On offload, 4G Americas says Wi-Fi offload of mobile traffic is at 35% today in the U.S., and is estimated to be 68% by 2016. There’s no source for these numbers, such estimates can vary, but these figures are reasonable.

Absent is a similar consideration of femtocell offload, but it can be expected to be smaller than that for Wi-Fi up to 2016, at least.

4G Americas then has an interesting paragraph on Cisco forecasts of mobile data growth:

Cisco’s VNI data on global mobile data traffic (Figure 23), which makes no distinction between historical and forecasted data, yields vastly different projections depending upon how much of the historical record is included in the fit. The following graphic shows the impact of selecting pre-2012 data points (in blue) and including Cisco’s own forecast to 2015. We see, then, that we live in a critical time, when the wireless data explosion is upon us, but its further outlines are only hinted at in current data. Careful analysis of the traffic statistics in the coming quarters may reveal the 2015 and 2020 expectations or perhaps see the unleashing of further pent-up demand.

So, 4G Americas apparently combines measured results pre-2012, and Cisco VNI data for 2012 and beyond, then fits a logistic curve (sometimes called an S-curve) to these data, which shows global growth “saturating” around 2020 at about 13 exabytes per month. The “critical time” refers to us possibly being at an inflection on the curve. We might be there because the year-to-year growth of Cisco’s forecast is decreasing. (Put another way, the percentage increase is smaller each year.) I suggested this is what is happening in a blog post last November. For anyone skeptical, look at any Cisco VNI forecast and calculate the year-to-year percentage increases.

The blue curve shows the infamous “exponential growth” curve, which continues to be invoked as a spectrum bogeyman, especially in the U.S; as you can see, no way. The red curve is a logistic curve fit to a 2.5x growth rate, which appears high compared to the green curve fitted to Cisco data.

This is just one scenario. Perhaps, as 4G America’s suggests, there will be an “unleashing of further pent-up demand.” We don’t know what’s going to happen, but this result is consistent with the transformation of mobile networks from macrocell-only to heterogeneous — bringing the user closer to the “base station,” which will increasingly be a small cell indoors because that’s where we are most of the time. When this happens, the user is offloaded from the macrocell, and demand on the macrocell is decreased. We’ll be using ever-increasing amounts of data, but it will be accessed more efficiently, with smaller percentages from macrocells. Regardless, this projection should not slow efforts to make spectrum policy more rational and spectrum use more flexible.

• The University of Iowa filed an application with exhibit for special temporary authority to transmit a 2.5 MHz signal from an aircraft trailing-wire antenna to measure the thickness of Alaskan glaciers. The antenna is 60 meters long. Transmit power is 10 watts. The modulation is specified as a 1 MBytes/sec. FM chirp 6 microseconds long with a duty cycle is 1%.

• Amateur Radio operator Frank Ravenswood filed an application with exhibit for special temporary authority to conduct experiments with spread spectrum on HF and VHF Amateur Radio frequencies. Operation will be from Hillsboro, Oregon in several Amateur bands between 1.8 and 54 MHz.
• ATSC Laboratories filed an application with exhibits for experimental license to conduct white-space equipment tests within the television broadcast bands 54-72 MHz, 76-88 MHz, 174-216 MHz, 470-608MHz, and 614-698 MHz. “ATSC will conduct research and experiments of fixed and personal/portable devices within the White Spaces to analyze the potential utility and feasibility of such operations and technology. In particular, ATSC wishes to determine the impact of such operations and technology in a densely packed ‘in use’ channel structure, consisting of underserved rural and urban populations.” Operation will be in Reno, Nevada.
• Amateur radio operator Brian D. Justin, Jr. filed an application with exhibit for special temporary authority to transmit on 70 MHz from Bedford, Virginia in support of trans-Atlantic Sporadic E propagation (E-skip) testing.
• Curtiss-Wright Controls filed an application with exhibits for experimental license to demonstrate its ground-penetrating 3d-Radar to prospective customers. Curtiss-Wright says it filed a Part 15 waiver request with the FCC in June 2010 seeking authorization to operate its 3d-Radar for non-federal use. That request was granted on January 11, 2012. The device, however, does not yet have FCC equipment authorization, thus this application. Operation will be at various, yet to be determined, locations and in the frequency range 140-3000 MHz.
• Lockheed Martin filed an application with exhibits for experimental license to conduct developmental testing of an AXCP ocean probe designed for NOAA and intended to profile water velocity and temperature. The probe’s transmitter has an integral monopole antenna that points toward the sky. In normal operation seawater acts as the ground plane. Operation will be at Marion, Massachusetts on 170.5, 172, and 173.5 MHz.

