After a decade of operation, and with only a handful of listeners to show for its investment, the Canadian Broadcast Corporation (CBC) says it has already flipped the disconnect switch on its four DAB signals in the city of Montreal, effectively ending the nation's attempted roll out of Eureka 147 DAB on spectrum allocations between 1452MHz and 1492MHz.

At press time, at least one commercial DAB multiplex or "pod" was reported to still be transmitting in Toronto, but a consensus of industry and government observers agree that the service has reached the end of the line. Discussion was already under way on how to best reallocate the spectrum it formerly occupied.

A post-mortem by industry observers suggests that DAB's failure to launch or even achieve ignition was due to a variety of factors, such as subpar performance of the MPEG-2 encoder and spotty propagation/penetration of the L-Band frequencies used. Receivers were a major problem, since almost all production SKU's were designed for the UK and Europe where DAB operates on VHF Band III.

With DAB's imminent demise, and with increased demand for analog FM frequencies taking place in Canada's growing urban centers, the question for Canada's radio community now becomes, "What next?"

While posts in online Canadian radio forums suggest a preference for HD Radio among hobbyists, government regulators and industry representatives still treat the the option with caution. Canada's Communications Research Centre, a governmental research body with an advisory role on telecom policy, has developed its own coverage analysis tool dubbed COVLAB to evaluate digital radio coverage and spectral compatibility, rather than simply deferring to U.S. data. IBOC digital radio testing has been conducted in Canada since 2006, and the Canadian government has said that it will accept experimental HD Radio digital hybrid applications from licensed FM stations, though few stations have stepped up to do so.

So industry opinion on IBOC's potential in Canada is checkered at best. With many stations moving away from AM altogether, and interference concerns among those who remain, AM HD Radio is probably a nonstarter.

As for FM HD, small commercial broadcasters seem wary of conversion and licensing costs, just as in the U.S.. Yet definite interest in the technology is being expressed by larger broadcast groups that see multicast capability and a wide offering of reasonably priced receivers as a real advantage.

Even so, the fact that U.S.-based iBiquity holds all license rights to the proprietary technology remains a troubling undercurrent for many in industry and government alike. And so it seems that Canada's movement towards adopting a new post-DAB digital radio strategy will likely remain a deliberate process, rather than a lurch.