HOHERFESTES , TWIP-EIGENSCHAFTEN ΆUFWEISENDES STAHLBAND ODER -BLECH UND VERFAHREN ZUR DESSEN HERSTELLUNG MITTELS "DIRECT STRIP CASTING "
Technical Field
5 The present invention relates to a method and a serving node for content based charging of Short Message Services in a telecommunications network supporting number portability. Background Art
In modern mobile communications networks, such as second
10 generation Global System for Mobile Communications (GSM) networks or third generation Universal Mobile Telecommunications System (UMTS) networks, mobile subscribers are identified within their home network by a Mobile Subscriber Integrated Services Digital Network Number (MSISDN), which is dialled for calling the subscriber by mobile or fixed networks, such
15 as a Public Land Mobile Network (PLMN), an Integrated Services Digital Network (ISDN) or a Public Switched Telephone Network (PSTN). The MSISDN is also used by the exchanges of the network such as the switching centres and by the location registers for routing calls and for updating subscriber location information.
20 With reference to Figure 1, GSM networks notoriously comprise a number of sub-networks, for instance networks 11 and 12, which are managed by a respective operator and cover the same or different geographical areas.
Each network comprises a Gateway Mobile Services Switching
25 Centre (GMSC) for switching calls to or from other mobile or public telephone networks. Referring to Figure 1, GMSCs 111, 121 are provided into mobile networks 11 and 12, respectively, and they are connected to each other and to a PSTN 13.
Networks 11 comprise respective Mobile Services Switching Centres
30 (MSCs) 112, 113, 114, 122 and 123, which are associated with respective
service areas and which may also share geographical areas. MSCs switch speech and data connections between Base Station Controllers (BSCs), other MSCs, other networks and external non-mobile networks. The MSCs also handle a number of functions associated with mobile subscribers, among others registration, location updating and handover between a user equipment and the PLMN.
As illustrated in Figure 1, a service area 110 of the network 11 is served by a BSC 116, which communicates with the MSC 112 of the service area 110 and with user equipments which are visiting the service area, such as mobile station 117. Similarly, in the network 12, MSC 122 serves a service area 120 visited by a mobile station 127, which communicates with the MSC 122 via a BSC 126.
Each MSC comprises or is connected to a Visitor Location Register (VLR): for instance, MSCs 112 and 122 are connected to VLRs 115 and 125, respectively. The VLR stores data about all the users that are roaming within the service area of the corresponding MSC. This data is updated through a location update procedure initiated from the user equipment of each subscriber via the MSC, or directly from the subscriber's home service node, such as Home Location Register (HLR) 118, 128. The HLR is the home register of the subscriber, which particularly stores information about the subscription, the subscriber's identification data and profile, the services that the subscriber is entitled to and the subscriber's location. When the subscriber roams into the service area of an MSC different from the home MSC, the HLR is updated accordingly. It is known that the HLR of a network permanently stores the
MSISDNs of the mobile stations of the subscribers to that network, for identifying their location when routing calls or short messages. Particularly, if a call to a mobile station 117 is initiated by a mobile station 127 of another network, the GMSC 111 of the called party is contacted by the GMSC of the calling party and accordingly it sends a Mobile Application
Part message to the HLR 118, which in turn interrogates the VLR 115 based on the MSISDN stored therein.
Since different ranges of MSISDNs are usually assigned to different operators, in the prior art the MSISDN explicitly and clearly identified the corresponding network operator. However, in the past few years Number
Portability (NP) has been introduced in order to allow subscribers to change the GSM or UMTS network operator without changing their telephone number, i.e. the MSISDN; in such cases, the mobile station ISDN number is called "portable number". A subscriber whose MSISDN belongs to a number range assigned to a first network operator and who has been ported to a second network operator is referred to as an "exported" subscriber, while a subscriber who has not been ported is a "home" subscriber.
While portability on one hand is a feature "that greatly improves flexibility and appeal of the mobile communications;, on the other hand its implementation is made difficult by the lack of key information data, namely the lack of a one-to-one relationship between, the MSISDN and the
PLMN operator.
In addition to the implementation difficulties, thie NP may not be fully adopted by certain network operators since the charging of the services they provide to their home subscribers may not apply to tke exported subscribers and, accordingly, exported subscribers may even benefit of such services for free.
One of such services is the Short Message Service (SMS), which allows to send a short text message (SM) via at least one serving node from an originating entity to a receiving entity.
