CN1078802C

CN1078802C - Method of routing international call to foreign mobile subscriber

Info

Publication number: CN1078802C
Application number: CN94195224A
Authority: CN
Inventors: 曼·伊尤·李
Original assignee: Nokia Telecommunications Oy
Current assignee: Nokia Oyj
Priority date: 1994-12-23
Filing date: 1994-12-23
Publication date: 2002-01-30
Anticipated expiration: 2014-12-23
Also published as: CN1174649A

Abstract

A new prefix which is an international mobile call prefix is arranged in a telecommunications network, such as PSTN, for confirming a routing of an international call originating from PSTN to a foreign mobile subscriber. When receiving the international mobile call prefix in a dialed telephone number, a local PSTN exchanger transfers the calling routing to a predetermined target in the same country; the predetermined target is a network unit having the capability of inquiring the international routing information of the home PLMN of the called foreign mobile subscriber. When the routing information is received from the home PLMN, according to the routing information, the call routing is transferred to the current location of the called foreign mobile subscriber. Thus, when the called mobile subscriber roams abroad, the present invention can avoid occupying unnecessary international lines.

Description

The route selection method of mobile subscriber's international call abroad

The present invention relates to the Route Selection of international call, for example from a PSTN user to Home PLMN in the Route Selection of a mobile subscriber's of foreign country calling.

Modern mobile telecommunications network provides a kind of new, attractive performance: several operations are the roaming between Public Land Mobile Nerwork (PLMN) independently.The roaming that is positioned between the PLMN of country variant is called international roaming.Usually mobile subscriber and a PLMN have predetermined relationship.This specific PLMN is called mobile subscriber's the PLMN that returns.The mobile subscriber also can obtain service from other PLMN, but all depends on predetermined various situations in various situations.A mobile subscriber who for example has predetermined relationship with the domestic PLMN of Finland also can carry out outgoing call and receive incoming call by another PLMN PLMN of Germany for example, and prerequisite is to reach an agreement between the network operator of this two PLMN.Another PLMN is sometimes referred to as visit PLMN.Pan-European digital mobile radio system GSM (Global Systems for Mobile communications) and its modified model DCS1800 (digital communication system) are exactly an example of supporting the modular system of international roaming.The SIM roaming of having only a subscriber identification module (SIM) mobile is also supported in the both travelling carriage roaming of supports mobile from a PLMN to another PLMN of GSM.The latter also can allow to have incompatible wave point, for example has the roaming between the PLMN of different operating frequency.

An obvious deficiency that makes international roaming reduce attraction is the expense of international call.Usually the calling party will pay for the first half Route Selection to callee's Home PLMN, and the callee be second half Route Selection paying from Home PLMN to visit PLMN.Therefore, the callee has to pay an expensive international call expense, though to he/do not want that the calling that receives also wants so.Expensive calling charge will make the mobile subscriber abandon using widely services of roaming.In fact, it is believed that most of mobile subscribers will make the incoming call locking when roaming.

In the international call of making a start to roaming mobile stations, call route selecting is optimised usually.Yet receiving end is that the call route selecting of roaming mobile stations is not optimized, and therefore can cause unnecessarily taking two international lines and pay very high international call expense.Below with reference to Fig. 1 and Fig. 2, utilize case method to explain this problem.

Among Fig. 1, be positioned at Australian PSTN user and carry out international call in Germany and a mobile station MS being sitting at Home PLMN to Home PLMN.PSTN user dials down prefix 0011 and mobile station ISDN number MSISDN, comprises country code cc among the MSISDN _xNational destination code NDC and Subscriber Number SN.Prefix 0011 is Australian international call code, and therefore local PSTN switch will be called out route switching to Australian international PSTN gateway.International PSTN gateway will be called out route switching to target state, i.e. Germany again according to country code cc.The international PSTN gateway of Germany will be called out the gateway MSC of route switching to the Home PLMN of called MS according to national destination code NDC.Gateway MSC inquires about to the home location register HLR of called MS according to NDC SN, and according to the mobile station roaming number MSRN that obtains by HLR, will call out route and receive called MS.Under above situation, PSTN user will be whole call payment.

The supposition called MS is roamed in Australian visit PLMN among Fig. 2.Similar with the first half Route Selection of last kind situation, call out and at first be routed home country and the Home PLMN of receiving called MS.Obtain the roaming number MSRN of travelling carriage then by HLR, call out then and will newly receive Australian MS by another international line route.The result has taken two international lines and corresponding call expense in this calls out.Pay the expense of another international line by the calling party, pay the expense of second international line by the callee.

