Open Spectrum: Latest Articles

FCC Approves White Space Devices

Cecille Isidro — Wed, 05 Nov 2008 14:42:00 -0500

Yesterday will go down in history as a bellwether moment. Few among us will soon forget the excitement of Obama's election. But there was an equally historic vote yesterday that for geeks, policy analysts, and technologists represents an entirely new trajectory in telecommunications. In essence, the FCC has begun the transition from command-and-control, single-user spectrum licensure to a more distributed system that holds the potential to eliminate the artificial scarcity that prevented widespread access to the public airwaves since 1927.

Yesterday, the FCC ruled that unlicensed white space devices would be allowed to operate on unused television channels--allowing an entirely new generation of technological innovation to begin. While the official order has not been release, here's the information that's been gleaned thus far (please note that this is tentative information and until the official Report and Order is issued by the FCC, while unlikely, is subject to change):

Both fixed and personal portable devices will be allowed. So look for base stations on cell towers as well as next generation PDAs and multi-media devices.
Personal portable devices will be allowed to operate at power levels up to 40mW.
On non-adjacent channels (i.e., where you have three unoccupied TV channels in a row, this would be the middle channel), higher power levels will be allowed (up to 100mW).
Unlicensed wireless microphones will not receive priority status except, potentially, on channels 2-4. On all other channels (through to channel 51), all devices will share secondary status to primary broadcasters (e.g., television stations and licensed microphones).
A geolocational database will back up spectrum sensing capabilities to ensure WSDs do not operate in restricted areas. Left unclear is whether licensed wireless microphone users will be allowed to exempt their venue from WSD use and whether this would also allow for unlicensed wireless microphone users to do likewise.
A Notice of Inquiry will be launched by the FCC to investigate higher-powered use as an additional service in areas with few digital TV stations. This would facilitate backhaul capabilities for Wireless Internet Service Providers (WISPs) and other service providers.

I first started working on this proceeding back in 2004. After years of work, and an ever-increasing amount of time and energy spent on this battle, I can honestly say that I'm amazed by how successful this work has proven. At the same time, much like the presidential election, this win provides only the opportunity for amazing new innovations and services and much work remains. We need to work with performing arts groups to ensure that they have access to the technologies they need to carry out their work. And we need to work with wireless ISPs and allied organizations to ensure that they have the resources they need to continue spreading connectivity to underserved communities across the country. Finally, though the foundation has been set, the most important battle is yet to come--opening up all underutilized bands for opportunistic spectrum reuse.

I expect a multi-pronged approach to what lies ahead. I've already begun talks with WISP allies to follow up on the FCC's announced NOI. Likewise, I'm hopeful that folks I've been talking with for months within the performing arts community will see the FCC's decision as a good reason to collaborate on future joint efforts. In the interim, I am working with my colleague, Victor Pickard, on opening up debate on opportunistic spectrum reuse--starting with government spectrum. Our revamped working paper should be out in the near future, laying out a policy agenda for what needs to be done at the down of the age of opportunistic spectrum reuse.

Here's the FCC's press release as well as Commissioners' statements: Martin Statement; Copps Statement;Adelstein Statement; Tate Statement; McDowell Statement

Broadcast to Broadband

Ron Tang — Sat, 01 Mar 2008 00:00:00 -0500

Although much public attention has focused on the US digital TV transition -- and the resulting reallocation of analog TV channels by auction to wireless carriers -- the US Federal Communications Commission will decide how to reallocate an even larger swath of prime TV band spectrum this year: the unused “white space” between occupied DTV channels. This reallocation of unused spectrum from broadcasting to broadband permits unlicensed access for both fixed and mobile applications.

In 2002, the FCC’s Spectrum Policy Task Force recommended that spectrum efficiency and innovation could be enhanced by reallocating unused and underutilized spectrum for both flexible-use licenses (by auction) and opportunistic use by smart-radio devices capable of sharing bands on an unlicensed basis.