According to the Technical Realization of the SMS of the 3rd
Generation Partnership Project, no. 23.040, release 5 (TS 3GPP 23.040 v5.0.0), PLMN networks comprise a Short Message Service Center (SC), which stores Short Messages and forwards them to destination mobile
stations. The SC is usually not a part of the GSM/UMTS PLMN, however the MSC and the SC may be integrated. One SC may be connected to several PLMNs and it may also be connected to several MSCs within one and the same PLMN. The skilled in the art is aware that the function of an MSC capable of receiving a short message from an SC5 interrogating an HLR-. for routing information and SMS info, and delivering the short message to the visited MSC or to the SGSN of the recipient MS is called Gateway MSC for Short Message Service (SMS-GMSC), and the function of an MSC capable of receiving a short message from within the PLMN and submitting it to the recipient SC is called Interworking MSC for Short Message Service (SMS- IWMSC). For simplicity, hereinafter reference will be made to MSCs in general regardless of their particular SMS-GMSC or SIVES-IWMSC capabilities. With reference to Figure 2, the basic network structure of the SMS comprises a sending/receiving mobile station (MS) 21, an MSC 23 of an area visited by the MS, the VLR 26 for that area, an SMS-GMSC/SMS- IWMSC 24 connected to an HLR 25 and an SC 22.
In a Mobile Originated Short Message (MO-SM), the originating (or sending) entity is the user of the mobile station who addresses a short message to the SC, which is a receiving entity having the special feature of storing and relaying the message. With reference to Figure 2. in the MO- SMS the MS 21 sends the short message to the MSC 23 (or to the SGSN in the case of a GPRS network), then the visited PLMN routes the message to the appropriate SMS-IWMSC 24 in the SCs PLMN5 transiting over other networks if necessary.
In a Mobile Terminating Short Message (MT-SM), tixe SC is the sending entity, while the destination mobile station is the terminating (or receiving) entity. The SC 22 sends the short message to the SMS-GMSC 24, then the SMS-GMSC 24 interrogates the HLR 25 to retrieve routing
information necessary to forward the short message and finally sends the message to the relevant MSC 23 (or SGSN), transiting over other networks if necessary. The MSC (or SGSN) then sends the short message to the MS 21. It is known that, in the MO-SMS and the MT-SMS, Short Messages are charged using the MSISDN of the terminating and of the originating entity, respectively. The MSISDNs of the terminating and originating entities are also called MSISDN-B and MSISDN-A5 respectively.
As anticipated, with the introduction of Number Portability in the mobile networks, the MSISDN is no longer a reliable identifier to perform the charging analysis, in that the MSISDN does not univocally identify the network of the originating or terminating entity. At the same time, the MSISDN has to be used in the SMS for correctly routing the short messages. Disclosure of the Invention
The aim of the present invention is to overcome the above mentioned drawbacks, by providing a method and a network which can correctly charge a user of an SMS in mobile networks supporting number portability. Within this aim, an object of the present invention is to provide a charging method and network which can charge a subscriber regardless of the ported status of the mobile station number.
Another object of the invention is to render the charging method independent of the particular implementation of the Number Portability function. A further object is to preserve the standard architecture of the radio communication networks without affecting the communications standards among the various entities interacting over the network.
Yet another object of the invention is to meet the needs of both the subscriber and the operator, by assuring the former that the Short Message Service is always provided and by satisfying the profit of the latter, who is
guaranteed that any SMS will be correctly charged.
This aim, these objects and others whicli will become better apparent hereinafter are achieved by a method for handling Short Messages in a telecommunications network supporting number portability at a serving node, comprising the steps of receiving a short message for a receiving entity and fetching a subscriber mobile station number from the short message; interrogating a number portability register for receiving a charging-related identifier representative of the network to which said mobile station number is ported; forwarding the identifier to a Service Control Function node for charging the short message according to porting information carried by the identifier; and sending the short message to the receiving entity.
The aim and the objects of the invention are also achieved by a serving node for handling Short Messages in telecommunications networks supporting number portability, the serving node comprising: means for receiving short messages for receiving entities; means for fetching subscriber mobile station numbers from the short messages; means for interrogating at least one number portability register, the means for interrogating comprising means for sending charging related queries to the at least one number portability register and means for receiving charging- related identifiers respectively representative of the network to which the mobile station numbers are ported, the serving node further comprising a Service Control Function node for charging trie short messages according to porting information carried by the corresponding identifiers. According to an embodiment of the invention, the serving node comprises a Mobile Number Portability Signalling Relay Function for relaying messages sent to the serving node. In such case, the interrogating, step preferably comprises the steps of sending a Mobile Application Part query message to the number portability register and receiving a Mobile Application Part acknowledgement message returning the identifier to the
serving node.
