CN100459806C

CN100459806C - Direct retrying method in call request

Info

Publication number: CN100459806C
Application number: CNB2006100021179A
Authority: CN
Inventors: 刘佳; 李新
Original assignee: China Mobile Communications Group Co Ltd
Current assignee: China Mobile Communications Group Co Ltd
Priority date: 2006-01-16
Filing date: 2006-01-16
Publication date: 2009-02-04
Anticipated expiration: 2026-01-16
Also published as: CN1802027A

Abstract

Present invention relates to a direct operation retry in call request. It contains 3 G switching center transmitting calling message to 3G wireless networks according to received call request, if satisfying direct operation retry condition then feeding back 2 G network response and containing direct operation retry 2 G network target cell list test request message.3mobile switching center transmitting switching containing said list to G mobile switching center, then transmitting switching request message target cell list to base station controller, feeding back list including modified target cell, target cell frequency and target cell identifying number, finally transmitting said modified target cell list to originating call request mobile terminal and connecting with these target cell. Said invention increases connected target cell number and raises direct operation retry success rate.

Description

Directed retry method in a kind of call request

Technical field

The present invention relates to the directed retry method in a kind of call request, especially a kind of in call request the method for directed retry repeatedly.

Background technology

Along with development of times, the upgrading of communication system is also very fast, though new communication network must replace original communication network, but at the initial stage of new communication network maturation, the network coverage is bad, and bearing capacity is smaller, and how utilizing original communication network is the major issue of pendulum in face of people.

So-called directed retry (Direct Retry) be meant when portable terminal when 3G network makes a call, for fear of network congestion or the like, can directly transfer to the switching of 2G network, as shown in Figure 1, be the signaling diagram of existing calling based on 3G network to the directed retry of 2G network, (regulation of the signaling in the following step is from 3gpp TS 25.413, TS23.009 and TS 25.331)

1,3G MSC (Mobile Switching Center, mobile switching centre) to 3G RNS (RadioNetwork Subsystem, RNS) send RAB Assignment Request message, this is an audio call of initiating from 3G network;

2,3G RNS returns corresponding RAB Assignment Response message to 3G MSC, and in this message, 3G RNS will notify this calling of 3G MSC to be arrived the 2G network by directed retry, by this calling of the 2G network carrying;

3,3G RNS sends Relocation Required message to 3G MSC, and in this message, 3G RNS will inform 3G MSC, and which concrete target 2G cell this calls out directed retry to;

4,3G MSC sends Prepare handover message to the 2G of this target 2G cell MSC, and request prepares to switch to the calling of 2G network;

5, this 2G MSC sends handoff request Handover request to the 2G of this sub-district BSC (Base Station Controller, base station controller), and whether inquiry can admit this calling;

If 6 2G networks can admit this to call out, then this 2G BSC returns the response Handover Request ACK of handover success to this 3G MSC;

7, this 2G MSC returns the response Prepare handoverResponse for preparing switching to this 3G MSC;

8, this 3G MSC sends Relocation Command to 3G RNS;

9,3G RNS sends Handover from UTRAN command message to the UE/MS that initiates this calling, comprises the frequency, target 2G cell number of target 2G cell in this message;

10, this UE/MS (portable terminal) is connected to this target 2G cell.

From last process as can be seen, existing 3G network is in the process of 2G network directed retry, and network is surveyed the information that only issues a 2G Target cell to terminal; If the covering of the 3G sub-district at this 2G cell and terminal place is not quite identical, perhaps when terminal attempts to connect this sub-district, because this Target cell generation traffic congestion or signal quality variation or interruption suddenly etc., cause this terminal by the directed retry failure of 3G network, the following processing of existing method to the 2G network:

A, UE/MS attempt to return again 3G network, and send Handover From UTRANFailure order to 3G_RNS;

B, 3G RNS are released to the respective resources that the 2G Target cell is prepared by signaled 2G network after receiving the Handover From UTRAN Failure of UE/MS transmission.

