“[S]tatistics can lie. But cast as ‘studies’ by commentors, they take on the weight that a decision maker chooses to make of them.”

– Daniel Brenner

As a follow-on to its National Broadband Plan, the FCC last year released a Technical Paper intended to validate the Plan’s prediction of a 300 MHz mobile-broadband spectrum deficit by 2014. The Paper describes a spectrum requirements model that totals current spectrum assigned to mobile broadband and applies a multiplier based on expected demand, taking into account expected increased tower density and improvements in air-interface spectrum efficiency. The model’s result is a predicted deficit of 275 MHz in 2014, which rounds to 300 MHz. On the way toward that result, however, the analysis uses just a few of the available data forecasts, ignores offloading of macrocell data to Wi-Fi and femtocells, and assumes the continuation of flat-rate plans for consumers. Some of these oddities I noted in a post at the time. I had hoped the FCC would make the Paper a subject of public comment. That hasn’t happened. So, I’ve looked at the Paper in more detail. I find that when looking at the above factors in a more realistic manner, predicted spectrum requirements go down significantly.

INVALID ASSUMPTION #1: THREE ARBITRARILY-PICKED FORECASTS ARE REPRESENTATIVE

To estimate spectrum requirements in 2014, the FCC’s model uses a multiplier based on an average of three forecasts of mobile-broadband data demand. These are by Cisco, Coda Research, and Yankee Group. From 2009 to 2014, they predict mobile broadband data growth of 4722%, 3464%, and 2332%, respectively, for an average of 3506% (or, if you prefer, 35x).

The FCC characterizes these as “industry analyst mobile data demand forecasts” when in fact only two are from industry analysts. Cisco is an equipment vendor. The preparation of its forecast is managed by a member of Cisco’s marketing team. The Cisco forecast is used to promote the sale of Cisco’s core-network hardware that can be used to help address the increased data demand the forecast predicts. The Technical Paper gives no indication as to why these three forecasts were chosen and others rejected. It would be as if the FDA looked at clinical trial data, ignored the statistics, and made decisions based on its favorite data points.

The decision to use Cisco’s forecast, and not those of other equipment vendors, is odd. Forecasts are also available from Alcatel-Lucent, Ericsson, and Nokia Siemens Networks (NSN), among others. Unlike Cisco, these companies have core competency in the 3G/4G radio air-interface that is the most challenging bottleneck when it comes to mobile capacity, so it would seem useful to include their findings. For the same time frame looked at by the FCC, 2009-2014, Alcatel-Lucent, Ericsson, and NSN predict data growth of 3893%, 2541%, and 811%, respectively. The 811% looks very low, but is consistent with recent forecasts predicting data increases in the 8x-10x range over the next several years; these lower estimates may be an indication of large-cell model of cellular hitting an inflection on a technology-maturation S-curve.

When the forecasts are considered with those of Cisco, Coda Research, and Yankee Group, the six-forecast average is 2961%, or 15.5% less than the FCC’s estimate of 3506%. What does this do to spectrum requirements? From the FCC’s own sensitivity analysis in the Paper (p. 22), this reduces the 2014 shortfall from 275 MHz to approximately 165 MHz.

INVALID ASSUMPTION #2: OFFLOADING IS AN ABSTRACT CONCEPT

Today’s typical macrocell (large cell) wireless systems have always expended disproportional resources trying to overcome building attenuation and reach user devices indoors; it’s been an outside-in approach. Adding to the challenge, we’re inside 70% of the time, and will be inside even more as time goes on, according to Informa estimates. Building attenuation is not the only indoor problem; signals indoors weaken as the distance to base stations increases. Furthermore, capacity available to a user goes down as more users join the cell.

At the same time, our indoors increasingly have fixed broadband service. This can be used in conjunction with small cells, such as Wi-Fi access points or femtocells, to offload data from the macrocell. When the user is close to small cells, a lot of good things happen, things beyond the ability of additional spectrum to provide. Building attenuation goes down because we’re not punching through as many walls. Signal strength increases because of the shorter distance. Throughput to the user goes up because capacity is no longer shared with several dozen others. (Throughput to those still on macrocells goes up, too, because they’re no longer competing with the small cell users.) As an added benefit, since the user is close to the cell, not as much power is needed on the uplink; handset transmit power goes down, increasing battery life. Taking all these factors into account, data rates available to a user can go up 80x or more using small cells depending on the deployment scenario.  In contrast, doubling available spectrum increases throughput only 2x. Allocating the entire 300-3000 MHz band to mobile broadband would increase throughput only 7x, were that a practical option.

The outside-in approach of macrocells is turning inside-out, bring the user closer to the base station. This offloading concept is consistent with the ITU’s 2003 vision of heterogeneous networks; each wireless access technology excels in certain circumstances, and shouldn’t be force-fit into others. It’s hopeless to reach the capacity increases that can be achieved through small cells by the use of additional spectrum. Qualcomm, a longtime advocate of more spectrum for mobile broadband, recently said that “the next performance and capacity leap will come from network topology evolution by using a mix of macro cells and small cells – also referred to as a Heterogeneous Network (HetNet) – effectively bringing the network closer to the user.” The same improvements in electronics technology that enable smartphones, and their increased data requirements, likewise enable new small-cell technology that can address the demand. Wireless innovation is not only on the user-device side.

Despite this progress in small cells, the Technical Paper inexplicably dismisses offloading:

“Since this paper is focused on mobile data traffic, strategies to offload traffic to femto?cells and WiFi is [sic] not directly considered. In addition, the rollout of such network architecture strategies has been slow to date, and its effects are unclear.”

First, mobile broadband data traffic and offloading go hand in hand and thus must be considered; the more data offloaded, the less carried by the mobile broadband network, and the less spectrum required for that network. Second, offloading strategies are ramping up quickly. The “effects” are clear. Less data is carried on the macrocell, reducing the need for new spectrum.

If the Technical Paper does not directly consider the effects of offloading, perhaps the input forecasts from Yankee Group, Coda, and Cisco do. It’s not clear, from information provided in the Paper, to what extent the three forecasts take offloading into account. Looking at the Cisco forecast separately, we can see it estimates that in 2014, 23% of wireless data in the U.S. will be offloaded to Wi-Fi and femtocells. More recent observations and forecasts, however, are substantially higher than Cisco’s. Commenting on the issue in its latest wireless competition report, the FCC said “AT&T has experienced significant growth in hot spot usage in the first half of 2010, with an estimated 40 percent of iPhone traffic in the United States being transmitted over a Wi-Fi connection.” Independent analysts ABI Research and Juniper Research predict worldwide offloading rates of 48% and 63%, respectively, in 2015. ComScore estimates that in August 2011, 37.2% of mobile phone data was sent using a WiFi connection, a percentage that grew almost 3 points in just the preceding three months.  For 2014, Juniper Research predicts North American offloading will reach 76.9%. Cisco’s underestimation of offloading contributes to its forecast usually being the highest of the bunch, making it the go-to forecast for spectrum crisis adherents.

The FCC didn’t directly consider offloading, but we can. For the purposes of this post, let’s average the low and high offload estimates, from Cisco and Juniper Research. That gives us 50% as an offload factor. Adjusting Cisco’s forecast using the 50% offload factor instead of 23%, one gets a Cisco 2014 data growth relative to 2009 of 3066%. This lowers the six-forecast average to 2685%, which is 23.4% less than the FCC’s estimate. Returning to the sensitivity analysis, the revised spectrum shortfall is approximately 115 MHz instead of 275 MHz.

INVALID ASSUMPTION #3 – FLAT-RATES RULE

Most U.S. operators have gone from flat-rate “all you can eat” rate plans to usage-based plans where the consumer is charged based on the amount of data used. AT&T made the change in June 2010, T-Mobile in April 2011, and Verizon Wireless in July 2011. (Sprint is the only major operator with an unlimited plan today, on its 3G network for the iPhone.) These new rate plans will further encourage users to offload data. The Technical Paper, again inexplicably, does not take this into account:

“The projections of mobile data demand used in this analysis are based in part on historic market dynamics, such as “all you can eat” pricing for data. The effect of new pricing strategies on consumer data demand is not yet known, but has the potential to impact data traffic projections if widely adopted in the market.”

