Beyond the short-term, these events are also adding fuel to a long-standing debate about spectrum use. Seeking to head off what the telecom industry has predicted could be a catastrophic shortage of bandwidth for mobile broadband services facing skyrocketing demand, the FCC has asked Congress for the authority to reclaim up to 120MHz of spectrum currently licensed to television broadcasters. Broadcasters are concerned about this, to put it mildly, and have been lobbying intensely to protect broadcasters’ control over spectrum. One of the broadcast industry’s key initiatives in this regard is the Open Mobile Video Coalition which seeks to convince the FCC to mandate the inclusion of TV receiver chips (based on the ATSC-M/H mobile television standard) in all mobile phones sold in the U.S.
On August 25, the OMVC issued an open letter to the FCC citing the earthquake as evidence of “the crucial importance of Mobile Digital TV during emergencies:”
“Wireless networks simply are not now, and never will be, in a position to deliver the sort of ubiquitous, bandwidth intensive information during a time of crisis that broadcast television and Mobile DTV stations delivered on Tuesday. Merely allocating additional spectrum to wireless networks will not enable them to do so. Cellular economics do not allow for the massive buildout of network infrastructure that would be necessary to support the large call and data volume that invariably is triggered by mass events of this nature.”
This declaration echoes conclusions from an earlier study sponsored by the OMVC which said,
“…the cost of providing video broadcasts over the cell networks — even 3G and 4G networks — is prohibitive because the unicast nature of these networks was not designed to serve broadcast-sized audiences simultaneously …”
Did you spot the rub? It’s “unicast.” And here’s where the engineers run away with the argument. IP multicast is the internet’s general answer to more efficient live streaming, but applying it in mobile circumstances is problematic. For those interested, the difficulties are outlined in an Internet Research Task Force paper, but they boil down to problems with handovers between cells and related issues. Among the paper’s telling recommendations, however, is this:
“Integrate multicast listener support into unicast mobility management schemes and architectural entities to define a consistent mobility service architecture, providing equal support for unicast and multicast communication.”
In other words, merge broadcast capabilities into Mobile IPv6 so that service providers can operate and optimize a single integrated transmission channel.
The carriers, for their part, are generally unenthusiastic about putting ATSC DTV receiver chips in mobile devices: not only do they raise device costs (which are still largely subsidized by service providers) but they presumably encourage a mode of free usage that doesn’t boost ARPU or reduce churn. (Some have made the counterargument that such usage could relieve data network congestion and even provide a gateway to paid mobile video services like Verizon’s V-Cast by stimulating mobile video viewing in general.) Still, they also want that spectrum.
Consumer demand for mobile TV has been, shall we say, cool as evidenced by the failure of Qualcomm’s FLO TV service which sold its FCC spectrum licenses to AT&T and suspended service earlier this year. Although the broadcast lobby is strong, it’s probably not strong enough to win any public subsidy for mobile TV in the current economic climate. And the FCC’s visionary National Broadband Plan which includes plans for spectrum reallocation is currently as paralyzed and embroiled in partisan politics as most matters of public policy in the U.S. today, with House Minority Leader John Boehner describing it as “a government takeover of the Internet.”
So what can we conclude from all this? First, it’s going to take a long time for the FCC, Congress, and the competing factions to sort out the mandates for mobile broadcasting (IP-based or otherwise). Perhaps this is for the best as it will take some time for innovations like cognitive radio to make their way to marketplace, and massive changes in spectrum allocation are not to be taken lightly.
Second, until we can get this sorted out, I’m keeping my battery-powered AM/FM radio handy for the next emergency.