Steven J. Crowley, P.E.
Archive for the ‘Cognitive Radio’ Category
In the first of a series of webinars, Qualcomm today began reporting on the results of its “1000x Data Challenge,” an initiative to meet what it sees as the need, someday, to increase mobile capacity 1000-times. The webinar, conducted by Rasmus Hellberg, Qualcomm’s Senior Director of Technical Marketing, was an overview. He discussed spectrum, small cells, and other techniques to increase capacity. More-detailed webinars on each of these are forthcoming: spectrum initiatives on September 18, small cells and heterogeneous networks on October 18, and more efficient networks, applications, and devices on November 14. Today’s webinar should be posted tomorrow, and a white paper should appear in about a week.
This summarizes a selection from 173 applications for the Experimental Radio Service received by the FCC during August and September 2011. These are related to long-range low-frequency radar, amateur radio, shortwave data, wireless microphones, single-sideband, mine detection, millimeter-wave communications, signal intelligence, automotive radar, satellite feeder links, meteor-burst communications, aircraft telemetry, white space systems, border security radar, 3G and 4G applications, RFID, wind turbine testing, unmanned aerial vehicles, spacecraft telemetry and control, aircraft passenger broadband, and autonomous aircraft landing systems. The descriptions are sorted by the lowest frequency found in the application.
Comments are in on the FCC’s Notice of Proposed Rulemaking in WT Docket No. 10-4 to create new technical, operational, and coordination rules for wireless signal boosters in various services. These include the Commercial Mobile Radio Services (CMRS) that are covered by Part 22 (Cellular), Part 24 (Broadband PCS), and Part 27 (AWS & 700 MHz) of the FCC’s Rules. The services covered also include Part 90 (Land Mobile) and Part 95 (Personal Radio).
This summarizes a selection of applications for the Experimental Radio Service received by the FCC during April and May 2011. These are related to TV white space, electromagnetic compatibility testing, train control, point-to-multipoint communications, satellite communications, radar, unmanned aerial vehicles, GPS, ultra-wideband, mobile satellite service, UMTS, mobile broadband picocells, wireless backhaul, and IEEE 802.11p. The descriptions are sorted by frequency.
This summarizes a selection of applications for the Experimental Radio Service received by the FCC during February 2011. These are related to cognitive radio, land mobile, TV white space, unmanned aircraft systems, satellite terminals, ultra-wideband, wildlife tracking, interference detection, and radar. The descriptions are sorted by frequency.
Stanford-developed Transceiver Operates Full Duplex on a Single Channel, Reduces Network Bottlenecks
To avoid interference, wireless transceivers can switch between transmit and receive on one frequency (Time Division Duplex (TDD)). Or, they can transmit and receive at the same time on different frequencies (Frequency Division Duplex (FDD)). There’s been a flurry of press reports about a new radio system, developed by Stanford researchers, that can operate full duplex on a single channel; that is, transmitting and receiving at the same time on the same frequency, something not done before.
This summarizes a selection of applications for the Experimental Radio Service received by the FCC during December 2010. These are related to FM broadcasting, Positive Train Control, TV white space, mobile satellite terminals, GSM, UMTS, through-the-wall surveillance radar, troposcatter communications, millimeter-wave propagation, flight test telemetry, Doppler weather radar, and air-to-air military radar.
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.
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.