Cause that this strange and expensive routing structure has several reasons in the international call.In the present route topological structure of telecommunications network a hundreds of switch is arranged, have a route to represent in each switch to find the correct route of calling.Safeguard that these routing tables are very consuming time and complicated, so these tables are done usually simply as far as possible.So, only analyze several in the telephone number of being dialled in each part of calling out route.For example, when PSTN user dialled down the telephone number of 0011 CC NDC SN, local PSTN switch was only recognized international prefix 0011, directly entered international gateways then, as in the situation shown in Fig. 1 and Fig. 2.Local PSTN switch has been ignored those content of back in the telephone number.Thereby suggestion can be to carry out the intelligent gateway that call route selecting is optimized in the HLR inquiry along any equipment in call treatment path in the GSM regulation.Yet, realize that this function will require in existing international gateways PSTN switch to realize GSM signaling performance, this will require some very expensive softwares to improve or because what use is that the old acquaintance changes platform and perhaps may.By utilizing the rerouting performance of the international gateways relevant, in fact can overcome these problems in the present regulation of CCITT with CCITT Common channel signalling system 7 (C7).But international carrier wave and PTT are difficult in and realize automatic rerouting function in their international gateways, and reason is as follows:

One international circuit is not the use of all supporting common channel signalling bar system 7.In non-C7 system, will be difficult to realize the rerouting function.

-common international call does not also require this function.Have only automatic international roaming or the International Call Forwarding situation of GSM or PCS1800 just to require the rerouting function.This only accounts for a quite little percentage in whole service.

--the expense that the rerouting function increases fast only can cause their incomes still less.No longer take two international lines because the Route Selection after optimizing can cause selecting, therefore can reduce the international long-distance expense.

So exist to improve the needs of international Route Selection, in international automatic roaming, to avoid PSTN to start and the international line of necessity that mobile terminating is called out.

An object of the present invention is to improve the Route Selection that international mobile terminating is called out.

Further purpose of the present invention is for the mobile subscriber's who is arranged in the mobile communication system of supporting international automatic roaming international call, avoids taking two circuits.

These and other objects of the present invention and advantage can realize in this way, be first user and carry out Route Selection to the international call of Home Public Land Mobile Network (PLMN) a mobile subscriber of second country from first telecommunications network of being arranged in first country, wherein:

Another user who is arranged in first telecommunications network of first country dials next predetermined the mobile station ISDN number of sewing with the callee, predetermined prefix is only kept by the international mobile subscriber terminating call in first country, and callee's Home PLMN is arranged in second country.

First telecommunications network in first country is according to said prefix, has a predetermined network element of international PLMN query capability in first country calling out route switching,

Predetermined network element is inquired about to the callee's who is positioned at second country Home PLMN.

Callee's Home PLMN sends the mobile subscriber who distributes to the callee to predetermined network element and swims number slowly,

Predetermined network element is called out direct route switching to destination according to the Mobile Station Roaming Number handle.

According to the present invention, for example among the PSTN, provide a new prefix at telecommunications network, the international call Route Selection that it is used for PSTN is started is to foreign mobile subscriber.The new prefix here is called international mobile calls prefix, and for the outgoing international call, it has replaced the common prefix before the standard telephone Subscriber Number.When local PSTN switch receive during international mobile calls prefix in dialing the number, it will be calling out the predeterminated target of route switching in the same country.This predeterminated target is that the Home PLMN that has to called foreign mobile subscriber carries out the network element of international road with the information inquiry ability.When Home PLMN receives routing information, will be according to routing information calling out route switching to the present position of called foreign mobile subscriber.For the situation that called foreign mobile subscriber roams outside Home PLMN, call out route and directly be transferred to visit PLMN, and need not take the unnecessary international line of Home PLMN.Be positioned at the situation of same country for visit PLMN and caller PSTN user, calling will be a quite cheap local call, and not take international line in calling.Compare with the routing infrastructure of prior art, promptly compare with the structure that will set up two international lines when roaming in the country of mobile subscriber the calling party, this can cause calling charge significantly to reduce.Same when called foreign mobile subscriber roams in third country, call route selecting is also optimised, than the routing structure of prior art more economically.In fact, the call route selecting that starts of PSTN will be optimised as mobile-originated call.PSTN arrives the requester network unit according to international mobile calls prefix calling out route switching, this network element can be the existing mobile switch of a PLMN in this country, or provides the specific purposes service centre of inquiry and route service for start foreign mobile subscriber's international call of PSTN.The inquiry and the network operator of route service can be the PSTN or the PLMN network operators of this country, perhaps also can with their independence mutually.The present invention can cause the calling roamed for the mobile subscriber outside Home PLMN, its calling charge reduces, thereby makes automatic international roaming all have more attraction to mobile subscriber and PSTN user.For those frequently travellings and expecting to have in these two countries for the mobile subscriber of a large amount of calling local calls between two countries, the present invention is particularly favourable.Calling out in many cases will be local call, perhaps be the calling that only takies an international line under any call case.The user also can utilize predetermined conditions, is not the situation of roaming or roaming outside these two countries in caller PSTN side country for the callee for example, comes the locking call route selecting.