Therefore there are the following problems for existing directed retry method:

The first, if UE/MS returns the 3G network success again, then do not reach expection by in call establishment, the 3G subscription directed retry being arrived the purpose of 2G network, can't effectively utilize the resource of 2G network;

Second, (for example: this moment, the signal quality of 3G network was very poor if UE/MS returns the 3G network failure again, may cause UE can't return 3G network smoothly), then make this audio call fail, the user experiences variation, do not reach simultaneously expection by in call establishment, the 3G subscription directed retry being arrived the purpose of 2G network yet, can't effectively utilize the resource of 2G network equally.

Summary of the invention

The objective of the invention is only provides a Target cell to portable terminal at the directed retry method network side in the existing call request, the defective of having only the target of a retry, the method of the directed retry in a kind of call request is provided, network side provides a plurality of Target cells to portable terminal during directed retry, portable terminal is the directed retry network repeatedly, increase the success rate of directed retry, effectively utilize Internet resources.

For achieving the above object, the invention provides the directed retry method in a kind of call request, may further comprise the steps:

Step 1, the call request that 3G mobile switching centre receives according to reception sends the RAB assignment request information to the 3G RNS, and this assignment request information shows that this call request is the call request under the 3G network;

Step 2 is if reach the directed retry condition then the 3G RNS returns the response message and the retry solicited message of this RAB assignment request information to this 3G mobile switching centre; This response message shows that this calling will be switched to the 2G network, and this retry solicited message comprises this calling can be tabulated by the Target cell of the 2G network of directed retry, otherwise sets up the connection under the 3G network;

Step 3, the 2G mobile switching centre under the Target cell of this 3G mobile switching centre in this Target cell tabulation sends the handover information that comprises this Target cell tabulation;

Step 4, the base station controller of the Target cell of this 2G mobile switching centre in these Target cell tabulations sends the handoff request information that comprises this Target cell tabulation;

Step 5, this base station controller returns the response of handoff request information to this 2G mobile switching centre, and this response comprises revised Target cell tabulation, comprises the frequency of the Target cell that can hold this calling and target cell identification number;

Step 6, this 2G mobile switching centre sends the preparation handoff request information that comprises revised Target cell tabulation to 3G mobile switching centre;

Step 7, this 3G mobile switching centre sends the retry command information that comprises this revised Target cell tabulation to the 3G RNS;

Step 8,3G RNS send the switching command information that comprises revised Target cell tabulation to the portable terminal of initiating this calling;

Step 9, this portable terminal is connected with these Target cells according to this revised Target cell tabulation.

Directed retry method in the call request according to claim 1, the directed retry condition in the wherein said step 2 are that the 3G cell load is high to certain threshold value.

In the step 2 of technique scheme, the preparation method of the Target cell in the described Target cell tabulation is for to dispose by actual drive test analysis or network planning result, if drive test analysis or network planning result show the 3G sub-district at the portable terminal place that makes a call and a certain 2G cell coverage lap is arranged, judge that then this 2G cell is a Target cell.In the described step 8, the 3G RNS also comprises the order of connection of the Target cell in the revised Target cell tabulation in the switching command information that the portable terminal of initiating this calling sends; In the described step 9, this portable terminal connects according to the Target cell of this order of connection in revised Target cell tabulation.And the described order of connection is the priority orders of Target cell, and in the described step 9, this portable terminal connects according to the Target cell of priority orders in revised Target cell tabulation of this Target cell.The decision method of the priority orders of described Target cell for the portable terminal place 3G sub-district directed retry that goes out to make a call by drive test or network planning interpretation of result to the probability of revising the different target sub-district in the cell list, the high more then priority of probability is high more.In the described step 9, if the Target cell that portable terminal connects in all revised Target cell tabulations is all failed, then portable terminal switches to 3G network, and sends the message of handoff failure to this 3G RNS.After described portable terminal sends the message of handoff failure to the 3G RNS, send the resource that the Target cell in the described revised Target cell tabulation of release is prepared to 2G mobile switching centre by 3G mobile switching centre.

