NOTIFICATION OF NETWORK INFORMATION TO A ROAMING SUBSCRIBER
This invention relates generally to outbound roamers. More specifically, the invention relates to a dynamic provisioning of information about features of the home network or networks in relation with the home network to a mobile in roaming.
Many operators that offer international roaming generates revenue due to the outbound roaming of fnobiles of their subscribers, i.e. when a subscriber of the operator of one network visits another network and makes calls. The selection of the visited network can be automatic or manual, but the subscriber has no information about the selected network, except the name thereof which is received in a "Welcome" message for instance.
When a subscriber is roaming out from a home network of operator "A" to a visited network, operator "A" serving in both the networks "A" and "B" and some other operator "C" also existing in the network "B", there is no way for operator "A" to send information about the existence of another network served by operator "A" or any other operator in agreement with operator "A" to the subscriber if he latches to other network not served by operator "A".
There is no mean for an operator of a subscriber to send network data to the subscriber in roaming out, the network data indicating by example the different tariffs of all the networks which are available and covering the area where the subscriber is located.
It is an object of the invention to provide information about features of the home network or other networks in relation with the home network to a mobile in roaming in order to give to the user of the mobile the possibility to select any network available which proposes cheaper tariff.
To remedy the problems referred to hereinabove, a method according one embodiment of the invention for providing network data relating to at least one network to a roaming mobile terminal which has subscribed to a home network and is located in a visited network, is characterized in that the method comprises :
after a location update procedure wherein a visitor location register of the visited network extracts information about mobility event included in a first message

sent by a home location visitor of the home network, sending a first message including a trigger element from the visitor location register to a first server included in the home network,
in the first server, detecting the trigger element included in the received first message, and
sending a request from the first server to a second server, the request
comprising network data relating to at least one network covering the location area
where the mobile terminal is located, in order that the second server sends a
second message comprising said network data to the mobile terminal.
A subscriber using the mobile terminal in roaming can get many
information about networks covering the area where the mobile terminal is located and can select for instance the network with cheapest tariff. Furthermore, the subscriber in roaming can feel nice to be informed that its home network is available and following him. Particularly, the network data can include service related data and configuration data permitting for instance the mobile terminal to use automatically a service provided by the network.
According to another feature of the invention, the network data can include
tariff information of a network which proposes cheapest tariff among several
networks covering the location area where the mobile terminal is located.
The subscriber can save money by selecting the network suggested by the
home operator in the second message. Moreover, the operator of the home network can make more revenue by guiding his subscriber to select his own network or any other network ties up with the home network.
According to another feature of the invention, the trigger element included in the first message can be a service key assigned to a service of the first server.
According to another feature of the invention, the first message can further
include an identifier of the location area where the mobile terminal is located and
said network data relating to at least one network comprised in the request can be
determined as a function of said identifier of the location area associated with said
at Teast one network.
According to another feature of the invention, the home network and the visited network can implement intelligent network services according to a Customized Applications for Mobile network Enhanced Logic.

According to another feature of the invention, the information about mobility event included first message sent by the home location visitor to the visitor location register can be a CAMEL Subscription Information.
According to another feature of the invention, the first message sent by the home location visitor to the visitor location register can be a InsertSubscriberData signaling message.
According to another feature of the invention, the request sent from the
visitor location register to the intelligent server can be a MAP_NOTE_MM_EVENT
signaling message.
According to another feature of the invention, the second message sent
from the message server to the mobile terminal can be a Short Message Service message.
The invention relates also to a server for providing network data relating to at least one network to a roaming mobile terminal which has subscribed to a home network and is located in a visited network, the server being included in the home network, characterized in that the server comprises :
means for detecting a trigger element included in a first message sent by a
visitor location register of the visited network, after a location update procedure
wherein the visitor location register extracts information about mobility event
included in a first message sent by a home location visitor of the home network, and
means for sending a request to another server, the request comprising
network data relating to at least one network covering the location area where the
mobile terminal is located, in order that the another server sends a second message
comprising said network data to the mobile terminal.
Other features and advantages of the present invention will be apparent more clearly from the reading of the following description of several preferred embodiments of the invention, given by way of non-limiting examples and with reference to the corresponding accompanying drawings in which:
FIG. 1 illustrates a schematic block diagram of a system in accordance with an embodiment of the present invention
FIG. 2 illustrates an algorithm for providing CSI of an outbound roamer in accordance with an embodiment of the present invention

