Dynamic allocation of radio resources in a packet switched communications-system

DETAILED DESCRIPTION In accordance with one aspect of the present invention there is provided a method of controlling communication between user stations using a mobile communications system having a radio interface, said method comprising: providing a data packet handler connected to a packet data network; holding control data, indicating a state of a call between a first user station and a second user station; dynamically assigning radio resources for the transfer of data packets carrying call data for said call over said radio interface, such that the amount of radio resources assigned varies in accordance with the amount of call data to be transferred at different points in said call; and controlling the transfer of data packets between said first and second user stations, using said data packet handler, in accordance with said control data.
The state of a call may be held in a network-side store, to allow control of the communication between the mobile stations.
The functionality provided by a packet data network, and the nature of radio resource allocation and control, is such that data transfer is possible throughout a call, even when the transfer of data is intermittent, without requiring an ongoing circuit-switched connection between the user stations.
The data transferred may be voice call data, or video call data.
In accordance with a further aspect of the invention there is provided a method of handling the transfer of data in a GSM-type mobile communications system, said method comprising: receiving a first data packet from a first user station, said first data packet containing a recipient ID; mapping said recipient ID to a packet network protocol address whereby routing to a second user station is identified by a gateway GPRS support node; and transmitting a second data packet to said gateway GPRS support node, said second data packet containing said packet network protocol address.
This aspect provides functionality allowing the transfer of data packets between user stations using GPRS, wherein a known recipient ID, rather than a packet network protocol address (which may be only temporarily allocated), may be used by the first user station to identify the second user station