On Sat, Jun 14, 2003 at 03:39:45PM -0700, Bernard Aboba wrote: > > We are engaged in a project that needs to provide internet access in a > > highway 150 kms with seamless mobility. > > You should understand that this is going to be a challenging project. At > vehicular velocities, the amount of time spent in the coverage area, let > alone the coverage overlap area, isn't very large. For example, 60 mph = > 88 feet/second. If the coverage overlap area is 10 feet, this means that > the vehicle is only present in that area for 114 ms. In that time it is > necessary to complete the 802.11 scan, authentication and association as > well IP layer network attachment detection, in order for connectivity to > not be interrupted.
Ok, been a lapsed ham for some time, but I'm forced to wonder here, what set of RF parameters -- and I assume I mean on the land side, you'd have to assume standard cards on the mobiles -- would give an overlap as small as 10 feet? I mean, for example, using a 200mw card with respectable receive sensitivity, into an anisotroipc antenna with a flat enough donut to *do* this sort of thing (or a yagi, I suppose, depending on the shape of the road), how far apart could you *get* the bases. Or, more properly, what would the coverage radius be? Is 10 feet unreasonably low to be planning on? Cheers, -- jra -- Jay R. Ashworth [EMAIL PROTECTED] Member of the Technical Staff Baylink RFC 2100 The Suncoast Freenet The Things I Think Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274 OS X: Because making Unix user-friendly was easier than debugging Windows -- Simon Slavin, on a.f.c -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