• NorthWestern Corporation, an electricity and natural gas utility, filed an application with exhibit for experimental license to test the usefulness of white-space frequencies and technologies for real-time communications with remote smart grid devices. “This includes point-to-multipoint wireless communications to capacitor banks, reclosers, voltage regulators and voltage sensors. This specific project is focused on improving power quality, power efficiency and outage restoration to rural customers in Montana along an unusually long distribution line.” The utility says it “has already installed smart grid devices which behave autonomously along the line without communications. Although power quality has improved, the line continues to experience problems. The expectation is that real time communications coordinated among the existing smart grid devices will improve power quality and efficiency.” This experimentation is supported by a grant from the U.S. Department of Energy. Operation will be on up to four 500 kHz-bandwidth channels between 174 and 216 MHz in the vicinity of Philipsburg, Montana.
• Fugro Earthdata Inc. filed an application with exhibits for special temporary authority to operate in support of research on determining the thickness of multiyear arctic ice associated with offshore ice flows using GeoSAR Interferometric Synthetic Aperture Radar (IFSAR). The applicant says P-band radar is known to penetrate several tens of meters into glaciers. The ability to accurately and simultaneously measure the top and bottom of the arctic ice from a high flying sensor, however, has not yet been established. Operation will be in an area centered on Barrow, Alaska on 270-430 MHz and 9.63-9.79 GHz.

• The University of Washington filed an application with exhibit for special temporary authority transmit from a free-flying balloon over Washington state on 433.845-433.995 MHz. This is in support of a class project entailing the building and operating of inexpensive equipment to collect atmospheric temperature-profile data.
• CBS filed an application with exhibits for experimental license to allow testing to “determine if digital spectrum efficient communication radios, capable of simultaneous voice and data channels, will improve the efficiency of its remote field news gathering and if the known latency and ‘cliff effect’ resulting from digital communications might adversely effect news gathering operations. While CBS believes that the benefits of using digital spectrum efficient radios are well advertised, the resulting audio latency issues experienced by the ‘on-­air’ talent during live broadcasts could be problematic.” CBS goes on to state that “As live broadcasts can be affected by digital latency, CBS seeks to determine if this will limit using digital cues and ‘on‐air’ program audio foldback to live talent broadcasting from remote locations. In addition to voice communications, GPS tracking of news crews, electronic script transfers, and teleprompter data will be tested using the proposed equipment and emission.” Operation will be in Denver, Colorado and vicinity on several frequencies near 450 MHz.
• Qualcomm filed an application with exhibit for experimental license to operate in San Diego, California on 536-548, 578-590, and 656-668 MHz (TV channels 25-26, 32-33, and 45-46, respectively). This is for white-space testing of up to 10 devices, each having a maximum transmit power of 100 mW and bandwidth up to 10 MHz.
• Microsoft filed an application with exhibit for experimental license to conduct femtocell research, including development of software techniques “to improve the user experience.” Microsoft “plans to operate 3GPP Femtocell Reference Platform (‘FRP’) units from Qualcomm. At the radio layer, the Qualcomm FRP is no different than commercially-available femtocells that use Qualcomm chips. At higher software layers, the biggest difference is that the FRPs will connect to core network emulators instead of connecting to a Home NodeB gateway inside a commercial mobile operator. These core network emulators will run on PC servers, and the FRPs will connect to them via Ethernet. The FRPs will be configured to advertise a particular test mobile network to particular UEs. These UEs will be standard, commercially-available 3GPP cellular phones with SIM cards that allow them to connect to the FRPs.” Operation will be in Redmond, Washington on 824-835, 869-880, 1850-1885, and 1930-1965 MHz.
• Coldplay Inc., a wholly-owned affiliate of the musical group Coldplay, filed an the application with exhibit for special temporary authority to transmit a 60 kHz-wide signal centered at 869.5 MHz during the 2012 Grammy Awards on February 12 in Los Angeles. According to the application, “Coldplay has recently integrated a distinctive, innovative audiovisual component into its live performances throughout Europe. Specifically, in recent performances, each audience member has received a Light Emitting Diode (“LED”) wristband that is synchronized with the group’s music and stage lighting. These wristbands, which are controlled by a single, centrally located radiofrequency transmitter flash en masse in coordination with the band’s music and stage lighting to create a stunning visual effect throughout the concert hall while simultaneously enabling individual audience members to immerse themselves in the live performance. Coldplay seeks STA authority from the FCC to test and demonstrate the underlying RF transmitter that provides command/control instructions to the aforementioned LED wristbands during its performance at the 2012 GRAMMY Award Show.” Coldplay says it received consent from AT&T Mobility LLC, the licensee of that frequency in that area.

