| 摘要 |
A mobile communications system comprises a mobile communications network and one or more communications terminals. The communications network is configured to transmit data to and receive data from the communications terminals and comprises a radio network part including a plurality of base stations arranged to transmit the data to and receive the data from the communications terminals via a radio access interface, and a core network part which includes at least one packet data network gateway which is arranged to route the data to and receive the data from the base stations of the radio network part via the core network and a mobility manager which is arranged to track a location of the communications terminals within the mobile communications network for routing the data to or receiving the data from the communications terminals via the radio network part in accordance with context information which is stored for each of the communications terminals. The mobile communications network includes a virtual mobility manager which is configured to store at least part of the context information of a communications terminal when the communications terminal enters an off-line state so that if a triggering event occurs when the communications terminal is in the off-line state, the virtual mobility manager can page the off-line communications terminal in the off-line state so that a communications bearer can be established with the communications terminal using the stored context information, for communicating the data after the communications terminal has moved to an attached state. An improvement can be provided when the communications terminals enter the offline state, because the location of each terminal is not tracked when changing designated tracking areas or a set of tracking areas and so paging can be co-ordinated by a higher level virtual mobility manager rather than a lower level mobility manager. |
