100Mbps – long range wireless through wind, rain, snow • The Register

100Mbps – long range wireless through wind, rain, snow

Pigeon-friendly lasers for last mile links

By John Leyden • Get more from this author

Posted in Data Networking, 29th October 2001 19:36 GMT

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TMA Technical innovations in free space optics can allow organisations to reliably set up laser communications links that reach up to 5km.

LaserBit Communications has developed patent-pending power compensation technology, which it says could allow infra-red (780nm) signals from its lasers to preserve connectivity despite adverse weather conditions such as high fog, snow or rain. It can also compensate for the effects of swaying buildings and refraction through the atmosphere, we were told.

Mike Acton, LaserBit's vice president for UK and Ireland, said that as weather conditions deteriorate its receivers can increase in sensitivity; transmitters up power while obeying health and safety regulations for laser transmissions. For shorter links, transmitters use one laser but to reach further this is upped to four lasers focused in a beam towards a receiver, which must have 'line of sight' to a transmitter.

Acton told us the power the lasers operate at (70mW) means animal welfare concerns weren't a constraint.

Pigeons have greater sensitivity in the infra-red range, so they see a beam and avoid it, Acton told us. "This is pigeon friendly technology."

Vultures are safe too, we're assured.

At the TMA2001 show in Brighton today, LaserBits added a 10-100Mbps Ethernet transmission system, which covers distances of between 50m to 5,000m, to its product range.

LaserBits, an American-British-Hungarian joint venture, reckons it can provide superior performance to spread spectrum radio at prices far lower than microwave or fibre-optic links for last mile communications.

Its technology is in use by Coventry University and Southern Rail in the UK as well as an unnamed F1 team, and is being used for applications such as
PABX to PABX connection and campus computer connection. LaserBits also sells its technology to telcos for applications such as GSM base station connectivity.

LaserBits products come in prices ranging from $3,250-$24,000, which it said compared favourably to the $100,000 it said would cost to establish a professional band microwave link. The firm dismissed 802.11b wireless networking as a competitor, though for shorter distances at where speeds of no more than 11Mbps are needed it would appear to be an option. ®