Operators crave 700 MHz
In many ways, the vast amounts of spectrum currently occupied by television broadcasters at 700 MHz is akin to a promised land for wireless communications.
For wireless engineers, the propagation characteristics at 700 MHz promise the ability to deliver broadband wireless applications more efficiently than is possible at frequencies of 1.9 GHz or higher. For broadcasters, the promise of clearing the spectrum means completing a complex transition to digital television, which promises an array of new capabilities. For Congress, these public-interest benefits are enhanced by the promise that auctioning this prime spectrum could generate billions of dollars to help offset budget deficits.
This valuable spectrum also has been the source of broken promises. The wireless community hoped the airwaves currently used for analog TV channels 51 through 69 would be available on Dec. 31, 2006 — the target date cited by Congress in 1996. However, the legislation included a substantial caveat: Broadcasters would not have to relinquish the spectrum until 85% of all U.S. televisions can receive digital signals.
But high-priced digital televisions have not sold well, so many experts believe it could be decades before broadcasters must vacate the 700 MHz band under the original interpretation of the law. With this in mind, FCC Media Bureau Chief Ken Ferree in June proposed that all televisions receiving cable or satellite service be deemed as digital-ready, meaning the 85% threshold has been met.
FCC Chairman Michael Powell last month expressed support for Ferree’s plan, but Precursor wireless strategist Rudy Baca said the proposal is “a little too creative” and likely would not survive judicial scrutiny under existing law. And the chances of Congress changing the law to accelerate the 85% threshold are remote because lawmakers know that broadcasters play a key role in their ability to remain in office.
“[For elected officials], the last people you want to piss off are broadcasters,” Baca said. “Because, when you do, they have a habit of saying bad things about you, and that makes it tougher to get re-elected.”
One aspect of the controversy appears to be indisputable: The 700 MHz band is well-suited for delivering broadband services wirelessly. In fact, former FCC Chairman Reed Hundt in June compared the 700 MHz airwaves to prime Manhattan real estate and indicated that the near-term viability of the broadband wireless industry may be linked to the availability of the spectrum.
The reason is the airwaves’ propagation characteristics. As evidenced with analog TV, the 700 MHz band can deliver a signal that is strong enough to penetrate the walls of a building with a significant coverage range without requiring the receiving device to sport an unwieldy antenna.
These attributes mean little to elected officials, but their impact can be tangible and very significant. For instance, a broadband wireless network being trialed for first responders in Washington provides coverage over the entire metropolitan area with just 10 sites, according to Robert LeGrande, deputy chief technology officer for the District of Columbia. To realize the same coverage using spectrum at 4.9 GHz would have required 400 sites, he said.
“That’s the beauty of 700 MHz,” LeGrande said.
Demonstrated to Congress last month, the Washington network uses Flarion Technologies’ FLASH-OFDM solution and Motorola’s new Greenhouse video dispatch application to deliver high-quality streaming video content to multiple public-safety agencies in the region, LeGrande said. The upfront costs of the $2.7 million network were not significantly less than a 4.9 GHz network, but using the 700 MHz band will save the district a great deal of money over time.
“What would have been prohibitive were the operational costs,” LeGrande said. “It costs a lot more to maintain 400 sites than it does to maintain 10 sites.”
Another hidden savings in the network is the fact that the antennas are only 3 or 4 feet tall and “aesthetically tolerable,” making deployment relatively easy compared to the often arduous and expensive task of securing a tower location for a traditional 800 MHz tower, LeGrande said.
In addition, the installation cost of the 700 MHz network likely was inflated because the project was a pilot that required customized equipment instead of mass-produced gear — an issue that would disappear if the band were available on a nationwide basis, according to LeGrande.
Meanwhile, the network’s benefits to first responders could be invaluable. Real-time video transmissions can provide valuable information about an incident, and emergency medical units can use the network to get preliminary assessments from remote doctors while on the scene and en route to a hospital. The Sept. 23 demonstration included a remote expert helping a bomb squad diffuse a fake explosive device while watching a video monitor depicting the action.
