Abstract: A communications system is provided, the system being operable to provide a communications session utilizing an internet protocol, such as for example IPv4, IPv6 and their extensions mobile IPv6 or IPv4. The system includes a mobile node having an application program and an operating system. The application program is operable to provide the communications session using an internet protocol address information. The operating system is operable to monitor the internet protocol address information and to inform the application program of a change of internet protocol address information. The application program is arranged to adapt the communications session in accordance with the change of internet protocol address information.

Abstract: A communication session between a first terminal and a second terminal is switched from a first network with no fixed infrastructure to a second network with a fixed infrastructure upon degradation on a first transmission channel between the terminals in the first network. In each terminal, a controller detects a degradation on the first transmission channel and stores the latest data received from the other terminal. An interface transmits an invitation message including connection parameters relative to a second transmission channel to the other terminal via one of the networks if the degradation is estimated as permanent. The second transmission channel from the other terminal is established through the second network so that the terminals are connected via the second network to thereby continue the communication session depending on the stored latest received data.

Abstract: A system for locating a communications terminal (10). The system comprises a location hybridization module (14) which comprises: a spatial filter (142); a temporal filter (141) for the geographical location adapted to compare a time corresponding to the age of the latest geographical location with a first predetermined maximum time and, in the event of a positive comparison result, to compare said time corresponding to the age of the latest geographical location with a second predetermined maximum time greater than said first predetermined maximum time; a speed filter (145) adapted to compare the speed at which said terminal (10) is moving with a predetermined maximum speed; a module (144) for estimating the uncertainty as to the geographical location; and a selection module (143) adapted to select either the area defined by the latest geographical location or the network-location area. Application is to mobile telephone services that need to know the location of the terminals.

Abstract: A communications system is provided, the system being operable to provide a communications session utilising an internet protocol, such as for example IPv4, IPv6 and their extensions mobile IPv6 or IPv4. The system comprises a mobile node having an application program (410) and an operating system (420). The application program (410) is operable to provide the communications session using an internet protocol address information. The operating system (420) is operable to monitor the internet protocol address information and to inform the application program of a change of internet protocol address information. The application program is arranged to adapt the communications session in accordance with the change of internet protocol address information.