Roaming arrangement

Abstract

The invention relates to a method of arranging roaming in a telecommunications system comprising a local network, at least one public land mobile network, and a terminal equipment. In the telecommunications system, public land mobile network identifiers and network element identifiers linked therewith are defined. These public land mobile network identifiers and the network element identifiers linked therewith are transmitted to the terminal equipment. The terminal equipment selects a public land mobile network by means of a comparison of the received public land mobile network identifiers and public land mobile network identifiers stored in the terminal equipment. Access is arranged for the terminal equipment via the local network to the network element determined by the network element identifier linked with the identifier of the selected public land mobile network.

1 . A method of arranging roaming in a telecommunications system comprising at least one wireless local network, at least one public land mobile network, and at least one wireless terminal comprising means for setting up a data transmission connection at least with the local network, the method comprising: 
 determining, in the telecommunications system, public land mobile network identifiers and network element identifiers linked with said public land mobile network identifiers,    transmitting said public land mobile network identifiers and the network element identifiers linked therewith to the terminal,    selecting a public land mobile network by means of a comparison of said received public land mobile network identifiers and public land mobile network identifiers stored on a memory medium of or connected to the terminal, and    providing the terminal with access via the local network to the network element determined by the network element identifier linked with the identifier of the selected public land mobile network.    
   
   
       2 . The method of  claim 1 , wherein said public land mobile network identifiers and the network element identifiers linked with said public land mobile network identifiers are stored in the local network, and 
 said public land mobile network identifiers and the network element identifiers linked with said public land mobile network identifiers are transmitted from the local network to the terminal after the terminal has set up a connection to the local network.    
   
   
       3 . The method of  claim 2 , wherein said public land mobile network identifiers and the network element identifiers linked with said public land mobile network identifiers are transmitted from the local network in response to a request received from the terminal.  
   
   
       4 . The method of  claim 1 , wherein said network element of the public land mobile network is an authentication server, the method further comprising: 
 carrying out the authentication of the terminal by an authentication server defined by the network element identifier linked with the identifier of the selected public land mobile network, and    allowing provision of data transmission services in the local network in response to successful authentication of the terminal.    
   
   
       5 . The method of  claim 4 , wherein the public land mobile network is a UMTS network, and the terminal comprises a universal subscriber identity module (USIM), which stores algorithms required for calculating an authentication response, and a subscriber identifier and a secret key, and 
 authentication is performed by the authentication server by comparing the authentication response (RES) calculated in the USIM of the terminal to an expected authentication response (XRES) received from an authentication centre of the subscriber's home public land mobile network.    
   
   
       6 . The method of  claim 4 , further comprising: 
 forwarding charging data about the telecommunications services used by the terminal to the charging system of the public land mobile network in response to successful authentication of the terminal.    
   
   
       7 . The method of  claim 1 , wherein said network element of the public land mobile network is an authentication server, the method further comprising: 
 performing authentication of the terminal by an authentication server defined by the network element identifier linked with the identifier of the selected public land mobile network, and    allowing provision of data transmission services in the selected public land mobile network in response to successful authentication of the terminal.    
   
   
       8 . The method of  claim 7 , wherein the public land mobile network is a UMTS network, and the terminal comprises a universal subscriber identity module (USIM), which stores algorithms required for calculating an authentication response, and a subscriber identifier and a secret key, and 
 authentication is performed by the authentication server by comparing the authentication response (RES) calculated in the USIM of the terminal to an expected authentication response (XRES) received from an authentication centre of the subscriber's home public land mobile network.    
   
   
       9 . The method of  claim 7 , further comprising: 
 forwarding charging data about the telecommunications services used by the terminal to the charging system of the public land mobile network in response to successful authentication of the terminal.    
   
   
       10 . The method of  claim 1 , wherein at least one list comprising the public land mobile network identifiers is stored in order of priority in the subscriber identity module contained in the terminal, 
 the identifiers on the list are compared in the terminal to the public land mobile network identifiers received from the local network in order of priority, and    a public land mobile network, the identifier of which is also found from the public land mobile network identifiers received from the local network, is selected.    
   
