CN1289516A - Method of automatically reconnecting a dropped call in a mobile communication - Google Patents

Abstract

An automatic dropped call reconnection method in a mobile communicating system is described. In the method of reconnecting a communication link terminated by a service impediment during service between a mobile terminal of a first subscriber and a terminal of a second subscriber communicating with the first subscriber through one of a plurality of base stations (BSs) connected to the mobile terminal and at least one of a plurality of mobile switching centers (MSCs) connected to the BS in a mobile communication system having the plurality of BSs and the plurality of MSCs, an MSC contacts a location register which registers the previous location of the mobile terminal when one of the plurality of BSs and the MSC connected to the BS receive a location registration request message from the mobile terminal after the service impediment. Then, the MSC determines whether information about the mobile terminal registered in the location register indicates service in progress, and attempts reconnection paging with the mobile terminal to thereby reinitiate the terminated service between the mobile terminal of the first subscriber and the terminal of the second subscriber, if the mobile terminal information indicates service in progress.

Description

The method that in mobile communication system, connects dropped call automatically again

Background of invention

1. invention field

The present invention relates generally to wireless communication field, relate in particular to the method that in mobile communication system, connects dropped call (dropped call) automatically again.

2. description of related art

Public Land Mobile Network (public land mobile network, PLMN) in, under wireless environment in the base station (base station, BS) and travelling carriage (mobile station connects between MS).In some cases, can not provide call service in the concealment area owing to the physical characteristic of wireless environment, these concealment areas can be propagated signal and be had a negative impact.When the terminal use went on a delightful trip on foot or move with car in motor vehicle, calling may be dropped temporarily.According to routine techniques,, determine that then call service can not provide and call release if call out the one section predetermined amount of time that dropped.In IS-95, the described scheduled time is approximately 5 seconds (that is, equaling a frame duration 20 milliseconds * 270).When the calling that takes place not expect discharged, calling party must be tried and call out the callee once more.

For overcoming the problem that above-described calling is dropped, several method has been proposed in the prior art, comprising:

(1) U.S. Patent No. 5,546, and 382: connecting circuit again, when bust this takes place, to continue to provide data communication services;

(2) U.S. Patent No. 5,239, and 571: by autonomous device being appended to terminal or revising this terminal and connect abortive communication link again.That is to say, utilize to be used to store the RAM that initiates and call out the information that stops about calling out in the terminal, under the situation that call exception disconnects, set up automatically and call out; With

(3) U.S. Patent No. 5,566,236: near the telecommunication system utilizing (for example, PBX: private branch exchange exchanges (Private Brach Exchange and Centrex) with centralized user: the PBX service (Centralized PBX Service) of concentrating) be connected the telephone communication that disconnects again, introduce the notion of intelligent network thus.

General introduction of the present invention

An object of the present invention is to provide a kind of method that in mobile communication system, connects the dropped call during the call service automatically again by location registers.

Another object of the present invention provides a kind of method that connects the dropped call during calling out in mobile communication system by location registers automatically again.

Briefly, above-mentioned and other purpose can by the automatic dropped call in a kind of mobile communication system again method of attachment realize.In in mobile communication system, being connected a kind of method of viability again by the communication link of service obstacle termination, described mobile communication system has a plurality of base stations (BS) and a plurality of mobile switching centre (MSC), described service is to carry out between first client's a portable terminal and second client's a terminal, described second client is by one among the described a plurality of BS that are connected to described portable terminal and be connected among described a plurality of MSC of described BS at least one, come and described first client communication, when one among described a plurality of BS and the MSC that is connected to this BS during at service obstacle when described portable terminal receives a position register request message, MSC detects a location register, and the previous position of described portable terminal is registered or stored to this location register.Then, MSC determines whether registration or the information about described portable terminal that is stored in the described location register indicate service in progress, and, if described information of mobile terminal indication service is in progress, then tentatively connect paging again, thereby between described first client's portable terminal and described second client's terminal, begin service again to described portable terminal.

