Over the years, the South Australian (Adelaide) branch of Koukourou Engineers have tried various ways of connecting a computer from their Research House soil testing laboratory, to their main network at Head Office. It was only 300m away, but with several buildings and offices in between, far enough away to be a nuisance when it came to running cable between them.
Modems proved too slow and unreliable. ISDN was considered, but required installation of an additional ISDN line at Head Office and would have proved too expensive. Plus it would still not have been a large enough connection (bandwidth) - only 64Kbps, marginally more than a standard 56Kbps modem you use at home.
We conducted a site survey, and established that there was a clear line of sight between the tops of both buildings. These conditions were perfect for a Microwave solution, using free spectrum available on the 2.4GHz Microwave band.
An omni-directional Antenna was fitted atop the main building, to allow connections from multiple locations, and a directional Antenna fitted atop the Laboratory. Given clear line of sight, distances up to 12.5Km could be achieved using the correct Antennae.
The Head Office network was connected to an Apple AirPort Access point, which was specially modified to fit an antenna connection, and a wireless LAN PCMCIA card installed in the PC at the Laboratory.
The Result: A whopping 11Mbps connection, roughly 200 times the speed of 64Kbps ISDN! To give you some idea of how fast this is, some PC's on the network are connected to the server at 10Mbps, although the standard these days is 100Mbps.
Enhanced security is achieved with 128-bit Wired Equivalent Privacy (WEP) encryption, so no one else can see or access the network.
The Cost: A once off cost about half that of the yearly cost of a 64Kbps ISDN connection! Sorry Telstra! ;-)
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