- This topic has 9 replies, 1 voice, and was last updated 19 years, 4 months ago by
monem.
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10th September 2005 at 14:34 #42151
monem
GuestHi all.
we meet some problem in our network in (cell border modefication). so made more mechanical tilt instead of antenna highet reduction & inter it in our planner.
so i ask is it sufficent to work just by M tilt instead of Ant highet, & no problem for propagation breakpoint (max highet is 50 m).
any body have more info on it.???
Regards11th September 2005 at 05:22 #42152Chefo
GuestHi Monem,
It is very important to make the cell borders as sharp as possible. Remember-the border is sharper when the beam is falling at steeper angle, so the higher the cell antenna-the better the borders. You should look for the -3dB of the antenna pattern (vertical) and this should be your border.
Good luck!11th September 2005 at 06:49 #42153monem
GuestThanks chefo.
OK.
let us say we have 40m antenna, & coverage area with 1.4 km radius.
if we need to optimize the radious to 1km, which way is better ( to reduce the antenna highet OR to make more down tilt) assume that there is no obstacle for fersnel zone even we made a high down tilt (open area).
Regards.13th September 2005 at 15:22 #42154monem
GuestThanks chefo.
OK.
let us say we have 40m antenna, & coverage area with 1.4 km radius.
if we need to optimize the radious to 1km, which way is better ( to reduce the antenna highet OR to make more down tilt) assume that there is no obstacle for fersnel zone even we made a high down tilt (open area).
Regards.14th September 2005 at 06:51 #42155jood
GuestMechanical downtilt angle depends at least on 2 factors.
1-Geometrical factor which is = arctan(h(bts)-h(MS))/d .
h(bts): bts antenna highet.
h(MS): mobile antenna highet.
d : distance to cell border.
2-Antenna beamwidth factor(vertical BW upper -3dB in V pattern)
so,two great impact on D tilt angle(V beam width & Ant geometric which depends mainly on Ant highet.
thus the antenna highet has great effect on tilt angle .BUT we must must define it at initial (nominal plan),& any optimization after that is better with tilt.(unless seldom emergency condition).
regards.14th September 2005 at 10:44 #42156Buddha
GuestHi,
Better study the book Mobile Communication by CY Lee
15th September 2005 at 14:34 #42157patrick
GuestI think that more down tilt is better to make indoor cover on your local area.
17th September 2005 at 06:04 #42158more
Guesthi all
I need to know about the relation between 3G CDMA band width, and the resulted coherence bandwidth of RF signal. and How the CDMA BW be narrow BW or wide BW according to the coherence BW.18th September 2005 at 05:28 #42159jood
GuestHi more:
coherence BW is approximately inverse of delay spread. thus coherence BW is wide when delay spread is small (indoor environment). So when coherence BW is >>>>more big than CDMA BW.the CDMA is assumed to be narrow band (espetialy indoor).10th October 2005 at 19:37 #42160monem
Guesthi all
How can i perform a consentric cell in network.& how can i use the forbiden interfered freq in inner zone(plan different reuse factor) & is it antenna for any zone =>> increase no of antennas.
please i need info & documentation……any body have???
TH in AD -
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