Brief description of drawings

By the detailed description below in conjunction with accompanying drawing, above and other objects of the present invention, feature and advantage will become more obvious, in the accompanying drawing:

Fig. 1 is the example block diagram of the mobile communication system that adopts of embodiments of the invention;

Fig. 2 is the flow chart of method that be used to handle dropped call of explanation according to one embodiment of the invention;

Fig. 3 is the flow chart of describing according to the MS control operation of one embodiment of the invention;

Fig. 4 is the flow chart of describing according to the BS control operation of one embodiment of the invention;

Fig. 5 is the flow chart of describing according to MSC (Mobile Switching Center, the mobile switching centre) control operation of one embodiment of the invention;

Fig. 6 is the flow chart of describing based on the call treatment in the conventional paging method of IS-634 standard;

Fig. 7 is the flow chart of describing according to VLR (Visitor Location Register, the visitor location register) control operation of one embodiment of the invention;

Fig. 8 A, 8B and 8C are described in MS client to move to the flow chart that is connected the calling that original MSC service area drops after the new MSC service area automatically again;

Fig. 9 is the state transition graph of traditional call treatment;

Figure 10 is the state transition graph according to the call treatment of one embodiment of the invention;

Figure 11 has described the signal＜enroll in notifications return results that connects sign (flag) that comprises again according to one embodiment of the invention〉form;

Figure 12 has described to resemble and has defined in IS-41, by general＜MSC ID〉and＜lane place ID〉append to＜register cancellation〉form of the location registers mandatum cassatorium message that constitutes;

Figure 13 has described according to the registration of the one embodiment of the invention form of connection message again;

Figure 14 has described the block diagram that is used for the BS method that detection of call drops according to one embodiment of the invention;

Figure 15 has described a plurality of paging zones, and each paging zone all comprises a respective cell and adjacent a plurality of sub-districts thereof; With

Figure 16 has described the example according to paging between the using system of the embodiment of the invention (intersystem page).

Detailed description of preferred embodiment

The preferred embodiments of the present invention are described below with reference to accompanying drawings.They in the following description, known function or structure are not described in detail, in order to avoid can cover the present invention with unnecessary details.

Term and definition

" call service is in progress ": the ongoing state of data communication that is meant voice communication and/or rest image, moving image etc.

" dropped call ": can not be the more interim or permanent calling that keeps that provides in call service is provided.Dropped call can cause by calling out to disconnect, and is perhaps caused by the noise on the particular channel, is perhaps caused by disabled service scenarios.

" call out and disconnect ": be meant that calling keeps the state that disconnects in the given time.

To embodiments of the invention be described with way of example in the context of North America digital mobile communication system standard (IS-95, IS-634 and IS-41 series) below.The present invention also can be applicable to 3GIS-95, and this 3GIS-95 provides Additional Services such as high-quality sound, high-speed data, moving image and internet browsing.

With reference to Fig. 1, the mobile communication system that embodiments of the invention adopted comprises: HLR (HomeLocation Register, former mat location register) 80; MSC (mobile switching centre) MSC0 70a and MSC1 70b; BSC (Base Station Controllers, base station controller) BSC00 64a, BSC01 64b and BSC10 64c; BTS (Base Station Transceiver Subsystems, BTS under CROS environment) BTS000 62a is to BTS101 62f; And MS 50.A plurality of HLR and MSC interconnect in PLMN, switch to carry out customer account management and to call out.As shown in Figure 1, single HLR 80 is connected to MSC0 70a and the MSC1 70b of a plurality of MSC.Each MSC is connected to a plurality of BSC successively, and each BSC is connected to a plurality of BTS.BS generally includes single BSC and a plurality of BTS.

MSC control is connected with PSTN (Public Switch Telephone Network, public switch telephone network) and PLMN's.BSC control Radio Link is also carried out handover, and BTS forms the Radio Link with MS, and managing radio resources, and HLR registered user position also is used as the database of storage customer information.Each MSC has a VLR (visitor location register), is used for interim information of storing the MS of the service area that enters MSC.If MS moves to another service area, then abandon institute's canned data.

For call setup, mobile communication system is distributed wireless channel between MS and BTS, forms between BTS and the BSC, between BSC and the MSC and the communication link between MSC and PLMN or extranets such as the PSTN.If the calling of setting up is because MS is in the fallback area or can not keeps the scheduled time owing to the characteristic of wireless environment, then mobile communication system disconnects calling usually.The problem of fallback area can be caused by multiple situation, for example comprises elevator, postpones to discharge the shadow region in the intensive area of long tunnel, high constructure of tunnel (relay-free tunnel) between neighbor cell.

The calling that defines in embodiment of the invention environment is dropped and can be occurred among Fig. 1 by those indicated positions of label 10,12,14 and 16.

The position of the dropped call in label 10,12 and the same MSC of the 14 indications district, and label 16 indications are by the position of the dropped call between the BTS of different MS C covering.Specifically, the calling of the MS 50 that BTS000 62a in the area of coverage of label 10 expression and BTS000 62a the communicates by letter position of dropping, the calling of the MS 50 that BTS000 62a in the service area of label 12 expression and BTS00 64a or BTS001 62b the communicate by letter position of dropping, and label 14 is represented the calling of the MS 50 that communicates by letter with BTS001 62b or the BTS010 62c position of dropping in its border or the area of coverage.

