Updating of internet access point settings in a mobile communication system

Update Internet access point settings in a mobile communication system

The invention relates generally to digital mobile communication systems and more particularly to supporting mobility in connection with Internet services in a mobile communication system.

Mobile communication systems generally refer to various communication systems that enable personal wireless data transmission while subscribers move within the system area. A typical mobile communication system is a public land mobile network (PLMN) built on the ground.

In addition to traditional voice transmission, digital mobile communication systems offer many other services: short messages, fax, data transmission, etc. Of these, the data transmission service in particular allows the mobile subscriber to access almost all fixed network data services, but wireless.

The fixed network has exploded into the TCP / IP (Transmission Control Protocol / Internet Protocol) data network, the so-called Using the Internet. As is well known, an Internet network is actually made up of a large number of TCP / IP networks that are interconnected. A number of TCP / IP application protocols are available on the Internet. The most significant for the end user are

- TELNET. This protocol allows a user terminal (or user application program) on one machine to communicate over the Internet with an application process on another computer, such as a word processor running on a remote machine, as if the user terminal were directly connected to it;

- FTP (File Transfer Protocol). This protocol allows a user terminal (or user application process) to access and interact with a remote file system;

- SMTP (Simple Mail Transfer Protocol). This protocol provides a network-wide mail transfer service between e-mail systems associated with different machines;

- The World Wide Web (WWW) consists of servers on the Internet and client programs for their use, called web browsers (Browser). The information on the web servers is organized into pages, which are from the basic unit of web technology, as the server and the browser always transfers entire pages, and in addition to text, the page may contain images and various other file types, such as audio and video. Pages used by web technology are described in Hyper Text Mark-up Language (HTML). Information about text formatting, images, etc. is coded into the actual text content with HTML codes (tags). These codes allow the browser program to format the VWVW page to the desired format.

Internet applications are used to connect to services on the Internet. Before a user can connect to the Internet, he or she must have an agreement with an Internet Service Provider (ISP) that provides access to the Internet through one or more Internet Access Points (IAPs). An ISP can be, for example, a commercial operator (such as Eunet in Europe), a university or its own company. An IAP is typically a server that a user can access from a regular landline telephone or cell phone by making a modem call (or data call) to a specific IAP access number.

Through the data transmission services of mobile communication systems, the services of the Internet are in principle also available to mobile subscribers. However, the use of a data transfer service typically requires a mobile station with data transfer capabilities and a computer connected to it. Today, mobile devices with an integrated computer, such as the Nokia Communicator 9000, are also available. The latter also includes built-in capabilities for connecting to the Internet.

An ordinary fixed-line subscriber usually only needs one IAP, which is closest to him and thus the cheapest in terms of call costs. However, a mobile subscriber can move very widely within the same state and even between different countries. If a mobile subscriber always uses the same IAP (home IAP) to connect to the Internet, the cost of a call (data transfer cost) can become very high. For example, if the subscriber is roaming in Germany and the home IAP is in Finland, the use of Internet services via the home IAP requires an international call Germany-Finland. To optimize data traffic costs, mobile subscribers would like to use local IAP no matter where they are. With a subscriber Internet service provided by an ISP (such as Eunet), there may be multiple IAPs available around the world. However, it is problematic for the mobile subscriber how to choose the best possible IAP easily, and if possible automatically.

One currently used method is for the subscriber to manually reconfigure / change / create a new IAP while in a new area. However, this requires a list of available IAPs that tells you how to set the correct IAP depending on the current location of the subscriber. However, manual configuration is cumbersome and error prone. In addition, ΙΑΡ-lists do not stay up to date for longer. For example, the Nokia Communicator 9000 is equipped with an interface that supports such a ΙΑΡ-list. The list may contain, for example, the following information: 1) The name of the service provider; 2) IAP phone number 3) User name (used for PPP authentication if necessary); 4) the password used, if necessary, for PPP authentication; 5) Subscriber's own IP address; 6) the IP addresses of the primary and secondary name servers.

