Abstract: The invention relates to a system for supporting a plurality of activities which includes a plurality of terminals for interacting with said activities. The system allows the user to relocate activities from one terminal to another. The relocation can be simplified by means of a physical token representing the activity to be relocated. Terminals are coupled to receptacles for receiving the physical tokens. If a token is removed from a receptacle, the activity is associated with the token. If the token is inserted into another receptacle, the activity is resumed at the terminal coupled to the other receptacle.

Abstract: A conditional access system comprising a plurality of devices interconnected in a network, the devices being grouped in a first group and a second group, the devices of the first group operating in accordance with a first security framework and the devices of the second group operating in accordance with a second security framework, each device operating using a particular middleware layer, said middleware layer being arranged to authenticate another middleware layer of another device, said middleware layer being authenticated by the security framework in accordance with which the device operates.

Abstract: In an MPEG-2 transmission system a plurality of programs each consisting of a plurality of elementary streams are multiplexed on a transport stream by a multiplexer (8). The transport stream is transmitted by the transmitting means (10) via a transmission medium (16) to a receiver (18). In the receiver (10) the signal is demodulated by the receiving means (12) and demultiplexed by the demultiplexer (14). In order to be able to find the different elementary streams which form a program several tables are used. Said tables which can change over time, are updated by information present in the transport stream. The tables are identified by a version number in order to be able to distinguish different versions of them. The version numbers are not necessarily subsequent numbers. In a prior art transmission system filtering has to be performed on all possible version numbers to find updates of a table.