• Cosmoglia, Inc. filed an application with exhibits for experimental license to operate in support of it’s “Dove 2” satellite project.  As the company states, “The Dove 2 mission is an internal company technology demonstration experiment to test the capabilities of a low-cost spacecraft constrained to the 3U cubesat form factor to host a small payload. Dove 2 will do this by transmitting health and payload data to the ground. The payload data consists of image data taken from an on board nadir pointing camera. The images will be downlinked over the ISM frequency band at 2.4 GHz and the earth observation frequency band at 8.2 GHz. The dimensions of the spacecraft are consistent with CubeSat and P-POD standards. It is a single unit with the dimensions of 10 cm X 10 cm X 33 cm. The total mass is about 5.8 kg. One important metric of mission success is the ability to build a solar panel/battery/power distribution system that will last for years in orbit, so the mission duration will be one year. The spacecraft will launch on August 31st into an elliptical orbit of 290 km by 575 km with a 64.9 degree inclination.” Operation will be on 1616-1626 MHz, 2401.6-2441.0 MHz, and 8.221-8.229 GHz. The operation on 1616-1626 MHz has been coordinated with Iridium.
• The MITRE Corporation filed an application and exhibit for experimental license to operate in Bedford, Massachusetts and McLean, Virginia on 1915-1920 MHz. According to the exhibit, “MITRE is developing innovative solutions for mobile ad hoc networks (MANETs). The main goal of the research is to develop network routing algorithms working on peer-to-peer prototype radios supplied by Qualcomm Corporation to enable multi-hop wireless communication networks. Prior explorations in this area have focused on the use of such radios as one- hop peer-to-peer devices. MITRE will perform research, development, testing, and demonstrations. This experimental work will be performed over a 2-year period.”
• Orbital Sciences Corporation filed an application with exhibits for special temporary authority to operate three spacecraft telemetry (return) links with its Cygnus spacecraft in support of a mission to the International Space Station. These links are to monitor spacecraft operation. Return links include: Mode 1: spread spectrum operation with NASA TDRSS, Mode 2: low data rate operation with NASA TDRSS (contingency mode only), and Mode 3: high data rate operation with ground stations. Operation will be on 2202.9-2207.1, 2213-2219, 2214.5-2217.5, and 2215.958-2216.042 MHz.
• Bran Ferren Corp. filed an application for special temporary authority to operate on 2215-2245 MHz at various locations in southern California, Nevada and Utah. This is for the development, testing and demonstration of a “unique airborne video production vehicle” that operates up to 400 feet above ground.
• Sprint filed an application with exhibits for experimental license to test wireless backhaul systems in the Overland Park, Kansas area on 2305-2310 and 2350-2355 MHz. The tested systems are intended to support Sprint’s Network Vision and related broadband deployment initiatives. The requested frequency bands are in the WCS A-block and are licensed to Nextwave, which has given its consent.
• Google Fiber filed an application with exhibits for special temporary authority to “test Bluetooth and Wi-Fi protocols and performance (including coordination of Wi-Fi channels between devices and in the presence of foreign signals) within an integrated access point as part of a fiber residential gateway.” Operation will be in Palo Alto, California on 2400-2483 and 5470-5725 MHz.
• Huawei filed an application with exhibit for special temporary authority to build an experimental network in Plano, Texas operating on 2578-2602 MHz. This is to demonstrate TDD-LTE backhaul technology to wireless operators. Huawei has permission to use the frequencies from their licensee, Clearwire.