The Nokia Communicator 9000 is equipped with a feature that allows the ISP service provider to configure the IAP with a special short message called SIAP SMS (Set Internet Access Point Short Message). This special short message sets all the necessary ΙΑΡ settings in the device and adds a new IAP to the list. However, the message asks the user to confirm the action before any action is taken. The advantage of this semi-automatic short message update is that the user does not have to update the data manually, which also eliminates errors. However, if this feature were used to support roaming, the user would need to call the service provider’s customer service and ask to send the best IAP information for their current location in a SIAP short message. This is inconvenient for the user, but can cause significant additional work for the service provider, especially when the number of subscribers is large. Alternatively, it could be thought that an IAP would send an SIAP short message (s) to all subscribers whenever an IAP configuration has changed in some part of the world. However, this is an inconvenient and costly solution for both users and ISPs.

The object of the invention is to provide the mobile subscriber with the easiest and automatic possible selection of a local Internet access point during roaming.

This is achieved by a method for updating the information of an Internet access point in a terminal of a digital mobile communication system capable of connecting to the Internet via a mobile communication system and a set of Internet access points. The method is characterized in that it comprises the steps of storing in the terminal the Internet access point settings last used to access the Internet, storing in the terminal system information from the mobile network or the part of the mobile network last used to access the Internet, receiving comparing said received system information with said stored system information, initiating a procedure for updating the stored Internet access point settings of the terminal with the settings of the recommended Internet access point of the currently used mobile network or part of the mobile network if said stored and received system information indicates a changed mobile network or mobile station.

The invention also relates to a server according to claim 8, a short message center according to claim 9, a terminal according to claim 13 and a mobile communication system according to claim 19.

In the invention, the mobile communication system is divided into areas to which recommended or preferred Internet access points (IAPs) are assigned. These regions are referred to in this application as ΙΑΡ regions. Typically, the recommended or preferred IAP is the Internet Service Provider's (ISP) local IAP, which has the lowest data call cost from a mobile station. The alue-zoning can in principle be anything. For example, each country or network of each mobile operator may form its own ΙΑΡ area. Alternatively, each mobile network may be divided into smaller ΙΑΡ areas, e.g., according to the network location area configuration. Once the ΙΑΡ-zone division has been agreed, the ISP only needs to name the primary IAPs for each ΙΑΡ-zone. Naturally, ISPs have different IAPs in the same alueella area. According to the basic idea of ​​the invention, a mobile station roaming the system tends to select each ΙΑΡ area as the primary IAP for Internet access. This can be called an IAP trek.

For ΙΑΡ-roaming, the mobile station stores the settings of the last used or updated IAP, as well as system information that identifies the IAP area (mobile network or part of the mobile network) where the mobile station was located during the last Internet transaction or ΙΑΡ update. The mobile station compares the system information broadcast by the serving cell with the above-mentioned stored system information. If it can be concluded from the comparison that the alue area has changed, the mobile station updates the stored ΙΑΡ settings with the appropriate IAP settings for that ΙΑΡ area, which it receives or retrieves via the mobile network. In a preferred embodiment of the invention, the mobile station retrieves the appropriate ΙΑΡ settings for its location from a server, database or the like maintained by the ISP. In the ΙΑΡ request, the mobile station indicates its location (ΙΑΡ area) using some system information, based on which the ISP server selects the appropriate ΙΑΡ settings for the location, which are sent in response to the mobile station. In another embodiment of the invention, the primary IAP settings are broadcast to mobile stations in the ΙΑΡ area in broadcast messages that allow the mobile station to update the ΙΑΡ settings as needed. This avoids a separate retrieval procedure but on the other hand imposes an additional load in the form of messages on both the network and the mobile stations. Message broadcasting services are not ubiquitous, which may limit the coverage of ΙΑΡ-roaming according to the invention.

