Airplay: Sector antennas that concentrate signal coverage have helped to elevate data rates for the UNH TV White Space trial.
Sector antennas, improved spectrum analysis elevate data rates significantly.
The second phase of the trial that uses TVWS spectrum to provide over-the-air Internet access from the University of New Hampshire campus to remote libraries produced significantly improved performance, with top downstream data rates nearing 10 Mbps, and upstream rates nearing 5 Mbps.
The UNH Broadband Center of Excellence connected three libraries and selected campus locations to base stations located at UNH’s Stoke Hall and Kingsbury Hall buildings. The networking trial used fallow airwaves within spectrum reserved for television broadcasting – the so-called “TV White Spaces.”
Rouzbeh Yassini, the Executive Director of UNH BCoE, said the results “demonstrate real potential for TVWS networks to make broadband connectivity available in rural and unserved areas of the country.”
UNH BCoE worked with Carlson Wireless Technologies of Arcata, Calif., in Phase 2 of a TVWS trial that took place in 2014. In Phase 1, downstream data rates languished in the sub-2 Mbps range, with occasional to frequent signal interruptions and difficulties establishing connectivity at some locations. But changes involving antennas, network configuration, modulation, software enhancements and other approaches triggered significant improvements.
But changes involving antennas, network configuration, modulation and other approaches have triggered significant improvements.
For example, the updated network implementation achieved a downstream rate of 5.66 Mbps and an upstream rate of 1.67 Mbps over the link connecting the directional antenna mounted on the Kingsbury Hall rooftop (see photo) to the Barrington, N.H. Public Library roughly 8 miles away. Within the more concentrated UNH campus footprint, downstream data rates approached 10 Mbps.
Also, a separate link was successful in establishing and maintaining a symmetrical 1 Mbps signal between the Stoke Hall antenna site and the Lee, N.H. library, where connectivity previously could not be achieved.
Here are some of the modifications the UNH BCoE team implemented in conjunction with Carlson Wireless to help lift the performance:
The UNH BCoE TVWS deployment used channels 22 and 23 within the television white space spectrum. Testing by UNH BCoE found strong propagation characteristics, along with low noise and ingress in these channels. (TVWS implementations rely on FCC-approved databases to indicate available channels by TV market).