Abstract: A scrambling and descrambling method that includes reading of original PID and TSC bits in the PID and TSC fields of a packet header of an MPEG2 stream which is at least partially scrambled. A temporary PID may be written in a PID field in place of the original PID, and may be a function of the original PID value and TSC bits according to a correspondence table of an original PID and TSC bits with the temporary PIDs. The value zero may be written in the TSC field in place of the original value, and scrambling of the stream with modified fields may occur. Applications include the satellite transmission of partially scrambled MPEG2 digital signals.

Abstract: A system for propagating encryption key information between wireless communication devices without the requirement of pairing each and every device. A wireless communication device may be paired with at least one device in a group of devices. When a secure link is established between these devices, a determination may be made as to whether encryption key information should be passed from one device to another. The additional encryption key information may allow a wireless communication device to create a secure link with other devices without having to first establish a trusted relationship (e.g., go through a pairing process) with the other devices.

Abstract: A broadcaster prepares primary content session stream data, and auxiliary content files, such as subtitle text. The auxiliary data may be provided using a two-level structure. Here, the first level can be is a file having plural entries each with a control information item, e.g. a timestamp, and a reference is found. A receiver at a time relating to a timestamp renders video content from a packet (43) having that timestamp, and also renders subtitle text from the second level file (46) having the same reference as the reference corresponding to the timestamp in the first level file. Thus, the broadcaster defines when subtitle text strings are to be rendered but without requiring streaming of packets including the auxiliary data. This makes it easy for a receiver to synchronise the auxiliary data with the primary content. A single level file structure can be used instead.

Abstract: A method for processing a channel change request in a television system operating according to the IP protocol. This method is implemented in a digital decoder of the subscriber and its purpose is to avoid overloading the access network in the case of burst zapping and avoid penalizing the reactivity time of the system in the case of simple zapping. In the case of reception of a burst of channel change requests separated by a time interval less than the duration of the predetermined timeout (Ttempo), the digital decoder transmits, to the access network of the system, two physical channel change requests, one for the first channel change request and the other for the last channel change request of the burst.

Abstract: A mobile component of a data exchange system, in particular a mobile telephone of a home mobile radio system, is equipped with an Internet interface in order to transmit control commands via the Internet interface to a control device in order to control one or more consumers, whereby the control device converts these control commands into a corresponding control of the required consumer.