Although Congress already has earmarked 24 MHz of spectrum in the 700 MHz band for public safety and the FCC ordered Nextel Communications to contribute another 4 MHz as part of the 800 MHz rebanding, LeGrande last month told a Senate committee that an additional 10 MHz is needed. LeGrande also requested that the airwaves be cleared by 2007, noting that terrorists already have access to commercial wireless broadband networks that are more robust than public-safety networks.
“Our first responders need better tools than the terrorists already have,” LeGrande testified.
Such pleas have not gone unnoticed in the post-Sept. 11 environment, and a Homeland Emergency Response Operations (HERO) Act, has been introduced in the U.S. House of Representatives that would require broadcasters to release 700 MHz spectrum to public safety by 2007, even if the 85% threshold has not been met. Sen. John McCain (R-Ariz.) reportedly is working on a draft of similar legislation on the Senate side.
Whenever the transition is made for public-safety spectrum, it is important that it is done simultaneously throughout the nation to provide an ample opportunity to enhance interoperability, according to Powell.
“Otherwise, while one town could use 700 MHz spectrum for public-safety communications, the adjacent community could still be waiting months or even years for the digital penetration level to reach 85% and the spectrum to be cleared of broadcasters,” Powell testified before the Senate last month. “In the unfortunate event of a disaster in the interim, the two communities’ first responders could not speak to one another.“
Meanwhile, Motorola has advocated that LeGrande’s request for an additional 10 MHz of spectrum be expanded to an additional 30 MHz of public-safety airwaves, to provide enough airwaves for disparate government agencies to communicate interoperably in times of crises, according to Gary Grube, chief technology officer for Motorola’s commercial, government and industry solutions group.
But this request likely will not get much support on Capitol Hill because it would nix all commercial uses of the valuable airwaves. Commercial wireless providers are expected to use the spectrum to provide broadband to remote locations via technologies such as Wi-MAX. Furthermore, proceeds from the auction are expected to fund subsidized analog-to-digital converters needed for consumers utilizing over-the-air TVs after the digital transition is made — a strategy used successfully in Berlin, Germany.
In addition to these social policies, lawmakers have been anticipating the opportunity for the FCC to auction 700 MHz airwaves to help fund other programs and offset budget deficits. For example, Democratic presidential candidate John Kerry’s (D-Mass.) entire platform for science and technology innovation would be funded by a 700 MHz auction that he estimates would deposit $30 billion into the U.S. Treasury.
LeGrande expressed optimism that the HERO Act would gain support and that broadcasters would not “fight too much” against the needs of public-safety communications. However, David Donovan, president of the Association for Maximum Service Television, told a Senate committee that broadcasters also want to clear the spectrum but do not want to do so in a manner that requires too much expense and/or creates significant problems.
“Proposals such as those advanced by H.R. 1425, however, would undermine the digital transition, requiring either the abandonment of 75 local television stations, including numerous Spanish-language and flagship DTV stations, or the relocation of these stations to a crowded in-core band that is currently unable to accept the unprecedented interference their operations would entail for the American public,” Donovan testified. “Such an approach could result in interference to more than 300 television stations, thereby limiting the viewing options of 86 million Americans.”
Given this potential situation, Baca said he doubts the 700 MHz spectrum will be available this decade, particularly for commercial users. Little has changed since 2002, when the FCC stopped trying to reschedule the 700 MHz auction after multiple postponements caused by uncertainty about the availability of the spectrum.
With 700 MHz proponents Powell and McCain expected to leave their posts as head of the FCC and the Senate Commerce Committee, respectively, Baca questioned whether the kind of dealmakers needed to resolve this complex political issue will emerge in the near future.
“I think people have chronically underestimated the power of broadcasters,” Baca said. “And I never bet against the power of inertia in Washington.”
|Block||Frequencies (MHz)||Bandwidth||pairing||Geographic area type||Number of licenses|
|A (Guard band)||746-747, 776-777||2 MHz||2 × 1 MHz||Major economic areas||52|
|B (Guard band)||762-764, 792-794||4 MHz||2 × 2 MHz||Major economic areas||52|
|C||747-752, 777-782||10 MHz||2 × 5 MHz||700 MHz EAG||6|
|D||752-762, 782-792||20 MHz||2 × 10 MHz||700 MHz EAG||6|