New flexibility in digital broadcasting: service facilities in DAB

Abstract

A new digital audio broadcasting (DAB) system has been developed by the European Eureka 147/DAB Project in close co-operation with the EBU. DAB promises high-quality sound and very rugged reception for all types of receivers. The benefit is particularly felt by the motorist because the technology has been designed with the mobile user in mind and constructive use is made of multipath propagation which sometimes mars FM reception. This also makes portable receivers, in the home, less critical as regards their positioning. The DAB broadcast channel supports a multiplex of services known as an ensemble containing, for example, up to six stereo programme services. However, it can be adapted to suit varying service needs. There is an opportunity to introduce new services, subject to the limit of the data-carrying capacity of the channel. The paper concerns the service facilities, including the service multiplex and support features, embracing service information and non-audio data services. The initial system requirements are discussed first. The conceptual multiplex frame is introduced and different audio options are examined. The service structure is presented and the basic administration of the multiplex is described, including the management of dynamic changes to the service multiplex. Finally, the broad range of service information features and nonaudio data services are described.