Fig. 2 is the flow chart according to the call handling process of one embodiment of the invention, wherein, discharges dropped call, then it is connected again.Fig. 3,4,5 and 7 is flow charts of describing the control operation of MS, BS, MSC and VLR according to one embodiment of the invention respectively.

With reference to Fig. 2 to 5 and Fig. 7 connection again according to the dropped call of one embodiment of the invention is described below.

When set up to call out and after be used for the current use of this call service (callings) Traffic Channel when disconnecting, whether the definite calling of MS and BS drops.In the step 400 of the step 300 of Fig. 3 and Fig. 4, MS and BS determine that call service is in progress.Then, when Traffic Channel disconnected, MS and BS determined to call out whether drop in the step 402 of the step 302 of Fig. 3 and Fig. 4.Resemble and ask No.09/294 in the U.S., disclosed in 046, if do not receive frame on the current business channel in (1 to 10 second) at the fixed time, perhaps, if the frame that receives is wrong continuously, then MS and BS think to call out and drop.The preferably 1.2 seconds described scheduled time.1.2 the time ratio of second is the approximately short 5 seconds time of call release in the prior art.

Below the mode that MS and BS detection of call drop will be described in more detail.

Figure 14 is the block diagram of the BS mode that drops of detection of call.With reference to Figure 14, the CDMA signal that receives by antenna 100 is by RF﹠amp; XCVB (Radio Frequency﹠amp; Transceiver Block.Radio frequency and transceiver piece) 102 be converted to IF (Intermediate Frequency, intermediate frequency) signal.CMDB (CDMA Modulation and Demodulation Block, CDMA modulation and demodulation piece) 104 is QCELB (Qualcomm Code Excited Linear Predictive coding, Qualcomm Qualcomm Code Excited Linear Prediction (QCELP)) grouping with this IF conversion of signals.In this operating process, CMDB 104 determines whether a packet frames is normal, it determines that mode is its CRC of check (Cyclic Redundancy Code, cyclic redundancy code) and check how much have in this frame be defective, and with unusual indication information (QualityMatrix (mass matrix): H ' 00-H ' ff) appends to the grouping of being changed.If unusual indication information is 0, then TSB 106 makes the grouping process abnormal operation that receives from CMDB 104.If this information is 1, then TSB 106 is converted to PCM (Pulse Code Modulaion, pulse-code modulation) signal with the packet frames that is received, and this PCM signal is sent to MSC.

When definite packet frames was bad frame, TSB 106 utilized the timer of per 20 milliseconds of generations to interrupt whether continuous mistake and the frame count that do not receive are dropped with final decision one calling.That is to say, determine whether frame interrupts receiving at each 20 milliseconds.

If receive 20 continuous bad frames from CMDB 104, then TSB 106 thinks that it predicts calling and drops.Then, if receive the continuous bad frame of predetermined number in first scheduled time, then definite calling of TSB106 dropped.Suppose that first scheduled time was 2 seconds, TSB 106 declares to call out when it receives 80 continuous bad frames and drops.Yet, if receive two continuous normal frame, initialization bad frame counter, and TSB 106 turns back to normal running.On the other hand, if do not receive any frame in 20 successive frames, then TSB 106 thinks that it predicts to call out and drops.Then, if do not receive successive frame in second scheduled time, the calling during then TSB 106 determines to make progress has been dropped.It is short that second scheduled time cand be compared to for first scheduled time most.

To describe below and call out the MS detection of dropping.Forward traffic channel under the MS monitoring traffic channel status in the MS control.When MS received the individual continuous bad frame of L (L is a natural number) on the forward traffic channel, then it forbade its transmitter work.Then, if receive the individual successive frame of M (M is a natural number), then MS allows its transmitter work.In the sub-state of traffic channel initialization of MS control, when transmitter was started working, MS activated decline (fade) counter of forward traffic channel under traffic channel state.When receiving the continuous good frame of M, the decline counter reset is to N (N is a natural number) second.If by all not receiving continuous good frame, then MS forbids transmitter work and declares to call out and drop up to the decline counter.

Call out when dropping when detecting in the step 402 of the step 302 of Fig. 3 and Fig. 4, in the step 304 of Fig. 3, it connects MS notice MS user waiting for again, and in the step 404 of Fig. 4, BS carries out and calls out release procedure.MS can by light LED (Light Emitting Diode, light-emitting diode), display message or send specific tone and notify MS user on terminal display.MS user also can connecting by the notified dropped call of said method automatically again.

