Concluding its six-year evaluation of Digital Audio Radio (DAR) systems, the Consumer Electronics Manufacturers Association (CEMA) filed its final report last month with the Federal Communications Commission (FCC). The report, "Technical Evaluations of Digital Audio Radio Systems: Laboratory and Field Test Results, System Performance, Conclusions," is available to the public from the FCC and through CEMA's website.

The DAR Subcommittee examined nine proposed technologies for broadcast digital audio radio. Of all the systems tested, the committee found that only the Eureka-147/DAB system offers the audio quality and robust signal performance that listeners would expect from a new DAR service in all reception environments.

According to the committee, three other systems had significant problems. The IBOC (in-band, on-channel) systems, as presented and tested, are considered not feasible at this time due to deficient performance in the areas studied: audio quality, performance with channel impairments, RF compatibility, and extent of coverage. The IBAC (in-band, adjacent-channel) system cannot be deployed due to interference with the current spectrum occupancy of the FM band. Finally, the VOA/JPL (Voice Of America/Jet Propulsion Labs) system at S-band frequencies is subject to continuous and/or repeated outages due to blockage. It is not clear that this can be totally remedied.

"Despite these results, last spring we halted advocacy of the adoption of any system at the request of the broadcasters, who said they needed more time to correct the flaws of the IBOC system. We look forward to broadcasters demonstrating in the near future a system that will work," said Gary Shapiro, CEMA president.