Therefore, directed retry method in the call request of the present invention, initiating 3G at portable terminal calls out, to the directed retry of 2G network the time, network side sends the 2G cell tabulation to portable terminal, comprises a plurality of 2G cells, portable terminal initiates to connect to these sub-districts, increase the number of times that connects, improved the success rate of directed retry, effectively utilized the resource of 2G network.

Below by drawings and Examples, technical scheme of the present invention is described in further detail.

Description of drawings

Fig. 1 is the signaling diagram of the directed retry method in the existing call request.

Fig. 2 is the flow chart of an embodiment of the directed retry method in the call request of the present invention.

The process chart of Fig. 3 after for the switching of the directed retry method in the call request of the present invention.

Embodiment

The present invention is that network side issues cell list to terminal when the retry network, can connect a plurality of sub-districts, and portable terminal can initiate to connect to a plurality of sub-districts, has improved the success rate of retry, has effectively utilized existing Internet resources.

As shown in Figure 2, the flow chart for an embodiment of the directed retry method in the call request of the present invention may further comprise the steps:

Step 101, the call request that 3G MSC receives according to reception sends RAB assignment request information RAB Assignment Request to 3G RNS, and this assignment request information shows that this call request is the call request under the 3G network; This call request is voice call request or Streaming Media call request or the like;

Step 102 is if reach the condition of directed retry then 3G RNS returns the response message RAB Assignment Response and the retry solicited message Relocation Required of this RAB assignment request information to this 3G MSC; This response message shows that this calling will be switched to the 2G network, and this retry solicited message comprises first Target cell tabulation of the 2G network that this calling can be switched, otherwise the connection of setting up 3G network;

Because be not that call request under the 3G network each time all will switch under the 2G network, therefore switching has switching condition, and the threshold value of for example predefined 3G cell load is if surpass this threshold value then directed retry; And the selection of Target cell is valid, for example can dispose or search for, dispose by actual drive test analysis or network planning result, if drive test analysis or network planning result show the 3G sub-district at the portable terminal place that makes a call and a certain 2G cell coverage lap is arranged, judge that then this 2G cell is a Target cell;

Step 103, the 2G MSC under the Target cell of this 3G MSC in this Target cell tabulation sends the handover information Prepare handover that comprises this Target cell tabulation;

Step 104, the 2G BSC of the Target cell of this 2G MSC in these Target cell tabulations sends the handoff request information Handover request that comprises this Target cell tabulation; The purpose that sends handoff request message is to seek these Target cells whether can hold this call request;

Step 105, this 2G BSC returns the response HandoverRequest ACK of handoff request information to this 2G MSC; This response comprises revised Target cell tabulation, comprise the frequency of the Target cell that can hold this calling and target cell identification number, because be not that Target cell in the tabulation of each Target cell all can hold this callings, therefore revised Target cell the tabulate frequency of having only the Target cell that can hold this calling and target cell identification number;

Step 106, this 2G MSC sends the preparation handoff request information Prepare Handover Response that comprises revised Target cell tabulation to 3G MSC;

Step 107, this 3G MSC sends the retry command information Relocation Command that comprises revised Target cell tabulation to 3G RNS;

Step

108,3G RNS sends the switching command information Handover from UTRAN command that comprises revised Target cell tabulation to the portable terminal of initiating this calling;

Step 109, this portable terminal is connected according to these Target cells of should revised Target cell tabulating with in this tabulation.

In

step

108,3G RNS also comprises the order of connection of the Target cell in the revised Target cell tabulation in the confidence that terminal sends, therefore in the step 109, portable terminal connects according to the Target cell of this order of connection in revised Target cell tabulation, this order of connection has a lot, the priority orders of Target cell preferably, the decision method of this priority orders is:

Step 301, the portable terminal place 3G sub-district directed retry that goes out to make a call by drive test or network planning interpretation of result is to the probability of revising the different target sub-district in the cell list;

Step 302 according to the order of probability height, is arranged the priority of Target cell, and the high more then priority of probability is high more;

At this moment, portable terminal connects according to the Target cell of this priority orders in revised Target cell tabulation, if connection failure then is connected with next sub-district.