According to another embodiment of the invention, the serving node has Mobile Number Portability Intelligent Network capabilities. In this case, the interrogating step preferably comprises the steps of sending an Intelligent Network Application Part query message to the number portability register and receiving an Intelligent Network Application Part acknowledgement message for returning the identifier to the serving node.
Advantageously, at the number portability register, it is checked whether the mobile station number is ported to a network different from a home network identified in the mobile station number and, if so, a network prefix representative of the different network and the mobile station number are returned. The network prefix and mobile station number are comprised in the identifier.
According to yet another embodiment of the invention, the serving node has Local Number Portability Intelligent Network capabilities. In this case, the interrogating step comprises the steps of sending a PRE Intelligent Network Application Part query message to the number portability register and receiving a PRE Intelligent Network Application Part acknowledgement message for returning the identifier to the serving node. Advantageously, at the number portability register, it is checked whether the mobile station number is ported to a network different from a home network identified in the mobile station number and, if so, a Location Routing Number and the mobile station number are returned. The Location Routing Number and the mobile station number are comprised in the identifier. According to further details of the present invention, the telecommunications networks involved support Customized Applications for Mobile Enhanced Logic.
Advantageously, if from the checking the mobile station number results not to be ported to a network different from the home network identified in the mobile station number, the identifier is returned comprising
the mobile station number only.
Serving Nodes may be any one of a Mobile Services Switching Center, a Gateway Mobile Services Switching Center, a Serving GPRS Support Node or any other exchange which can switch and relay incoming short messages. The telecommunications network may be any one of a 2G or 3 G mobile communication network, such as a GSM or a UMTS network. Brief Description of the Drawings
Further characteristics and advantages of the present invention will become better apparent from the following detailed description of preferred but not exclusive embodiments thereof, illustrated by way of non-limitative examples in the accompanying drawings, wherein:
Figure 1 is a schematic view of an arrangement of mobile networks supporting number portability;
Figure 2 shows known links between the entities involved in Short Messages Services;
Figure 3 is a network architecture supporting Mobile Number Portability Signaling Relay Functions according to a first embodiment of the invention;
Figure 4 is a network architecture supporting Mobile Number Portability Intelligent Network Functions according to a second embodiment of the invention;
Figure 5 is a network architecture supporting Local Number Portability according to a third embodiment of the invention;
Figure 6 is a flow diagram of a procedure for receiving/forwarding short messages at the serving node according to the invention;
Figure 7 is a flow diagram of the identifier retrieval procedure at a Number Portability register node according to the invention;
Figure 8 is a flow diagram of the charging procedure at the gsmSCF according to the invention.
Ways of carrying out the Invention
With reference to Figure 3, the network entities involved in Mobile Originating and Mobile Terminating Short Message Services handled in a Mobile Number Portability environment comprise a mobile station (MS) 31 and a Service Center (SC) 32 which are connected to an MSC 33. In the following description it is assumed that the MSC is integrated with the SMS-IWMSC/SMS-GMSC, so that it can communicate directly with the Short Message Service Center (SC) using one of the Interface protocols for the connection of Short Message Service Centers to Short Message Entities, described for instance in the Technical Specification of the 3rd Generation Partnership Project no. 3GPP TS 23.039. Obviously, the MSC and the SMS- IWMSC/SMS-GMSC can communicate using Mobile Application Part procedures.
The network according to the invention is advantageously provided with known tools to help the network operator to provide the subscribers with the operator specific services even when the subscribers roam outside the home PLMN. Such tools are called Customized Applications for Mobile network Enhanced Logic (CAMEL) and they are thoroughly discussed in the Technical Specification of the 3rd Generation Partnership Project no. 3GPP TS 23.078.
A serving node on which CAMEL features are implemented comprises or is connected to a Service Switching Function, a functional entity which serves to interface the serving node (such as an MSC or a GMSC) to another functional entity which contains the CAMEL service logic to implement operator specific services, namely the Service Control Function. - - - - - -
In mobile GSM networks, the entity providing the Service Switching Function is the gsmSSF and the entity providing the Service Control Function is the gsmSCF. With reference to Figure 3, the MSC 33 is connected to a gsmSSF node 35, which is in turn connected to a gsmSCF
node 36. The gsmSSF 35 and the gsmSCF 36 communicate with each other using a CAMEL Application Part protocol (CAP).