Shortly after this report, the FCC surprised almost everyone by issuing a Notice of Inquiry asking for comment on the feasibility of reallocating the TV white space for advanced wireless services. In May 2004, under then-chairman Michael Powell, the FCC issued a Notice of Proposed Rule Making (NPRM), tentatively concluding that opening at least some of the vacant channels for unlicensed access would be feasible and beneficial.

Although this policy is strongly supported by high-tech companies and consumer advocates, it’s just as strongly opposed by broadcast licensees and other incumbent users of the TV band.

The opposition is primarily led by the band’s incumbent licensees -- the US National Association of Broadcasters (NAB) and wireless microphone makers and users (such as the sports leagues and entertainment venues that intermittently use white spaces). The NAB refers to white spaces as “interference zones,” and broadcasters agree because they feel mobile broadband devices, even operating at low power, would inevitably interfere with DTV reception and microphone systems. The NAB and its engineering affiliate, the Association for Maximum Service Television (MSTV), have filed studies showing that Wi-Fi-type devices could cause both co-channel interference (if they can’t reliably detect a DTV transmission in a given location) and adjacent-channel interference (the unlicensed device’s transmission could leak and disrupt DTV reception).

In contrast, high-tech firms and consumer groups have argued that a variety of proven technologies are capable of avoiding interference with DTV reception. Intel, Dell, Microsoft, Google, and other members of the high-tech White Spaces Coalition argue in their filings that because proven technologies exist for detecting and avoiding DTV signals, barring mobile devices represents an enormous loss for consumers and potential broadband innovation.

For its part, the FCC has consistently assumed that several technologies are capable of ensuring that white-space devices can identify vacant channels in a local market and operate without interfering with DTV reception on neighboring channels (or in neighboring media markets). In its 2004 NPRM, the FCC’s Office of Engineering and Technology (OET) described three different approaches that white space devices could use to avoid such interference:

Geolocation / database. In this scheme, the unlicensed device (such as a wireless ISP access point) would use a GPS receiver to cross-check its own location against an online database of licensed TV transmitter locations.
Beacon permission. An alternative approach, aimed at allowing networks of mobile devices, would require that an unlicensed device not transmit unless it receives a “green light” signal indicating that the specific channel is free to use in that locality.
“Listen-before-talk” sensing. Another approach strongly favored by the high-tech company coalition would require that each individual device scan and identify unused TV channels before transmitting (with the accuracy enhanced by sharing sensing data with other devices in range)...

For the full text of Calabrese's article, please see the PDF attached below.

Public Needs to Know How Government Runs Its Airwaves

Cecille Isidro — Wed, 10 May 2006 03:00:00 -0400

Popularly known as the "public airwaves," spectrum is becoming to the information era what land was to the agricultural era and energy to the industrial era: its defining and most valuable natural resource.

Spectrum allows people and machines to communicate without being connected to wires. Most households have dozens of spectrum using devices, including cordless phones, cellular telephones, garage door remotes, FM radios, satellite TVs, wireless car keys, Bluetooth headphones, invisible fences, and WiFi broadband connections.

Most spectrum is reserved for the federal government, and not for private use. The federal government allocates spectrum, and not unsurprisingly, allocated most for its own use. Since all agencies communicate, they all have a need for spectrum. More than 30 federal agencies have allocations of spectrum, with the Departments of Defense and Homeland Security widely believed to have the largest allocations.

The ostensible division of responsibility in spectrum management is that the Federal Communications Commission (FCC) manages spectrum for private companies and local governments whereas the National Telecommunications and Information Administration (NTIA) manages spectrum for federal agencies. In reality, the agencies, not the NTIA, make most of the key decisions regarding federal government spectrum use. The military, for example, reveals minimal information about its spectrum use to the NTIA and is more than an equal partner in assessing its own spectrum needs.

The FCC’s and NTIA’s standards of spectrum transparency and accountability are far different. For example, rules concerning spectrum usage at the FCC are subject to the Administrative Procedures Act, which calls for publicly posting and inviting comment on proposed rule changes, but those of the NTIA and agencies are not. Similarly, all FCC spectrum assignments are public and easily accessible via a public website, while federal government spectrum assignments need not be public and information about those that are not classified can only be requested via Freedom of Information Act requests.