• Enterprise Electronics Corp. filed an application with exhibits for experimental license to “investigate and refine weather surveillance methods to enhance the detection accuracy of severe weather phenomenon. This involves enhancing the design of radar hardware, (transmitters, receivers), and refining software algorithms used to detect, model and display the resulting data. Case studies of weather events are analyzed throughout multiple seasons and refinements are thus integrated into existing radar detection schemes.” Operation will be at Enterprise, Alabama on 2700-2900, 5300-5600, and 9300-9400 MHz.
• Northrop Grumman filed an application with exhibit for experimental license to operate at Hanover and Linthicum, Maryland on 3.1-3.5 GHz. This is for “tests and demonstrations of newly-designed equipment being developed for sale to the U.S. military. Six 50-MHz channels . . . are required for these purposes, with 50 MHz spacing between the channels. The antenna center will be pointed at 237 degrees from North, elevated 15 degrees above horizontal, and capable of scanning +/- 60 degrees in azimuth and elevation. Equipment is Northrop Grumman prototype.”
• General Dynamics filed an application with exhibit for experimental license to operate in support of development of a government system known as Prophet, not described but apparently a signals intelligence and electronic warfare system. Operation will be in Scottsdale, Arizona on 3424-3452 and 3524-3552 MHz.
• Qualcomm filed an application for special temporary authority to complete “propagation testing in support of developing next generation wireless technologies and advanced receivers.” “A single fixed transmitter will be configured per the requested frequencies. Receive power will be measured in the immediate area of the fixed transmitter.” Operation will be in San Diego, California on 3650-3700 MHz and 5790-5820 MHz.
• iRobot Corporation filed an application for special temporary authority to test range, mobility, and other attributes of robots. Operation will be on 4940-4990 MHz in Gaithersburg, Maryland.
• Electronic Warfare Associates filed an application with exhibit for experimental license to test its “Counter – Unmanned Aerial System” radar, said to be capable of acquiring and tracking multiple low-radar-cross-section targets. Operation will be in Mt. Laurel, New Jersey on 5.4-5.9 GHz.
• Georgia Tech Research Institute filed an application for special temporary authority to “Support testing of the recently launched WGS-4 satellite under Army contract. The Georgia Tech Research Institute (GTRI) provides test and measurement support to the U.S. Army via contract W911W5-11-D-0001. Under this contract, the U.S. Army has tasked GTRI to support testing of the recently launched WGS-4 satellite located at 121.9 degrees west. GTRI will utilize an approved ground terminal to generate various waveforms to test the satellite. The average duty cycle for the overall test is projected to be 3 minutes ON and 8 minutes OFF. All testing will be monitored by the U.S. Air Force Space Protection Program.” Operation will be on 7.90-8.02 and 8.345-8.400 GHz.
• 3 Phoenix Inc. filed an application with exhibits for experimental license to operate in support of development of an improved periscope detection radar. This work is part of a contract with the U.S. Navy. Operation will be in Wake Forest, North Carolina on 8.51-8.99 GHz.
• Telephonics Corporation filed an application with exhibit for experimental license to test an Advanced Radar Surveillance System (ARSS). The ARSS is to be used by U.S. Customs and Border Protection at the southern U.S. border.   Operation will be in Huntingdon and Farmingdale, New York on 8850 MHz.