The MS 31 and the SC 32 respectively act as an originating entity and a receiving entity for SMs in the case of MO-SMS. In this case, the CAP is preferably implemented using the phase 3 technical specification of CAMEL.
In the MT-SMS case, instead, the MS 31 and SC 32 respectively act as a receiving entity and an originating entity, and the CAP is preferably implemented using CAMEL phase 4. In order to support Mobile Number Portability, the network according to the first embodiment of the invention comprises a Signaling Relay Function (MNP-SRF) node 34, for correctly routing messages received by an HLR of the network via the MSC 33 to other EQLRs or networks which do not belong to the operator network where such messages are generated. To this aim, the MNP-SRF node 34 comprises a number portability database (MNP-SRF DB), which contains the porting/routing information to identify the subscription network associated with a particular national MSISDN.
With reference to Figure 4, the network according to a second embodiment of the invention employs an Intelligent Network (IN) solution, in which a mobile station 41 and an SC 42 are in communication with an MSC 43, which is provided with a gsmSSF 45 and is able to call IN supplementary services by means of queries to a Service Control Point (SCP). The SCP comprises a gsmSCF 46 and a Mobile Number Portability IN-related register node 44, which comprises stored information about the porting/routing information to identify the subscription network associated with a particular national MSISDN. ~ ~
The MNP IN-based solution for charging SMS depicted in Figure 4 can be adopted in a similar way when subscribers benefit of Local Number Portability (LNP), i.e. when they can keep their phone numbers even though they have changed service providers. In this case, as it is shown in Figure 5,
an MSC 53 having IN call capabilities is connected to a mobile station 51 and to an SC 52 and it is set to communicate with a gsmSCF 56 by means of a gsmSSF 55. As it will be explained here below, a Local Number Portability register node 54 can be accessed to by the MSC 53 for receiving a Location Routing Number (LRN) of the recipient subscription network, based on the MSISDN of the A-subscriber or the B-subscriber for MT-SMS or MO-SMS, respectively.
The serving nodes 33, 43 and 53 of the above identified network arrangements operate as indicated in Figure 6, in the particular case of an MO-SMS. As it is known, as a mobile subscriber MS 31, 41 or 51 starts an MO-SMS at step 605, the VLR of the MSC serving such mobile subscriber receives an Access Request from the MS at step 610 and, if the Access is granted, the short message SM is transferred from the MS to the MSC at step 615. The MSC then may optionally activate the known sendlnfoFor- MO-SMS operation for verifying from the VLR that the mobile originated short message transfer does not violate restrictions or supplementary services that have been invoked.
At step 620, the MSC starts a procedure for retrieving porting status information about the B-subscriber, i.e. the destination subscriber. Before starting such procedure, the MSC fetches the MSISDN-B number and then sends a query for receiving a charging-related identifier representative of the network to which the MSISDN-B number is ported to a number portability register node, which comprises any one of an MNP-SRF DB, an MNP-IN DB and an LNP DB, according to the network architecture. If the number portability register is an MNP-SRF database, the query is a MAP operation aimed at receiving a Network Prefix from the database. Such operation, using the ASN.1 formal description, is hereby referred to as Network Prefix Information NPI/NPI-ack and is preferably set as follows:
NetworkPref ixlnf ormation : : =OPERATION PARAMETER SEQUENCE { msisdn [ 0 ] IMPLICIT IsdnAddres s String }
RESULT {
Networkprefix } ERROR {
DataMissing
UnexpectedDataValue }
The new NPI MAP message is sent to the MNP-SRF node together with a Translation Type (TT) value indicating "charging related query" and the procedure 700 for analyzing the message is started at step 705. The new^ TT value is introduced to facilitate the recipient node and intermediary SCCP nodes to identify the type of query and distinguish it from other Global Title Translation (GTT) functions.
As it is known, the Translation Type is the first part of the Global Title, the second part being the Global Title Address (GTA), and it is described in the Technical specification ANSI T 1.112.
The new TT value indicating "charging related query" is set to 14 and is preferably used in conjunction with Translation Type 10, conventionally used for SCCP routing of all PCS 1900 MAP messages that use the E.164 global title address. In particular, the MAP messages that are SCCP routed based on Network Entity address preferably use Translation Type 10 and the messages that are SCCP routed based on the MSISDN use TT 14.