I expect the effect of these new pricing strategies will be that consumers moderate their less essential use of mobile broadband. This will be especially so for the data hogs, a few of whom consume the bulk of mobile broadband data in each cell. There is not much public information yet on consumer response to these new pricing plans, but it’s something to watch out for, and then we can make a further correction to the spectrum deficit estimate.

The effects of usage based plans on data consumption will be far reaching. With the cost of bits more aligned with what it costs the operator to supply them, the consumer has more price signals on which to act upon. These signals, in turn, will be felt by the rest of the wireless ecosystem. Under flat-rate plans there was little incentive for consumers to be conscious about how efficiently-coded the phone’s operating system or applications were. Under newer plans that charge by use, consumers will have a heightened awareness of how much data they’re using, and for what purpose. Software will increasingly compete on efficiency. On the application side, operators know where every bit goes, and which applications consume the most data. There is no such awareness on the consumer side. Perhaps the industry will provide greater granularity in data metering, to the application level, so users can better prioritize usage of their data plans. Once this happens, developer sensitization to the issue will increase.

Some of this software-based improvement is nearly “free,” requiring only improved programming practices. Last year, the World Wide Web Consortium adopted a recommendation for best practices in mobile web application development.  As one example in the recommendation, mobile web applications often use several static images to represent buttons. Each image that is sent uses a separate HTML request. HTML requests can be reduced to one by combining the buttons into one static image, sending that image, and cutting the buttons from the image. That saves data. Under flat-rate plans, why bother?

On the operating system side, different phones can vary greatly as to the amount of data needed to perform the same function. One analysis, sponsored in part by Research in Motion, finds that across multiple applications and for the particular smartphones studied, the BlackBerry used much less data than the iPhone or Android phones. For web browsing, the Blackberry was 2.1 times more efficient (i.e., used 2.1 times less data) than iPhone iOS or Android. For e-mail, the Blackberry was 4.5 times more efficient than Android and 11.4 times more efficient than iPhone iOS. As users become more aware of what data they’re getting for their money, competitive pressures will lead the less efficient operating systems to become more so.

FURTHER ADJUSTMENTS TO THE ESTIMATED SPECTRUM DEFICIT

We’ve looked at the estimated spectrum deficit from the basis of demand and the FCC’s model. Before we finish, let’s take a quick look at where we are today on the supply side. The following efforts show promise for making more spectrum available for mobile broadband within the 2014 timeframe:

• LightSquared is seeking approval to use 40 MHz of spectrum near 1500 MHz for terrestrial mobile broadband. Such use is pending resolution of GPS interference issues.

• The FCC has an open proceeding looking at maximizing the mobile broadband potential of a total 75 MHz of spectrum around 2 GHz. Some 40 MHz of that belongs to Dish Network, which recently asked the FCC for permission to deploy a hybrid satellite and terrestrial mobile and fixed broadband network. Qualcomm, Dish, and others have various smaller pieces of the 700 MHz band, which might be practical for use with LTE in a TDD mode using unpaired spectrum.

• NTIA has issued a plan and timetable identifying over 2200 MHz of Federal and non-Federal spectrum that might provide opportunities for wireless broadband use. For mobile use, the most promising band in the near term is 1755-1850 MHz. NTIA is finishing a detailed review of the band to determine to what extent it can be made available for commercial broadband use. The review was supposed to be completed by September 30, 2011 but is running late; perhaps we’ll see the results by the end of the year. I hoping at least 40-50 MHz becomes available from this band.

An accurate and current inventory of frequency assignments and usage would help identify new mobile spectrum, but such an inventory doesn’t exist. The preliminary steps the FCC has taken so far are so laden with disclaimers they can’t be relied upon. On the Federal side, the Government Accountability office (GAO) recently reported that “NTIA’s data management system lacks transparency and data validation processes,  making it uncertain if spectrum management decisions are based on accurate and complete data.” The U.S. should conduct a thorough spectrum inventory, informed by measurements.

CLOSING THOUGHTS

We’ve seen that reasonable updating of the FCC’s spectrum deficit model significantly reduces the short-term forecast deficit for 2014. As adjusted, the Technical Paper doesn’t support the National Broadband Plan’s mobile broadband spectrum recommendations, as was its intent.

We might step back and ask why the FCC is forecasting spectrum demand at all. If the U.S. moves more toward a property-rights and marketplace regime for spectrum use, as it may with the incentive auction approach, the Technical Paper estimates and National Broadband Plan recommendations become less important as the market will tend to allocate spectrum resources efficiently. To the extent it does not, and fails to meet a public policy goal, policymakers can change the market outcome.

If a forecast is to be maintained, the FCC should reconcile the National Broadband Plan with an updated forecast spectrum deficit, openly prepared with broad input and using the latest data. Part of that examination should be the validity of other methodology used the Technical Paper. The work should be thorough enough that the FCC Chairman no longer feels the need to cite Cisco’s forecast in speeches, and can instead cite the work of the FCC’s own staff — with authority.

For the TV broadcasting spectrum, voluntary incentive auctions have long been on the horizon. Many broadcasters aren’t opposed to the idea in principle, but want assurances that existing or equivalent coverage is maintained during any channel repacking. For all they know now, it could be cut in half. This anxiety is heighted because the FCC refuses to make available for inspection pre-release versions of the software used to calculate a repacked channel plan.

This refusal follows the FCC dismissing a noteworthy study prepared by the NAB on the wireless capacity crunch, and rejecting an attempt by broadcaster to try to innovate and experiment with new broadband technologies. Add to that the FCC Chairman being associated with a policy of marginalizing the broadcast industry, some broadcasters may rather take their chances on the next FCC.

I think there may be another way forward. The Advanced Television Systems Committee (ATSC) is starting a process to develop a next-generation TV standard, ATSC 3.0. That new standard doesn’t have to be backward-compatible with current TVs. I suggest that as part of this standardization process the ATSC look at cellularization as a new architecture. Others have done this before, and the main objection has been it’s too expensive compared to the current single-transmitter model. It’s time to look at cellularization again, in light of less expensive cell site equipment and published work suggesting such a system for all broadcasters could occupy less than 100 MHz of spectrum, perhaps freeing up more than the planned 120 MHz. TV broadcasting could enter, and perhaps influence, the global LTE standards ecosystem with its economies of scale, its interoperability, and, crucially, its evolution. There’s also the potential for a return path. Looking at cellularization now might help avoid repacking the TV channels twice in a short time frame:  following a spectrum auction and then again for ATSC 3.0. If such a cellularization scheme is seen as becoming practical, it could simultaneously result in a more durable strategic advantage for broadcasters, and more than 120 MHz for mobile broadband. There’s also the potential for a return path. Looking at cellularization now might help avoid repacking the TV channels twice in a short time frame:  following a spectrum auction and then again for ATSC 3.0. If such a cellularization scheme is seen as becoming practical, it could result in a more durable strategic advantage for broadcasters, and more than 120 MHz for mobile broadband.

Continuing our spectrum survey, the LightSquared proceeding will likely result in at least some of 59 MHz of spectrum around 1500 MHz becoming available, with the rest available once issues with potential interference to precision applications of GPS are resolved.

The FCC has an open proceeding looking at maximizing the mobile broadband potential of a total 75 MHz of spectrum around 2 GHz. Some 40 MHz of that belongs to Dish Network, which recently asked the FCC for permission to deploy a hybrid satellite and terrestrial mobile and fixed broadband network.  Qualcomm, Dish, and others have various smaller pieces of the 700 MHz band, some of which are in play now.

An accurate and current inventory of frequency assignments and usage (based on measurements) would help identify new mobile spectrum, but the preliminary steps the FCC has taken so far are so laden with disclaimers they can’t be relied upon.

