On Tuesday 18 April 2006 09:20 pm, Rony Bill wrote: > jtd wrote: > > Throughput deteriorates as the mesh size increases. U have > > increased latency and reduced per user bandwidth. These are > > things which are being addressed. Latency is the issue for voip > > over 802.11.
> Optical trancievers will provide almost similar high bandwidth as > the optic fibre cables and can be mounted on independent towers > that are solar powered during the day and rechargable batt. during > the night. A thin long laser beam should be adequete enough to > reach a few kms. In order to overcome the wind sway of the tower > tops, This is the problem. Not just wind but ground vibirations from passing vehicles, causes the link to loose connection all the time. Beside scattering due to rain and dust storms. > the optical sensors can be mounted at the focus of parabolic > reflectors that are sized as per the maximum deviation of the beam > due to the sway. You need a very expensive servo head at both ends. > A more sophisticated approach could be to use (if > available and not expensive) the military type sensors used in > laser guided weapons systems to be able to track moving beams. The > entire assembly can be mounted in a sealed all weather box and a > water pump positioned to automatically spray water at an off peak > hour can be used to clean the optical system everyday, thus > eliminating the need for a human touch every day for every tower. > Water can be made available once a month from a tanker or from an > underground tube well. Bore well water is full of calcium and residues will make the lens opaque faster than dust. > I don't know if this idea may work but an experiment can be carried > out in laser based optical connectivity between two tall buildings > in Mumbai. Not cost effective at all. Wireless PtP links are far better. But from an academic point it would be very interesting. -- Rgds JTD -- http://mm.glug-bom.org/mailman/listinfo/linuxers