The agencies and their advocates argue that this secrecy helps America because if the information were publicly released, national security would be endangered; that is, enemies would be able to jam or intercept vital communications. For example, they argue that terrorists seeking to blow up a hydroelectric dam operated by the Tennessee Valley Authority could have an advantage if they knew on which frequencies the Authority communicated.

According to economic theory, federal agencies should have minimal economic incentive to use spectrum efficiently because they don’t pay for it and thus don’t face its economic opportunity cost. Meanwhile, according to political theory, if agencies are using spectrum inefficiently, they should have a strong incentive to hide this information and do so by using national security or another plausible pretext.

In June 2003 President Bush launched a "spectrum policy initiative" to "stimulate more efficient and beneficial use of Government spectrum."

Nearly three years later, federal government spectrum use remains as clandestine as ever. A February report by the Technology CEO Council, concludes, "no one seems to know even the value of the spectrum used by the government, let alone how much economic benefit could be gained by using it more efficiently. This situation must change."

The time has come for policymakers to act on these calls for change. More federal spectrum should be declassified and publicly inventoried.

Actions should also be taken to deal with agencies’ conflict of interest in disclosing information about their own spectrum holdings and uses.

We must make it easier to appeal agency secrecy decisions via an independent spectrum appeals court. This could be modeled after the Interagency Security Classification Appeals Panel, which handles classification appeals for conventional government documents.

As spectrum becomes the lifeblood of our information economy and the animating medium of our democratic speech, the cost of potentially misused government spectrum is becoming larger than ever.

Achieving the right balance between secrecy and openness will not be easy. But the current balance has clearly erred too far in the direction of secrecy.

Which is More Important for Spectrum Policy: FCC or DOT?

Cecille Isidro — Sun, 08 Jan 2006 04:00:00 -0500

Which has more influence on spectrum policy: the Federal Communications Commission (FCC) or the various federal, state, and local departments of transportation? Conventional wisdom would place the FCC as the hands down winner. Surely, that continues to be the case. But if current technological trends continue, the departments of transportation, especially the United States Department of Transportation (USDOT), could end up a strong second. We're all familiar with the growing importance of municipal Wi-Fi. But why not highway Wi-Fi? Why should Wi-Fi stop at city boundaries?

That's where the USDOT's planned Intelligent Transportation System (ITS) could come into play.

In 1999, the FCC allocated 75 MHz of dedicated spectrum for ITS, and in December 2003 it adopted service rules for the band, called Dedicated Short-Range Communications Services (DSRC). See FCC Report & Order 03-324A1, posted to the Federal Register in August 2004.

DSRC works at very short ranges--under 100 yards, or about the same distance as WiFi--and can be used for communications between vehicles and roadside terminals or between vehicles that are close together.

The ITS band, located at 5.850 GHz to 5.925 GHz, is adjacent to the 5 GHz unlicensed band and has many of the same service characteristics of that band. Indeed, the basic standard for the band, 802.11p (also known as the Wireless Access for the Vehicular Environment [WAVE] standard), is derived from the 802.11 family of standards in the unlicensed bands.

You might ask why does USDOT need a dedicated short-range communications services band of spectrum for ITS when unlicensed spectrum could have done the same job? Such a question could easily have been dismissed in 1999, when the WiFi revolution had not yet begun. But, at least on policy grounds, it is harder to dismiss today.

Consider this fact: roads cover a lot of the United States but the cumulative territory they cover is less than 1% of U.S. land surface area. Why shouldn't other people be able to use that spectrum locally when it wouldn't otherwise be used? Similarly, only public safety vehicles are likely to demand continuous high bandwidth use of the ITS network. When the roadside network is not being used for transportation related information, why shouldn't it be used to transmit other types of information?