Then we have the Federal spectrum. NTIA has issued a plan and timetable identifying over 2200 MHz of Federal and non-Federal spectrum that might provide opportunities for wireless broadband use.  I wouldn’t call any of that “pipeline” at this point. NTIA is, however, finishing a detailed review of the 1755-1850 MHz band to determine to what extent it can be made available for commercial broadband use. This review should be completed by September 30. Since this band might be considered a best-case for repurposing Federal spectrum, the results of this review may give us a sense on how we’ll fare with other Federal bands.

Anecdotal evidence suggests there is more Federal spectrum available. Below is a figure from a report prepared by Shared Spectrum Company, which conducted spectrum occupancy measurements at its suburban Washington, D.C. office.

Shared Spectrum notes that, because of its methodology, some of these bands may be utilized but hard to measure, such as GPS satellite signals in the 1575 MHz region. Other fallow spectrum may be in a pipeline, but for services other than mobile broadband. One field test is not the basis for spectrum planning. These general results, however, have been replicated by Shared Spectrum elsewhere, and by NTIA at various locations.

In addition to measuring what’s out there, one might think to examine the NTIA’s database of Federal frequency use to see what’s open. Unfortunately, the Government Accountability Office (GAO) recently reported that “NTIA’s data management system lacks transparency and data validation processes, making it transparency and data validation processes, making it uncertain if spectrum management decisions are based on accurate and complete data.” A new, improved database system is in the works but isn’t scheduled to be online until 2018 (not a typo).

Other problems with the current Federal spectrum management process, as found by the GAO, include heavy reliance on agencies to self-evaluate and report their current and future spectrum needs, lack of specific spectrum management requirements for federal agencies, and limited assurance that federal agencies are recording accurate data. In a recent review of a sample of Federal spectrum assignments for one agency in the Detroit area, approximately half of that agency’s assignment records were inaccurate. There’s also a spectrum warehousing issue: some federal agencies are concerned that if they say they are no longer using an assignment, it will be deleted and they will not be able to get it back if needed later.

The NTIA database problems point to another reason why a spectrum inventory, of Federal and non-Federal bands, should be informed by measurements. Repurposing existing databases known to contain errors, under layers of disclaimers, is not a spectrum inventory.

Though not one of the usual spectrum candidates, it might be time to look again at the 1435-1525 MHz flight test telemetry band. This have been tried at least a couple of times before, by satellite radio and by land-mobile proponents. Both attempts didn’t get anywhere. This time I’d suggest looking at it with more of a goal toward sharing. I can’t help but notice that, today, the band is routinely shared under special temporary authority by video production entities looking for bandwidth to relay video during special events. One application was recently approved for an event in the middle of Washington, DC. If a hole is there why not use it for mobile broadband as well? I’d think . . . hope . . . that most flight testing is not done over major cities where the capacity crunch is the greatest. Flight test links are usually air-to-air or between air and ground, not ground-to-ground, so I’d expect considerable antenna discrimination that would reduce the potential for interference with other services.

By the time we reach the National Broadband Plan’s 10 year deadline for 500 MHz of new broadband spectrum (for fixed and mobile), many promising technologies and techniques found in the record of the FCC’s proceeding on dynamic spectrum access will become a reality, increasing the capacity of existing spectrum. These will make it easier to implement shared spectrum use using cognitive radio techniques.

Moreover, moves toward a property-rights regime for spectrum use and creation of markets for licenses, recognizing that government can improve market outcomes, would remove some of the headaches inherent in sorting out the above. We wouldn’t have to worry as much about filling the pipeline. It would fill itself.

A 3G feature phone on Verizon’s network uses about 1.25 MHz of spectrum. Using the above multipliers, a smartphone would need 30 MHz and a tablet 150 MHz, more than the total spectrum inventory of some carriers. In reality, smartphones and tablets use the same 1.25 MHz. What’s going on?

I assume the numbers Mobile Future cites come from the latest Cisco forecast (p7), but those are for increases in data traffic, not spectrum. Mobile Future seemingly equates the two, but they’re different. Data traffic increases with smartphones and tablets, but that data takes up capacity in existing spectrum. At some point, that spectrum runs out of capacity. More spectrum, along with other techniques, can be used to add capacity.

I sense the hand of a PR firm in this, which means it wasn’t cheap. Fortunately, the error seems confined to the voiceover, which can be redone relatively easily. To be breezy about it, for the sake of a two-minute video, the revised message might be that spectrum capacity is limited, smartphones and tablets use much more, when we run low performance suffers, more spectrum adds capacity improving performance.

Wireless service rationing? Millions of new jobs? Hey, it’s an advocacy video. I’d be very pleased if this video drew more attention to spectrum issues, and did not contribute to the myths.

NAB – Shortages of Capacity, Not Spectrum

The NAB report is prepared by Uzoma Onyeije, a consultant who was once Broadband Legal Advisor to the Chief of the FCC’s Wireless Telecommunications Bureau. The main claims are that there is no need for an urgent and massive reallocation of spectrum, that there are numerous alternatives to spectrum that can boost network capacity, and that sources of spectrum other than TV are more readily available.

It starts by noting there wasn’t a “spectrum crisis” until the American Recovery and Reinvestment Act of 2009, which required the FCC to promote broadband access. The National Broadband Plan followed calling for 500 MHz of spectrum to be made available for broadband within 10 years, with 300 MHz of that for mobile within five years, and 120 MHz of that to come from television broadcasting. Seven months after concluding that 300 MHz was needed in the short term, the FCC released a Technical Paper intended to support the 300 MHz figure. In November I wrote on that Paper, pointing out several factors not considered that, had they been, would have acted to reduce the estimate of short-term spectrum requirements. Later, I questioned the appropriateness of the FCC relying on a forecast prepared by the marketing department of an equipment vendor, without critically and openly examining the assumptions that went into the forecast. Onyeije shares some of the concerns I had, and still do, with that Paper.

I expect the American Recovery and Reinvestment Act turned some spectrum wants into needs, but by all accounts mobile network data volumes are increasing significantly, fed by a volatile mixture of old flat-rate plans and new bandwidth-hungry devices, though the growth rate of those data volumes is decreasing. Getting additional spectrum is a natural option to consider for more capacity. Onyeije provides a list of non-spectrum options. Some have been mentioned here before – offloading to Wi-Fi and other technologies, adjusting rate plans so largest data users pay more, tighter software coding of applications and operating systems. I don’t think I’ve discussed channel bonding, which is a technique that uses non-contiguous spectrum – combining a sliver here and a sliver there. Support for this will be appearing in LTE-Advanced, going on the air in a few years. Backhaul is also something I haven’t focused on; how much of the current spectrum crunch is really due to backhaul bottlenecks?

Another capacity-increasing technique mentioned is sectorization – changing a non-directional transmission system to a directional one using two or more sectors at the same cell site. In the most congested urban areas in the US, antenna systems are generally configured with three sectors, with each sector 120 degrees wide. You don’t see many six-sector configurations, in which each sector is 60 degrees wide. Theoretically, that doubles capacity from the same tower. A long time ago there was more activity in six-sector antenna systems, but the sense then was it wasn’t too practical; you might end up with just a 70% capacity increase because of real-world issues such as imperfect antenna patterns. It was hard to justify the expense. These days, however, with better transmission technology, it should be looked at again. I note SK Telecom in Korea is deploying 500 six-sector sites, after good results with 20 test sites.

Onyeije looks at the spectrum warehousing issue. If an operator has spectrum that isn’t being used, but is on track to build it out, I’m fine if it is fallow for a year or so. Maybe longer if the delay is to wait for much more efficient transmission technology that is on track in the standards process. If it is just sitting there with no build-out requirement and no prospect for utilization, I’d think the operator’s investors would create pressure to sell it. If a spectrum holder has “no plans to sell, lease or use” its spectrum, to quote one in Onyeije’s report, I’m more concerned.