According to a preferred embodiment of the invention, the mobile station checks whether an update of the ΙΑΡ settings is necessary only when a new Internet transaction is being initiated, i.e. an IAP is required. This avoids unnecessary updates while the mobile is on the network. This is particularly advantageous in the embodiment where the ΙΑΡ settings are retrieved from the ISP server. On the other hand, this can cause a delay (up to 10-15s) in setting up the first Internet data call in a new area. In an embodiment where new ΙΑΡ settings are received in broadcast messages, this delay is less. In one embodiment of the invention, the mobile station updates the ΙΑΡ settings whenever it detects a change in the ΙΑΡ range. This way, the ΙΑΡ settings are always up-to-date and there is no delay in the first Internet call.

In a preferred embodiment of the invention, a special message service center is provided, which is directly or via a data network connected to the hardware or application maintaining the AP settings of the IAP areas, which in this description is called an ISP server. The mobile station requests ΙΑΡ settings by sending a special request to the service center “Internet access point” message, RIAP message. In a preferred embodiment of the invention, the RIAP message also contains system information identifying the current IAP area of ​​the mobile station. It is also possible that the service center knows or manages the IAP6 area information itself. The service center then requests the ΙΑΡ settings from the ISP server according to the interface between them or the protocol required by the data network. This request may include system information that identifies the ΙΑΡ range and allows the ISP server to select the appropriate IAP settings for the location of the mobile station. These IAP settings are sent to the service center, which sends them in a special set Internet access point ”message, SIAP message, to the mobile station. The mobile station updates the stored IAP settings with the IAP settings received in the SIAP message.

In one embodiment of the invention, the message service center retrieves the unsorted IAP settings of the ΙΑΡ areas from the ISP server and selects from them the ones suitable for the location of the mobile station. For example, when the ISP server is on the Internet, the service center can retrieve an entire VWWV page that contains the IAP ranges and their primary IAP settings. From these, the service center selects the appropriate IAP settings for the mobile station and sends them in a SIAP message to the mobile station. In this embodiment, the Internet service provider only needs to maintain the VWVW page.

The invention provides many significant advantages over the prior art. The ΙΑΡ-migration of the invention is a simple automatic procedure for the user, which guarantees up-to-date IAP settings and low-cost call costs. For the ISP of the Internet service provider, only a minimal amount of work and cost is required when maintaining the necessary data on the server.

Preferred embodiments of the invention will now be described with reference to the accompanying drawings, in which Figure 1 is a system diagram showing two mobile networks, local and international telephone networks, Internet network, Internet access points, ISP server and Internet short message service center, Figures 2 and 3 are flow charts illustrating ΙΑΡ roaming and ΙΑΡ settings update by the mobile station, Fig. 4 is a signaling diagram, Fig. 5 is a flowchart illustrating the operation of the service center SC, Fig. 7 is a flowchart illustrating the operation of the MS when retrieving the ΙΑΡ- settings from the network, Fig. 8 is a flowchart illustrating the operation of the MS when IAP settings are received in broadcast short messages.

The present invention can be applied to all mobile communication systems supporting circuit-switched voice5 and data services, in which the terminals are able to establish a data connection to the Internet via special Internet access points. The invention can be applied particularly well in mobile communication systems with a short message service. In this patent application, a short message service generally refers to the transmission of any type of short text message between a mobile station and a particular short message service unit without the need to establish an end-to-end traffic route.

Therefore, the transmission of a short message can take place even when the mobile station is already in the process of transmitting voice or data on a circuit-switched end-to-end traffic connection. Short message transmission is limited to one message, or in other words, the transmission of the entire single message is the entire transmission transaction. The short message service is thus a completely different matter from packet-switched data transmission. An example of a short message service is the short message service of the GSM system as defined in the recommendation ETSI GSM 03.40. Another example of message transmission suitable for the purpose of the invention is the USSD (Unstructured Supplementary Servi20 ce Data) defined in the recommendations ETSI GSM 02.90, 03.90 and 04.90.

The invention will now be described in connection with digital GSM (Global System for Mobile Communication). Since the operation and structure of the mobile communication system are not essential to the invention, they are described only to the extent that it helps to understand the short message service. For a more detailed description of the GSM system 25, reference is made to the GSM Recommendations and to the book 'The

GSM System for Mobile Communications, M. Mouly & M. Pautet, Palaiseau, France, 1992, ISBN: 2-9507190-0-7.

