- This topic has 64 replies, 1 voice, and was last updated 12 years, 4 months ago by Taqi.
1st April 2007 at 17:38 #46534PixGuest
It doesn’t seem logical at all !
So there is no explanation for it, except maybe to assume that, with RXLEV ACCESS MIN = -96dBm, you’re forbidding calls with rxlev < -96dBm and with a GOOD quality, while still allowing calls with -90dBm but POOR quality... perhaps 🙂 That might just be the case for some cells, but not all of them.1st April 2007 at 18:08 #46535TufailGuest
I thinks that is the case.
Tufail5th April 2007 at 17:57 #46536SambitGuest
Plzz Anybody can explain me about CA & BA in TEMS, about MAIO and what is difference between RxQual sub & RxQual Full?
Actually diff. between sub and full.
Looking for reply.
Sambit7th April 2007 at 16:06 #46537ahmedGuest
what is difference between RxQual sub & RxQual Full?8th April 2007 at 16:05 #46538SambitGuest
Plzz any body can tell me about BA, CA and about MAIO.
Waiting for reply.
SAMBIT7th June 2007 at 18:24 #46539Da ArchitectGuest
FULL – Sub is corresponding to DTX OFF – DTX ON13th June 2007 at 15:32 #46540nachiGuest
How would one know that the SDCCH congestion is due to the ghost Rach.14th June 2007 at 05:52 #46541NiitnGuest
Some time when neighbours parameters are not defined properly, then H.O shows 100% Failure.For eg. at the time of IP creation for site CI:10011 you have defined BCCH:112, BSIC:10 & LAC:201, but at the time of neghbour creation CI:10011 is the neighbour of CI:10021 & by mistake you difined parameters for CI:10011 is BCCH:111 instead of 112 or you defined wrong BSIC & LAC etc then thier is a 100% h.o filure. Sp plz check your neighbour databse first.
Nitin16th June 2007 at 07:32 #46542Da ArchitectGuest
you may detect Phantom RACH from Timing Advance measurments since you will notice samples from impossible distances.
ex: i made a drive test for a cell that can barely cover 5 KM, and I had High SDCCH assignment failure, from timing advance measurments it reported many samples from 20Km and 26Km which was impossible! therefore increasing RxLEvAccessMin from -108 to -106 made a lot of improvement in the sdcch assignment success rate (from 40% to 10%)18th June 2007 at 15:03 #46543PixGuest
the TA measurements were performed on the Abis, isn’t it ? It looks like it is the only way to ensure those are ghost RACH.
With other methods, you can only assume that they are…
for instance, if you see a constant amount of SDCCH assign failure due to radio, at any hour during the day, you can safely assume those are due to ghost rach…
Regards,21st June 2007 at 23:39 #46544akefaGuest
A phantom RACH? Is it a real problem or just a good exist from the problem ? everything has a reason so what is the source of ghost RACH? hardware or radio? and how?
as I know TA is measuring the distance of the MS’s based on the signal trip time. I mean it is not a direct distance measure; it just measure the distance by multiplying the time by the speed of the signal. Your high TA maybe caused by the fast cars moving away from the site !22nd June 2007 at 07:44 #46545PixGuest
That’s a good one 🙂 The timing advance does not depend on the speed of the mobile !! It is a measure of the real distance between MS and BTS, by using the delay in propagation. The speed of a EM wave is 300.000km/h. A car moving a 300km/h would not change a thing here…
Ghost RACH are usually an effect of hardware distubances, or maybe fluctuations of EM in the atmosphere ?? Anyway, the ghost RACH contains dummy information, and the TA of a ghost RACH is “unrealistic”.24th June 2007 at 08:12 #46546akefaGuest
Maybe there are rockets 😀
You are right !
It is amazing for me to see some people here talking about tunning t3101 ! It seems only in Erricsson, this timer is unchangable !! Am I right ? My boss told me it is a fixed value !!24th June 2007 at 08:14 #46547PixGuest
Never trust your boss… It is changeable in alcatel, and in most systems i think.24th June 2007 at 08:43 #46548akefaGuest
I will do myself more efforts to prove it.