The key argument used by advocates for dedicated ITS spectrum was that when lives are at stake, you don't fool around with unlicensed spectrum. It is the same type of argument the public safety community used to win 50 MHz at 4.9 GHz for a similar short-range Wi-Fi-like service. Service rules for the 4.9GHz band were adopted in 2004, shortly after the ITS band rules.

Unfortunately, complaining that the 75 MHz is inefficiently allocated only to transportation is like complaining over spilled milk. I don't believe there is anything practical that can be done about it.

But this still leaves two other very big policy issues on the table. First, if the government spends $3 to $10 billion dollars developing this ITS network beginning around 2009, why doesn't it add Wi-Fi functionality on the adjacent 5 GHz unlicensed band for a very modest additional expenditure?

Second, the entire world is moving to short-range wireless networks because that is the only way to achieve super high speed broadband speeds with high quality of service. For example, that's why 3G mobile telephone networks, where towers are often spaced a mile or more apart, use more than twice as much spectrum but can only achieve speeds less than 5% the speed of Wi-Fi networks. It's why, for example, the 18,000 light posts in New York City have suddenly become such valuable telecommunications real estate. So why should we be banning exactly the type of roadside broadband network architecture for mobile Internet service that clearly uses the spectrum most efficiently and is the most technologically advanced?

Intelligent Transportation System

The Intelligent Transportation System (ITS) is actually a loose conglomeration of an amazing variety of different technologies that often have very little to do with each other and range from very low tech (such as highway EZ Pass lanes and electronic overhead weather-traffic alert signs) to very high tech (such as the science fiction scenario of cars and roads so intelligent that cars don't need human drivers). Much of the excitement about ITS consists of technologies at an intermediate level of sophistication. This includes applications that alert human drivers of dangerous conditions (e.g., drifting across lanes without a turn signal on) and activating machines without human intervention in highly circumscribed conditions (e.g., activating an air bag microseconds before two cars will crash into each other). Two helpful overviews of ITS can be found at http://www.its.dot.gov and http://www.itsa.org.

ITS advocates believe ITS can reduce the expenses associated with transportation accidents involving injuries or fatalities ($260 billion/year) and traffic congestion ($100 billion/year). The goal of ITS is zero highway fatalities and delays. The ITS literature is filled with factoids (such as 88% of rear-end accidents are caused by drivers who fail to concentrate, or get too close to the car in front, and in 2003 alone, 8,569 people died and more than 1.4 million suffered injuries as a result of intersection-related crashes).

Vehicle infrastructure Integration (VII) Initiative

The part of the ITS system that I believe is most interesting from a highway Wi-Fi perspective involves the architecture of the DSRC network and specifically what has in the past several years come to be known as the Vehicle infrastructure Integration (VII) initiative.

In its initial stages the VII network will not be ubiquitous. Indeed, the advocates of ITS have gone out of their way to assure the telecommunications industry that it will be a crippled network with highly limited coverage and service applications. But even then, it is anticipated to include about a half million hot spots centered at traffic intersections and other accident prone stretches of road such as sharp turns and bridges especially vulnerable to icy conditions. Some of the applications suggested for the VII network include intersection collision warning, curve speed warning, rollover warning, emergency brake warning (from nearby vehicles), and vehicle navigation map updates. Components of the network would include road sensors (including speed, rain, ice, snow, fog, temperature, and lane change sensors), in vehicle sensors (within a few years vehicles are expected to have up to 200 built-in sensors to monitor all facets of a vehicle's condition and maintenance needs), telecommunications to communicate with the sensors (.e.g. for roadside slippery conditions alerts and collision avoidance alerts), telecommunications to conduct transactions (e.g., payment of tolls and parking meters), and telecommunications to access the Internet (for weather, traffic, tourist, and other transportation related information). Even at vehicle speeds up to 120 mph, the network is expected to be able to communicate at broadband speeds up 27mbps, more than 30 times the speed of the fastest 3G networks.