Simultaneously, when detecting dropped call, BS utilizes existing message or new message notification to call out the MSC that drops.In the previous case, the cell value in the existing message makes up, and to any modification of existing message, perhaps the cell value of redetermination does not append to existing message, the MSC that drops with notification call.

Call out when dropping when detecting, BS is used in the MSC that the message informing calling of calling out in the dispose procedure is dropped.With reference to Fig. 2 calling dispose procedure among the BS (step 404 of Fig. 4) is described below.

Call out when dropping when detecting, BS sends to MSC with normal signal, and notice MSC bid drops.Release signal is＜request of removing (DROP)〉or＜release (DROP) 〉, as shown in Figure 2.If be included in calling in the release signal drop announcement information for example be set to 1 (=DROP), then release signal may be defined as the calling release signal that dropped call causes.If described information setting be 0 (=NORMAL), then release signal may be defined as the normal call release signal.

When discharging when in the step 502 of Fig. 5, receiving the request of release signal＜removing during the calling in the step 500 of Fig. 5 (call service)〉or＜, in the step 504 of Fig. 5, MSC determines based on the calling announcement information that drops whether dropped call will connect again.For example, if call out the announcement information that drops be set to 1 (=DROP), then MSC determines that dropped call should connect again.

The calling announcement information that drops can be included in the request of existing release signal＜removing in two ways〉or＜discharge in or append in this signal.In a kind of mode, notifying parameters is dropped in calling can be based on IS-64, with the request of release signal＜removing〉or＜discharge form, utilization " Cause (reason) " defined usable levels of information unit in various type of messages is provided with, and described various type of messages are " Cause ", " Circuit Identity (circuit identity) " and " Code Extension (code expansion) ".Each value of calling out the notifying parameters that drops that can be used as that defines in " Cause " information unit comprises Uplink Quality (Cause:0x02), Uplink Strength (Cause:0x03), MS not equip (0x20) and BS notequip (0x25).In the second way, call out the notification unit that drops and append to＜removes request based on IS-634〉or＜release signal format.

Except existing release signal, BS also can use the message of redetermination to send to MSC and call out the announcement information that drops.The formation of new information and signal＜removing request〉or＜discharge constituted mode consistent.

If determine no longer to connect dropped call in the step 504 of Fig. 5, then in the step 520 of Fig. 5, MSC discharges this calling.On the contrary, if connect dropped call again, then in the step 506 of Fig. 5, MSC sends other client that informational message notifies wait to connect again.This informational message is taked voice message, music, tone or quiet form to other client in the communication, and data communication clients and data, services supplier is taked the form of remainder certificate.

In the step 508 of Fig. 5, MSC activates a timer with timer value T-Val1.This timer value T-Val1 instruct MS C should be from BS receiving position register request message＜position updating request〉time period, after MSC receives the calling release signal that dropped call causes, MS with its location registers to described BS.The scope of described timer value T-Val1 be from several seconds to hundreds of second, this value is registered as initialization data, and according to system operating state and client's characteristic and changed by the operator.For T-Val1,, between BS and MSC, carry out exemplary call release procedure based on IS-634 (clear command, finish, SCCP RLSD and SCCP RLC) in the step 404 of Fig. 4 and the step 510 of Fig. 5.

With reference to Fig. 3, call out when dropping when detecting, in step 304, MS notify the user its wait for again and connecting, and activate the timer that is set to timer value T-Val2 in step 306.Timer value T-Val2 is tens seconds, preferably 30 seconds, and be to call out the scheduled time that should receive beep-page message after dropping from BS detecting.In step 308, MS is initialised.Executive system is caught again during initialization, and keeps the MS idle condition.

Under this state, the wireless channel that call release has dropped, the service channel between MS and the BS for example, simultaneously, between BS and the MSC, between MSC and another MSC and/or the service channel between MSC and other side communicate by letter with MS.

If MS shifts out the service obstacle district, then in the step 310 of Fig. 3, MS sends position register request message＜registration message to BS 〉.In the step 406 of Fig. 4, BS determines whether to receive＜registration message from MS 〉.When receiving＜registration message〉time, in the step 408 of Fig. 4, BS is with signal＜position updating request〉send to MSC, thus the request position is upgraded.

In the step 512 of Fig. 5, MSC determines whether to receive location update request signal＜position updating request by preceding from BS at the T-Val1 timer 〉.When receiving＜position updating request〉time, this MSC determines whether the MSC of request location registers is in its area of coverage, if then in the step 514 of Fig. 5, MSC sends to its VLR with position register request.That is to say that MSC sends signal＜enroll in notifications to its VLR 〉.

