Mike Bresnahan wrote: > > NEWBIE ALERT > > I'm very new to this wireless stuff and have never played with radio > equipment beyond Citizen's Band (CB radio), but I know enough to have a > couple questions about the range of 802.11b. > > What little I have read about 802.11b and its counterparts (e.g. bluetooth > wireless) discusses effective ranges of 10-100 meters. My limited > experience with my Linksys Prism2.5 card confirms this range. How is it > that people on this list are discussing ranges upwards of 23 miles? Perhaps > the stuff I have been reading assumes very small antennae? The things that make the biggest difference in the distance it works are the quality of your antennas and what's between the two systems. The antenna that's built into the cards is a so-so antenna with no gain to it that's usually in a very poor location. Adding a small antenna that just sticks up above the metal in your computer can easily double the range you get. Something like this http://www.maxrad.com/maxrad_products/broadband/2-6ghz/pdf/mig_tape_mount_omni_series.pdf . > > After seeing the coverage maps of the Twin Cities displayed at the meeting, > I'm left with some confusion. What good is it to put up a big antennae > backed by a big amplifier and coat a very large area with 802.11b? Can > people with ordinary WLAN cards in their laptops actually communicate with > the access point? I can understand how they might be able to recieve data, > but how can they hope to transmit over such a large distance with their > wimpy amplifier and antennae? Do you need a big antennae only on one end to > make it work? No. You need a balanced system. If the transmitter power on one end is alot higher than the other end it'll just be transmitting alot farther than it can hear the replys from. In the maps I refered to in my earlier message today the equipment I'm using on my end is a Cisco LMC352 100 milliwatt card, 100 feet of very low loss coax and a 10db gain omni antenna that's 180 feet above most of the ground level around me. It's also assuming a 40 foot tall antenna on the other end to get it above alot of the trees. Will I realisticly be able to get that kind of range out of it? Probably not. Mostly because of interference from other systems that my tall system can hear but the other end cannot that will be transmitting at the same time. -- Bryan Halvorson bryan at edgar.sector14.net