On Fri, 2006-09-15 at 20:05 +0800, Dinesh Nair wrote: > > On 09/14/06 21:44 trixter aka Bret McDanel said the following: > > that with a 802.11b/g device which uses the same set of spectrum, given > > how close the BT and wifi antennas would be to each other would cause a > > dramatic reduction in range from the AP due to desensitizing the > > antennas of the other rf unit. > > that would explain why the 802.11 range on the nokia e-series phones suck > big oranges. however, would this still be the case if bluetooth was turned > off in the phone ? >
it shouldnt, when you have 2 antennas really close on similar frequencies basically one overpowers the other and think of it this way ... in a large open building (gymnasium for example) if you are next to one person talking to you and someone is at the other end talking you will hear the one next to you and only maybe be able to faintly make out the guy at the other end. If the person at the other end is really loud or has a reall distinct voice you can hear em better. Its kinda like that for radio devices, the guy next to you desensitizes your ear from the guy all the way at the other end, so he either has to yell or he has to have a higher/lower pitched voice for you to hear (the pitch being similar to a really different frequency). In addition if you are in a gymnasium with a ton of people all chatting away, you can hear the people near you, but there is so much noise that you cant hear anyone that far away. And generally you have to be closer to whomever you want to hear (relative power is stronger) to hear them and understand what they are saying. That is like having a ton of devices all on the same frequency, and the effects on range are similar. With radios you have 2 properties (which unfortunately arnet disclosed enough). Sensitivity and selectivity. Sensitivity is how faint of a signal can be 'heard' and selectivity is how well the radio can distinguish one signal from another that is close in frequency. Generally if you have one that is really good, the other suffers. When I speak of 'desensitizing' a radio, its the sensitivity property that I speak of. When the antennas are close to each other the relative power that is received on the other is so high that it kinda overdrives the front end of the radio and causes it to not be able to tell that signal from another. This is akin to having someone stand next to you yelling in your ear while you try to listen to someone a little distance off. -- Trixter http://www.0xdecafbad.com Bret McDanel Belfast IE +44 28 9099 6461 DE +49 801 777 555 3402 Utrecht NL +31 306 553058 US WA +1 360 207 0479 US NY +1 516 687 5200 FreeWorldDialup: 635378 http://www.trxtel.com the VoIP provider that pays you! _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- asterisk-biz mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-biz