Describing the MS that sends location registers message with reference to Fig. 2 below is client's the situation that receives the MSC of position register request subsequently.In Fig. 2, if running into to call out in the zone by label 10,12 and 14 indications, MS drops, then this MS is the client of the VLR 72a of MSC0 70a.

Yet, when shifting out the service area of MSC1 70b at MS and enter the service area of MSC0 70a, call out and drop the time by label 16 indications regional, from the angle of MSC0 70a, this MS is not the client of this MSC0 70a.

Below with reference to Fig. 2 describe MS be the registration MSC the client time calling connect again, then with reference to Fig. 8 A and 8B describe MS be not the registration MSC the client time calling be connected again.

If the MS of request location registers is the client of MSC, then in the step 514 of Fig. 5, MSC sends to its VLR with position register request.That is to say MSC general＜enroll in notifications〉send to its oneself VLR.

In the step 700 of Fig. 7, VLR is from MSC reception＜enroll in notifications 〉, and the step 702 of Fig. 7 determine about the internal registration information of corresponding MS whether the call service (calling) of instruct MS be in progress.If the call service of this MS (calling) is in progress, then its position register request that is implying MSC is the connection again that is used for existing call.Therefore, in the step 704 of Fig. 7, VLR confirms position register request response message＜enroll in notifications MSC being provided with to connect under the sign situation of (connecting sign=1 again) again〉send to MSC.On the contrary, if the call service of described MS (calling) not in progress, then in the step 706 of Fig. 7, VLR confirms position register request response message＜enroll in notifications MSC not being provided with connect under the sign situation of (connecting sign=0 again) again〉send to MSC.

Figure 11 shows confirming based on position register request response message＜position informing IS-41, that have the additional sign of connection again according to one embodiment of the invention 〉.With reference to Figure 11, connect again and indicate 1 bit that occupies in the free area.Because successful positions is registered thereby can be connected dropped call again, this connects sign again and is set to 1 (=DCR:Drop Call Reconnection (call out and connect)) for indication.

Step 516 at Fig. 5, MSC determines whether to receive again the connection sign and is set to position register request response message＜enroll in notifications affirmation of 1 from VLR 〉, and, if receive, then in the step 518 of Fig. 5, location registers is confirmed that response＜position upgrades acceptance〉send to BS.

In the step 410 of Fig. 4, BS determines whether to receive location registers and confirms that response＜position is upgraded and accept 〉, and, if receive, then in the step 412 of Fig. 4, location registers affirmation response＜registration is taken orders (Order) send to MS.Then, in the step 312 of Fig. 3, MS receives this location registers and confirms that response＜registration takes orders 〉.

Sending the renewal acceptance of location registers affirmation response＜position〉afterwards, MSC is with signal＜SCCPRLSD〉send to BS, and from BS received signal＜SCCP RLC.

Then, in the step 520 of Fig. 5, MSC will be used for paging (paging) request＜paging request that dropped call connects again〉send to BS.MSC is with signal＜paging request〉send to corresponding BS separately or send to corresponding BS and neighbor bss thereof together.Latter event is preferred.

To describe the paging zone that dropped call connects again that is used for below in detail according to one embodiment of the invention.The paging zone that is used for connecting again can be preset as the internal data of MSC.Paging is carried out to connect in the residing single sub-district of called party client again, perhaps the paging zone that comprises neighbor cell is carried out paging.Perhaps, MSC can carry out paging to the broad area (broad area) that comprises all sub-districts that covered by MSC.In one embodiment of the invention, paging respective cell, paging zone and broad area are called cell paging, PAI (Paging Area Identification, paging zone identification) paging and broad paging.

Originally, implementing cell paging, is in order to obtain the paging success rate higher than cell paging and use the PAI paging.Preferably the PAI paging is used as elementary paging auxiliary paging afterwards, perhaps as elementary paging.Broad paging is to use when not detecting the position of MS, or for after elementary paging failure by utilizing broad paging to improve paging success rate.

Simultaneously, in the step 414 of Fig. 4, BS determines whether to receive＜the paging request 〉.When receiving the paging request, in the step 416 of Fig. 4, BS sends to MS with beep-page message, as shown in Figure 2.Although Fig. 2 shows beep-page message once situation only takes place, best, when BS is tentative when connecting paging again, this BS sends beep-page message repeatedly.According to one embodiment of the present of invention, best, the tentative cell paging of BS as elementary paging, as the PAI paging of auxiliary paging, be to cross over another PAI paging of broad area rather than previous PAI paging then.Broad paging is preferably carried out when not detecting the position of MS.Paging success rate can improve by according to environment and paging number of times paging zone being set.