   
       11 . A telecommunications system comprising at least one local network, at least one public land mobile network, and at least one wireless terminal configured to set up a data transmission connection at least with the local network, wherein 
 public land mobile network identifiers and network element identifiers linked with said public land mobile network identifiers are configured to be determined in the telecommunications system,    said public land mobile network identifiers and the network element identifiers linked therewith are configured to be transmitted to the terminal in the telecommunications system,    the terminal is configured to select a public land mobile network by means of a comparison of said received public land mobile network identifiers and public land mobile network identifiers stored on a memory medium of or connected to the terminal, and    the terminal is configured to set up a connection via the local network to the network element determined by the network element identifier linked with the identifier of the public land mobile network selected by the terminal.    
   
   
       12 . The telecommunications system of  claim 11 , wherein the local network is configured to store said public land mobile network identifiers and the network element identifiers linked with said public land mobile network identifiers, and 
 the local network is configured to transmit said public land mobile network identifiers and the network element identifiers linked with said public land mobile network identifiers to the terminal after the terminal has set up a connection to the local network.    
   
   
       13 . The telecommunications system of  claim 12 , wherein the terminal is configured to select a network by means of the public land mobile network identifiers contained in the subscriber identification module located in the terminal, and 
 said network element is an authentication server configured to perform authentication of the terminal by comparing an authentication response calculated by the subscriber identification module of the terminal to an authentication response calculated in the public land mobile network.    
   
   
       14 . The telecommunications system of  claim 11 , wherein the terminal is configured to select a network by means of the public land mobile network identifiers contained in the subscriber identification module located in the terminal, and 
 said network element is an authentication server configured to perform authentication of the terminal by comparing an authentication response calculated by the subscriber identification module of the terminal to an authentication response calculated in the public land mobile network.    
   
   
       15 . A wireless terminal apparatus configured to set up a data transmission connection at least with a wireless local network, wherein the terminal apparatus is configured to receive public land mobile network identifiers and network element identifiers linked therewith, 
 the terminal apparatus is configured to select a public land mobile network on the basis of a comparison of said received public land mobile network identifiers and public land mobile network identifiers stored on a memory medium of or connected to the terminal apparatus,    the terminal apparatus is configured to set up a connection via the local network to a network element defined by the network element identifier linked with the identifier of the public land mobile network selected by the terminal apparatus.    
   
   
       16 . The terminal apparatus of  claim 15 , wherein the terminal apparatus is configured to access a subscriber identification module containing subscriber data required for using services of the public land mobile network, 
 the terminal apparatus is configured to select a network on the basis of the public land mobile network identifiers contained in the subscriber identification module of the terminal apparatus,    the subscriber identification module is configured to form an authentication response used in the authentication, and    the terminal apparatus is configured to transmit the authentication response to the network element.    
   
   
       17 . The terminal apparatus of  claim 15 , wherein the terminal apparatus is configured to transmit a request to the local network for transmitting said public land mobile network identifiers and the network element identifiers linked with said public land mobile network identifiers, and 
 the terminal apparatus is configured to receive said public land mobile network identifiers and the network element identifiers linked with said public land mobile network identifiers from the local network in response to a request received from the terminal apparatus.    
   
   
       18 . The terminal apparatus of  claim 15 , wherein the terminal apparatus is configured to set up the connection via the local network to an authentication server for authenticating the terminal apparatus as a precondition of provision of data transmission services via the local network in response to successful authentication of the terminal apparatus.  
   
   
       19 . The terminal apparatus of  claim 15 , wherein the terminal apparatus comprises an Integrated Circuit IC card reader, and 
 the terminal apparatus is configured to obtain the public land mobile network identifiers from an IC card inserted in the terminal apparatus.    
   