Embodiments of the present invention are described below by way of example only. These examples represent the best ways of putting the invention into practice that are currently known to the applicant although they are not the only ways in which this could be achieved.
Referring to FIG. 1, a mobile terminal MT is provided to a subscriber by an operator who manages a home network HN and the mobile terminal MT is roaming toward a visited network VN. The home network HN is a network to which the
roaming mobile terminal is originally subscribed and the visited network VN is a network which covers the area where the mobile terminal is situated in roaming. The home network HN and the visited network VN are respectfully a Home Public Land Mobile Network HPLMN and Visited Public Land Mobile Network VPLMN, which can be cellular networks of numerical radio communications, of type GSM or
UMTS.
The home network HN and the visited network VN implement a Customised Applications for Mobile network Enhanced Logic CAMEL which enables in particular the subscriber to roam between both networks, that can be in different countries, and to be always reachable with the same phone number, in order to
have only one bill from the operator of the home network. CAMEL is a method of allowing operators to add new services to the existing network infrastructure. Preferably, CAMEL is in phase 3 that allows roaming subscribers to access their full portfolio of Intelligent Network IN services and connects the home and visited mobile networks to various IN platforms used throughout national networks to
provide features such as pre-paid roaming services, special numbers and more complex location dependent services.
In FIG. 1, there is represented only the principal elements of the location area of the visited network where the mobile terminal MT is at a given moment. The location area includes a home Mobile Switching Center MSC which is connected
through a Base Station Controller BSC to a Base Station BS connected by a radio connection to the mobile terminal MT. The mobile switching center MSC is connected to a Gateway Mobile Switching Center GMSC which interacts with a Visitor Location Register VLR to obtain routing information.

The mobile switching center MSC is able to communicate with entities of the home network HN like a Service Control Point SCP and a Home Location Register HLR via a gateway GW similar to the gateway GMSC. The service control point SCP hosts a database that holds the instructions needed for an intelligent application, and can control a Short Message Service Center SMSC that delivers messages to subscribers when they are available. The both gateways can communicate together via a telecommunications network with high flow, like the Internet or any Intranet network.
The home location register HLR is similar to a database containing for each subscriber in particular a user profile of the subscriber including for instance an International Mobile Subscriber Identity IMSI attached to the subscriber, a MSISDN number, HLR and VLR numbers, bearer and supplementary services. This user profile may include different CAMEL Subscription Information (CSI), like mobility management CSI (M-CSI), Terminating CSI (T-CSI) or Originating CSI (O- CSI). Information CSI identifies a requirement of CAMEL support for the subscriber and identities the logical entities of the network to be used for that support.
The visitor location register VLR plays the part of relay of home location
register HLR in the zone of localization and contains the characteristics of the
subscriber whose mobile terminal is located in the zone of localization.
Preferably, the mobile terminal MT is a mobile terminal of cellular radio
communications. In alternative, the mobile terminal MT is a communicating Personal Digital Assistant PDA, or an intelligent telephone like SmartPhone.
According to an embodiment of the invention, the service control point SCP is a server that includes a store operator information module SOI and includes or communicates with a database DB. The database DB stores information on available networks whose operators propose cheap tariff and have agreement with the operator of the home network. In particular, information on available networks includes network data, which are relating to these available networks and which can be service related data or configuration data for instance. The module SOI has the functionality for determining whether the home network is available in the location of the subscriber or any special offer is present.
The different entities described above and included in the home and visited networks define a communication system according to an embodiment of the

invention that provides information to a roaming subscriber indicating the different tariffs of networks available for the subscriber.
Referring to FIG. 2, a method for providing network information message to roaming subscriber includes steps S1 to S10 executed automatically in the communication system according to an embodiment of the invention.
At a preliminary step, the database DB of the service control point SCP stores a table comprising location area identifiers, network operator identifiers and network data including tariffs proposed by network operators. Each location area identifier is associated with a list that comprises a least one network operator in correspondence with network data and tariffs proposed by the network operator. For instance, the tariffs concern any call sent or received by the subscriber in the location area.
In other terms, each network operator is associated with at least one location area identifier, which means that such operator network is available in such associated area with specific tariffs.
In particular, the operator of the home network HN provides the database BD with all tariffs associated with networks which are available in different location area and whose operator have agreement with the home network operator.
At the step S1, the mobile terminal MT enters the area of the visited network VN and sends a connection request ReqC to the mobile switching center MSC, via the base station BS covering the area where the mobile terminal is
situated and the base station controller BSC connected to the center MSC. For instance, the connection request ReqC is aimed at registering and connecting the mobile terminal to the visited network and includes an identifier IdTM of the mobile terminal, which is for instance the IMSI of the subscriber using the mobile terminal or a Temporary Mobile Subscriber Identity TMSI. The connection request ReqC can
be a "Location-update-to-other-VLR" signalling message or a "IMSI-attach" signalling message.