Aside from the warehousing issue, Onyeije identifies a few bands that have been languishing at the FCC for years and makes the point that, since they have been idle for so long, the spectrum crisis must not be so great. These are the AWS-3 spectrum at 2155-2175 MHz, H block spectrum at 1915-1920 MHz and 1995-2000 MHz and J block spectrum at 2020-2025 MHz and 2175-2180 MHz, 700 MHz D block at 758-763 MHz and 788-793 MHz. What’s the story there?

Onyeije suggests mandatory receiver standards. Receivers are already very good in mobile broadband because of vendor competition and the need to operate in a congested environment. Receiver design is proprietary and an important source of differentiation among vendors. I’d think continued improvement of receiver performance in the marketplace, in the long run, would achieve greater capacity benefit than imposed government standards.

The report calls on the FCC to complete and publicly release a comprehensive spectrum inventory, along the lines of the Snowe-Kerry RADIOS Act, which includes measurements. The FCC has made available several spectrum tools online, including LicenseView and the Spectrum Dashboard, which it says is its inventory. According to their disclaimers however, LicenseView “is not intended for analysis of spectrum utilization or spectrum holdings of licensees” and “the FCC makes no representations regarding the accuracy or completeness of the information maintained in the Spectrum Dashboard.” Regarding federal spectrum, I’d add that an inventory becomes more important in light of GAO’s report on NTIA processes that said “NTIA cannot ensure that spectrum is being used efficiently by federal agencies” in part because “NTIA’s data collection processes lack accuracy controls and do not provide assurance that data are being accurately reported by agencies.” Thus, “it is unclear whether important decisions regarding current and future spectrum needs are based on reliable data.”

CTIA , CEA, and WCAI dismiss the NAB report, saying it’s a stalling tactic and they know these things already. One of Onyeije’s points, however, is that it’s the Commission that needs to know these things, and fully investigate and quantify the impact of all capacity-generating alternatives. It has not. It tried with the Technical Report, but inadequately.

CTIA Establishes the Efficient Properties of Cellularization

The CTIA report is intended to demonstrate that US mobile wireless providers are “extremely efficient” in their use of spectrum. The report was prepared by Peter Rysavy, a consultant known in wireless circles for his series of technical reports, with many pertaining to spectrum, air-interface, and mobile device issues.

This report seems to be a response to an NAB claim, some time back, that broadcasting is a more efficient user of spectrum than wireless. I presume NAB’s claim is based on broadcasters’ DTV system transmitting about 19 Mbps in a 6 MHz bandwidth, while the wireless operators are sending about 10 Mbps in 10 MHz bandwidth. (So, TV has more bits per Hertz.) This is kind of an apples and oranges comparison, but the comparison has been made and we have this report in response. Having spent a lot of time in 3G and 4G standards battles, I have no doubt that those participating are trying wring out all the efficiency that is both possible and practical. Wireless standards groups sweat to get another tenth of a dB improvement. Of course, part of efficiency is an implementation issue and not covered by standards. I agree cellular services are more efficient at delivering unicast traffic. Broadcasters, however, can be more efficient in another way. The efficiency debate occurs in part because we have not agreed on a definition of efficiency. More on this below.

The CTIA paper starts with a section on spectral efficiency. It discusses its fundamental measures and technologies that have been used to continually improve it, including adaptive modulation and coding. (Rysavy says his list of technologies is not exhaustive, but to his list I’d add Hybrid Automatic Repeat Request as a key enabler.)

Rysavy observes that the industry’s technologies are operating close to the Shannon Bound, the theoretical limit on the spectrum efficiency that can be had for a given signal-to-noise ratio. Capacity improvements thus must come from advanced antenna techniques (such as MIMO) and topology evolution (e.g., adding picocells to a macrocell).

The report is hopeful on the prospects for Wi-Fi and femtocells to relieve traffic on the macro-cellular network. I’m somewhat more cautious on the potential of femtocells to relieve the capacity crunch.  For various reasons, including interference management, what I think may happen with femtocells is that they get pulled out of the home and put up in neighborhoods using existing structures for support. (The more-favorable pole-attachment rules recently adopted by the FCC are timely.) There are many small-cell trials underway but I haven’t seen much in the way of results.

Network evolution is discussed in a larger sense, focusing on developments in heterogeneous networks, but Rysavy says that’s not enough and that more spectrum is needed, too.

Back to the efficiency issue, the efficiency of cellular systems is compared to that of broadcast television. The point made is that if you take many small cells and place them within a larger area  covered by one transmitter (e.g., one for TV), the cellular system can deliver many times the unique bits in that area. This is true, if that is the definition of efficiency. Let’s look at it another way and compare the maximum number of users served by each scheme. As a best-case scenario, assume the cellular users are using a low-bit-rate application such as LTE VoIP. In 10 MHz we can support about 400 users. That times 3 sectors is 1,200 users per cell. That times 30 cells (as per the example in the paper) is 36,000 users that can be supported at once. In contrast, a TV  station covering the same area can support an unlimited number of users, albeit one-way, since it isn’t limited by uplink capacity nor MAC addresses. Is it a fair comparison? No. One is broadcasting and the other is cellular. Can’t cellular broadcast also? Yes, but to the extent it does the unique-bits argument becomes weaker. We can go around and around. The television example is used, along with other analysis in that section, in an attempt to persuade the reader that “cellular architectures represent a configuration that is capable of providing tremendous service capacity to its users.” I’m convinced, but I was before reading the report.

Rysavy depicts how voice minutes, message volume, and data volume have increased on cellular networks over the years. Yesm growth has been dramatic, but the growth rate is slowing.

Epilogue

Concurrent with this debate, ATSC is in the early stages of planning and developing the second DTV standard to replace the current one that’s been around for about 15 years. LTE specifications support broadcasting, which can be done in a cellular manner on the same frequency. Transmissions are synchronized so the terminal can combine energy from multiple sites. The broadcasters looked at cellularization a year ago assuming use of the current ATSC DTV standard, and rightly found it was not practical. It just wasn’t designed for that purpose. With the new LTE standards, it’s time to look at TV cellularization again but with LTE as a core technology. There could be a return path, inexpensive chips for receivers, and it might  be able to be done in less than 100 MHz, making over 200 MHz available for auction. With DTV, the broadcasters found significant deployment and operating costs with cellularization, but with LTE infrastructure would be shared; it remains to be determined if it’s a business. The technology is there; it just has to be architected by broadcasters and infrastructure vendors into suitable form.

UPDATE 5/20/2011

The FCC issued a Public Notice today seeking comment on using the 2 GHz bands identified as “languishing” by NAB. Some are listed above. 75 MHz total.

Making wireless services co-primary with broadcasting is a simple change to the Table. Doing it now facilitates things when service rules are written later.

Channel sharing is straightforward, at least technically. Two or more stations would share a single 19.4 Mbps data stream in a 6 MHz channel and would multiplex their programming. It’s possible to send two HD programs in one stream, sort of. Due to limitations in video compression, depending on the programming content, one or both programs would suffer more picture quality degradation than if only one program were sent; stations will have to decide who takes the quality hit and when. Instead of sending two HD programs, three or more stations might decide to send standard-definition programs. Another issue with channel sharing is that when a station moves to a common transmitter site, it may lose some of its existing coverage. How should these service losses be balanced against benefits? Non-technical issues include media ownership rules and must-carry rights.

The FCC also wants to improve VHF TV reception. Today, reception at VHF suffers from high noise and inefficient receiver antennas, compared to UHF.  Improving VHF TV would not only help today’s VHF stations, it would make that band more attractive for a possible repacking of some UHF stations into VHF, freeing more UHF spectrum for mobile broadband.

