The measured performance of a VHF single-frequency network for dab

Described the first results from field tests of the EUREKA DAB system. These tests are being conducted in and around London using four, 1 kW, VHF transmitters operating as a single-frequency network The results show wide area coverage from these transmitters which is in reasonable agreement with experimental predictions. This indicates that the current equipment, built to the EUREKA DAB specification, is operating in the way that would be expected from theoretical studies and simulation. The results also provide quantitative values which can be used for coverage prediction and for international coordination of services. These values are similar to those measured in early work. Finally, the performance of the system demonstrates a number of the benefits of the EUREKA DAB system for mobile and portable reception. In particular, the reliability that can be achieved without needing very high-power transmitters; this results from the frequency diversity which is inherent in the system and the spatial diversity which can be obtained if more than one transmitter radiates the same signal at the same frequency. All this has given the BBC the confidence to proceed with plans towards implementing a UK national single-frequency DAB network for its national programme services, which is expected to begin in 1995.