• Lockheed Martin filed an application with exhibit for special temporary authority to conduct “verification of performance of new radar technology for domestic border security for state officials. Data of this improved radar sensor will be used to show performance improvements compared to current operating sensors used by state law enforcement officials for border security.” Operation will be in Syracuse, New York and Sierra Blanca, Texas on 9.2-10.0 GHz.

• Ultra Electronics Advanced Tactical Systems filed an application with exhibit for special temporary authority to test a ground surveillance radar system in support of a response the company is preparing to an RFP by the U.S. Department of Homeland Security. The RFP pertains to an intelligence, surveillance, and reconnaissance (ISR) system for the U.S. Border Patrol. Operation will be in the Marana, Arizona area on 9300-9500 MHz and 15.75-17.20 GHz.

• Qualcomm filed an application with exhibit for special temporary authority to test Next Gen Air-Ground System antenna performance using a single fixed transmitter on the ground and measuring the received power in an aircraft.  As background, Qualcomm says it “recently filed a Petition for Rulemaking to Amend The Commission’s Rules To Establish A Next-Generation Air-Ground Communications Service On A Secondary Licensed Basis In The 14.0 to 14.5 GHz Band, RM-11640. Comments and Reply Comments were filed on the Petition in September and October 2011.” “Qualcomm has also met with the FCC staff in IB, OET, and WTB to discuss the request and the expected performance of the Next- Gen Air-Ground system.” Operation will be on 14.0-14.5 GHz at Bakersfield and San Diego, California.
• General Dynamics filed an application with exhibits for experimental license to test a prototype border protection system to support “US Government contract pursuits.” The system includes a surveillance radar capable of detecting moving ground targets out to a distance of about 20 miles. Operation will be in Wittman, Arizona on 16.2-17.2 GHz.
• The Technische Universitaet Darmstadt Institute of Phys. Geodesy filed an application for special temporary authority to operate on 17.1-17.3 GHz in Princeton, New Jersey. This is to determine the oscillation of steel cables during construction of a building using a microwave interferometer. “Attached to the cables are big glass planes as part of the construction of the building. The measured eigenfrequency shall give information about the tension of the cables.”
• Peabody Powder River Mining filed an application for special temporary authority to test technology designed to detect movement in the walls of a mine by measuring the return-time of a reflected RF signal. Operation will be in Wright, Wyoming on 17.2 GHz. During processing of the application, FCC staff asked the applicant for details on the mine; here’s the response: “Peabody’s mine is a surface mine where holes are dug into the ground’s surface, much like a rock quarry. The holes run as high as several hundred feed deep and up to approximately 750 feet wide. As a result, the walls are hundreds of feet high from the base of the large hole.”
• Google filed an application to extend the duration of previously-granted special temporary authority to “Conduct experiments using test vehicles equipped with automatic cruise control radars in a manner that extends the sensing range of the radars when a vehicle is not in motion. Google is developing advanced driver assistance systems with the goal of improving the safety and convenience of vehicular transportation. Each Google test vehicle contains several off-the-shelf automatic cruise control (ACC) radars certified for use in the 76.0-77.0 GHz band. These radars are used to sense the environment around the vehicles.” Google goes on to say that “Testing the vehicles performance in complex traffic situations (for example, when the vehicle is stopped at intersections, or when a vehicle is about to make a right turn on to a busy road, in which case the range of a left-sensing radar must be sufficient to inform the vehicle to allow high-speed traffic to pass before proceeding) will provide critical data that will guide the development of more effective driver assistance technology. The results of these experiments will inform the need for a longer term experimental license. The location of the proposed experiments will be the San Francisco Bay, California area, extending south to Santa Cruz, California and north and east to South Lake Tahoe, California.” Google says that current FCC radar power limits will be exceeded in its tests when the vehicles are not in motion, but it does think that interference will be a problem.
• Raytheon Missile Systems filed an application with exhibit for special temporary authority to “demonstrate the effectiveness of using solid state W-band technology for improving high-bandwidth point-to-point communications in harsh environments.” Operation will be in Van Nuys, California on 92-93 GHz or 91-93 GHz (the application and exhibit are inconsistent with regard to frequency). The exhibit states that “Raytheon is working on a new product that uses high bandwidth solid state W-band (91-93 GHz) technology, making it possible to deliver compact, secure communications systems with orders of magnitude reductions in size, weight and power. Reducing the size, weight and power needed by broadband data links is essential when working in harsh climates. Traditional point to point technologies operating in this frequency band use large antennas that are buffeted by wind. The buffeting causes a significant drop in data rates, which leads to inefficient communications, lowering of available bandwidth, slowing of vital communications, and wasted power by the transmitters. This technology offers significant advances in power consumption, rapid deployment, and effective high-speed data transmissions under all conditions.” Raytheon expects to achieve 320 Mbps on a 1 km link.

“[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.

The due date for comments was July 25; reply comments are due August 24. (You can look at the comments and submit a reply through the first link above.) Comments and reply comments were originally due 30 days earlier; the FCC granted a request for deadline extension filed jointly by Verizon Wireless and Wilson Electronics (a booster vendor), who cited progress toward a solution that could benefit both manufacturers and carriers. They’ve submitted a joint proposal and I’ll spend most of this article looking at that.