   
       20 . The terminal apparatus of  claim 15 , wherein the terminal apparatus is configured to check public land mobile network identifiers on a list stored in a subscriber identity module in order of priority, 
 the terminal apparatus is configured to compare the identifiers on the list to the public land mobile network identifiers received from the local network in order of priority, and    the terminal apparatus is configured to select a public land mobile network, the identifier of which is also found from the public land mobile network identifiers received from the local network.    
   
   
       21 . The terminal apparatus of  claim 20 , wherein the subscriber identity module comprises a first list of public land mobile network identifiers controlled by a user and a second list of public land mobile network identifiers controlled by an operator, and 
 the terminal apparatus is configured to check identifiers of the first list before checking identifiers of the second list.    
   
   
       22 . The terminal apparatus of  claim 15 , wherein the public land mobile network identifiers contained in the terminal apparatus are supplemented by an identifier indicating an access technology.  
   
   
       23 . A computer program product operable on a processor of a mobile station, the computer program product comprising a computer program code portion for causing the mobile station to select a public land mobile network on the basis of a comparison of received public land mobile network identifiers and public land mobile network identifiers stored on a memory medium of or connected to the mobile station, and a computer program code portion for causing the mobile station to set up a connection via the local network to a network element defined by the network element identifier linked with the identifier of the selected public land mobile network.  
   
   
       24 . A method for a wireless terminal configured to set up a data transmission connection at least with a wireless local network in a system further comprising at least one public land mobile network, the method comprising: 
 receiving public land mobile network identifiers and network element identifiers linked therewith,    selecting a public land mobile network by means of a comparison of said received public land mobile network identifiers and public land mobile network identifiers stored on a memory medium of or connected to the terminal, and    setting up an access via the local network to the network element determined by the network element identifier linked with the identifier of the selected public land mobile network.    
   
   
       25 . An access controller for a wireless local network, wherein the access controller is configured to determine public land mobile network identifiers and network element identifiers linked with said public land mobile network identifiers, and 
 the access controller is configured to transmit said public land mobile network identifiers and the network element identifiers linked therewith to the terminal.    
   
   
       26 . An access controller of  claim 25 , wherein the access controller is configured to operate as a gateway in data transmission between an access point of the local area network and a public land mobile network.  
   
   
       27 . An access controller of  claim 25 , wherein the access controller is configured to operate as an authenticator for an EAP (Extensible Authentication Protocol) applied for the terminal.  
   
   
       28 . An access controller of  claim 25 , wherein the access controller is configured to transmit an EAP message to an authentication server in a public land mobile network on the basis of an EAP request or response message from the terminal, 
 the access controller is configured to forward an authentication request from the authentication server to the terminal,    the access controller is configured to forward an authentication response from the terminal to the authentication server,    the access controller is configured to receive information on success of the authentication from the authentication server, and    the access controller is configured to allow data transmission services to be provided to the terminal in the wireless local network in response to information from the authentication server indicating successful authentication.    
   
   
       29 . A method for providing system information for roaming in a telecommunications system comprising at least one wireless local network, at least one public land mobile network, and at least one wireless terminal comprising means for setting up a data transmission connection at least with the local network, the method comprising: 
 determining, in access controller for the wireless local network, public land mobile network identifiers and network element identifiers linked with said public land mobile network identifiers, and    transmitting said public land mobile network identifiers and the network element identifiers linked therewith to the terminal.    
   
   
       30 . A method of  claim 29 , wherein the access controller operates as an authenticator for an EAP (Extensible Authentication Protocol) applied for the terminal.  
   
   
       31 . A wireless terminal apparatus comprising: 
 means for setting up a data transmission connection at least with a wireless local network,    means for receiving public land mobile network identifiers and network element identifiers linked therewith,    means for selecting a public land mobile network on the basis of a comparison of said received public land mobile network identifiers and public land mobile network identifiers stored on a memory medium of or connected to the terminal apparatus,    means for setting up a connection via the local network to a network element defined by the network element identifier linked with the identifier of the public land mobile network selected by the terminal apparatus.