Let’s see, the US UHF digital switchover spectrum sell off brought in around $20 billion, and one of the key uses of this spectrum will be to produce long range radio signals so that rural America can be covered more cheaply with mobile and mobile broadband coverage.
Similarly the tremendous improvements in antenna technology has meant that satellite and in particular mobile satellite systems, have become ‘de rigueur’ to offer a huge land footprint from space for a few hundred $million.
But what started out 20 years ago as the fairly laughable idea of using hot air or helium balloons to either transport freight or to act as base stations in the sky, is now approaching reality, and if it can be perfected could deeply unsettle existing telecommunications. What would happen to all that spectrum’s value if it turns out existing spectrum can be used to cheaply deliver rural telecommunications?
All of that can immediately be seen as possible with the trial result from Space Data, which this week put a mobile network in the sky on the back of a conventional weather balloon.
At the moment Space Data provides the South USA with something it calls Skysite, using its own narrow 900 MHz spectrum slice to offer private communications to the Oil & Gas, Transportation and Utilities industries in southern USA (See map below)
What it has done now is put a digital CDMA network into the sky using a miniaturized base station weighing a few pounds, carried by a balloon, to reach a 20,000 square mile coverage area from 60,000 feet. The experiment was using 1900 MHz spectrum in the PCS band and backhaul in the 2.4 GHz band. After completion of each flight, the base station was released, parachuted to the ground and recovered intact for future re-use. SkySite high-altitude, balloon-borne transceivers need to be launched every 8 to 12 hours. But of course why stop there, why not launch a number of them concurrently for redundancy.
Because of the distance which direct line of site signals will travel, it means that in an area with a well understood prevailing wind, a balloon can be released, fly over a huge area of a country, reaching a massive footprint, and then based on location information sent down to a local Network Operations Center (NOC), it can release itself from the balloon, deploy a parachute, and be collected and re-used the following day. A balloon can go up as often as required and a fraction of the miniature base stations would be required compared to terrestrial deployment.
If each CDMA SkySite, can provide coverage over 20,000 square miles, then the entire USA could have minimal coverage with under 200 of these base stations operating at any point in time.
During two trial flights, a prototype miniaturized CDMA 1X-RTT base station was carried over a remote area in western Utah by the SkySite balloon platform to altitudes as high as 60,000 feet. At that point, the base station was used to carry calls from, to, and between ordinary CDMA handsets located on the ground 60 miles away.
Call quality was excellent claims Space Data, with low frame error rates on both the forward and reverse channels. The company says the trial confirmed the technical feasibility of serving ordinary wireless handsets from substantial distances using the SkySite system. Applications include serving remote areas of low population densities, ‘fill-in’ for coverage gaps in rural networks, and the provision of emergency communications while terrestrial systems are out of service ‘ another of the vital revenues streams for MSS systems in the US.
‘There are many parts of the Western US where aside from intermittent highway corridor and single tower small towns there is no cellular service for miles and miles,’ stated Jerry Knoblach, CEO of Space Data, ‘we are grateful to the carrier that provided spectrum for this breakthrough for rural America and look forward to offering all CDMA carriers the ability to provide ubiquitous coverage.’
Space Data currently provides 24×7 two-way data communications coverage throughout Texas, Oklahoma, and Louisiana, as well as New Mexico, Arkansas and the Gulf of Mexico, as shown below. ‘We are always looking for opportunities to expand into other areas and to eventually provide service across the United States,’ the company said.