Figure 1 shows two GSM mobile networks 11 and 17. The GSM network 17 is located in Finland and the GSM network 11 is located in Sweden.

In the GSM network, the mobile services switching center MSC takes care of the connection of incoming and outgoing calls and performs functions specific to mobile call traffic, such as location management of subscribers, in cooperation with the subscriber registers of the network.

With VLR and HLR, the HLR is the subscriber's home register where subscriber information is stored permanently. The visitor location register VLR is a regional register to which subscriber information from the HLR is copied when a mobile subscriber visits the area of ​​the VLR. The mobile stations MS connect to the exchange MSC via the base station systems BSS. The BSS consists of a base station controller BSC and base stations BTS, i.e. fixed radio transceivers, through which the mobile stations MS communicate by radio with the mobile network.

An MSC that acts as a gateway to another network (such as PSTN, ISDN, public data network PDN) is called a gateway MSC, GMSC. In Figure 1, the GSM networks 11 and 17 are shown connected to the local PSTN / ISDN networks 16 and 18, respectively. The PSTN / ISDN networks 16 and 18 are connected to each other and to the PSTN / ISDN networks of other countries by the international transmission network 20.

Internet 12 is a worldwide set of TCP / IP compliant networks. Other telecommunication networks, such as PSTN / ISDN, connect to the Internet through IAPs of Internet access points. The ISP providing the Internet access service may be, for example, a commercial operator such as Eunet. An ISP can have its own IAP in each country, such as IAP 14 (Eunet Finland) and IAP 15 (Eunet Sweden) in Figure 1. a university or its own company. An IAP is typically a server that a user can access from a standard fixed network subscriber interface or mobile station by making an ISDN / PSTN modem call (or mobile network data call) to a specific telephone number, the so-called IAP acccessnumeroon.

Through the data transmission services of mobile communication systems, the services of the Internet are in principle also available to mobile subscribers. However, the use of a data transfer service typically requires a mobile station with data transfer capabilities and a computer connected to it. Today, mobile devices with an integrated computer, such as the Nokia Communicator 9000, are also available. The latter also includes built-in capabilities for connecting to the Internet. In the following description, it is assumed by way of example that the mobile station MS is of the Nokia Communicator type integrated terminal.

As stated above, the settings of at least one IAP are stored in the MS, on the basis of which the MS makes a data call to the IAP for an Internet transaction. ΙΑΡ settings may vary in different applications, but typically include at least an IAP access number and a service provider (ISP) name. Assume that the home network of the MS is GSM 17 (Finland) and the home lAP is IAP

Finland. For example, when an MS is roaming on a GSM network 11 in Sweden, it would be advantageous for the subscriber to use a local IAP15 instead of a home IAP to avoid the cost of an international call. However, as described in more detail in the preamble of the application, the problem is how the MS or the subscriber knows the most suitable IAP for each location.

In the invention, the mobile communication system is divided into areas to which recommended or preferred Internet access points (IAPs) are assigned. These areas are referred to in this application as IAP areas. In Figure 1, the GSM network 17 forms one ΙΑΡ area and the GSM network 11 forms another IAP area. However, the alue-zoning can in principle be anything. Each ISP may designate one or more primary 10 IAPs in the ΙΑΡ area. In the example of Figure 1, it is assumed that for one ISP (e.g. Eunet) the primary IAP of the GSM network 17 is IAP14 (Eunet Finland) and the primary IAP of the GSM network 11 is IAP15 (Eunet Sweden). According to the basic idea of ​​the invention, a mobile station roaming in the system detects a change in the IAP area based on the system information broadcast by the serving base station and updates the ΙΑΡ settings so that an Internet call can be established via the primary IAP of the new IAP area. This procedure will be described in more detail with reference to the flowcharts of Figures 2 and 3, which illustrate the operation of the MS in the ΙΑΡ-hike according to the invention. The system information can be any information transmitted by the network that can be used to identify the network or part of the network 20. Examples are country code, operator name, operator code, network name, network code, and location area identifier.