As to the other comments, there are booster vendors naturally arguing for flexibility in design and operation. The in-building distributed antenna system folks are fine with boosters but don’t want any new rules to harm them. Public interest groups don’t want boosters tied to any one carrier, and want simple designs to keep the cost down. A company called Smart Booster brings concepts from dynamic spectrum access to boosters – intelligent units that know when and where to amplify or not. As noted above, the rulemaking proceeding also deals with Part 90 and Part 95 services; APCO addresses concerns about interference and unauthorized use in Part 90, and WCAI discusses various issues related to Part 90 and Part 95.

Most noteworthy, in my view, is the joint agreement among Verizon Wireless, its wireless engineering consultant V-COMM, and Wilson Electronics, that specifies requirements for the design, operation, and installation of boosters to help avoid harmful interference. This is a significant achievement for parties who are traditionally adversaries. The agreement provides for three categories of signal boosters: Carrier Installed Boosters, Certified Engineered and Operated Boosters, and Consumer Boosters. I’ll briefly discuss the first two, and spend some more time on the third.

The Carrier Installed Boosters would be installed by FCC licensees to operate exclusively on the licensees’ frequencies. The agreement doesn’t say much else about this, but there’s not much to say. Carriers have long been free to do pretty much what they want within the broad parameters of their license, and the agreement would not change this. They’re motivated to implement hardware that won’t interfere with themselves.

The Certified Engineered and Operated Boosters would be for large areas, such as campuses or large offices (CEO – get it?), and would require professional installation and close carrier coordination. The joint proposal provides a framework for these boosters, with technical standards yet to be developed.  They would be operated under the wireless licensee’s authority.

Then we have the Consumer Boosters. Under the joint proposal, these could be purchased only by wireless service customers. They would basically be bi-directional RF amplifiers with antenna systems that transmit and receive signals using an outdoor antenna for transmission and reception to a CMRS base station, and an indoor (or in-vehicle) antenna (or direct connection to the mobile device). V-COMM provides a set of specifications for these. They’re technology neutral and intended to provide protection to all CMRS network technologies on all relevant bands. Among other things, the specifications include requirements for automatic gain control to protect against out-of-tolerance operation in instances of overload, anti-oscillation protection to limit power when the inside and outdoor antenna are too close, and limits on uplink and downlink EIRP of 1 Watt and 0.05 Watt, respectively. The uplink transmitter has to turn off if no signal is received from the mobile device in 15 minutes. Noise limits are specified.

Also part of the specifications, Consumer Boosters must be registered with the licensed carrier, either manually or through a Bluetooth connection. In the Bluetooth registration method, the booster operates as an extension to the mobile device and is controlled by it. The manual registration process provides for the customer to give their address, phone number, and other information to the carrier so  it will know whom to contact if it suspects a particular booster is a source of interference; the customer would then be expected to turn it off.

An issue with the manual method is that it requires good faith on the part of the customer.  Others commenting, including T-Mobile and CTIA, prefer that the booster be under some form of direct control by the licensee, so it can be turned off in the event of interference. Without direct control, the manual process is rather open ended. There isn’t much of an incentive for the customer to complete the registration process, registration information that is given will fall out of date, and boosters will be sold second-hand and no longer be linked to the original phone of record. WCAI goes into some of these issues in depth.

I’m surprised to see this manual approach in light of V-COMM’s position in the FCC’s experimental license proceeding (ET Docket No. 10-236), in which it opposed any experimentation by third parties in the CMRS bands due to interference concerns. As a carrier concerned about interference, I’d be less worried by Part 5 experiments than by many more boosters that are out of my direct control. But I’d also realize that many applications for boosters are now inside buildings, and deployments of Wi-Fi and femtocells will gradually displace boosters to some extent, while providing better performance. In addition, the operator may be able to tell which wireless device the malfunctioning booster is associated with and disable the device, thus disabling the booster indirectly once it times out.Still, I’m used to CMRS operators being able to control dozens of parameters on a cellphone, including those related to power control. It’s hard for me to not want control of one parameter on a booster – whether it’s on or off.

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.

