are by suitable dedicated channel protocol frame--and downlink synchronization and uplink synchronisation are set up synchronously for the Radio Link that has existed between them.Begin downlink transmission by IP Node B subsequently.Need to prove that if set up synchronization failure, the expression purpose is unreachable, but because SRNC and DRNC are all the IP transmission manner, initiating to set up with DRNC too can be unreachable.Think that then this sets up failure.

Step 8:ATM SRNC sends radio resource control information by Dedicated Control Channel to subscriber equipment and carries out the active set renewal--increase by a wireless links.Comprise for example updating type, sub-district ID, descending scrambler, power control information and adjacent cell information etc. in this radio resource control information.

Step 9: subscriber equipment sends cell update to ATM SRNC and finishes message.

Need to prove, when having a plurality of Node B to be added into the active set of subscriber equipment in the zone that IP DRNC covers, will repeat above process.

Subsequently, when the migration of ATM SRNC decision under certain condition, send migration request message to CN.CN begins to initiate the foundation of the RAB between CN and the IP DRNC subsequently, the transmission bearer between IP DRNC initiation simultaneously and the IP Node B.After finishing above-mentioned two carryings, original core net and ATM SRNC, and the radio bearer between ATM SRNC and the IP Node B will be released.Thereby IP DRNC becomes IP SRNC, finishes transition process.

Processing and signaling process that the present invention has optimized existing DRNC come, and have realized that 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 to the IP floating radio network controller and sets up request by SGW;

Step 2:IP floating radio network controller is set up the resource information that comprises in the request message to the Radio Link of IP service wireless network controller and is judged, determine whether available, if available, then the IP floating radio network controller sends Radio Link to the ATM wireless base station and sets up request;

Step 3:ATM wireless base station reports Radio Link to set up response message, and notice IP floating radio network controller has been set up success;

Step 4:IP floating radio network controller sends Radio Link to the IP service wireless network controller and sets up response;

The Radio Link carrying is set up in step 5:IP service wireless network controller and ATM wireless base station;

Step 6 and step 7:ATM wireless base station and IP service wireless network controller are set up synchronously for the relevant link that has existed;

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

Step 9: subscriber equipment sends cell update to the IP service wireless network controller and finishes message.

2. the soft handover method in the WCDMA network as claimed in claim 1, it is characterized in that, in step 1, described Radio Link is set up and is comprised following resource information in the request message: 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, IP service wireless network controller, and the local terminal udp port that distributes of IP service wireless network controller number.

3. the soft handover method in the WCDMA network as claimed in claim 1, it is characterized in that, in step 2, the request of setting up of described Radio Link comprises following parameter: the transmission format set of sub-district ID, each designated lane, the set of TFS Transport Format Set, frequency and uplink scrambling code.

4. the soft handover method in the WCDMA network as claimed in claim 1, it is characterized in that, in step 3, described Radio Link is set up and is comprised following parameter in the response message: the transport layer address information that signaling link is ended, bearer context for data transmission is set up, comprise transport layer address, ATM wireless base station in the described transport layer address information, and binding ID.

5. the soft handover method in the WCDMA network as claimed in claim 1 is characterized in that, in step 4, comprises the transport layer address information in the described response message.

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

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

Step 2:IP floating radio network controller is set up the resource information that comprises in the request message to the Radio Link of ATM service wireless network controller and is judged, if determine it is available, then the IP floating radio network controller sends Radio Link to the IP wireless base station and sets up request;

Step 3:IP wireless base station Radio Link is set up response and is sent to the IP floating radio network controller;

Step 4:IP floating radio network controller sends Radio Link to the ATM service wireless network controller and sets up response message;

The Radio Link carrying is set up in step 5:ATM service wireless network controller and IP wireless base station;

Step 6 and 7:IP wireless base station and ATM service wireless network controller are set up synchronously for the Radio Link that has existed between them;

Step 8:ATM service wireless network controller sends radio resource control information to subscriber equipment and carries out the active set renewal;

Step 9: subscriber equipment sends cell update to the ATM service wireless network controller and finishes message.

7. the soft handover method in the WCDMA network as claimed in claim 6, it is characterized in that, comprise following resource information in the request message in the described step 1: parameters such as the transmission format set of sub-district ID, each designated lane, the set of TFS Transport Format Set, frequency and uplink scrambling code.

8. the soft handover method in the WCDMA network as claimed in claim 6, it is characterized in that, in step 2, comprise following parameter in the described request message: parameters such as the transmission format set of sub-district ID, each designated lane, the set of TFS Transport Format Set, frequency, uplink scrambling code.

9. the soft handover method in the WCDMA network as claimed in claim 6 is characterized in that, in step 3, described Radio Link is set up and comprised following parameter in the response message: transport layer address and binding ID on IP wireless base station correspondence and the interworking unit.

10. the soft handover method in the WCDMA network as claimed in claim 6, it is characterized in that, in step 4, described Radio Link is set up and is comprised following parameter in the response message: parameters such as transport layer address information, adjacent cell message, wherein, the transport layer address information comprises the AAL2 address that the IP wireless base station reports, and data link carrying AAL2 binding ID.