IEEE Publishes TV Band WRAN Standard


Last month IEEE 802.22. This is the standard for Wireless Regional Area Networks (WRANs) operating in the VHF and UHF TV frequency bands. Such frequencies allow broadband wireless access throughout a large area of up to 100 km distant from the transmitter. The IEEE said that each WRAN could deliver up to 22 Mbps per channel and that the technology would be especially useful in serving less densely populated areas of the country, and also in developing nations.

The IEEE 802.22 technical reference linked above describes some of the unique characteristics of the technology. While the FCC has dropped the sensing requirement for most devices in favor of geolocation, the IEEE 802.22 proposal provides TV and wireless microphone protection via sensing. The physical layer is optimized to tolerate long channel response and frequency selective fading, and the MAC layer compensates for the long roundtrip delays that are possible with such long range transmissions. Cognitive radio technology allows the unlicensed devices to cooperate with other 802.22 cells on the same frequency, as well as to protect primary users.

The IEEE 802.22 document provides an excellent example of spectrum sharing that benefits new users without hurting incumbents. The IEEE 802.22 standard committee members kept the broadcast community up to date on its work by presenting papers and taking questions at events such as the annual IEEE Broadcast Technology Symposium. Broadcaster input was welcomed by the committee.

Unlike some of the proposals in the National Broadband Plan, IEEE 802.22 is targeted at rural areas where television broadcast spectrum is available, and where the long range characteristics of the VHF and UHF TV bands can be put to best use.

Compare this to the National Broadband Plan's recommendation to take away half the UHF TV channels, essentially squeezing out sharing such as that described in IEEE 802.22. The plan would also give up UHF spectrum to wireless carriers in urban markets where its greater transmission range would be a detriment to efficiency and small cell frequency reuse, unless, of course, it's used for wide area point-to-multipoint multicasting. In other words, IP broadcasting.

Edwin Kee has a nice overview of 802.22 in his Aug. 1 article WiFi 802.22 can cover 12,000 km on Ubergizmo.com.

Doug Lung

Doug Lung is one of America's foremost authorities on broadcast RF technology. As vice president of Broadcast Technology for NBCUniversal Local, H. Douglas Lung leads NBC and Telemundo-owned stations’ RF and transmission affairs, including microwave, radars, satellite uplinks, and FCC technical filings. Beginning his career in 1976 at KSCI in Los Angeles, Lung has nearly 50 years of experience in broadcast television engineering. Beginning in 1985, he led the engineering department for what was to become the Telemundo network and station group, assisting in the design, construction and installation of the company’s broadcast and cable facilities. Other projects include work on the launch of Hawaii’s first UHF TV station, the rollout and testing of the ATSC mobile-handheld standard, and software development related to the incentive auction TV spectrum repack.
A longtime columnist for TV Technology, Doug is also a regular contributor to IEEE Broadcast Technology. He is the recipient of the 2023 NAB Television Engineering Award. He also received a Tech Leadership Award from TV Tech publisher Future plc in 2021 and is a member of the IEEE Broadcast Technology Society and the Society of Broadcast Engineers.