AT&T tries broadband over power lines again
'Project AirGig' shows the classics never die, but radio hams might feel homicidal
AT&T has charged up the paddles, yelled “clear!”, and fired the defibrillator into one of telecommunications' worst ideas: broadband over power lines (BPL).
Except, as chief strategy officer John Donovan stressed in a media call, this isn't BPL, it's kind of wireless-broadband-near-powerlines.
The Reg wasn't invited to the call, and AT&T's statements and video (below) are annoyingly vague about the technology.
However, Donovan said the company's gone public because the patents it's been filing for “AirGig” were starting to attract attention, so we went to the USPTO.
The general AirGig system is outlined in this patent, granted in October 2015.
It covers “surface wave” transmissions along power lines, in the 30 GHz to 300 GHz range:
“Base station nodes and/or antennas can be installed on utility poles, and the network connection can be provided by transmitters that send millimeter-wave surface-wave transmissions via the power lines between nodes.
A single site with one or more base stations can also be connected via the surface-wave transmission over power lines to a distributed antenna system, with cellular antennas located at the nodes.”
The idea is to get the high-frequency wave to couple with the surface of the power line, using the latter as a waveguide between the low-cost plastic antennas.
AT&T envisages the system being used to provide backhaul for mobile base stations, for connectivity to individual households, and to push signals into tunnels. In other words: if surface wave transmission in the 30-300 GHz band works, AT&T will own it.
Which is at least a better idea than another recent AT&T patent.
Radio hams will probably sharpen their pitchforks when they find AT&T still likes the idea of power line transmissions in the 30-300 GHz bands – enough, at least, to file a patent for it. ®