Of great importance, the major automobile companies that are expected to deploy the 802.11p technology in their vehicles beginning around 2009 are expected to also include 802.11a/b/g Wi-Fi capability. One reason is that even if it takes 802.11p technology some years to have much practical use, the 802.11a/b/g technology will have immediate practical use, if only to download from home to car various media including music, audio books, and weather reports. Note that two updated Wi-Fi standards expected to be released later this year, 802.11r and 802.11s, will incorporate mesh and high speed handoff technologies necessary for non-proprietary highway Wi-Fi.

So what great harm would be done if when the 802.11p network went up a Wi-Fi hot spot, at nominal cost, was added to each node? The answer is that such a proposal would cause the mobile telephone industry to rise up in arms. If the transportation and public safety industries hadn't assured the mobile telephone industry that they would build a crippled, limited purpose ITS network, they never would have been able to get the spectrum in the first place. And if they renege on that promise, the political opposition to ITS could rapidly become overwhelming. What would you prefer: a crippled ITS network or no network at all? The practical folks at the departments of transportation are happy to take the crippled network.

Smart Politics vs. Good Public Policy

However, just because highway Wi-Fi is considered a political pipedream doesn't mean it isn't good public policy. More hopefully, what is considered politically hopeless one day may turn out not to be. After all, a lot of people felt the same way about municipal Wi-Fi not too long ago.

Moreover, highway Wi-Fi might be far less expensive than anyone could have dreamed of when the ITS proceeding first began at the FCC in the late 1990s. For example, the military has developed optical fiber with RJ45 nodes (the telephone plug like outlets used to plug in Ethernet wire and wireless routers) spliced into it at the factory (think of Christmas lighting with light bulbs factory attached to the wire). That means that in Iraq the military can quickly lay a super high-speed broadband network, including secure and inexpensive Ethernet or wireless nodes. At a rate of a mile or more per hour, a special moving vehicle can lay this fiber 6 inches below a dirt surface like flexible irrigation pipe can be laid underneath a lawn or golf course. Of course, many other implementation scenarios can be imagined. But the point is that it is not currently in the interests of anyone at national, state, or local transportation departments to think this way.

In 2005, the state of Arizona, with a grant from the Department of Homeland Security, deployed highway Wi-Fi along a 32 mile stretch of the CANAMEX highway near the Mexican border in Arizona. The network, developed by New Zealand company RoamAD (see www.RoamAD.com), allows public safety vehicles to access the Wi-Fi network at speeds up to 80mph and at broadband speeds faster than available even on the most advanced 3G networks.

The era of single purpose networks such as the one the USDOT is proposing should be brought to an end. They may be appropriate for the analog age but not for the digital age we are entering. In the digital age, it is an economic travesty to build single purpose networks because telecommunications is becoming a fixed cost business. Once a high-speed network is built, it costs relatively little to add extra users and applications. Perhaps transportation bits should have the highest priority. But when capacity is left unused, other types of bits should also be allowed to share the network. Imagine how you would react if one day you were told that over your home high speed network you could only send transportation-related bits. Using public resources for a highway Internet solely dedicated to transportation bits is a similar travesty.

Spectrum Reform an Urgent U.S. Priority

Cecille Isidro — Wed, 04 Feb 2004 04:00:00 -0500

At the recent World Economic Forum in Davos, Switzerland, one of the hottest topics was WiFi, the technology that uses license-exempt (unlicensed) spectrum to share high-speed wireless Internet connections. In the United States, wireless networking is the fastest-growing segment in telecommunications, while in less developed countries it is seen as the means to leapfrog the lack of a wired infrastructure.

While the WiFi boom has been about short-range mobility, roughly 1,500 wireless Internet service providers (WISPs) already are using unlicensed spectrum to offer high-speed broadband to homes and businesses up to 30 miles from the Internet backbone. This is particularly important for rural areas, where wired connections are unavailable or unaffordable.

As the world goes wireless, demand for access to the airwaves will explode. Big retailers and manufacturers are investing millions to replace bar-coding with wireless inventory controls. And Intel is planning for a future in which unlicensed devices are cheap and ubiquitous, with dozens and possibly hundreds of them scattered around houses in beehive-like wireless networks.

