The reason is that if you increase the bandwidth of the channel the power density decreases thus you need more signal on a wider channel for the same signal you would get on a narrow channel. It works out to about 3 db difference per 5 MHz channel width.
Thank You, Brian Webster -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Rogelio Sent: Wednesday, September 24, 2008 4:53 PM To: WISPA General List Subject: [WISPA] better propagation on 4.9's 5 MHz channels So, I'm interested in learning more about why 5MHz channels go farther than 20MHz channels on the public safety 4.9 GHz band. I have no real numbers or theory, just some anectotal evidence by other RF guys saying that's been the case in their experience. Supposedly, RSSI is better at these lower channel sizes, and cop cars can get about 3 Mbps, which is more than they'll ever need. In the end of the day, a higher RSSI and lower Mbps of "goodput" blows away higher speeds at lower RSSI. Any thoughts or comments on this? ---------------------------------------------------------------------------- ---- WISPA Wants You! Join today! http://signup.wispa.org/ ---------------------------------------------------------------------------- ---- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
