Subject: [NEXTEL-1] Propagation through a busy tunnel

From: Marcel <[email-masked]>
Date: Tue, 29 Oct 2002 19:34:51 -0500

-------- Original Message --------
From: Davor Virkes <[email-masked]>
Subject:Propagation through a busy tunnel

Hi all,

recently I encountered a problem related to propagation through a busy 
tunnel. It is circa 5.5 km long, has a GSM 900 base station transceiver on 
one end, and a repeater on the other end. Repeater is set there due to the 
local environment reasons, and is supposed to "hold" up to the toll booths 
nearby.
Both base station and repeater are set with vertical polarization yagis.
There is a funny problem arising from this setup - signal at the repeater 
varies significantly (about 20 dB), obviously due to the reflection from 
passing through vehicles, and this variation affects the repeater. Obvious 
solution is switching to circular polarization. Problem is that I am not 
acquainted with any paper that describes this solution.
Can anyone help me with information about use of circular polarization for 
propagation through tunnels?

Thank you

Davor

------------------------ Yahoo! Groups Sponsor ---------------------~-->
Looking for a more powerful website? Try GeoCities for $8.95 per month.
Register your domain name (http://your-name.com). More storage! No ads!
http://geocities.yahoo.com/ps/info
http://us.click.yahoo.com/auyVXB/KJoEAA/jd3IAA/61FxlB/TM
---------------------------------------------------------------------~->

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/