We can try to achieve this future goal of pervasive connectivity by relying on a pair of regulated monopolies o one cable, one copper o to trench fiber into every home and small business. We also could wait for national wireless carriers to blanket the nation with the thick quilt of cell towers.

Alternatively, we can spread our bets by promoting competition in the last-mile by opening more spectrum to thousands of entrepreneurial WISPs and community-access networks that are already offering last-mile connections on unlicensed frequencies.

As usual, our political institutions lag far behind technological change. The conventional wisdom is that we suffer from a severe shortage of spectrum. In reality, even the prime low frequencies that pass easily through walls, trees and weather are barely used at all. Over downtown D.C., near the White House, we found that 60 to 80 percent of the prime frequencies are barely in use.

What is scarce is government permission to access the airwaves. The most useful spectrum has all been allocated on an exclusive basis to broadcasting, the military and other services that now need only a fraction of the frequencies they license thanks to digital technologies.

All sides of the spectrum debate agree that the FCCis outdated command-and-control approach o based on rigid zoning by service and zero cost licensing o has created artificial scarcity, stifling competition, slowing innovation and restricting citizen access to the airwaves.

While delicensing frequencies and relying on markets for technologies like WiFi would represent true deregulation, the predominant view at the FCC is that the most practical solution is to simply grant spectrum incumbents complete and permanent control over the frequencies they now borrow. Todayis licenses would become de facto property.

The FCC is already moving in this direction. Last May, the commission decided to facilitate secondary markets for spectrum that allow firms, whether or not they paid for licenses, to more easily sell or sublease underused spectrum.

The commission is also proposing a so-called itwo-sided auctioni that would allow incumbent licensees to pocket auction revenues when the FCC seeks to clear a band for new uses. According to senior FCC staff, the logic is that broadcasters and other licensees have so much political clout that the only practical way to reduce scarcity is to bribe them to bring their spectrum to market.

This approach to spectrum flexibility transfers a massive and unnecessary windfall to lucky incumbents that never paid a nickel for their now-scarce licenses. In addition to costing billions at a time of ballooning budget deficits, it is being pursued despite the fact that Congress explicitly rejected this sort of giveaway when it passed emergency legislation in June, 2002 canceling auctions for TV Channels 60 to 69.

A longer-term problem is that freezing the old zoning system into permanent property rights will forestall emerging ismarti radio technologies that could dynamically share todayis underutilized spectrum space. Exclusive ownership of frequencies turns sharing into itrespassingi and allows licensees to demand payment for access to their airwaves.

Spectrum deregulation can be achieved without costly giveaways and without strangling unlicensed technologies that promise more affordable and ubiquitous high-speed broadband.

Strange as it may sound, government should both lease spectrum and give it away.

By leasing, I mean that licensees should be given nearly complete flexibility, but in exchange for paying a modest annual user fee, or royalty, as we do with other public resources. While spectrum capacity may be plentiful, exclusive government licenses to operate profitable services like broadcasting remain scarce. Congress adopted this approach in 1996 when it gave broadcasters the flexibility to use their new DTV channel to sell ancillary services, but only in exchange for a fee the FCC set at 5 percent of gross revenue.

By giving away, I mean that we need a substantial reallocation of wasted spectrum capacity to shared, unlicensed access. Rather than focus on private markets to sell spectrum access, expanding free and shared access to the airwaves can encourage markets for new generations of WiFi equipment and mitigate spectrum scarcity.

Some bands can be reallocated for unlicensed wireless broadband on a primary basis, while others can be opened for opportunistic sharing by ismarti devices that hop frequencies and avoid harmful interference with existing services. This year the FCC will be considering to what degree analog TV channels 52-69 can be opened for unlicensed sharing since they are due to be returned once the DTV transition is complete.

Just as public highways have proved far more efficient than relying exclusively on toll roads or fixed-line railroads, meshed networks of cognitive radios can share the airwaves based on basic irules of the road.i That is the icommonsi model: spectrum as a common carrier that is, thankfully, already owned by the public.