In the embodiment of Figure 2, the checking of the IAP area and the possible updating of the IAP settings are performed only when the user has initiated the establishment of a new Internet call (Internet transaction) to the terminal equipment MS as defined. This avoids unnecessary updates when the MS is roaming but not using the Internet service. On the other hand, there is a delay in setting up the first Internet call in the new ΙΑΡ area. It is first assumed that the settings of the IAP used in the previous Internet call are stored in the memory of the MS, as well as system information identifying the IAP area used (mobile network 30 or a part thereof). When the user initiates a new Internet transaction (step 21), the MS receives the system information broadcast by the serving base station on the control channel (step 22). The MS compares the received system information with the stored system information of the IAP area used in the previous call to check whether the ΙΑΡ area has changed (steps 23 and 24). If the ΙΑΡ range has not changed, the 35 MS does not need to change the ΙΑΡ settings, but the MS establishes an Internet call according to the old ΙΑΡ settings via the old IAP (step 25). If a change in the IAP range is detected in step 24, the MS updates its IAP settings to match the settings in the new ΙΑΡ range (step 26), as will be described in more detail below. The new IAP settings and the system information of the new ΙΑΡ area are stored in the MS (step 26). The MS then establishes an Internet call according to the new ΙΑΡ settings via the new IAP (step 27).

In the embodiment of Figure 3, the MS updates the IAP settings whenever it detects that the ΙΑΡ range is changing. This embodiment ensures up-to-date IAP settings and high-speed Internet call set-up. On the other hand, frequent updates can put a strain on both the MS and the network. It is initially assumed that the settings of the IAP used or last updated in the previous Internet call and the system information identifying the ΙΑΡ area used (mobile network or part thereof) are stored in the memory of the MS. The MS continuously receives the system information broadcast by the serving base station (step 31). At appropriate times, e.g., when changing a cell, location area, or network, the MS compares the received system information with the stored system information to verify whether the ΙΑΡ area has changed (steps 32 and 33). If the ΙΑΡ range has not changed, the MS does not need to change the ΙΑΡ settings. If a change in the ΙΑΡ range is detected in step 33, the MS updates its IAP settings to match the settings in the new ΙΑΡ range (step 34), as will be described in more detail below. The new IAP settings as well as the system information of the new ΙΑΡ range are stored in the MS (step 34).

The actual update steps 26 and 34 of the ΙΑΡ settings in Figures 2 and 3 can be implemented in several alternative ways. In a preferred embodiment of the invention, described below with reference to Figures 4-6, the MS retrieves the new IAP settings from a network-side hardware, application, database, server, or the like, commonly referred to as a server. The server is preferably maintained by the ISP and outside the mobile network. In principle, the retrieval of ΙΑΡ settings can be done by making a data call directly to the server. However, in a preferred embodiment of the invention, the search is performed using a short message service, such as GSM SMS or USSD

The European Telecommunications Standards Institute (ETSI) standard GSM 03.40 defines a point-to-point (PP) short message service (SMS) for the GSM system. The SMS of the GSM network provides the means for sending a limited number of short messages (160 ASCII characters) between the mobile stations MS and the short message service center SC 10, which is outside the GSM network 11. Mobile outgoing (MO) and mobile terminating (MT) short message transmissions are defined as different services. MO short messages are forwarded from the 5 MS to the service center SC. These short messages can be addressed to other mobile users or fixed network subscribers. MT short messages are transmitted from the service center to the SC MS. These short messages may have arrived at the service center SC from other mobile users or other sources. The protocol used between the SC and the MS is called SM-TP (Short 10 Message Transport Protocol).

The service center SC is connected to the mobile network via a specific MSC, which is called the SMS GatewayMSC in the case of MT short messages and the SMS interworkingMSC in the case of MO short messages. This application uses the common name SMS-Gateway (SMS-GW). The SMS-GW transmits short messages between the MS and the SC and performs the HLR (and VLR) queries required for the MT message in the call. The service center SC is given its own ISDN number in the GSM network number space, with which the MS can address a short message to the SC.

