Spectrum of Issues

KEY RECENT AUCTIONS OF SPECTRUM With spectrum scarce, U.S. telecom companies have spent billions on licenses to use it. In 2008, Verizon snapped up large portions of the 700-megahertz band to build up its 4G LTE network; two years earlier, T-Mobile won enough spectrum near two gigahertz to build its 3G network. $19.0 $13.8 graphiti OPENING UP "WHITE SPACES" BILLION BILLION Even before the switch to digital TV, broadcasters were using less and less of the bands that they had been granted decades ago. These frequencies are especially valuable because they can be used to transmit information over long distances. $124 MILLION 700-MHz BAND 1.4 GHz 1710-1755 MHz, 2110-2155 MHz U.S. RADIO FREQUENCY ALLOCATIONS Advanced Wireless Services (30 MHz-3 GH2) FREQUENCY (MHz) BROADCASTING DAmateur ITelevision TV channels 2-4 TV 5-6 FM radio TV 7-13 TV 14-36 •-- Unlicensed Radio COMMUNICATION 4G 4G AWS-1 AWS-2 SMS Fixed IMobile PCS Land mobile (public safety) Cellular and two-way radio i Mobile broadband İSM SCIENCE, NAVI GATION, LAND, AND SEA IOther Air Traffic Control GPS -- --GP Source: The graphác ás based on the ational Telecormarounications Information Admirástra- tion's Urited States FrequencyAlocations chart. Categories have been sárplijied, so "Fioed" and "Fined Satellite, "or énstance, are here grouped as one. "Other"inckudes aeronau ticaland mobile commundcationms, radiolocation and radionavi- gation, scientific and meteorological research, space operation and research, and inter-satellite commurication.Auction data is from the Federal Information graphic by TOMMY MCCALL and MATT MAHONEY Cormmurácations Cormerission. 3 kHz Very Low Frequency 30 kHz Low Frequency 300 kHz Medlum Frequency 3 MHz High Frequency 30 MHz Very High Frequency 300 MHz Ultra High Frequency 3 GHz Super HIgh Frequency 30 GHz Extremely High Frequency 300 GHz Unlicensed, experimental "lowfer" broadcast 160-190 kHz Communication with CB radio Police/construction Coast guard broadcast of storm warnings 2.67 MHz Amateur short- High-altitude ra dar hurricane research (18.8-20.2 GHz) Microwave ovens- L. Sprint and Clearwire's 4G network (2.5 GHz) Radio astronomy (85-150 GHz) Verizon's 4G LTE Potential smart- Tridium satellite navy submarines 20 kHz (27 MHz) companies (30-50 MHz) wave radio network (20 GHz) grid frequency (1.4 GHz) 5.9-26.1 MHz (700 MHz) AT&T opens up 850-MHz spectrum for iPhone (850 MHz) Microwave data links for wireless backhaul (245 GHz) (39 GHz) Spectrum of Issues to underused slices of the spectrum pre- Sprint, and T-Mobile to improve 3G networks and build their faster next-gen- eration networks. But in September, the he radio frequency spectrum, which band services over the so-called "white channel is unoccupied and available for viously reserved for government. In the United States, auctions for those licenses spaces," unused areas between stations in the TV broadcast spectrum. Vastly more broadcast in a particular area are still being finalized. But if the experiment once seemed to offer virtually unlim- ited capacity for communication, has become crowded as smart phones and other wireless devices increasingly gobble white spaces are available now that TV broadcasters have switched from analog have been going on since 1994; in recent Federal Communications Commission works and more wireless devices can Increased demand for wireless bandwidth is forcing regulators to get creative. years, these multibillion-dollar spectrum gave its final approval to a potentially more revolutionary policy. It allows cer- tain wireless networks to provide broad- peacefully share the public airwaves, it up bandwidth. One obvious solution has been to let the private sector buy access auctions have allowed telecommunica- to digital transmissions. The exact details could lead to a much more efficient and tions companies such as AT&T, Verizon, of how wireless devices will know if a flexible use of the entire spectrum. E 34 Graphiti technology revlew November/December 2010 www.technologyreview.com Graphiti 35 1525 1850 0661 2110 *