Steven J. Crowley, P.E.
Consulting Engineer
Archive for the ‘Spectrum’ Category
FCC Takes Further Steps toward Mobile Broadband in TV Spectrum
On November 30, the FCC adopted a Notice of Proposed Rulemaking (NPRM) as a preliminary step toward making the current TV broadcast spectrum available for use by fixed and mobile wireless broadband services. The proposed rules would do three things: 1) make fixed and mobile wireless services co-primary with broadcasting in the FCC’s Table of Frequency Allocations, 2) create a regulatory structure giving two or more TV stations the option to share one 6 MHz channel, and 3) improve VHF TV reception through power increases and adoption of receiver antenna standards. No service rules are being proposed; they’re to come later. Congress has yet to approve incentive auction authority.
The FCC’s Spectrum Deficit Estimate
The FCC’s National Broadband Plan (NBP) recommends that the Commission make available 500 MHz of new spectrum for wireless broadband, including 300 MHz for mobile use. In support of that recommendation, on October 21, the FCC released an FCC Omnibus Broadband Initiative technical paper: Mobile Broadband: The Benefits of Additional Spectrum. The paper concludes that mobile data demand is likely to exceed capacity in the near term and, in particular, that the spectrum deficit is likely to approach 300 MHz by 2014.
The Spectrum Famine
Mitchell Lazarus writes in the October 2010 issue of IEEE Spectrum on The Great Radio Spectrum Famine — the challenges of getting more spectrum for mobile broadband. He notes the importance of incentives that can lead users to optimize or reduce spectrum usage on their own. There is some great historical information as well. It is another informative and thought-provoking article from Mr. Lazarus, who can also be found from time to time on the CommLawBlog.
A comment of mine was posted along with the article today. I copy my comment below:
Thank you Mitchell for sharing your insights and providing an important historical perspective. I had almost forgotten about the assignment by industry in two-way. Another scary tale if I run out of ghost stories this Halloween.
I, too, have followed the decline in terrestrial TV viewing for years. Today, though, I see more people “cutting the cord” and dropping cable or satellite. They use a combination of internet and over-the-air viewing. I wonder if this downward trend is ending.
In the Capitol Hill neighborhood in Washington, the local wireless internet service provider is now offering a service called “free TV.” You pay them $300 to put an antenna on your house and hook it up to your TV. Twenty channels with no monthly fee. They market this as an innovation, and it sells.
We see these large projections for future mobile broadband demand; a lot of that is video. Mobile operators have been working about 10 years to engineer and make a business case for broadcasting. Technically, they can make it work but it’s not a business yet, anywhere in the world, in part because of the system capacity tied up in providing the service.
In the hierarchy of mobile needs, I’d say voice is most basic closely followed by text. Video is nice, but less essential to my life. I’ll use it on my unlimited data plan. If a per-byte tiered-pricing plan is put in place, I may pass. I’ll download it at home and move it to my phone. Or wait until I’m near a Wi-Fi hotspot.
I do believe in the next few years we’ll see some significant technologies that allow for more efficient spectrum use. Source coding technology will be one of those areas. There will also be better networking protocols for heterogeneous radio networks what will allow for more seamless handover among 3G, 4G, Wi-Fi, and even Ethernet; this will make it easier for operators to move off crowded mobile broadband spectrum whenever possible. Applications can be more tightly coded.
None of the above is meant to deter the search for more spectrum for mobile broadband. I like the FCC’s plan for the voluntary transfer, using financial incentives, of TV allocations to mobile broadband. As you suggest, incentives help. I like the suggestion involving a non-profit group. In addition, I wonder if spectrum can be made more like property; when people own something, then tend to take care of it and maximize its value.
One comment here suggests femtocells as part of the solution. Femtocells are a good fix to fill in coverage holes. From what I have seen so far, however, they won’t be much help with the spectrum crunch. Interference issues preclude ubiquitous placement.
FCC Finalizes White-Space Rules
The FCC finalized its white-space rules today, acting on petitions for reconsideration of its earlier decisions. It issued an 88-page Second Memorandum Opinion and Order that explains its decisions and includes the final white-space rules. A much-shorter press release was also issued.
At least one FCC observer has noted an uncharacteristic level of hype in today’s announcements. The FCC calls it “super Wi-Fi,” and adds the “potential uses of this spectrum are limited only by the imagination.”
Over two years ago, Google called it “Wi-Fi on Steroids.” It was later picked up by the popular press. Not all agree; it’s “Wi-Fi on Crutches” according to one who dares to consider the realities of physics and economics.
I’ll call it “Wi-Fi on Caffeine,” at least with respect to better range and coverage — if not data rates — compared with current Wi-Fi equipment. This is partly due to operation in the UHF-TV band instead of the 2.4 GHz band. In major markets and their suburbs, there will be few or no channels available for white space use. In rural areas and other less dense areas, the technology will be a good fit with Wireless Internet Service Providers (WISPs) and other longer-distance applications.