Can realize the present invention with a kind of simple mode.In the PSTN network, new international mobile calls prefix must join in the routing table of switch.Having new prefix calling and will be routed the requester network unit that is transferred to, can be the existing gateway mobile switch that international call has been had essential inquiry and routing capability.

When the explanation below reading in conjunction with the accompanying drawings, these and other purpose and advantage of the present invention will be obvious, in the accompanying drawing:

Fig. 1 describes the PSTN international call of starting to be sent to the system block diagram of the foreign mobile subscriber's who is positioned at Home PLMN prior art call route selecting,

Fig. 2 describes PSTN to start international call to the system block diagram in the prior art call route selecting of a foreign travelling carriage of visit PLMN roaming,

Fig. 3 is according to the present invention, describes PSTN and starts international call to system block diagram in the foreign mobile subscriber's of visit PLMN roaming call route selecting,

Fig. 4 describes specific purposes inquiry switch and PSTN to start international call to the system block diagram of the foreign mobile subscriber's who visits the PLMN roaming call route selecting,

Fig. 5 describes specific purposes inquiry switch and PSTN to start international call to the system block diagram of the foreign mobile subscriber's who is positioned at Home PLMN call route selecting,

Fig. 6 describes specific purposes inquiry switch and PSTN to start international call to the system block diagram in the foreign mobile subscriber's of third country's roaming call route selecting,

Fig. 7 represents the structure of travelling carriage telephone number,

Fig. 8 illustrates a MSISDN who has international mobile calls prefix,

Fig. 9 illustrates a routing table that has international mobile calls prefix according to the present invention, and

Figure 10 A and 10B illustrate the MSISDN that comprises international mobile calls prefix.

The present invention can be used in the international call from other circuit switched radio communications networks to any one mobile communication system of supporting automatic international roaming.

Calling can be from providing the circuit switching telecommunication service, for example any one telecommunications network of speech, fax or bearer service.The general character of these networks be they according to the numeral of being dialled to calling out the route of determining from the originating terminal to the termination ends, the numeral of being dialled is normally numbered with the isdn number form.Other such network also comprises, for example the public land mobile telecommunications network of PSTN (public switch telephone network), ISDN (integrated services digital network) and other kind, for example NMT etc.Below, will contrast execution mode of the present invention be described in conjunction with PSTN.Yet the present invention is not limited only to this ad hoc network.

The purpose network of calling out can be for example European digital mobile telephone system GSM (Global Systems for Mobile communications) and its modified model PCS1800 (digital communication system).The both travelling carriage roaming of supports mobile from a PLMN to another PLMN of GSM also support to have only the mobile SIM roaming of a User Recognition chess piece (SIM).The latter also allows to have incompatible wave point, for example roaming between the PLMN of different operating frequency.Below in conjunction with gsm system preferred implementation of the present invention is described.But, the present invention is not limited to this special system.

The special construction of the routing procedure that mobile terminating is called out in mobile communication system and the mobile communication system is not the most basic to the present invention.Therefore will no longer describe here.Can be about description referring to GSM regulation and " mobile communication gsm system " book of publishing at French Palaiseau in 1992 by M.Mouly and M.Pautet to gsm system, book number is ISBN:2-9507190-07-7.

