Researchers at the National Institute of Information and Communications Technology (NICT) and Hitachi Kokusai Electric say they have used the IEEE 802.22 standard for TV white spaces to achieve a "historic breakthrough" in long-range broadband communications. Using an 802.22 base station and equipment conforming to the 802.11af standard, NICT and Hitachi Kokusai reached data rates of 5.2 Mbps downstream and 4.5 Mbps upstream over a distance of 12.7 kilometers.
Although developers initially predicted 802.22 data rates of up to 22 Mbps per TV channel over distances up to 100 kilometers, the chair of the committee that developed the standard recently said a more realistic typical range estimate is roughly 10 kilometers.
NICT and Hitachi Kokusai also have created an enhancement to the 802.22 standard that uses two discontinuous TV channels to support throughput of 15.5 Mbps downstream and 9 Mbps upstream over a distance of 6.3 km.
For the trial, the researchers used 802.22 in a multi-hop configuration to create the backbone network. They tested video-calling and road-monitoring applications that could be useful in areas without landline broadband.
"These achievements show feasibility of broadband services in rural areas and supporting communications in case of disasters," the researchers say.
View Full Article
Abstracts Copyright © 2014 Information Inc., Bethesda, Maryland, USA
No entries found