Cellular operators would like some of the white space on a licensed basis for backhaul in rural areas. They didn’t get it today, but the FCC is actively considering it and we may hear more on that by the end of the year. No way are all these vacant channels going to be occupied by internet services in the most rural areas, so the proposal of the operators makes sense.
In IEEE 802, Working Groups 802.22 and 802.11 are working on standards that can be used by equipment in these applications; 802.22 may be the one with longer range. Working Group 802.19 is trying to facilitate coexistence between the two. Now, there are asymetric interference effects, which is causing friction between the two groups beyond the normal competition. (802.22 takes the harder interference hit.)
There will be other standards and equipment as well. The white space concept is international, but unique to each area of the world.
Equipment is not easy; it’s challenging to develop sufficiently-broadband power amplifiers and antennas, and to meet the emission mask in a cost-effective manner.
Another challenge is developing a business plan when 120 MHz of TV spectrum could be taken away under the National Broadband Plan.
Ultra-Wideband: How Regulatory and Standardization Delays Slowed a Wireless Technology
The FCC recently issued an order denying reconsideration petitions in its ultra-wideband (UWB) proceeding. That effectively ends the 12-year UWB rulemaking process. Mitchell Lazarus recounts how UWB became bogged down at the FCC and in a failed standardization attempt in IEEE 802.
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.
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Cultural Barriers to Federal Spectrum Reform
As the FCC searches for more spectrum for mobile broadband services, its National Broadband Plan points to federal spectrum as a candidate. Since the National Telecommunications and Information Administration (NTIA) is responsible for allocating federal spectrum, the FCC can’t do much more. Still, the FCC’s recommendations are good. One is for the FCC and NTIA to “develop a joint roadmap to identify additional candidate federal and non-federal spectrum that can be made accessible for both mobile and fixed wireless broadband use, on an exclusive, shared, licensed and/or unlicensed basis.” In support of that, the “FCC and . . . NTIA should create methods for ongoing measurement of spectrum utilization.”
Variations of these proposals have been around for decades, formally and informally. Once in a while, progress is made. In 1995, NTIA suggested the changing the 3650-3700 MHz band from federal-only to mixed-use (federal and non-federal). That happened, and in 2005 the FCC adopted rules that resulted in the creation of the IEEE 802.11y standard. (That allows high-powered Wi-Fi equipment to operate on a co-primary basis in the 3650-3700 MHz band in the US, except when near certain satellite earth stations.)
So, it can happen. That, and recent FCC talk of “unleashing” broadband made me think the above recommendations in the FCC’s Plan might get some traction. I’m less sure now after following the latest writings on the topic by spectrum expert Michael Marcus.
In an August 17 post on his blog, Marcus asks why NTIA isn’t measuring occupancy of the almost exclusively-federal 225-400 MHz band. He finds that the Interdepartment Radio Advisory Committee (IRAC), NTIA’s advisory committee of federal users, is concerned that measurements in major cities – where spectrum is most needed – will show low occupancy because the band is primarily used by military aircraft. Marcus says enough with these delays; in the new era of cognitive radio and dynamic spectrum access technology, it’s time to see some hard spectrum data so sharing options can be examined.
If you’re intrigued by that, there’s more. An August 9 post says an NTIA spectrum advisory committee “evades some major issues and pushes the parochial agendas of some committee members without trying to relate them to the broader public interests.” A May 10 post takes you inside that committee’s meeting, and observes a general effort to protect incumbent spectrum users.
It can happen, but these reports suggest the timetable will be later rather than sooner.
Experimental Radio Applications at the FCC
This summarizes a selection of applications for the Experimental Radio Service received by the FCC during June 2010. These are related to aircraft systems, WiMAX, sports telecast support, public safety communications, tactical cellular service, medical telemetry, satellite, antennas, radar, white-space devices, weapons telemetry, spacecraft communications, and broadcasting.
- AAI/Textron Systems Corporation filed an application (with supporting exhibits) for experimental license. The company wants to test its Shadow 200, Aerosonde, Orbiter and other unmanned aircraft systems. This is related to work for the United States Marine Corp. Operation is to be on 310-390 MHz, 902-928 MHz, 1090 MHz, 1350-1390 MHz, 1700-1859 MHz, and 4400-4999 MHz. Transmitting equipment is manufactured by Microhard Systems Corporation, Free Wave Technologies, Advanced Microwave Products, Global Microwave Systems, and Microair Avionics.
FCC staff has asked for several items of information before approving the application. The FAA operates in the frequency bands 328.6-335.4 MHz, 1090 MHz, and 1215-1390 MHz; FCC staff asks for coordination of these bands with the FAA Regional Office. In addition, the frequency bands 225-328.6 MHz and 335.4-399.9 MHz are used for military purposes, and the applicant was asked to coordinate with NTIA’s Interdepartment Radio Advisory Committee (IRAC).