At the step S2, on receipt of the connection request ReqC, the mobile switching center MSC triggers a location update procedure and sends a request of location update area ReqA to the visitor location register VLR.
At the step S3, on receipt of the request of location update area ReqA, the visitor location register VLR sends a request of location update ReqLU to the home location register HLR, via the gateway GMSC of the visited network VN and the gateway GW of the home network HN. The request of location update ReqLU message further includes information identifying the new serving center MSC and the visitor location register VLR. The request ReqLU can be a "UpdateLocation" signaling message.
At the step S4, on receipt of the request of location update ReqLU, the home location register HLR retrieves the user profile by way of the identifier of the
mobile terminal, extracts some information from the user profile, and inserts the extracted information into a message of location update MLU, which can be a "InsertSubscriberData" signaling message. The information comprised in the message MLU is for instance a CAMEL Subscription Information, like a mobility management CSI (M-CSI) profile, and concerns any mobility event. In particular, the
message MLU comprises the report of a mobility event like the "IMSI-attach" procedure started at step S1, and identifies a single server, i.e. the service control point SCP, which has to be notified for mobility management events. The home location register HLR sends the message MLU to the visitor location register VLR via the both gateways GW and GMSC.

At the step S5, on receipt of the message MLU, the visitor location register VLR extracts the information comprised in the message MLU, especially the CSI information.
The visitor location register VLR confirms the reception of the message
MLU by sending a message of acknowledgement MA to the home location register HLR. The message MA can be a "lnsertSubscriberData_Ack" signaling message.
At the step S6, on receipt of the message of acknowledgement MA, the home location register HLR concludes the location update procedure by sending a

response of location update RepLU to the visitor location register VLR, which sends then a response of location update area RepA to the center MSC. The response RepLU can be a "UpdateLocation_Ack" signaling message.
The mobile terminal is ready to latch the visited network VN.
At the step S7, the visitor location register VLR, supervising any CSI information and listening to any mobility event, triggers Intelligent Network functionality as a result of a detected mobility event. The visitor location register VLR triggers Intelligent Network functionality after the detection of a mobility event reported in the received message of location update MLU. Alternatively, a mobility event is considered detected by the visitor location register VLR after the sending of the response RepA, which means that the mobile terminal is allowed to be attached to the visited network.
The visitor location register VLR sends a triggering message MesT to the
service control point SCP. The triggering message MesT is a notification that informs the service control point SCP of the mobility event and includes a trigger element that can be interpreted by the service control point SCP.
In particular, the message MesT can be a "MAP_NOTE_MM_EVENT" signaling message. The message MesT includes a parameter, like "IMSI attach",
indicating the mobility event that has lead to the sending of the notification. The message MesT further includes a service key, like a number, which identifies a service provided by the service control point SCP and is the trigger that can be interpreted by this latter. The message MesT further includes a location information indicating the location of the served network of the subscriber, i.e. the visited
network. The message MesT can also include a parameter indicating which phases of CAMEL are supported by the visitor location register VLR.
At the step S8, the service control point SCP triggers the functionalities of the module SOI on receipt of the triggering message MesT, after having analysed the content of the message and having detected of a trigger element included in the message.
In particular, the service control point SCP finds a service key in the triggering message MesT which is a unique number assigned to the module SOI. The service control point SCP can include other modules than the module SOI,

each module implementing a specific service and being assigned to a unique number. The service control point SCP triggers the module SOI by sending a message according to a "SensSMS" mechanism, the message including all the information present in the triggering message MesT.
At the step S9, the module SOI retrieves the location information initially included in the message Mesl and determines the corresponding location area identifier stored in the database DB by the way of the retrieved location information. For instance, the location information included in the triggering message MesT and the location area identifier are written under the same form or can be found equivalent in a correspondence table.
The module SOI determines the networks available in the location area where the mobile terminal is located as a function of the location information and generates a request of message transfer ReqMT comprising network data relating
to at least one network covering the location area. For instance, the network data comprise instructions and/or parameters and/or codes that can be interpreted automatically by the mobile terminal to use a service provided by said at least one network covering the location area, and can further comprise tariffs proposed said network.
For instance, the module SOI determines the operator with cheaper tariff
included in the list associated with the location area identifier in the database and generates a request of message transfer ReqMT as a function of at least the identifier of the cheaper operator. In addition, the request ReqMT can provide an indication like "Select the "X" network for cheapest tariffs", where "X" is the name of
the operator corresponding to the identifier of the cheaper operator. The request ReqMT can include the name or the identifier of the operator with cheaper tariff included in the list associated with the location area identifier in the database ReqMT. Alternatively, the request of message transfer ReqMT comprises the list associated with the location area.