• Brian D. Justin, Jr., an amateur radio operator, filed an application with exhibits for special temporary authority to operate a propagation test beacon on 70.005 MHz at Bedford, Virginia. In his application, he reports an increasing interest in trans-Atlantic VHF communications by amateur radio operators, in part because of recent changes in EU regulations. A beacon would help operators know when sporadic E propagation (E-skip) conditions were good for communications near that frequency. (E-skip is enabled by scattered regions of relatively dense ionization that develop seasonally and reflect signals up to about 150 MHz.) Today, there are beacons on 50 MHz, and FM broadcast stations act as beacons in the 100 MHz range. There’s a gap at 70 MHz; AM video carriers once served as beacons (e.g., VHF channel 4 with a video carrier at 67.25 MHz), but those have gone away with the DTV transition.

• The University of Michigan’s Professor James Cutler filed an application with exhibits for experimental license to operate communication links for the Michigan Multipurpose Minisat (M-Cubed), a small student-built satellite that will capture images of Earth and transmit them to a ground station. The satellite weighs 1.3 kg and forms a cube 10 cm on a side. The imaging system consists of a 2.0 Megapixel CMOS sensor and Field Programmable Gate Array (FPGA) coprocessor. The test is to prove the reliability of the radiation-hardened FPGA in the space environment and assess the performance of the processing algorithm that will resolve the images in the satellite. M-Cubed will be launched from Vandenberg Air Force Base on a Delta-II rocket in the fall of 2011. The uplink will be on 144-146 MHz. The downlink will be on 437-439 MHz using an Astrodev Li-1 radio.

• Carlson Wireless Technologies filed an application with exhibit for special temporary authority to test TV white-space radios in rural, rugged, and forested areas. Testing will take place in various areas around New England on 174-216 MHz.

• Rockwell Collins filed an application with exhibit for special temporary authority to demonstrate its FlexNet software-defined radio technology at the 2011 Coalition Warrior Interoperability Demonstration,  an annual event directed by the Chairman of the Joint Chiefs of Staff that is intended to showcase new information technology. Operation will be on 245-327 MHz at Peterson Air Force Base in Colorado Springs, Colorado.

• Telephonics Corporation filed an application with exhibit for special temporary authority to test an existing 2.4 GHz ISM band product modified for operation in the 300-400 MHz military band. In addition to the change in frequency, the multiple-access method will be changed to frequency-hopping spread spectrum. The objective is to achieve superior communications in urban environments compared to 2.4 GHz operation. Testing will occur in Sterling Heights, Michigan.

• Panasonic Avionics Corp. filed an application with exhibit for special temporary authority to conduct ground testing in support of the Panasonic’s Global Communications Suite, featuring the eXConnect Ku-band aeronautical mobile-satellite service (AMSS) system, providing broadband connectivity to passengers in flight. Panasonic wants to test the potential for interference from transmitting portable electronic devices to aircraft avionics and communications. The test will use a signal generator to simulate the operation of multiple devices. Test results will be used to support certification of Panasonic’s aircraft equipment with the FAA. The tests will occur in Roswell, New Mexico on various frequencies between 410 MHz and 5.825 GHz.

• Carlson Wireless Technologies filed an application with exhibits for special temporary authority to test fixed white-space devices with attached cellular femtocells. Carlson Wireless and Vergennes Broadband are working jointly with Spectrum Bridge to investigate the applicability of white space spectrum for use in rural broadband applications, including support of femtocells. Operation will be in Vergennes, Michigan on 470-698 MHz.

• Microsoft filed an application with exhibit for special temporary authority to demonstrate interactive Xbox Live HD (1080p) video streaming over TV-band white-space spectrum during the April 11-14 NAB Show at the Las Vegas Convention Center. The demonstration was to incorporate Microsoft Research’s prototype white-spaces database, which controls white-space device access to help protect incumbents from interference. The frequency bands requested were 512-608 MHz and 614-698 MHz.

• Shared Spectrum Company filed an application with exhibit for experimental license to conduct tests as part of DARPA’s Wireless Network after Next (WNaN) program. The goal of the program is to “develop and demonstrate technologies and system concepts enabling densely deployed networks in which distributed and adaptive network operations compensate for limitations of the physical layer of the low-cost wireless nodes that comprise these networks.” Operation will be on 902-928, 2400.0-2483.5, 4400-4900, and 5650-5925 MHz in Stafford and Prince William Counties in Virginia.