- AAI/Textron Systems Corporation also filed an application (with supporting exhibits) for special temporary authority to operate on 420-450 MHz and 2000-2400 MHz for a government project apparently involving the Orbiter miniature unmanned aircraft system. There is not much information about the proposed operation, and FCC staff has asked for more details.
In correspondence to the applicant, FCC staff notes that the “Aerospace & Flight Test Radio Coordinating Council (AFTRCC) oversees the frequency bands; 1435-1525 MHz, 2310-2320 MHz, and 2345-2390 MHz. These frequency bands need to be removed or need to be prior coordinated.”
- Sportvision filed an application (with supporting exhibits) for special temporary authority for testing of an automobile race track wireless data system that is to provide data communications between vehicles in a race track and one or more fixed base stations installed along a track. Operation is to be on 2395-2400 MHz.
One application seen for this system is video image enhancement for television broadcasting of automobile racing events. The would allow television viewers to see, displayed on screen, the real-time location of cars during a racing event.
The vehicles would be equipped with GPS receivers and other sensors that generate a data packet every 200 milliseconds. The wireless system would collect those packets and deliver them to a control station in real time. “The radio itself is a direct sequence spread spectrum unit, using production radios for 2.4 GHz. The system may ultimately be deployed on an unlicensed basis in the 2.4 GHz band or elsewhere, but the high noise levels in that band in the test locations (commercial automobile race tracks) are unsuitable for development and testing of the product.”
“An Intersil baseband processor performs the Direct Sequence modulation and demodulation. It is part of a five-chipset developed for the 802.11b standard. It uses 1/4th of the standard 802.11 speed resulting in a narrow occupied RF bandwidth.”
The frequency band requested is allocated on a primary basis to the Amateur Radio Service, and coordination is to be performed with the ARRL. This application was granted on June 4.
The FCC’s Broadcast Engineering Forum
The FCC held its Broadcast Engineering Forum on June 25, 2010.
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.)
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3G Americas Workshop Focuses on Latin American Mobile Broadband
The Mobile Broadband for the Americas Workshop was held in Rio de Janeiro on April 26, sponsored by 3GPP and 3G Americas. Presentations may be downloaded.
A marketplace update provided facts about the Latin American market. At the end of 2009, Latin America had 509 million wireless users. Average ARPU is US $14. Data as a percentage of service revenues in Q3 2009 is 17% compared to 28% in the US. In December 2009, GSM-UMTS-HSPA had a 91% market share, up from 88% in December 2008.
A 3GPP Technology Standards Roadmap provided an overview of 3GPP and key 3GPP issues. It is a good snapshot of where 3GPP stands today.
Operators Vivo, Claro, and NTT DOCOMO presented their strategies for mobile broadband. The Vivo presentation is more market-oriented and is written in Portuguese. The Vivo and NTT DOCOMO presentations include more technical content. Vivo seems concerned about the backhaul-capacity issue.
Ericsson Brazil discussed HSPA evolution in terms of bit rate, latency, MIMO, and multicarrier; related RAN backhaul improvements were also addressed.
Deployment of mobile broadband was addressed. Nokia Siemens Networks discussed migrating from HSPA to HSPA+ and LTE, and noted it has 11 commercial LTE deals, six of which have been announced. Huawei discussed some of its products.
A presentation on spectrum policy by 3G Americas identified some Latin America issues. There is no spectrum for advanced mobile broadband services. Governments are promoting new entrants by using spectrum caps. There are high taxes for wireless services and equipment. Likely bands for 4G will be 2.5 GHz, 1.7/2.1 GHz and 700 MHz.
An analysis by 3G Americas shows that spectrum aggregation limits impose serious costs on existing providers, which are paid by consumers. In markets with constrained providers, consumers may pay twice as much for LTE if spectrum is limited to only 2×5 MHz as compared to 2×10 MHz, and four times as much as compared to 2×20 MHz.
The Broadcast and Wireless Industries: Latest Spectrum Arguments at the FCC
The FCC is working under a Congressional deadline of February 17, 2010 to develop a National Broadband Plan. That work includes looking for additional spectrum for wireless broadband services.
On December 2, 2009, the FCC issued a Public Notice asking for more comment on spectrum licensed to broadcast TV stations, and on market-based mechanisms that would encourage broadcasters to make spectrum available for wireless.
TV broadcasters generally like their spectrum as it is. They argue that over-the-air TV is a public service. It is the only source of video programming for some. A large investment was made in the recent DTV transition. They are working on advanced technologies including Mobile DTV and other content delivery platforms. Multicasting provides greater choice in programming without the need to subscribe to a cable or satellite service.
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