The module SOI submits the request ReqMT to the short message service center SMSC. For instance, the request ReqMT is submitted to the center SMSC according to a "submit_sm" PDU (Protocol Data Unit) of protocol SMPP (Short Message Peer to Peer Protocol), the submit_sm PDU comprising among other

things an indication for the center SMSC to send a message comprising the content of the request ReqMT to the mobile station MS.
At the step S10, the short message service center SMSC analyses the request of message transfer ReqMT and sends a message of network information MNI comprising the content of the request ReqMT to the mobile terminal MT. The message of network information MNI comprises particularly the network data included in the request ReqMT. The message MNI can be a SMS (Short Message Service) message. The center SMSC stores the message until the message is
successfully delivered to the mobile terminal, or until the message validity period expires.
The message of network information MNI can further comprise cheapest tariffs proposed by a least one network covering the location area where the mobile terminal is located. For instance, the message is in a written form and can be read
by the subscriber, or the message is in a vocal form and can be listened by the subscriber.
If the visited network VN to which the mobile terminal is latched does not correspond to the cheapest operator displayed in the message MNI, the subscriber using the mobile terminal can select the operator displayed in the message MNI, for
instance by means of instructions included in the message MNI.
If the visited network VN to which the mobile terminal is latched corresponds to the cheapest operator displayed in the message MNI, the message MNI has a purpose to inform the subscriber of that situation.

REVENDICATIONS
1. A method for providing network data relating to at least one network to a
roaming mobile terminal (MT) which has subscribed to a home network (HN) and is
located in a visited network (VN), characterized in that the method comprises :
after a location update procedure wherein a visitor location register (VLR) of the visited network (VN) extracts information about mobility event included in a first message (MLU) sent by a home location visitor (HLR) of the home network (HN), sending (S7) a first message (MesT) including a trigger element from the visitor location register (VLR) to a first server (SCP) included in the home network (HN),
in the first server (SCP), detecting (S8) the trigger element included in the received first message (MesT), and
sending (S9) a request (ReqMT) from the first server (SCP) to a second server (SMSC), the request (ReqMT) comprising network data relating to at least one network covering the location area where the mobile terminal is located, in order that the second server (SMSC) sends (S10) a second message (MNI) comprising said network data to the mobile terminal (MT).
2. A method according to claim 1, wherein said network data include tariff information of a network which proposes cheapest tariff among several networks covering the location area where the mobile terminal is located.
3. A method according to claim 1 or 2, wherein the trigger element included in the first message (MesT) is a service key assigned to a service of the first server (SCP).
4. A method according to any of claims 1 to 3, wherein the first message (MesT) further includes an identifier of the location area where the mobile terminal is located and said network data relating to at least one network comprised in the request (ReqMT) are determined as a function of said identifier of the location area associated with said at least one network.

5. A method according to any of claims 1 to 4, wherein the home network (HN) and the visited network (VN) implement intelligent network services according to a Customized Applications for Mobile network Enhanced Logic.
6. A method according to claim 5, wherein the information about mobility event included first message (MLU) sent by the home location visitor (HLR) to the visitor location register (VLR) is a CAMEL Subscription Information.
7. A method according to claim 5 or 6, wherein the first message (MLU) sent
i by the home location visitor (HLR) to the visitor location register (VLR) is a
InsertSubscriberData signaling message.
8. A method according to any of claims 5 to 7, wherein the request (Reql)
sent from the visitor location register (VLR) to the intelligent server (SCP) is a
MAP_NOTE_MM_EVENT signaling message.
9. A method according to any of claims 1 to 8, wherein the second message
(MNA) sent from the message server (SMSC) to the mobile terminal (MT) is a Short
Message Service (SMS) message.

10. A server (SCP) for providing network data relating to at least one network
to a roaming mobile terminal (MT) which has subscribed to a home network (HN)
and is located in a visited network (VN), the server being included in the home
network (HN), characterized in that the server comprises :
means (SOI) for detecting a trigger element included in a first message
(MesT) sent by a visitor location register (VLR) of the visited network (VN), after a location update procedure wherein the visitor location register (VLR) extracts information about mobility event included in a first message (MLU) sent by a home location visitor (HLR) of the home network (HN), and
means (SOI) for sending a request (ReqMT) to another server (SMSC), the
request (ReqMT) comprising network data relating to at least one network covering the location area where the mobile terminal is located, in order that the another server (SMSC) sends a second message (MNI) comprising said network data to the mobile terminal (MT).