Above with reference to figure 1 and Fig. 2, go abroad traditional Route Selection of the international call of employing the family from PSTN user has been described more.Comprise Australian international call code 0011 and travelling carriage telephone number MSISDN in the telephone number that PSTN user dialled, comprise country code cc, national destination code NDC and Subscriber Number SN among the MSISDN.Fig. 7 shows the structure of MSISDN.It is similar to standard P STN or ISDN number that MSISDN seems, but that the NDC sign is a mobile system network operator in the country, rather than an area code.Because MSISDN is not meant a telephone wire or a position, and then first bit digital among the Subscriber Number SN of NDC is used for identifying the HLR of relevant user in the Home PLMN.Comprise that so-called final goal is the MSC that GSM user is visiting in order to now to call out the necessary information of final goal in the HLR record.Therefore, have only inquiry just can carry out last Route Selection behind the HLR.First's Route Selection only uses the information that obtains from called number MSISDN to carry out, and with callee's location independent.For any one ISDN number, utilize the table in the receiver of each participation can both determine this part Route Selection.For example, when dial international prefix down before MSISDN, for example Australia is 0011, then as with reference to figure 1 and Fig. 2 the time described like that, the PSTN switch the calling route switching to the PSTN international gateways.

In PSTN, provide a new prefix according to the present invention, be used for PSTN is started the international call pathfinding to foreign mobile subscriber.New prefix is called international mobile calls prefix G+ here, as shown in Figure 8, has replaced the common international prefix before the MSISDN for the outgoing international call.Perhaps also can resemble and to draw among Figure 10 A and the 10B, the example that will describe in Fig. 4 utilizes the part of MSISDN as prefix like that below.Have this new prefix (or a plurality of prefix) in the routing table in the PSTN switch.A routine routing table shown in Fig. 9, it comprises the prefix 0011 that is used for PSTN international gateways (IntlGW), is used for the prefix 041 of OPTUS GSM (Australian GSM net) and is used for the prefix 049 of GSM inquiry MSC according to the present invention.As described below, use

prefix

041 or 049 to be used as international mobile calls prefix according to concrete application.

When the PSTN switch is received international mobile calls prefix G+, it will call out the predeterminated target of route switching in the same country.This predeterminated target is to have a network element of carrying out international route information query ability to the Home PLMN of called foreign mobile subscriber MS.This requester network unit can be a gateway mobile switch GMSC among the existing PLMN as will be with reference to figure 3 described.During this situation, prefix G+ can be the prefix that has the PLMN of some additional characters, is 0411999 for Optus GSM for example.Perhaps, the requester network unit also can as will with reference to figure 4,5 and 6 described like that, be the service centre of specific purposes.At this moment, can be a private code according to international prefix of the present invention, be 049 for example to the inquiry of the GSM among Figure 10 MSC.Prefix G+ can be different in country variant, perhaps, can use GSM and expect in the country of automatic roaming business at all, distributes a prefix G+ to be used to provide this neoteric route.When using international C7 net to realize according to international Route Selection of the present invention, this point is particularly favourable.

Referring now to Fig. 3,4,5 and 6 utilize example, explain according to Route Selection of the present invention.

Among Fig. 3, Australian PSTN user carries out international call to Home PLMN at Germany, present mobile station MS in Australian visit PLMN roaming.Prefix 0411999 was as the international call prefix under PSTN user dialled before MSISDN.Local PSTN arrives Australian Optus GSM network according to 0411999 these numerals calling out route switching.In the numbering plan of Optus GSM net, distribute a special service layer to numeral 0411999.In other words, the gateway MSC among the Optus GSM is with 0411999 special layers that is interpreted as being used to roam MS.Gateway MSC will analyze the CC NDC among the MSISDN, and the HLR of identification Germany.Gateway MSC utilizes the signaling protocol MAP inquiry HLR of GSM.HLR in the Home PLMN of Germany roaming MS will send mobile station roaming number.Because MS Australia's roaming, MSRN will be the address of a MSC/VLR among the Optus GSM, so inquiry gateway MSC can receive the MSC that is arranged in Australian local plmn calling out route.Therefore do not need international line, and only with setting up a local call.

According to another embodiment of the invention, utilize a kind of specific purposes service centre to inquire about and be that international mobile calls is determined route.Among Fig. 4, the GSM inquiry MSC that provides has the GSM query capability.We suppose once more: in Germany, the MS in Australian visit PLMN roaming carries out international call to Australian PSTN user now to Home PLMN.PSTN user dials international mobile calls prefix 049 down earlier before MSISPN.Australian local PSTN is according to the routing table among Fig. 9, calling out route switching to also inquiring about MSC at Australian GSM.The HLR of GSM inquiry MSC in the called MS Home PLMN in Germany inquires about.Among Fig. 4, CC is not the numeral under dialling, but hint is in 049 prefix.HLR sends the MSRN that indicates a MSC/VLR in the local plmn (visit PLMN) to GSM inquiry MSC.So GSM inquiry MSC is calling out route switching to Australian local plmn.