Not much can be done to reduce noise; to help address the issue, the FCC plans to allow some stations to increase power to the extent that they don’t cause new interference to other stations. For receiving antennas, the FCC proposes that antennas be required to comply with standards ANSI/CEA-2032-A for indoor TV performance, which incorporates standard ANSI/CEA-744-B for antenna measurement. Conformance with these standards would result in higher-gain indoor antennas and thus better quality reception. Not mentioned by the FCC is CEA’s standard for smart antennas, CEA-909, which uses signal quality data from the TV to make antenna adjustments that reduce noise, increase signal strength, and improve impedance matching. There hasn’t been much pickup of that standard that I can tell. Attention by the FCC might reinvigorate that technology; it already exists in other wireless services and doesn’t have to be reinvented for broadcasting.

As it does on many documents relating to the National Broadband Plan and spectrum, the FCC in the NPRM reiterates that the Plan recommends making 500 MHz spectrum available for wireless broadband in 10 years, with 300 MHz of that for mobile flexible use within 5 years. Since the FCC refreshed this estimate with release of a related Omnibus Broadband Initiative technical paper on October 21, I thought the FCC might address that paper and its analysis in this NPRM. It does not. The assumptions used by that analysis are out of date or incomplete. To the extent that the FCC continues to rely on the 300 MHz estimate, it should, sooner rather than later, make it a prime topic for consideration.

For views on the NPRM from a legal perspective, see the CommLawBlog and the Broadcast Law Blog.

The methodology described in the paper is relatively straightforward and pragmatic, in contrast to methodologies used by other spectrum estimates cited in the NBP. The paper looks at current spectrum use and adjusts it upward based on forecasts of mobile data demand, downward based on air-interface spectral-efficiency improvements, and downward based on increased cell-site density. With such an approach, the demand forecasts are critical. Forecasts from Cisco Systems, Coda Research, and Yankee Group are used and averaged to get a single forecast.

Related to the 300 MHz estimate, directly or indirectly, are the three items the FCC has placed on the tentative agenda for its November 30 meeting: TV spectrum innovation, opportunistic spectrum use, and experimental licensing rules. Perhaps as part of one of these proceedings, the FCC will seek comment on the paper and the three forecasts. Here are some areas for consideration:

• Rate plans. The paper says, “projections of mobile data demand used in this analysis are based in part on historic market dynamics, such as ‘all you can eat’ pricing for data.” There is anecdotal evidence, however, of movement toward “pay as you go” pricing.
• Offloading of mobile broadband data onto Wi-Fi and other technologies. The paper chooses to not consider such offloading “directly.” Certain of the forecasts consider it, but incompletely, at least from what I can tell (see the last point below). As we see improvements in, and deployment of, interworking technologies for Wi-Fi and 4G, and perhaps more rationalization of rate plans away from “all you can eat” single flat rates, consumers will have more incentive to offload mobile broadband data. A reference cited by the paper downplays this effect by saying that a mobile user is often not near a Wi-Fi hotspot. The Cisco forecast, however, cites data showing that most mobile broadband use is at home or at work — locations increasingly having hotspot coverage.
• Scenarios for mobile broadband video use. Cisco predicts that video will account for 66% of mobile data traffic by 2014. It also predicts that in 2014, smartphones will use 21% of mobile data traffic and “laptops and other mobile ready portables” will use 70%. Looked at another way, video on laptops and portables is predicted to consume almost half of mobile broadband data. If we reconsider offloading of data and rate plans, estimates of mobile broadband video use can likewise be reconsidered.
• New technology. The paper looks at improvements in technology and the resulting increased spectral efficiency with respect to the air interface. Other technologies have the potential to reduce the number of bits needed to do the same thing. For example, video and audio compression technology continues to improve. What practical advances can be realized and when? Related to new technology, I’d also include software improvements resulting in reduced application data requirements and phone operating system overhead. If the industry is moving toward “pay as you go,” programmers will have greater incentive to reduce unnecessary data overhead.
• Use of non-public data. Many references cited by the paper or in the forecasts are described as proprietary or unpublished or are accessible only at considerable cost. Perhaps the FCC can encourage these sources to make more data publicly available.

There’s more that could be said about the technical paper and the three forecasts, but the above points are the first considerations that come to mind.

• INOVA Geophysical Equipment Limited filed an application (with supporting exhibits) to test a proprietary mobile radio system in the 30-36 MHz and 150-174 MHz bands. The radio links would be used to control remote geophysical seismic recording equipment, which INOVA manufactures. At the end of testing, INOVA plans to put the radio equipment into production and lease it to customers.

• Fortress Technologies filed an application for experimental license to test several of its secure mesh-networking products developed for military applications. Several exhibits are included but they are not publicly available due to a confidentiality request. Operation is to be on 4.9425-4.9875 GHz.

• The Port Authority of New York and New Jersey filed an application for special temporary authority to operate on 5250-5500 MHz while testing to find the best location for an Elta 2127 ground surveillance and movement detection radar at JFK Airport. Three similar applications were filed for testing at La Guardia, Newark, and Teterboro Airports.

• General Dynamics Armament and Technical Products filed an application (with supporting exhibit) for special temporary authority to operate on 1760-1850 MHz and 2200-2300 MHz to conduct testing based on Department of Defense requirements for fully-digital data links for small unmanned aircraft systems to allow for higher concentrations of unmanned aerial vehicles (UAVs) operating in the same battle space. A new data link is to be tested. The new data link is compatible with ground based Remote Video Terminals (ROVERs) allowing for real-time reception of video imagery by ground troops.

• Fujitsu Ten Limited filed an application (with supporting exhibits) for experimental license to operate on 76-77 GHz. The exhibits are not available for viewing, presumably because of a confidentiality request. From other information, this appears to be a test of radar for safe-driving assistance systems. This application was granted on August 27.

• Sikorsky Aircraft filed an application (with supporting exhibits) for experimental license to operate on 30-400 MHz. This is to test Rockwell-Collins AN/ARC-210 radios on military helicopters being sold to the United Arab Emirates (UAE). According to the applicant, the “Rockwell-Collins AN/ARC-210 radios will have several unique frequency hopping waveforms which are proprietary to Rockwell-Collins. These waveforms are called TALON and Quicklook waveforms, respectively. The AN/ARC-210 TALON/Quicklook radios will be used aboard the [helicopters] to communicate with UAE ground forces. The Quicklook frequency hopping waveform is used in the 30-90 MHz band. The TALON frequency hopping waveform is used in the 90 to 400 MHz bands.”

• Abbott Diabetes Care filed two applications to test equipment at 433 MHz. The company has requested confidential processing of its application, and few other details are publicly available from the FCC. This may be related to Abbott’s wireless glucose monitoring products. The company announced in April 2010 that it had supply problems with a wireless product.

• WCA Holdings III, LLC filed an application (with associated exhibits) for special temporary authority to operate on 14.00-14.47 GHz for on-ground and flight testing of a single aircraft earth station antenna. This is to assist with Federal Aviation Administration Supplemental Type Certification testing, as well as further testing and demonstration of the functionality of the antenna with the eXConnect Ku-band Aeronautical Mobile-Satellite Service (AMSS) system. WCA has partnered with Panasonic Avionics Corporation, proponent of the eXConnect System.

The eXConnect System is Panasonic’s. It is designed for in-flight passenger internet access and other communication services. It can be looked at as a replacement for the now-defunct Boeing Connexion system. Lufthansa, for one, plans to use eXConnect on the majority of its 70 aircraft already fitted with Connexion hardware.

This application was received on August 6. On September 1, the application record was updated to note that WCA’s operating partner, Panasonic Avionics Corporation, is in the process of developing a detailed coordination agreement with NASA to protect existing and future Tracking and Data Relay Satellite System (TDRSS) operations from potential interference from Ku-band AES operations. The application was granted on September 7.

• Pro Xplor Services filed an application but few details are available due to a request for confidential processing, which FCC staff has asked the company to justify. It also requested a nationwide license, and FCC staff has suggested that a smaller operating area would suffice.

