- This topic has 10 replies, 1 voice, and was last updated 12 years ago by sa.
2nd December 2005 at 05:37 #43219swiftsuGuest
there are questions about GSM O&M.
why did my nokia mobile phone say the RX_QUAL is bad(5 or 6) while the RX_LEV is OK(-50dbm) when i am calling?
what’s the problem?and how can i deal with it?
swift2nd December 2005 at 05:41 #43220swiftsuGuest
BTW,i’m a novice in the Repeater field.2nd December 2005 at 09:59 #43221alexanderGuest
swiftsu, RX_QUAL is RX quality, RX_LEV is RX level, so I guess you know that quality and level are two different words, two different things, you may have signal with high level but it may have low quality (high amount of errors because of interference, HW problems)
http://www.dx200.biz4th December 2005 at 14:12 #43222RSVGuest
Do you have any sound transmitted duiring this test in DL? If no and BTS have a DTX mode on than the mobile trying to measure “nothing” and quality is obviously bad. But may be it is a interference.5th December 2005 at 07:43 #43223BokoGuest
If you use DTX you must go for Sub values.
Boko6th December 2005 at 11:20 #43224RSVGuest
Than the question should be this way : What you are measure? RX_QUAL_FULL or RX_QUAL_SUB.
RSV6th December 2005 at 14:43 #43225MMRGuest
You might want to check the freq planning in that area.13th December 2005 at 21:15 #43226MihaiZGuest
If the signal is provided by a GSM repeater, the problem described by you can be due to repeater auto-oscillation (part of the signal comming out is “feeding” the input of the repeater) !!!
The problem can be corrected if the following condition is satisfied:
Antennas separation > Repeater’s Gain
So, either you increase the separation between the pick-up and donor antennas or reduce the repeater gain.
Most of the modern repeaters may have a AGC circuit (Automatic Gain Control).
Good Luck!19th July 2010 at 03:45 #43227saGuest
why do we need isolation between donor and serving antennae in repeater solutions?19th July 2010 at 13:31 #43228JasonGuest
I compair needing isolation between a donar and a serving antennas in a repeater, with when you hold a microphone too close to a speaker that it is broadcasting to. The mic picks up its own brodcast then it aplifies it and broadcasts it even louder, and again and again and again, until you remove the mic or shut down the amp.21st July 2010 at 00:33 #43229saGuest
Thanks.It’s clear now.