Turning back to Figure 7, the MNP-SRF node receives the MAP message at step 710 and handles it directly on Transaction Capabilities Application Part (TCAP) level with the new TT value 14 without passing on the Signaling Connection Control Part (SCCP) level.
At step 715 it is checked whether the MSISDN B-number is actually ported to a network other than the original one. If so, at step 725 a charging- related identifier representative of the network to which the mobile station number is ported is built, which comprises the Network Prefix of the recipient network and the MSISDN B-number.
Then, at step 730 the identifier is sent from the MNP-SRF node 34 to the MSC 33 and the MNP-SRF returns to idle mode at step 735.
If, at step 715, the MSISDN does not result to be ported, either because it is actually a non-ported number or an error has occurred while retrieving porting information from the MNP-SRF database, then the procedure jumps to step 720, wherein a charging-related identifier is returned which comprises the MSISDN B-number and no routing information about networks other than the original network identified by the MSISDN itself. Again, after having sent the NPI-ack MAP message to the MSC comprising the identifier, the MNP-SRF returns to idle mode at step 735. Therefore, in case of errors the SMS handling proceeds as in the prior art SMS handling for non ported numbers.
As the charging-related identifier ID is returned to the MSC, the MO- SMS procedure originally started at step 605 jumps to step 625, where the identifier is sent to the gsmSCF 36 via the gsmSSF 35 using the CAMEL Application Part (CAP) protocol. If, according to the procedure 700, the destination subscriber results to be ported, the identifier comprises both the network prefix and the MSISDN B-number, otherwise the identifier comprises the MSISDN B-number only. The CAP protocol has to be updated to foresee the transfer of the ne"w data. In particular, the Initial DP message will convey a new information element containing the network prefix. Appropriate scripts can be implemented on the gsmSCF node to charge the SMS according to the network prefix without any effort by the skilled in the art. With reference to Figure 8, the procedure for handling the charging of
SMS at the Service Contrornode is started at step 805, when the gsmSSF 35 is provided with the charging related identifier returned by the Number. Portability register.
At step 810, the gsmSCF 36 receives an Initial Detection Point (DP) SMS information flow, which comprises the identifier, e.g. the network
prefix and the MSISDN/B-number.
Then, at step 815 the originating mobile subscriber 31 is charged according to the network prefix and the MSISDN/B-number, thus guaranteeing that the recipient network operator, in which the destination MS is subscribed, takes profit from the Short Message Service it offers.
At step 820 the same network prefix and MSISDN/B-number are forwarded to the Call Data Record (CDR) of the originating mobile subscriber using the existing "originating address" parameters.
Finally, at step 825 the gsmSCF 36 sends to the gsmSSF 35 the information flows "Connect" and "Continue", which are respectively used to request the gsmSSF to perform the actions to route the Short Message to a specific destination and to request the gsmSSF to proceed normally.
As soon as the Continue message is received by the gsmSSF 35, the Service Control Function node returns to idle mode at step 830, the MSC 33 is instructed to proceed at step 630 and the Short Message is sent to the Service Center 52 for delivery at step 635.
Finally, at step 640 the procedure for routing a Mobile Originated Short Message to a Service Center is terminated.
It is clear from the above description that the same steps for charging a Short Message apply to Mobile Terminated SMS. In summary, after the
MT-SM is received by the serving node (MSC, GMSC, SGSM) from the
Service Center 32, the MSISDN of the originating subscriber (called
MSISDN/A-number) is fetched, the Network Prefix information query is sent from the MSC to the MNP-SRF node, which reads the Network prefix of the originating subscriber from the MNP-SRF database and returns the
MSISDN/A-number and, if the originating subscriber is exported to a mobile network different from his/her home network, returns also the
Network Prefix of the originating subscriber. The identifier received by the
MSC is then forwarded to the Service Control Function node to charge the SMS and it is further written in the terminating CDR using the "Terminating
address" parameter.
While the above described steps have been directed to the particular case in which an MNP-SRF is implemented, it is clear that similar steps can_ be followed in other particular network arrangements, such as IN-relateΛ networks in which no MNP-SRP is implemented or in which Local Number
Portability is implemented.
The main differences regard the kind of identifier returned by node comprising the number portability database and the communicatiort protocols between the serving node and the node comprising the number portability database.
