- This topic has 4 replies, 1 voice, and was last updated 11 years ago by Chris Edwards.
25th January 2010 at 11:57 #60858Chris EdwardsGuest
I am working on ZTE equipment and we are facing a unique problem.
Cell traffic is very low but still tch overflow occurs for short period of time and this problem occur on random sites in random times to very difficult to trace one site.
Trx are ok,no alarm related to hardware or transmission.
Frequency plan is also ok.
Experts please help me out.
Thanks in advance.26th January 2010 at 05:45 #60859PixGuest
There are many reasons for blocking a call. Most of them related to interfaces or equipment congestion.
1/ there is no more resource in the cell (but that’s not your case)
2/ there is no resource on the Abis interface
3/ the BSC believes there is no more resource in the cell (algorithm issue, or fake o&m alarm in the cell ?)
4/ the BSC capacity is maxed out : no more calls can be handled by the inner boards.
5/ there is no more resource on the A-interface or on the Ater-mux interface.
pix27th January 2010 at 13:10 #60860Chris EdwardsGuest
1st of all thanks a lot for your time and giving response to help me out.
This problem is unique in a sense that it only occurs on 900 band sites and 1800 band sites have no issue at all.
We have around 700 odd sites in which 45% sites are GSM-900 sites.
As this problem occurs on random sites at random sites which makes it more complicated.27th January 2010 at 17:32 #60861PixGuest
Well, random times make it indeed very difficult to investigate. Even during low traffic periods (night, mid-afternoon) there are those kind of tch overflows ?
I’ll let ZTE experts share their experiences about this…
Pix28th January 2010 at 12:41 #60862Chris EdwardsGuest
yes it is in those times and overflows are not very high they are mostly around 1 to 5 in every hour and traffic varies from 0.etc to 1-4 erl in most cases.
It occurs on random sites in random times.
only 900 band sites are having this problem.
thanks for your response.