Interference caused by ducting phenomena

[alaa92]

Hi all,

I am working on studying ducting effect on cellular systems in EGSM and how to reduce the interference caused by ducting

can anyone helps me with useful links or informations about the height above the sea level where ducting occurs or any other details

thanks in advance

 

[alaa92]

can anyone knows what is the current solution for interference from ducting ??!

 

[Adrenaline]

First hit from google at least describes the phenomenon (and gives altitude example):

/>http://www.privateline.com/Cellbasics/radio.pdf

 

[alaa92]

i google it but i didn't find specific information about height of ducting or how to solve the ducting interference without affect the coverage of BS

thank you for your link i read it before

 

[blybrook PE]

I probably don't have much useful information or able to help much as I have only experienced this phenomena on the 146MHz and 446MHz amateur radio bands. I have never tried it higher than that as I don't have the equipment in my shack for the frequencies in which my license covers. Both instances experienced were tropospheric level ducting due to just the right weather conditions and were not repeatable. I know a few guys that play in the microwave band (~1.24GHz); but their signals are mainly line of site, there are no ducting effects that I'm aware of, but I'm not familiar enough with that band to really have a good feeling for it.

Since you are dealing with commercial band services and different power output levels, I don't know how ducting will affect your service. I think it would depend on the antenna gains of your equipment, transmit power and the antenna location.

I thought cell sites were typically 5w or less to avoid any possible interference affects; but I may be wrong on that output number and thought process.

You may want to search for tropospheric ducting and see if there's any information there that may help you answer your questions. Good luck.