• LightSquared filed an application with exhibit for experimental license to communicate with SkyTerra-1, a licensed and in-orbit satellite, and conduct a six-month test of two prototype models of Access Terminals (ATs) using the L-band spectrum coordinated for LightSquared’s satellite system. The ATs will transmit on 1626.5-1660 MHz and receive on 1525-1559 MHz. Testing will occur throughout North America.

• Lockheed Martin filed an application with exhibit for experimental license for flight tests of real-time video transmission using the company’s F-35 Joint Strike Fighter. The video source will be the F-35’s Electro Optical Targeting System (EOTS).  EOTS video data will be compressed and routed to an L-3 VORTEX transmitter. The transmitted signal will be received by an L-3 ROVER 5 handheld transceiver with the video displayed on a screen in the device. Operation will be at several locations around the US on 1710-1850 and 2200-2500 MHz.

• GBL Systems filed an application with exhibit for experimental license to develop, test and validate homeland security applications based on a peer-to-peer system under development by Qualcomm. Operation will be in Camarillo, California on 1915-1920 MHz.

• Row 44 Inc. filed an application with exhibit for experimental license to conduct tests using its aeronautical-mobile satellite service (AMSS) network. The tests will use a GSM picocell connected to Row 44′s Ku-band network in a simulated aircraft cabin environment. The objective is to understand the operation of GSM devices in the on-board environment. The tests will take place in Lombard, Illinois on 1930-1990 MHz.

• L-3 Communications filed an application for special temporary authority to operate on 2025-2120 MHz at Simi Valley, California. L-3 builds antennas for satellite tracking, telemetry, and control. The company says it has been experiencing high passive intermodulation (PIM) distortion that “causes transmitter noise to bleed into the receive band.” The testing is intended to resolve this problem.

• AeroVironment Inc. filed an application with exhibits for experimental license to conduct experiments with small unmanned aircraft system (SUAS) technologies intended for use by to state and local public safety agencies. Operation is to be on 4940-4990 MHz in the Camp Roberts and Simi Valley areas of California.

• Kongsberg Seatex AS, a Norwegian company, filed an application with exhibit for experimental license to test its Embedded Maritime Broadband Radio (EMBR) system. The system is intended to provide maritime users with reliable broadband data links using a system with no moving parts such as mechanically-steerable antennas. The system can operate at 5 Mbps when the distance between the nodes is up to 10 km. To eliminate the mechanically-steerable antenna, the system uses an electronically-steerable antenna array comprised of 60 antenna/transceiver sub-units. While there are other maritime broadband data link systems, such as those based on Wi-Fi and WiMAX, this system is said to outperform those due in part to a custom Physical Layer and Media Access Control Layer. Operation will be at 5220-5240 MHz on a route between Galveston, Texas and a Shell oil drilling rig in the Gulf of Mexico.

• Raytheon Network Centric Systems filed an application with exhibit for special temporary authority to test its Pathfinder maritime radar system in border surveillance applications.  Operation will be on 9.41-9.71 GHz in McKinney and Falcon, Texas.

• SRC Inc. filed an application for special temporary authority to conduct demonstrations of the SR Hawk ground surveillance radar at Fort Benning, Georgia. Operation will be on 16.21-16.50 GHz.

• Laurel Technologies Partnership filed an application with exhibit for special temporary authority to test the operating capability of the Manportable Surveillance and Target Acquisition Radar (MSTAR) after its integration into a border and force protection ground surveillance system. The system is comprised of a trailer-mounted telescoping mast that supports a sensor package. That package includes the MSTAR radar and two video cameras (for day and night). The experiment will test and evaluate target detection and tracking capabilities of the radar and visual capabilities of the cameras once a target is acquired. Testing will be on 16.75-17.25 GHz in the Largo, Florida area.

• Samsung filed an application for special temporary authority to conduct sounding and propagation measurements on 28 GHz in Richardson, Texas. Samsung wants to better understand the outdoor mobile environment and impacts to path loss, angular spread, delay spread, non-line-of-sight beamforming, and blocking issues.

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.