Generic service request procedure in a multimode system

Abstract

Generic service request signaling is defined where a multimode terminal is allowed to request any service that it supports in any of the modes (e.g., access technology like GERAN/UTRAN/CDMA2000/Bluetooth/WLAN/ . . . ) supported by the terminal. The network may then decide to move the terminal to other system if possible and necessary in order to establish the service. Mostly existing terminal capability indication for each system mode is used.

What is claimed is: 
     
         1 . A method of operating a multimode terminal configured to operate in a communication system in a plurality of modes using different radio access technologies, the method comprising:
 in a first mode, sending service request signaling over a first radio access network to a network node to request a service supported in at least a second mode of the plurality of modes but not supported by the network node, the service request signaling configured according to signaling messages defined for the first radio access network and including one or more parameters enabling the network node to identify the requested service; and   responsive to handover of the multimode terminal from the first radio access network to a second radio access network, establishing the requested service through the second radio access network according to the second mode.   
     
     
         2 . The method of  claim 1 , wherein the requested service is not supported by a first radio access technology corresponding to the first mode. 
     
     
         3 . The method of  claim 1 , wherein the requested service is supported by a first radio access technology corresponding to the first mode. 
     
     
         4 . The method of  claim 1 , wherein the service request signaling comprises service request parameters indicating that the requested service is not supported by the multimode terminal in the first mode. 
     
     
         5 . The method of  claim 4 , wherein the service request parameters indicate that the requested service exceeds capabilities of the multimode terminal in the first mode. 
     
     
         6 . The method of  claim 1 , wherein the service request signaling comprises an identifier of the second radio access network to which the network node can direct the service request. 
     
     
         7 . The method of  claim 1 , wherein the service request signaling comprises service request parameters indicating that the requested service is not supported by the multimode terminal when attached to the first radio access network and operating according to the first mode. 
     
     
         8 . A multimode terminal operable in a communication system in a plurality of modes including at least a first mode and a second mode, wherein each mode uses a different radio access technology, the multimode terminal further configured to:
 in the first mode, send service request signaling over a first radio access network to a network node to request a service supported in at least the second mode of the plurality of modes but not supported by the network node, the service request signaling configured according to signaling messages defined for the first radio access network and including one or more parameters enabling the network node to identify the requested service; and   responsive to handover of the multimode terminal from the first radio access network to a second radio access network, establish the requested service through the second radio access network according to the second mode.   
     
     
         9 . The multimode terminal of  claim 8 , wherein the requested service is not supported by a first radio access technology corresponding to the first mode. 
     
     
         10 . The multimode terminal of  claim 8 , wherein the requested service is supported by a first radio access technology corresponding to the first mode. 
     
     
         11 . The multimode terminal of  claim 8 , wherein the service request signaling comprises service request parameters indicating that the requested service is not supported by the multimode terminal in the first mode. 
     
     
         12 . The multimode terminal of  claim 11 , wherein the service request parameters indicate that the requested service exceeds capabilities of the multimode terminal in the first mode. 
     
     
         13 . The multimode terminal of  claim 8 , wherein the service request signaling comprises an identifier of the second radio access network to which the network node can direct the service request. 
     
     
         14 . The multimode terminal of  claim 8 , wherein the service request signaling comprises service request parameters indicating that the requested service is not supported by the multimode terminal when attached to the first radio access network and operating according to the first mode. 
     
     
         15 . A method of operating a multimode terminal configured to operate in a communication system in a plurality of modes using different radio access technologies, the method comprising:
 in a first mode, sending service request signaling to a network node of a serving system based on a first radio access technology to request a service supported in at least a second mode of the plurality of modes but not supported by the multimode terminal attached to the serving system and operating according to the first mode, the service request signaling configured according to signaling messages defined for the first radio access technology and including one or more parameters enabling the network node to identify the requested service and to initiate a handover to a non-serving system based on a second radio access technology; and   responsive to handover of the multimode terminal from the serving system to the non-serving system, establishing the requested service through the non-serving system according to the second mode.   
     
     
         16 . The method of  claim 15 , wherein the service request parameters indicate that the requested service exceeds capabilities of the multimode terminal when attached to the first radio access network and operating according to the first mode. 
     
     
         17 . The method of  claim 15 , wherein the service request signaling comprises an identifier of the second radio access network to which the network node can direct the service request. 
     
     
         18 . A multimode terminal operable in a communication system in a plurality of modes including at least a first mode and a second mode, wherein each mode uses a different radio access technology, the terminal configured to:
 in the first mode, send service request signaling to a network node of a serving system based on a first radio access technology to request a service supported in at least the second mode of the plurality of modes but not supported by the multimode terminal attached to the serving system and operating according to the first mode, the service request signaling configured according to signaling messages defined for the first radio access technology and including one or more parameters enabling the network node to identify the requested service and to initiate a handover to a non-serving system based on a second radio access technology; and   responsive to handover of the multimode terminal from the serving system to the non-serving system, establish the requested service through the non-serving system according to the second mode.   
     
     
         19 . The multimode terminal of  claim 18 , wherein the service request parameters indicate that the requested service exceeds capabilities of the multimode terminal when attached to the first radio access network and operating according to the first mode. 
     
     
         20 . The multimode terminal of  claim 18 , wherein the service request signaling comprises an identifier of the second radio access network to which the network node can direct the service request.