On July 7 of this year, the FCC denied the company’s request for waiver of the technical rules in Section 90.259 of the Commission’s Rules in order to permit certain proposed secondary telemetry operations.  At the time, it had sought authorization to operate in parts of Arkansas, Louisiana, and Texas on 217/219 MHz frequencies with up to fifteen watts output power on 600-kilohertz and 800-kilohertz channels.

• INSITU filed an application (with supporting exhibit) for special temporary authority to test the SeaLancet IP network radio in a flight test on 2367 MHz.

• Boeing filed an application (with supporting exhibits) for special temporary authority to test an Electronic Support Measures (ESM) system installed on a modified Boeing 767. Operation is to be on 800 MHz, 5.4 GHz, and 9.4 GHz. “The test involves personnel walking around the aircraft with a signal generator and horn antenna directed at the aircraft to stimulate ESM sensors mounted on the aircraft skin.” This application was granted on August 27.

• Sensus Spectrum filed an application (with supporting exhibits) for special temporary authority to test Smart Grid devices on 410-430 MHz. Sensus manufacturers similar products on 900 MHz for the US market. The requested frequencies are for testing of devices intended for Europe and the Middle East.

• Lockheed Martin filed an application (with supporting exhibits) for experimental license to operate on 9.595-9.750 GHz and 10.15-10.43 GHz to operate a ground station used to exchange data with an airborne system. The equipment is said to be an improved version of a system previously delivered to a customer under the US Government Foreign Military Sales for the Peace Krypton program. According to the Federation of American Scientists, the “mission of the Peace Krypton system program (known internally to Lockheed Martin Corporation as the Eagle program) is to collect reconnaissance imagery of selected areas during long range missions using an airborne Synthetic Aperture Radar (SAR) imagery intelligence collection system.”

• Bowling Green State University filed an application (with supporting exhibits) for experimental license to use a Furuno FR-1525Mk3 marine radar to track bird and bat activity in areas of existing and planned wind turbine development as well as comparative control sites. Operation will be on 9.3-9.5 GHz.

• SET Corporation, founded by former DARPA scientists and now a subsidiary of SAIC, filed an application (with supporting exhibits) for experimental license to operate in and around Denver, Colorado on 35.75 GHz. Details of the proposed test are confidential.

• Raytheon Missile Systems filed an application (with supporting exhibit) for experimental license to test advanced antennas operating in the 80-200 MHz range. The testing will be used to determine three-dimensional far-field radiation patterns of the antennas.

UWB, as authorized by the FCC, operates across 3.1 to 10.6 GHz, with very low power at any one frequency; its tendency to cause or receive interference is very low.

IEEE 802 attempted to create a UWB standard in IEEE 802.15.3a but did not, as neither of two competing proposals reached the necessary voting threshold for approval. One of the competing proposals, Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM), has since seen some consumer success in Wireless USB, which is based on a platform maintained by the WiMedia Alliance; data rates are up to 480 Mbps at a range of about 10 feet.

UWB was eventually standardized in IEEE 802.15.4a, where it exists as an alternative physical-layer to standard IEEE 802.15.4-2006, a standard for very low power, low data rate devices. (The IEEE 802.15.3 family is for higher data rates with higher power consumption.) It uses what was the other competing proposal in 802.15.3a, Direct Sequence UWB (DS-UWB). This standardized form of UWB has been commercialized for asset tracking and other location services, but not yet for consumer applications.

As Lazarus says, though UWB is successful in several applications outside the home, it has not made as much progress in the consumer market. A big reason for this is that UWB’s competitors were not so encumbered with regulatory and standardization delays.

• Standard IEEE 802.11n-2009 (high-throughput Wi-Fi) was approved a year ago with uncoded bit rates up to 600 Mbps in a 40 MHz bandwidth at 2.4 or 5 GHz.

• The Wireless Home Digital Interface (WHDI), which operates in 40 MHz of bandwidth in the 5 GHz unlicensed band, was standardized late last year by the WHDI Consortium. The targeted market is transmission of uncompressed (better-quality) HD video, with data rates up to 3 Gbps. IEEE 802 was not involved, though the technology is similar to 802.11n.

• There are two new millimeter-wave technologies that offer multi-gigabit data rates. These 60-GHz technologies are not direct competitors with UWB, but some overlap in applications could emerge. The data rates are much higher, but 60 GHz is blocked by most any obstruction, and power consumption is high making it unsuitable for mobile devices at this time. As with WHDI, the main market is the transmission of uncompressed HD video.

WirelessHD operates in the 57-64 GHz unlicensed band and is based on the IEEE 802.15.3c-2009 standard that was published about a year ago. The Wireless Gigabit Alliance is another 60 GHz proponent; its specification is to be based on the IEEE 802.11ad standard, which is under development and should be completed around the end of 2012.

If someone tried to standardize UWB in IEEE 802.15.3 today, they would have a better chance of success due to meeting process improvements. In making decisions in IEEE 802, it has traditionally been one-person, one-vote. That has sometimes motivated companies to send as many as possible to the standards meetings so they can earn voting rights and vote as a block, a practice frowned on by ANSI, IEEE 802’s accrediting body. Since the failure of the UWB standardization in 802.15.3, and because of evidence of block voting in other groups, IEEE 802 has modified its voting procedures to make block-voting harder. Everyone participating in the meetings now has to declare an “affiliation,” the definition of which is carefully worded to lead to the primary entity paying the participant. Consultants, for example, have to declare affiliation with their client, not their consulting firm; they often didn’t do this before. If roll-call votes show evidence of block voting, the group may be switched to entity voting (e.g., one company, one vote). That helps. IEEE 802.20 got bogged down, switched to entity voting, instantly made progress and completed its standard.

With these and further process improvements, IEEE 802 is a good home for these unlicensed standards. One advantage is that all IEEE 802 wireless projects are required to address coexistence with other IEEE 802 wireless standards. That’s hard, as many are using the same spectrum, but the affected groups sometimes can make accommodations with each other to reduce mutual interference. Also, many companies prefer the more-open process of an accredited standards development organization. The decision to go it alone or with a proprietary specification, however, is ultimately a business decision.

UWB remains unique in terms of its interference-resistant characteristics. As more RF devices enter the home, as they will with increased machine-to-machine communications, UWB could help as the more-popular relatively-narrowband devices increasingly interfere with each other. UWB may then become successful in the home out of necessity, if not as an option.

As background, the National Broadband Plan recommends repurposing 120 MHz of from the TV bands to mobile broadband. On June 14 the FCC released an Omnibus Broadband Team Technical Paper that describes some of the analyses supporting this repurposing. Chairman Genachowski asked the Commission staff to hold the Forum to consider ideas in the Paper.

At this Forum there were four areas discussed:

• Advancements in Compression Technology
• Cellularization of Broadcast Architecture
• Improvements in VHF Reception
• Methodologies for Repacking the TV Band

Each area had been the subject of discussion by groups in workshops earlier in the day. At the Forum each of the four groups reported  preliminary findings and recommendations.

After hearing the Forum, which is a preliminary effort, I”d say its gist is that technical changes in the TV industry aren’t going to free up significant TV spectrum for mobile broadband.  There are no advancements in compression technology that can be implemented in a timely manner (i.e., less than 13 years). State-of-the-art in compression technology, and market realities, makes channel sharing by different licensees impractical. Cellularization of broadcast architecture is seen as not practical nor economical. There is room for improvement in VHF reception, perhaps through higher transmit power levels and better, smart receive antennas. An examination of methodologies for repacking the TV band shows no scenarios where stations can avoid sharing channels, unless some stations voluntarily go off-the-air. (And, as we heard in the presentation on compression, sharing is seen as impractical.)

The slides used in each of the four sessions are to be made available on the FCC web site. For those interested in more details now, I share my notes below.

Advancements in Compression Technology

The results of this group were presented by Andrew Setos from the Fox group.

MPEG-2 was published in 1994, and no significant improvements are expected.

Compression equipment has improved such that artifacts are less noticeable, but they are still there. For example, where five years ago there might have been an obvious pixilation, now there is more of a blurring effect.

