The NAB says there’s no need for further industry testing before the FCC can allow AM stations individually to switch to all-digital operation on a voluntary basis.
It also opposes any notification period, instead favoring a simple immediate approach. It sees no need to put a carrier frequency tolerance standard in place. And it hopes the FCC will recommit to IBOC rather than reopen discussion of other formats.
In comments filed with the FCC, the broadcast association has reiterated its support for allowing all-digital on the AM band in the United States for those stations that want to adopt it. The NAB said that nearly all others who have commented to the commission have supported the idea.
In addition to reviewing the various reasons it had listed earlier (reaching more listeners, improving signals, allowing additional programming), the association now has made some specific additional points:
- It argues that no additional testing is needed because it considers the all-digital MA3 mode as proven, based on field and lab tests as well as the experimental operation of a station in Frederick, Md.;
- NAB disagrees with those who think testing is needed to determine potential interference to co-channels during nighttime hours. “The evidence shows that all-digital signals will cause fewer interference concerns than hybrid operations and eliminate any concerns about interference to adjacent channels. … WWFD has been broadcasting all-digital nighttime service for 20 months without any problems. Also, the rollout of all-digital is expected to be fairly gradual, which will provide the FCC and industry time to monitor and address any interference problems, as NPR suggests.”
- NAB agreed with Xperi, which told the FCC that although NAB Labs’ tests may not have exhaustively tested every conceivable all-digital AM operational scenario, “the success of the WWFD experiment confirms that there is more than an adequate foundation for FCC action.” The NAB said the FCC can simply address individual cases of interference as they arise, under current practice.
- The commission had asked whether to impose a carrier frequency tolerance standard on AM stations of 1 Hz as a way to improve all-digital reception. NAB says no, calling the idea “an unnecessary burden on AM broadcasters who will continue to operate in analog mode.” It agreed that tightening the carrier frequency tolerance would benefit analog and all-digital operations by reducing the impact of co-channel interference. “However, given today’s extremely challenging economic climate for radio broadcasting, especially AM service, such a new requirement would be a burden and counterproductive to the FCC’s goal of AM radio revitalization.” At most, it said, the FCC should table the idea for the time being.
- NAB supports a proposal from Nautel regarding the allowed operating power (nominal power) limits. Nautel wants the relevant section to be applied “to the average all-digital signal power including the digital signal power and the unmodulated analog carrier power” and not simply the “unmodulated analog carrier power” as proposed in the FCC notice. NAB called this “an important modification which makes good technical sense” and would make it easier for more AM stations to be switch to MA3.
- The broadcast association reiterated support for the plan to incorporate the NRSC-5-D standard by reference into the digital audio broadcasting rules — in other words, for the FCC to verify its commitment to IBOC. “Adopting NRSC-5-D as a formal technical standard will provide stakeholders the regulatory certainty needed to confidently invest in providing digital broadcasting service and products,” NAB wrote. “Contrary to the requests of Dolby and a few others calling for the FCC to start over with a reevaluation of alternatives to IBOC as the standard for all-digital AM service, confirming IBOC as the single standard for digital audio broadcasting will avoid completely upending the long-standing and ongoing progress of digital radio in the United States.”
- And NAB supports a simple notification procedure for AM stations’ conversion. It opposes a request from the Society of Broadcast Engineers for a longer prior notification period (such as 60 days) for converting to all-digital service to allow co- and adjacent analog channel stations to determine certain baseline data before digital service starts. “NAB submits that NAB Labs’ extensive testing and WWFD’s real-world experience confirm that such a requirement is unnecessary.”