The Airports Company of South Africa (ACSA) realised huge savings recently when it chose an Avaya Orinoco Wireless extension to its Cape Town International LAN. Coming in at a third of the cost of a fibre installation, which would have included major runway upheaval, the technology does not suffer from or cause interference with aircraft avionics.
Steve Pinkney, CEO of CCI, a nationally-based specialist in computer cabling, networks, voice and building management systems, says the wireless solution, which uses radio-frequency (RF) technology, is an ideal fit for the airport scenario and similar campus situations.
CCI`s task involved linking a new workgroup, which networks the airport`s outside maintenance division, to the wired main buildings across a runway apron, where aircraft land and take off within the line of sight between the buildings.
"Coming in at just over R60 000, a third of the cabling option, RF was decided to be the best choice. Cabling would have been much more expensive, because, given the distance (500m as the crow flies), the appropriate cabling would have been fibre optics," says Pinkney.
"Not only is fibre more expensive, but it would have required apron trenching, which would be very debilitating to the normal run of business. The foundations of a runway apron go far deeper than ordinary roads, so it is quite an engineering operation to dig up all that," Pinkney explains"
Wireless RF operates in the 2.4GHz unlicensed spectrum, which means it does not interfere with the licensed frequencies within which aviation instruments transmit and receive data. Forming part of the EtherNet specification, it is furthermore self-correcting, so that even if links are dropped, the transmission will re-try, with no packet loss.
The new addition to the network will have 11mbps of bandwidth with which to receive and send e-mail, and to share normal network resources, meaning the solution is well-suited to the application in question.
The installation was tested for dropped links and interference - both with aircraft instruments and the network - and this yielded unblemished results on all counts, Pinkney adds. Another wireless option was infrared, a much costlier technology, running at speeds not needed at this instance, and IR is furthermore subject to limitations - including the need for a clear line of sight between antennas.
Equipment installed included two access points at both ends, consisting of an Avaya WaveLAN bridge router each, with two 14dBi directional antennas.
Share