There are more-modern compression technologies such as MPEG 4. Current TVs do not support MPEG-4, and it could take 13 years to migrate that technology to consumer TVs.

The FCC Technical Paper scenario of multiplexing two HD programs for two different licensees in one 6 MHz channel is not viable due to quality degradation that would result when needing to choose a winner and loser when one HD stream exceeds the bandwidth of the other.

Statistical multiplexing efficiencies are lost with two separate licensees. It can work with the same licensee because the licensee knows what is in the different programs.

As far as pairing an HD station and an SD station in one 6 MHz channel, this is not viable as the trend is toward all HD.

The bit allocation for Mobile DTV is a straight carve-out, and statistical multiplexing does not help.

Cellularization of Broadcast Architecture

Bob Seidel of CBS presented the results of the cellularization group.

A Single Frequency Network (SFN) is much easier with OFDM than with the current 8-VSB modulation method.

“Self-jamming,” or interference between two cells in a SFN, was raised as an undesirable artifact of SFNs that would result in lack of coverage between cells.

SFNs will not help improve reception at the edge of coverage areas because of desired/undesired signal ratios that must be maintained there.

The lack of performance requirements for DTV equalizers is an issue.

Practical issues involved in implementing SFNs include feeding programming to multiple sites, and the cost of building and maintaining multiple sites.

It was suggested that, regarding Mobile DTV, wireless broadband providers should work with broadcasters. The point here is, why broadcast, say, the Super Bowl from hundreds of cell sites when Mobile DTV from one broadcast site will suffice.

Little or no UHF TV spectrum can be repurposed from cellularization.

Improvements in VHF Reception

Kerry Kozad from Dielectric Communications reported on the VHF reception panel.

The group was focused on fixed reception; mobile operation on VHF is not contemplated due to the large mobile antennas that would be required.

The low-VHF band (channels 2-6) is a bigger problem than the high VHF band (channels 7-13). Noise is a bigger problem, for one thing.

There are only 39 stations in the low-VHF band.

Noise varies from location-to-location at low-VHF, making it difficult to have consistent  performance and use common planning factors. There are also undesirable propagation effects at the low VHF band. It would likely require an impractical 15 to 20 dB power increase to alleviate these problems.

High-band VHF suffers from the same noise problems, but not as much. A 10 dB power increase would be required to help significantly.

Receiver antennas can be improved, but not much. The best candidate for improved antenna performance is indoor reception, perhaps through smart antennas working in conjunction with the TV set. The TV and antenna manufacturers have to work together for this to happen.

The FCC should not set consumer antenna performance standards. There are too many variables for a one-size-fits-all performance standard.

It would help to standardize descriptive terminology and performance measurement standards.

The FCC should increase maximum power limits, but be aware that there can be more interference with higher power.

Methodologies for Repacking the TV Band

The spectrum repacking session was led by Bruce Franca from MSTV.

He summarized the status of new modeling efforts and reviewed Technical Paper study assumptions.

Population loss (loss of people served) is one of the costs in reclaiming spectrum.

The focus is on reclamation in the UHF band, as mobile broadband operators are not interested in VHF spectrum.

The study assumptions included locating all stations in channels 2-30, and adding no new stations to channels 2-6.

The minimum number of stations that must share in this scenario are 248. From 20 to 40 percent of Designated Market Areas (DMAs) are impacted and must share, depending on border protection.

A more careful approach to DTV interference is suggested. In analog television, interference can be increased 8 dB before someone notices, and can increase 20-30 dB  before someone stops watching. In DTV, however, most TV sets go from perfect picture to no picture in 1 dB.

Interference performance is governed mostly by DTV receive performance.

Different propagation models are available, but there is no indication any are generally better than the Longley-Rice model.

One question was whether protected service areas should be adjusted to more accurately reflect viewing practices, and if so, how. Nielsen reports 10.9 million over-the-air homes, but it is not clear what that means. For example, a home with both FIOS and over-the-air reception is not considered over-the-air by Nielsen.

Hispanic households have a high percentage of over-the-air reception: 20% in Los Angeles, 35% in Houston, and 28% in Phoenix.

50 million DTV converter boxes were sold.

In discussion, it was noted that this panel’s results refer to sharing being “required.” That assumes no stations voluntarily choose to go off the air. If sufficient stations choose to go off, sharing is not required.

• Polytechnic Institute of NYU filed an application (with supporting exhibit) for experimental license to conduct a network research project using WiMAX on 2535-2540 MHz. This is part of the nationwide Global Environment for Network Innovations (GENI) project, a suite of infrastructure that will support experimental research in network science and engineering. GENI is supported by the National Science Foundation and managed by the GENI Project Office at BBN Technologies.

• Mnemonics, Inc. filed an application (with supporting exhibits) for experimental license to operate in support of a research project that is to develop and demonstrate the viability of wirelessly extracting measured data from a network of passive surface acoustic wave (SAW) sensor devices. This sensing technique is said to have several advantages over existing sensors, including no wired connections needed to extract data, no power requirements, operation up to 1000 degrees C., and sensor cost in-quantity in the tens of cents each. Operation will be on 915 MHz.

• Worcester Polytechnic Institute filed an application (with supporting exhibits) for special temporary authority to operate on 512-608 and 614-698 MHz. This is in support of research and evaluation of equipment that uses radio-location technology to precisely identify the location of firefighters and firefighter deployed sensors within a building.

• Zimmerman Associates filed an application (with supporting exhibits) for special temporary authority to test prototype equipment that uses ultra wideband (UWB) technology developed by Time Domain Corporation. The equipment generates a signal that is pulse position modulated. The position of the modulated pulse varies randomly in time producing an emission that approximates Gaussian noise. The nominal center frequency of the signal is 4.4 to 4.5 GHz with the half power point bandwidth at 3.1 to 5.6 GHz. The radiated power of the device is below the general limits set forth in Part 15. This testing is in support of a U.S. Army contract.

• The Moment Lab, University of California, Santa Barbara filed an application (with supporting exhibit) for experimental license to conduct experimentation regarding use of the TV white spaces. The Lab seeks to evaluate its solutions for modulation and coding scheme and channel width adaptation on long-distance (rural) white-space links. Operation will be on 512-608 and 614-698 MHz.

• Panasonic Avionics Corporation filed an application (with supporting exhibit) for experimental license  to conduct ground testing in support of Panasonic’s Global Communications Suite (GCS) featuring the “eXconnect” Ku-band aeronautical mobile-satellite service (AMSS) system supporting wireless connectivity for devices such as GSM phones and Wi-Fi enabled laptops. Using low-power wireless transceivers onboard aircraft, GCS processes passenger communications for transmission to ground networks via satellite communications networks. Operation will be on various frequencies between 421 and 5825 MHz.

• Ingegneria Dei Sistemi S.p.a. filed an application for special temporary authority to operate equipment for landslide monitoring as part of a demonstration for the US Geological Survey. The equipment is classified in Europe as a portable Short range Device (SRD) as it said to be compatible with primary services. Compliance testing of this equipment with the applicable requirements in the US, however, has not been yet been accomplished. Operation will be on 17.1-17.3 GHz.

• DRS EW & Network Systems filed an application for special temporary authority to test identification, friend or foe (IFF) equipment that is being developed under a contract with Italian Air Force. Operation is between 1030 and 1090 MHz.

• Boundary County Community Television filed an application (with supporting exhibits) for experimental license to operate using vacant spectrum in the television broadcast bands (white spaces) for the testing of fixed white-space devices. Boundary County Community Television is working jointly with Spectrum Bridge in investigating the usefulness of available white space (UHF/VHF) spectrum by providing “rural broadband access and support of video, sensor, low power AM broadcast radio using IP streaming, Wi-Fi access and medical records exchange.” The two companies will also be working with the U.S. Customs and Forest Service in application development and evaluation. Operation will be on 174-216, 470-608, and 614-698 MHz near Bonners Ferry, Idaho.

