Google to build 80,000 foot radio tower?

The truth hertz

Posted in Wireless, 21st February 2008 18:56 GMT

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Google's quest to deploy wireless networks without all that mucking about with steel towers has led its roving eye to settle on Space Data Corp. The company, which provides wireless connectivity via hydrogen-filled balloons floating around the southern US, has caught Google's interest according to reports in the Wall Street Journal.

But the search giant isn't alone in this mission. Even with the existing 2G, 3G and Tetra technologies the UK has over 52,000 cell sites, connected by more then 40,000 licensed microwave connections. According to AntennaSearch the USA has nearly two million antennas (some of which will be on the same tower), so anyone looking to deploy a new nationwide network is going to find locating their sites problematic to say the least.

However, with the 700-MHz auction trundling on in the USA and parts of 900MHz becoming available in the UK - not to mention the rest of the digital dividend - anyone buying up a significant chunk of spectrum is going to have to put up an awful lot of new towers, or find some other way of reaching out to their customers.

Anatomy of a cell site

Cell sites typically consist of six directional panels, each covering 60 degrees (sometimes only three, each spanning 120 degrees), and a circular dish for microwave back haul. At the bottom of the tower is a small shack, or box, with half a dozen rack-mounted transceivers and baseband controllers. Adding 3G to a site means replicating that, and towers used by more than one operator also tend to have a complete replication of the kit.

In the UK, just under a third (16,870) of sites host multiple technologies, or companies, with over a third (22,602) of the remainder being 2G only, and just under a fifth (9,644) being dedicated to 3G (the rest are Tetra). It would be interesting to see how that would change given Vodafone and Orange's recent move to share 3000 sites - but we're unlikely to find out, as last year the operators stopped voluntarily providing information. Ofcom remains "optimistic" that they'll eventually come round and update the info, but until then the information we have access to become more out of date every day.

Sharing sites is complicated by the need to talk to each other when you need access - the same thing that prevents bolting cell phone receivers onto electricity pylons - in addition to the understandable reluctance of cell-phone engineers to go climbing around pylons (interference can also be a problem, but one that can be mitigated).

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