It should be noted that it is irrelevant to the invention how the support of the ly20 message service is implemented in the mobile communication system. For example, in the GSM system, the invention is suitable for use in existing networks that support short message service. Such is, for example, Radiolinja Oy's GSM network in Finland. The mobile station can also be any mobile station that supports the short message service. These include the Nokia 25 2110 GSM and the Communicator 9000.

It is not essential for the invention how the SC communicates with the ISP server, via the Internet or other data network or with a direct link. In all cases, the procedure can be, for example, according to Figure 4.

When using the USSD service, the service center SC 10 can be implemented in substantially the same way. However, in the case of the USSD service, the SC typically connects to the GSM network via the HLR, as illustrated by the dashed line in Figure 1. In addition, the message exchange between the HM and the SC naturally takes place as defined for the USSD.

Referring to Figure 4, the MS requests IAP settings by sending a short message35 to the exchange SC to specifically request the Internet access point “short message, RIAP

SMS (or RIAP USSD). In a preferred embodiment of the invention, the RIAP SMS also includes system information identifying the current IAP area of ​​the MS. It is also possible that the SC knows or derives the ΙΑΡ-area information itself. The SC then requests the ΙΑΡ settings from the ISP server according to the interface required by the interface between them or the data network, IAP Request. This request may include system information that identifies the ΙΑΡ range and allows the ISP server to select the appropriate ΙΑΡ settings for the location of the mobile station. These IAP settings are sent to the SC in response to the IAP Response. The SC sends them to the MS in a special set of Internet access point in a short message, SIAP SMS (or SIAP USSD), to the mobile station. The MS updates the stored ΙΑΡ settings with the IAP settings received by the SIAP in the SMS. For example, the format of SIAP SMS may be similar to that supported by Nokia Communicator 9000.

Referring to Figure 1, in a preferred embodiment of the invention, the service center SC is connected to the Internet network 12 so that it can be used as a gateway between the GSM network and the Internet network. The connection of the short message center SC to the Internet may be a direct connection, or the SC may be connected to a separate computer hardware with access to the Internet 12. Such a separate hardware is illustrated by the CPU 19 in Figure 1.

The SC thus makes the information sources of the Internet network 12 available to the mobile subscribers via the short message service. The implementation of the SC and the retrieval of information by means of short messages are described in more detail in the applicant's parallel application FI963659, which is incorporated herein by reference. In general, the SC uses HTTP and HTML protocols in 12 directions of the Internet. The HTTP protocol, in turn, uses TCP / IP interfaces. VWVW server and client programs for various operating systems (such as Unix) are commercially available that can be used on the service center computer (s) SC to perform web page searches on the Internet in accordance with the HTTP and HTML protocols. The interface 41 between the GSM network and the service center SC may be similar to that of current short message service centers.

In a preferred embodiment of the invention, such an Internet SC is utilized to retrieve ΙΑΡ settings from an Internet Service Provider (ISP) server on an Internet network, such as the ISP server 13 in Figure 1.

If desired, the ΙΑΡ settings from a VWVW page of the Internet, the MS sends an RIAP short message (step 71, Fig. 7) addressed to the service center SC of the home network 17 (step 71, Fig. 7) containing an identifier that directly or indirectly indicates the web page in question. The direct expression includes, for example, the address of the VWVW page, the URL. Examples of URLs are http://www.nokia.com and http://www.uspto.gov/. In one embodiment of the invention, the user writes a short identification code instead of a URL in the short message, which indirectly indicates the desired VWVW page. This can be, for example, the name of an ISP, such as Eunet Finland. The SC database of the service center contains a table linking the identification codes and the addresses of the web pages. In addition, the RIAP SMS includes a system identifier that identifies the current IAP area of ​​the MS.