Figure 15 shows the example that is used to call out the paging zone that comprises respective cell and neighbor cell thereof that connects paging again.In Figure 15, C1 represents each sub-district to C18.If the MS that bid drops is arranged in sub-district C1, then MSC all sub-district C1 in regional PAI 1 send elementary paging request to C6.The sub-district can be to be in the service area of identical MSC or different MS C.If to the response of elementary paging, then MSC can be to sending the paging request than regional PAI 1 wideer zone.That is to say, MSC can to regional PAI 2 or in comprising MSC the broad paging zone of all sub-districts send auxiliary paging request.

In the sub-district that request connects paging again is that a back MSC should send a paging request to previous sub-district by inter-system paging under the situation about being among the different MSC of the MSC that is adjacent the sub-district.

Figure 16 shows the example according to the inter-system paging of one embodiment of the invention, is called inter-system paging 2 (Intersystem Page2).With reference to Figure 16, if the sub-district of end call is sub-district C3, then MSC1 each sub-district in regional PAI 1 is that C2 connects the paging request again to C5 proposition sub-district.MSC1 can directly send the paging request to sub-district C2 and C3, but must send the message of the ID that comprises sub-district C4 and C5 by inter-system paging 2 to MSC2.When receiving this message, the tentative paging request of MSC2 to sub-district C4 and C5.When receiving this paging request responding from BS, MSC2 sends the response that receives by inter-system paging 2 to MSC1.Inter-system paging 2 can improve the client's who is used to be in the boundary between the MSC paging success rate.

Get back to Fig. 3, be to receive location registers from BS in the step 312 and confirm that response message＜registration takes orders afterwards, in the step 316 of Fig. 3, MS determines whether receive beep-page message from BS during T-Val2.If this MS does not receive beep-page message during T-Val2, then in the step 318 of Fig. 3, this MS discharges informational message, notify the user it connect waiting for again, enter the idle condition of the step 320 of Fig. 3 then.When the step 316 at Fig. 3 received beep-page message during T-Val2, in the step 322 of Fig. 3, MS stopped the work of T-Val2 timer, and in the step 324 to 334 of Fig. 3, set up communication link by the conventional paging method of IS-634.

With reference to Fig. 2, piece 200 expressions there is shown the signal in the piece 200, to understand embodiments of the invention better based on the conventional page procedure of IS-634.Fig. 6 is the flow chart of the call connection process that carries out of the IS-634 paging method of routine indicated in the piece of describing by Fig. 2 200.

Provide the description that is connected again for the calling of after receiving beep-page message, in MS, BS and MSC, carrying out with reference to Fig. 2 to 6 below by MS.After receiving beep-page message, at the step 324 of Fig. 3 and the moment C of Fig. 6, MS sends page-response message.When the step 418 of Fig. 4 and Fig. 6 the moment, C received page-response message the time, BS will indicate the message of successful paging, promptly＜finish L3 information: page response (Complete L3 Info:Paging Response) 〉, send to MSC.In the step 522 of Fig. 5, MSC is by receiving or do not receive signal＜finish L3 information: page response〉determine whether successfully paging.When receiving signal＜finish L3 information: page response〉time, to U, MSC sets up communication link again at the moment F of the step 524 of Fig. 5 and Fig. 6.Then, in the step 526 of Fig. 5, MSC discharges and waits for the notice that connects again from another communication clients.Simultaneously, if do not receive＜finish L3 information: page response in the step 522 of Fig. 5 〉, then in the step 528 of Fig. 5, MSC sends and notifies the opposing party the informational message of connection failure again, then, in the step 530 of Fig. 5, call release.

When the step 418 of Fig. 4 and Fig. 6 the moment, C received page-response message the time, BS carries out follow-up paging step (the step D of Fig. 6 is to the step 420 of U and Fig. 4) with conventional paging method, and the step D that resembles at Fig. 6 sends signal＜finish L3 information to MSC: page response 〉.Like this, in the step 424 of Fig. 4, call service (calling) is in progress.

In the step 324 of Fig. 3 after BS has sent page-response message, MS carries out follow-up paging step with the paging method of routine.More particularly, at MS after BS sends page-response message, step 326 at Fig. 3, MS determines whether to receive signal＜warning information (Alert withInfo) 〉, when receiving signal＜warning information〉time, in step 328, MS discharges and waits for connection notice again, in the step 330 of Fig. 3, produce ring sound then.If MS user responds in the step 332 of Fig. 3,, enter call service state (call state) then in the step 334 of Fig. 3.