Fig. 5 described when Australian PSTN user to having Home PLMN in Germany, the call route selecting the when MS that is positioned at Home PLMN now carries out international call.PSTN user dials prefix 049 down once more before MSISDN.Similar with Fig. 4, call out route switching to Australian GSM inquiry MSC, the HLR in the Home PLMN of Germany inquires about then.Because called MS is positioned at Home PLMN, HLR will send the MSRN of a MSC in the German Home PLMN of indication.When receiving MSRN, Australian GSM inquiry MSC will call out route switching to Australian PSTN international gateways, and then receive the PSTN international gateways of Germany, at last to the gateway MSC that is positioned at German Home PLMN.The described situation of this situation and Fig. 1 is similar, only needs an international line.

Among Fig. 6, in Germany, the MS in the visit PLMN of foreign country of third country roaming carries out international call to Australian PSTN user now with Home PLMN.PSTN user dials international mobile code prefix G+ again, calls out route and is transferred to GSM inquiry gateway.GSM inquiry gateway is inquired about to the Home PLMN that is positioned at Germany, and receives the MSRN of a MSC who indicates the visit PLMN of foreign country that is positioned at third country.Therefore, GSM inquiry gateway will be called out route switching earlier to Australian PSTN international gateways, arrive the PSTN international gateways of third country again, the PLMN that goes abroad then.International line between Australia and Germany will be avoided taking once more.

GSM inquiry MSC is that the calling of foreign number can have blocking function to those MSRN.For example, have only when MS in Australia or when German, GSM inquiry MSC just can be with call route selecting.

The network operator of GSM inquiry MSC can be a PSTN or PLMN network operator, and is perhaps all independent with them.Use international mobile calls prefix will carry out independent call charging, but expense is more much lower than the expense of international call.Have only those PSTN or PLMN users of having preengage international mobile calls prefix service separately, just allow to use international mobile calls prefix.

Accompanying drawing and relevant description are only in order to explanation the present invention.Details of the present invention can change to some extent in the scope and spirit of appended claims.

Claims

1. method is used for for first user from first telecommunications network of first country carries out Route Selection to the international call that the mobile subscriber with Home Public Land Mobile Network in second country carries out, wherein:

First user in first telecommunications network of first country dials down the number of predetermined prefix and callee's travelling carriage ISDN(Integrated Service Digital Network), should predetermined prefix only be that the international mobile subscriber terminating call keeps in first country, the ownership mobile network that is moved the user is positioned at second country

First telecommunications network in first country is according to said prefix, calling out the predetermined network unit that route switching has international mobile network query capability in first country,

The predetermined network unit is inquired about to the callee's who is positioned at second country ownership mobile network,

Callee's ownership mobile network sends the Mobile Station Roaming Number of distributing to the callee of the current location be used for determining the callee to the predetermined network unit,

Direct route switching will be called out to destination according to Mobile Station Roaming Number in the predetermined network unit.

2. according to the process of claim 1 wherein,

First telecommunications network of first country is according to said prefix, the mobile switch of calling out in route switching has international mobile network query capability to first country the mobile network.

3. according to the process of claim 1 wherein

First telecommunications network of first country, to call out the switch of route switching to a specific purposes according to said prefix, this switch is the international call of starting from first telecommunications network of first country, provides inquiry and definite route service to the ownership mobile network the mobile subscriber of foreign country.

4. according to the process of claim 1 wherein

First telecommunications network of first country is according to said prefix, calling out route switching to mobile network inquiry gateway.

5. according to the method for claim 1, comprise the following steps:

By predetermined network element analysis mobile station roaming number,

By the predetermined network unit, forbid call route selecting to the destination that is positioned at outside first and second country.

6. according to a kind of method of claim 1, comprise the following steps:

By predetermined network element analysis mobile station roaming number,

By the predetermined network unit, forbid the destination of call route selecting outside first country.

7. the method for any one in requiring according to aforesaid right, wherein first telecommunications network is a public switch telephone network or ISDN(Integrated Service Digital Network).