Therefore, and have two kinds of results being connected of Target cell, referring to Fig. 3, the process chart after the switching, handle as follows:

Step 201, first kind is successful connection, then switches to the calling of 2G network;

The equal connection failure of all Target cells during if step 202 is tabulated with all second Target cells, then portable terminal switches to 3G network, and sends the message Handover From UTRAN Failure of handoff failure to this 3G RNS;

Step

203,3G RNS are released to the respective resources that the 2G Target cell is prepared by signaled 2G mobile switching centre after receiving the Handover From UTRAN Failure of portable terminal transmission;

Step

204,2G Target cell discharge the corresponding resource of preparing.

Therefore, the method of the directed retry that call request of the present invention is, after portable terminal is initiated the 3G calling, when the 2G network switches, network side sends the 2G cell tabulation to portable terminal, comprises a plurality of 2G cells, portable terminal initiates to connect to these sub-districts, increase the number of times that connects, improved the success rate that switches to the 2G networking, effectively utilized the resource of 2G network.

It should be noted last that, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, although the present invention is had been described in detail with reference to preferred embodiment, those of ordinary skill in the art is to be understood that, can make amendment or be equal to replacement technical scheme of the present invention, and not break away from the spirit and scope of technical solution of the present invention.

Claims

1, the directed retry method in a kind of call request, comprising following steps:

Step 1,3G mobile switching centre sends the RAB assignment request information according to the call request that receives to the 3G RNS, and this assignment request information shows that this call request is the call request under the 3G network;

Step 2, if reach the directed retry condition, then the 3G RNS returns the response message and the retry solicited message of this RAB assignment request information to this 3G mobile switching centre, this response message shows that this calling will be switched to the 2G network, and this retry solicited message comprises the Target cell tabulation of the 2G network that this calling can be switched; Otherwise set up the connection under the 3G network;

Step 5, this base station controller returns the response of handoff request information to this 2G mobile switching centre, this response comprises the tabulation of revised Target cell, and this revised Target cell tabulation comprises the frequency of the Target cell that can hold this calling and target cell identification number;

2, the directed retry method in the call request according to claim 1, the directed retry condition in the wherein said step 2 are predefined 3G cell load threshold value.

3, the method for the directed retry in the call request according to claim 1 and 2, in the wherein said step 2, Target cell in the described Target cell tabulation disposes by actual drive test analysis or network planning result, if drive test analysis or network planning result show the 3G sub-district at the portable terminal place that makes a call and a certain 2G cell coverage lap is arranged, then this 2G cell is a Target cell.

4, the directed retry method in the call request according to claim 1 and 2, in the wherein said step 8, the 3G RNS also comprises the order of connection of the Target cell in the revised Target cell tabulation in the switching command information that the portable terminal of initiating this calling sends.

5, the directed retry method in the call request according to claim 4, wherein said step 9 is specially: this portable terminal connects according to the Target cell of this order of connection in revised Target cell tabulation.

6, the directed retry method in the call request according to claim 4, the wherein said order of connection are that the wherein said step 9 of the priority orders of Target cell is specially: this portable terminal connects according to the Target cell of priority orders in revised Target cell tabulation of this Target cell.

7, the directed retry method in the call request according to claim 6, the decision method of the priority orders of wherein said Target cell is specially:

Step 11, the portable terminal place 3G sub-district directed retry that goes out to make a call by drive test or network planning interpretation of result is to the probability of revising the different target sub-district in the cell list;

Step 12 according to the order of probability height, is arranged the priority of Target cell.

8, the directed retry method in the call request according to claim 1 and 2, in the wherein said step 9, if the Target cell that portable terminal connects in all revised Target cell tabulations is all failed, then portable terminal switches to 3G network, and sends the message of handoff failure to this 3G RNS.

9, the directed retry method in the call request according to claim 8, after wherein said portable terminal sends the message of handoff failure to the 3G RNS, send the resource that the Target cell in the described revised Target cell tabulation of release is prepared to 2G mobile switching centre by 3G mobile switching centre.