The calling of describing when MS is not the client of registration MSC with reference to Fig. 8 A, 8B and 8C is connected again below.Fig. 8 A, 8B and 8C are described in MS client to shift out and call out after the original MSC service area drop, move to the flow chart that the automatic calling in wherein the new MSC service area connects again MS client.

With reference to Fig. 8 A, 8B and 8C, when the MS from current MSC request location registers was not the client of this current MSC, this current MSC was with position registration request signal＜enroll in notifications〉send to its VLR (current VLR).This current VLR is in response to＜location registers〉and determine whether it stores the information about corresponding MS, but it is not about the information of this MS, because this MS is not the client of current MSC.Like this, current VLR is with position registration request signal＜enroll in notifications〉send to original HLR.This original HLR sends the location registers mandatum cassatorium to original VLR 〉.

Figure 12 illustrates according to one embodiment of the present of invention, as the structure of the location registers mandatum cassatorium message that defines in IS-41, wherein gives＜the registration cancellation〉added MSC ID and lane place ID.This MSC ID and lane place ID are used for inter-system paging 2.

When receiving＜register cancellation〉time, original MSC determines that whether indicating this MS about the information of corresponding MS is in call service.When carrying out normal call release (when by the opposing party or MS client's end call), original MSC cancels the MS information that is registered among its VLR in response to the registration mandatum cassatorium of its VLR, notifies completing successfully of HLR registration mandatum cassatorium then.Yet when calling had been dropped, the MS information that is registered among the VLR remained call service in progress.

Therefore, if MS information does not have the indicating call service in progress, then original VLR deletion MS information is also carried out normal running.Fig. 8 C is the flow chart that is described in normal running in the case.With reference to Fig. 8 C, original VLR deletes MS information and sends response message to HLR, and notification enrollment mandatum cassatorium result is successful.That is to say original VLR general＜registration cancellation return messages (success)〉send to HLR.This HLR is with this signal＜registration cancellation return messages (success)〉send to current VLR, current VLR sends to current MSC with this signal again successively.Current MSC confirms with location registers that response message＜position upgrades and accepts〉send to current BS.Then, current BS takes orders location registers response message＜registration〉send to MS.

Turn back to Fig. 8 B, if corresponding MS information indicating call is served in progress, then original VLR general＜enroll in notifications is returned (failure)〉send to HLR, but do not delete MS information.This original VLR will register connection message again and send to original MSC.

Figure 13 illustrates according to the registration of the one embodiment of the invention structure of connection message again.This registers again, and connection message comprises following parameters: Electronic Serial Number (electronic serial number, ESN), mobile identifier (mobile identification number, MIN), MSC ID and lane place ID, these all are used for inter-system paging 2.ESN is the production number of terminal, and MIN is that customer ID, MSC ID are the ID of MSC, and lane place ID indication paging zone.

Turn back to Fig. 8 B, when receiving from original VLR＜enroll in notifications return results (failure)〉time, HLR is general＜enroll in notifications return results (failure) successively〉send to current VLR, this current VLR general＜enroll in notifications return results (failure)〉send to current MSC.This current MSC refuses response message＜position with location registers and upgrades refusal〉send to BS.This BS successively again should＜refusal is upgraded in the position send to MS.

Simultaneously, receive the original MSC that registers again connection message from original VLR inter-system paging is tried in the zone of being indicated by the lane place ID that is included in the MSC ID that registers again the connection message.That is to say that original MSC is with message＜inter-system paging 2〉send to current MSC, and this current MSC is by the tentative paging to MS of BS.Then, current MSC sends to BS with page request signal, and BS sends to MS in response to this page request signal with beep-page message.

Then, shown in Fig. 8 A, MS sends to BS with page-response message, and then, BS is with signal＜finish L3 information: page response〉send to current MSC.In response to＜finish L3 information: page response 〉, current MSC is with signal＜inter-system paging 2 return results〉and send to original MSC.

Follow-up calling Connection Step again thereby has been saved description of them with shown in Figure 2 identical.

Fig. 9 and 10 is respectively in the prior art with according to the state transition graph of the call treatment of one embodiment of the invention.In the prior art, as shown in Figure 9, when in calling procedure, receive call release request or after calling is dropped the scheduled time directly enter idle condition for example after 5 seconds.Compared with prior art, in one embodiment of the invention, as shown in figure 10, call out afterwards when dropping when first scheduled time in the call service process (preferably 1.2 seconds), enter stand-by state, with Waiting for Call connection request again, and this stand-by state is transformed into dialogue state by the calling paging that connection request carried out again through utilizing location registers to carry out.Yet, continue second scheduled time (preferably 30 to 60 seconds) if call out to drop at stand-by state, enter idle condition.If request call discharges in dialogue or stand-by state, then enter idle condition immediately.

