Wednesday, May 28, 2008

Spectrum Politics

In real estate, value depends on “location, location, location.” The same is true for RF real estate, with $19.6 billion changing hands at the FCC’s recent auction of the 700 MHz portion of the spectrum. The results of that auction will have a major impact on mobile wireless access, as will the FCC’s pending ruling on the use of the remaining white spaces in the compacted broadcast TV spectrum (channels 2-59). Where there’s money involved, there’s politics—and in this case there’s plenty of both.

C Block

On February 17, 2009, analog TV in the U.S. will go off the air. The digital TV channels will be compacted into channels 2-51 (54-698 MHz), freeing up the 700 MHz portion of the spectrum (Channels 52-69, 698-806 MHz). The FCC auctioned off that real estate in March.

Google weighed in early on with a letter to the FCC requesting that access to this spectrum be open to all devices. When the FCC ruled in Google’s favor, Verizon filed suit challenging the ruling; faced with a firestorm of bad PR, they later withdrew their suit. Google, meanwhile, anted up $4.7 billion to bid for Block C (746-757 and 776-787 MHz). Verizon eventually outbid Google and paid $9.36 billion for six C Block licenses, promising that they would abide by the open access provisions (details to follow). This spectrum will now be used primarily for wireless telephony and data services, as well as TV broadcasts optimized for mobile and handheld devices.

AT&T, the other big auction winner, then announced that they too would open up their network (details to follow). Skeptics and conspiracy theorists abound, but implementations issues aside, Google’s having “put in the fix” for open wireless access is bound to spur wireless innovation and even faster adoption of portable wireless devices.

Google got what they wanted for next to nothing. “Gaming the system!” as their critics charge, or just good business? Both, it seems to me, and I couldn’t care less, since it’s smart, ethical and works out well for both designers and consumers.

White Spaces

With the 700 MHz spectrum now off the table, the scramble is on for the remaining “white spaces” or guard bands between the new digital TV channels. In 2004 the FCC issued a notice of proposed rulemaking (NPRM) that would open up these chunks of spectrum for unlicensed low-power, portable devices as well as higher-power fixed devices that could provide broadband wireless access to portables—as long as they include a “spectrum sensing” capability that would enable them to avoid interfering with TV broadcasts and wireless microphones. The IEEE quickly started to work on IEEE 802.22, a standard for wireless regional area networks (WRANs) that would work in these white spaces. The SDR Forum got very focused on the spectrum sensing problem, since that’s one area where cognitive radio holds considerable promise.

Google wrote a letter to the FCC stating, “Coupled with the ‘Android’ open-source platform for mobile consumer devices, TV white spaces can provide uniquely low-cost mobile broadband coverage for all Americans.” Joined by Microsoft, Dell, HP, Intel, Philips and others—now calling themselves the White Spaces Coalition—Google called for unlicensed, open access to this spectrum.

It didn’t take long for the Empire to strike back. The CTIA, representing carriers and broadcasters, suddenly thought it would be a great idea to license and auction off these spaces to the highest bidder. The CTIA was joined by the NAB, the NFL, NBC, Disney and Shure—leading “a broad coalition of high-profile wireless microphone users, organized as the Microphone Interests Coalition (MIC).”

Microsoft didn’t help out here. In August 2007 they proudly sent the FCC a cognitive radio they developed that they claimed “detected DTV signals at a threshold of -114 dBm in laboratory bench testing with 100 percent accuracy.” The test device failed for FCC engineers not once but twice. This brought demands from broadcasters to give up on spectrum sensing and just license the frequencies (presumably to them). Philips is hoping to ride to the rescue with its own cognitive radio system before the FCC ends field testing in June. Look for a ruling in October.

So while you toil away over a hot oscilloscope or compiler, your wireless future is being worked out in C Block and the White Spaces. As Dave Barry would say, hey, what a great name for a rock band!