Currently, there is a large scale deployment of digital terrestrial and satellite television networks, which are bound to gradually replace their analogue counterparts. There is also a growing demand for streaming video services over the Internet, as well as for video conferencing services over data networks. The trend is towards convergence of the telecommunications, broadcasting and information technology (IT) industries, in order to provide seamlessly interactive multimedia services to the end users.
This trend is supported by international standards for multimedia coding. Particularly for video sequences, there is a plethora of standards for different qualities and applications, each applying efficient techniques to remove the source redundancy inherent in digitised video, in other words, compress the information. This is a very demanding task in terms of computing performance, but advances in processing capabilities enable its execution within the real-time requirements imposed by the industry. With compression, it has become practical to store and manipulate digital video with currently available storage systems.
Whether it has become practical to deliver video to the users, depends on the underlying network technology, as well. While broadcast networks, be them cable, terrestrial, or satellite, have been designed with relatively large bandwidth capacity, they are not yet optimised for transmitting digital information. On the other hand, Internet Protocol (IP) data networks do not currently fulfil neither the bandwidth, nor the latency and Quality of Service (QoS) requirements for the average user. It is well understood that future broadband systems using Asynchronous Transfer Mode (ATM) technology, will accommodate digital video transmission in their wide range of services.