As mentioned above, the invention has the advantages that, connect dropped call automatically again, alleviated the inconvenience that recovers the calling of in elevator or tunnel, temporarily dropping by the location registers in PLMN.Therefore, exempted the worry that the client drops to calling, and improved calling service quality.

Though illustrate and described the present invention with reference to embodiments of the invention above, but it will be appreciated by those skilled in the art that, under situation about not breaking away from, can carry out modification on various forms and the details to the present invention by the defined the spirit and scope of the present invention of claims.

Claims (12)

1. method that in mobile communication system, is connected the communication link that viability stops by service obstacle again, described mobile communication system has a plurality of base stations (BS) and a plurality of mobile switching centre (MSC), described service is to carry out between first client's a portable terminal and second client's a terminal, described second client is by one among the described a plurality of BS that are connected to described portable terminal and be connected among described a plurality of MSC of described BS at least one, come and described first client communication, described method comprises step:

After described service obstacle, receive a position register request message from described portable terminal;

Described message is sent to location register, and this location register is stored the previous position of described portable terminal;

Whether the information of determining to be stored in the described location register about described portable terminal indicates described obstacle; With

Tentative connection again between described portable terminal and client.

2. the method for claim 1 also comprises: if described information of mobile terminal indication obstacle then carries out BS and begins service again between described first client's portable terminal and described second client's terminal.

3. the MSC that the method for claim 1, wherein is connected to BS carries out and sends, determines, tries at least one step in the step.

4. the method for claim 1 also comprises step: if service obstacle continues first predetermined amount of time at least, then notify described second client's terminal wait to connect again.

5. the method for claim 1 also comprises step: if service obstacle continues first predetermined amount of time at least, then notify described first client's portable terminal to wait for connection again.

6. the method for claim 1, also comprise step: if the service between described first client's portable terminal and described second client's the terminal begins to have failed again, then informational message is sent to described second client's terminal, begin again to have failed with the Terminal Service of notifying described second client.

7. the method for claim 1, wherein described location register forwarding step also comprises step: a position register request is sent to current temporary position register.

8. method as claimed in claim 7 also comprises step:

One position register request is sent to a former mat location register; With

When the location register of the described current temporary position register previous position that is not memory mobile terminal, a registration cancellation request is sent to the location register of the previous position of memory mobile terminal.

9. method as claimed in claim 8 also comprises step in determining step:

When the location register of the previous position of memory mobile terminal has the information of mobile terminal of indication service in progress,, then send the message of the invalid registration cancellation of indication if receive registration cancellation request.

10. method as claimed in claim 8 also comprises step in determining step:

Deletion is stored in the positional information of the portable terminal in the location register, and this location register is stored the previous position of described portable terminal; With

When the described location register of previous position of the described portable terminal of storage has the indication service not during the information of mobile terminal in progress, send the message of indicate successfully registration to cancel.

11. method as claimed in claim 9 also comprises step in determining step:

The message of the invalid registration cancellation of indication is sent to current temporary position register; With

When the step that sends invalid registration cancellation message is when being carried out by the location register of the previous position of memory mobile terminal, message that will the invalid registration cancellation of indication sends to the MSC that links to each other with the BS of receiving position register request message.

12. method that in mobile communication system, is connected viability by the communication link of service obstacle termination again, described mobile communication system has a plurality of base stations (BS) and a plurality of mobile switching centre (MSC), described service is to carry out between first client's a portable terminal and second client's a terminal, described second client is by one among the described a plurality of BS that are connected to described portable terminal and be connected among described a plurality of MSC of described BS at least one, come and described first client communication, described method comprises step:

Determine whether described service obstacle has continued to be at least first predetermined amount of time;

If described service obstacle has continued described at least the first predetermined amount of time, then notify the described portable terminal of described first client to connect again in the service of waiting for, and the described portable terminal of initialization;

If described service obstacle has continued described at least the first predetermined amount of time, then an informational message is sent to described second client's described terminal, notify the described terminal of this second client to connect again in the service of waiting for, and the described portable terminal of initialization;

If a MSC receives position register request message by a BS from described portable terminal, then by described MSC one location register of the previous position of storing described portable terminal is sent, described MSC is connected in the described BS that is wirelessly connected to described portable terminal;

Whether the information of mobile terminal of determining to be stored in the described location register indicates service in progress;

Connect paging again by described MSC is tentative; With

If described information of mobile terminal indication service in progress, then begins the service between described first client's described portable terminal and described second client's the described terminal again.

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