• Magna Electronics filed an application (with supporting exhibits), apparently for experimental license (the application form is not available at this time). Magna Electronics says it is developing an automotive 77 GHz radar for use in the reduction of vehicular accidents through situational awareness. Research is underway to detect forward objects of interest that may cause an accident, to either warn the driver or autonomously brake the vehicle to reduce the impact energy. Magna also notes that over 1.8 million rear end collisions are reported in the United States annually; this is more than 1/3 of all reported accidents and is the leading accident type.

• Dell Marketing filed an application (with supporting exhibits) for special temporary authority to conduct market studies that focus on consumer acceptability of mobile digital television transmitted using the ATSC A/153 standard. This authority applies only to reception devices.  Transmission will be made from regularly licensed TV stations. The reception devices to be used in the test (up to 1000 specially configured Dell Netbook computers) will include tuners for the reception of ATSC A/53 conventional DTV signals and ATSC A/153 mobile DTV signals but not analog tuners. Frequencies to be used include 54-72, 76-88, 174-216, and 470-698 MHz.

According to Dell, “The receivers at issue are not to be sold directly to the public. Instead,, the receivers are to be sold to Dell commercial customers who, as a result of the tests they are to conduct, will be able to provide feedback as to such issues as the field performance of the receivers, acceptability of the user interface, consumer expectations and acceptability of possible prices (e.g. “Would you be willing to pay _____ for this device, provided that it includes DTV/MDTV reception capability?”), consumer use data (hours per day of viewing, principle reasons for viewing, reasons for stopping viewing), and perceived value of the service.”

Dell also says “Half of the proposed units will be sold to a major multi-channel video programming provider for use in a test in which the provider will make the receivers available to selected consumers who agree to participate in the test. The others are to be made available for sale to broadcast television transmission equipment makers who will provide them to broadcast stations for demonstration and consumer feedback purposes in connection with the launch of mobile television service this summer. In both cases, a condition of Dell’s sale will be to provide Dell feedback that will assist Dell in both product design and marketing, including being able to set initial prices should the Commission agree ultimately to permit the widespread marketing of portable receivers without analog tuners that are designed for on-the-go reception and are powered primarily from batteries.”

• Alcatel-Lucent filed an application (with associated exhibits) for experimental license to operate on various frequencies between 698 and 2155 MHz to evaluate LTE technology over-the-air. Specific tests are to include validation of call processing, handoffs, power control, and data scheduler algorithms.

• Inmarsat Hawaii filed an application (with supporting exhibits) for experimental license to conduct technical demonstrations using new, pre-production Global Satellite Phone Service (“GSPS”) prototype handsets, test these handsets in connection with their production and the deployment of other parts of the GSPS network, and otherwise develop radio techniques, equipment, operational data and engineering data related to GSPS. Inmarsat Hawaii says that “GSPS will be a highly competitive offering in terms of hardware costs, airtime rates and service quality, with a strong combination of form and functionality that Inmarsat believes will change the landscape in the provision of the mobile satellite services. The requested experimental authority would facilitate the introduction of GSPS to the U.S. by enabling Inmarsat to develop the technical expertise to extend and enhance existing uses of L-band spectrum through the introduction of GSPS.”

• Associated Air Center filed an application for special temporary authority to perform electromagnetic interference susceptibility tests to demonstrate that the use of on-board cell phones do not cause interference on any electrical equipment installed on the aircraft while on the ground. “A direct influence on the aircrafts navigation and communication systems is not expected, but a susceptibility investigation is considered neccessary [sic] as the electromagnetic field levels are in close vicinity of the signal source might raise to levels that cause interference. The testing will concentrate on demonstrating the electromagnetic compatibility of RF bands used for CDMA, GSM, PDC and UMTS cell phones within a aircraft environment [sic].” Operation will be on various frequencies between 410 and 2700 MHz.

• Booz Allen Hamilton filed an application for special temporary authority to evaluate the RF performance of commercial IEEE 802.16e (Mobile WiMAX) equipment for United States Air Force Global Broadcast Service applications. Operation is to be on 2620.250-2628.500 MHz.

• Raytheon Network Centric Systems filed an application for special temporary authority to test a Ground Surveillance Radar (GSR) system, intended to provide all-weather detection and tracking capability for facility/critical infrastructure and border security programs. Operation is to be on 3100-3500 MHz.

• Vexcel, a Microsoft subsidiary, filed an application (with associated exhibits) for experimental license to demonstrate a specialized short range, low power trailer-mounted radar system that illuminates a rock wall next to a highway and maps the surface profile in detail. Vexcel says that this technique can be used to detect potential dangerous rockfalls that could damage vehicles and travelers on the adjacent highway. Operation is to be on 10.7-11.2 GHz.

As background, Vexcel says that in October 2007, it “made a presentation to the Department of Transportation’s Federal Highway Administration (FHA) office proposing the use of Synthetic Aperture Radar (SAR) technology for the detection and monitoring of rock fall and landslides on steep slopes that border busy transportation corridors. Vexcel had previously demonstrated through software simulation that integrating the interferometric SAR data processing technique into a ground-based system would enable the measurement of surface displacements on the order of a millimeter at stand-off distances of up to several hundred meters. Since surface displacements are a precursor to rock wall failure, the ability to measure surface displacement over time yields a capability to predict wall failures. This predictive capability would enable transportation authorities to schedule mitigation activities during low traffic periods thereby minimizing the risk to life and limb of rock wall failures and significantly reducing their negative economic impacts.”

“To properly verify the system operation, Vexcel needs to measure several different types of rock formations. To do this, the system will be installed on a trailer which can be towed to each experimental site. A drawing depicting the trailer system is shown in Figure 1. Directional horn antennas are used to transmit and receive the radar’s radio frequency signal. The antennas are mounted on a linear rail system and are moved horizontally and vertically along the rails. The motion is such that the antenna pointing direction is not changed during operation. The horizontal rail allows for 5 meters of motion. The vertical rail allows for 1.6 meter of motion. The antenna’s highest position above the ground during operation is 2.6 meters.”

• TWC Wireless, the wireless division of Time Warner Cable, filed an application (with supporting exhibits) for experimental license to test WiMAX (IEEE 802.16e) equipment and applications over-the-air. These tests are intended to support system, application and device development, as well as quality assurance. Operation is to be on 2513-2535 MHz.

• L-3 Communications Linkabit Division filed an application (with associated exhibits) for experimental license to conduct a series of experiments with HF and VHF multiband radio equipment. The purpose of the experiment is to confirm performance of the equipment against engineering specifications, characterize field performance of the equipment, and rehearse scripted equipment demonstrations in support of marketing activities. Operation is to be on various frequencies from 1.8 to 107.5 MHz. The communications will be primarily voice with very limited digital data. Also, encrypted (AES 256) and unencrypted communications will be evaluated. Upon successful conclusion of the experiments, the equipment will be offered for sale worldwide, subject to US export regulations.

• Morehead State University filed an application for special temporary authority to operate a ground station and characterize the Mini-RF radar instrument, one of seven instruments on NASA’s Lunar Reconnaissance Orbiter (LRO). The LRO is currently orbiting the Moon. The science team has a program requirement to characterize the transmit and receive paths of the Mini-RF instrument on a regular basis. The characterizations require one week of testing and repeated every 9-12 months. Operation is to be on various frequencies from 2370 to 7150 MHz.

• Telcordia Technologies filed an application (with supporting exhibit) for experimental license to conduct testing on 495-505 and 525-535 kHz in support of deliverables under a Department of Defense research program for the Laboratory of Telecommunication Sciences. The project includes experiments to better understand vulnerabilities of critical infrastructure to natural and man-made phenomena. In particular, Telcordia proposes to conduct experiments on the impact of radio frequency interference (RFI) into advanced communications services such as broadband access. It proposes to do this by running short term transmission experiments at a number of locations using conventional AM transmissions, but just below the commercial AM band to avoid interference with commercial broadcasts.