On Fri, 2002-12-06 at 18:07, Kevin Lahey wrote: > I'm curious about using 802.11 from my car. > > No less an authority than Jim Thompson explained to me at BAWUG > last night that 802.11 was useless when the two communicating > systems had a greater than 40-mph speed differential. This is > apparently due to the doppler shift.
I thought "doppler" has something to do with differences between originally sent wave and its reflection from the object (so you can determine the object's speed). Correct me if I am wrong. > As he pointed out, this wouldn't be a big problem with cars driving > past access points, but would make it tough to put a directed > antenna pointing down the road, since the cars would close in > on it at fairly high speeds. I guess an omni way off the side of > the road could provide service for a reasonable distance. Don't forget, those waves have speed of light. I don't think car's speed makes any difference, as long as there is no objects between AP and the car itself. What matters is the signal level (power of the antenna). Correct me if I am wrong. > Could anybody expand on this for me? I have to admit that I've > had visions dancing in my head of in-car access for quite awhile, > and I'd hate to think that it was unlikely to work... Kevin,just curious, what do you need this for when you drive? -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