With reference to Figure 4, the MO-SMS in the IN-based MNP architecture follows the steps 605-615 described above. Then, at step 620, the MSC 43 starts a procedure for retrieving porting status information-. about the B-subscriber. Before starting such procedure, the MSC fetches the MSISDN-B number and then sends a query for receiving a charging-relatecL identifier representative of the network to which the MSISDN-B number is ported to the MNP-IN database. The query is a Intelligent Network: Application Part (INAP) operation aimed at receiving a Network Prefix: from the database. The MNP IN node 44 receives the INAP message at step 710. Then, at step 715 it is checked whether the MSISDN B -number is actually ported to a network other than the original one. If so, at step 725 the charging- related identifier is built, which comprises the Network Prefix of the recipient network stored in the database and the MSISDN B-number. At step 730 the identifier is sent from the MNP IN node 44 to the
MSC 43 and the MNP IN node returns to idle mode at step 735.
If, at step 715, the MSISDN does not result to be ported, either because it is actually a non-ported number or an error has occurred while retrieving porting information from the MNP IN-DB, then the procedure jumps to step 720, wherein a charging-related identifier is returned, which-
comprises the MSISDN B-number and no routing information about networks other than the original network identified by the MSISDN itself. Again, after having sent the INAP acknowledgement message to the MSC comprising the identifier, the MNP IN node 44 returns to idle mode at step 735. In case of errors the SMS handling proceeds as in the prior art SMS handling for non ported numbers.
As the charging-related identifier ID is returned to the MSC, the MO- SMS procedure originally started at step 605 jumps to step 625, where the identifier is sent to the gsmSCF 46 via the gsmSSF 45 using the CAP protocol. Then the procedure continues as described in the MNP-SRF case.
It is clear that the MT-SMS case is handled in a similar way, the MSISDN/A-number being the parameter which is sent to the MNP IN node 44 and is used by the SCF together with the network prefix of the originating subscriber for charging the SMS. If Local Number Portability is implemented in the network, the steps for charging the SMS are similar to those described in the foregoing description. Steps 605-640, 705-735 and 805-830 simply change with regard to the parameters exchanged by the network entities identified in Figure 5. In particular, the serving node (MSC, GMSC or SGSN) is set so as to send a query to the LNP IN node 54 for receiving a Location Routing Number (LNR).
If the LNR returned by the LNP database corresponds to the MSISDN of the terminating or originating subscriber (in the MO-SMS or MT-SMS case, respectively) the number is not ported and the SMS is handled as in the known architectures. Otherwise, if the MSISDN is ported, the LNR is the address of the subscription network in which such number is ported. - - In case of errors in the LNP-DB, the SMS is handled as in the prior art technique for non ported numbers.
The received LNR and the MSISDN/B-number (or MSISDN/A- number) are sent to the Service Control Function node for charging the MO-
SMS (or MT-SMS), according to steps 805-830.
In order to store the LNR separately from the MSISDN/B-number (or MSISDN/A-number) in the Mobile Originating (or Mobile Terminating) CDR, a new tag is introduced. The skilled in the art easily understands that the above described steps may be performed by any computer hardware and/or software and telecommunication means programmed through conventional techniques in order to take into account the additional information data needed by the present invention. Thus, it is straightforward to the skilled in the art to suitably provide the serving node according to the invention with, means for receiving short messages, means for fetching subscriber mobile station numbers from said short messages and means for interrogating a number portability register in accordance with the above description.
A combination of CPU, memory and communications means, well in the reach of the skilled in the art, is required in order to perform the steps according to the invention. The invention is therefore preferably implemented by introducing new functionality in existing systems, which enhancements are clearly in the reach of the average technician and are not hereby discussed in detail. It has thus been shown that the present invention fulfils trie proposed aim and objects. In particular, the method and the networks according to the invention allow the operator to apply different tariffs to different subscribers in case of Mobile and Local Number Portability, since the operator is informed about the subscriber type (Imported, Exported or Home). Moreover, the invention can be applied to either prepaid or postpaid subscribers.
Clearly, several modifications will be apparent to and can. be readily made by the skilled in the art without departing from the scope of the present invention. Therefore, the scope of the claims shall not be limited by the illustrations or the preferred embodiments given in the description in the
form of examples, but rather the claims shall encompass all of the features of patentable novelty that reside in the present invention, including all the features that would be treated as equivalents by the skilled in the art.