The RIAP short message is transmitted to the service center SC as normal

MO short message when the MS roams in another GSM network, such as network 11 in Sweden, the RIAP SMS is transmitted to the home network 17 and via the SMS-GW to the service center SC. After receiving the short message, the SC retrieves the URL from the table based on the identification code. The SC then sends a ΙΑΡ setting request, IAP Request, to the ISP server 13 corresponding to the URL, which contains a system identifier identifying the current ΙΑΡ area of ​​the MS. The ISP server 13 contains a list linking the alue ranges and the primary IAP settings. When the ISP server 13 receives the IAP Request (step 51, Figure 5), it searches the received system information for the ΙΑΡ settings that best match the current location 20 (IAP area) of the MS (step 52). The ISP server then sends the selected ΙΑΡ settings To the SC in response to the IAP Response (step 53).

The SC forwards the ΙΑΡ settings to the MS in the SIAP short message. The MS receives the SIAP short message (step 72, Figure 7) and optionally displays the new ΙΑΡ settings to the user for confirmation and / or to make any user-specific additions or changes (step 73). The MS then updates the ΙΑΡ settings (step 74).

In the above embodiment, the selection of ΙΑΡ settings was performed by the ISP server. One way to implement said list and selection functions is to use web pages with query scripts, i.e. query expressions made in a command language. In other words, the web server already maintaining the web page filters the relevant ΙΑΡ settings from the list on the web page according to the received system information (alue area) and returns them as a web page to the service center SC. The service center must know the query format of each web page (service).

In another embodiment of the invention, the ΙΑΡ lists are implemented as a web page of the ISP server, but the selection of the ΙΑΡ settings is performed by the SC. After receiving the short message, the SC retrieves the URL from the table based on the identification code (steps 61-62, Fig. 6). The SC then preferably checks whether the web page in question has already been retrieved and stored in the SC's database 5 (step 63). If the page is not in the database, the SC URLs match the WVWV page from the Internet and store it (step 64). The SC separates or filters only the relevant ΙΑΡ settings from the web page according to the current IAP area of ​​the MS (step 65) and sends them in an SIAP short message to the MSJI (step 66).

In both embodiments described above, the principles presented in application FI963659 can be directly applied.

An optional feature of the GSM system is the Short Message Service Cell Broadcast ”, SMS-CB. It consists of broadcasting digital information messages (short messages) cyclically to a mobile station MS in a certain geographical area. According to current GSM recommendations, cellular broadcast short messages are not encrypted or addressed, so any MS designed for this service can receive and decode them. However, the recommendations do not specify who and how these messages are produced for the network. A classic example of the use of cellular broadcasting is road traffic information.

In another embodiment of the invention, the primary cell broadcast is used to update the ΙΑΡ settings of steps 26 and 34 of Figures 2 and 3. A dedicated short message service center or other application, such as the service center SC in Figure 1, produces cell broadcast messages containing the primary ΙΑΡ settings of a particular IAP area. The content of these short messages may be in the format of the above-mentioned SIAP short message. The short messages are broadcast in all cells in the alueella range mentioned. Other IAP areas broadcast different ΙΑΡ settings. All mobile stations in the ΙΑΡ area that support the SMS-CB receive short messages (step 81, Figure 8) 30 and can update the ΙΑΡ settings as needed (step 83). The MS may also display the new ΙΑΡ settings to the user and request confirmation (step 82). In a preferred embodiment of the invention, the MS allows the ΙΑΡ settings to be updated only when the IAP area changes. The MS could update the ΙΑΡ settings each time it receives a broadcast short message, but this is not a very practical exchange35 condition. An update based on SMS-CB avoids a separate IAP settings retrieval procedure. On the other hand, a significant transmission of messages is caused, which burdens both the network and the mobile stations. On the other hand, not all networks and all mobile stations are likely to support SMS-CB, which may limit the coverage of the ΙΑΡ-roaming according to the invention.

In one embodiment of the invention, the subscriber may have additional subscriber-specific settings defined on the server 13. In this case, the subscriber's MSISDN can also be transferred to the server in the RIAP request, on the basis of which the ISP server is able to send back the IAP settings to the subscriber.

The invention has been described above with reference to preferred embodiments. However, the invention is not limited to the solutions presented, but the invention may be modified within the scope and spirit of the appended claims.