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31st May 2011 at 06:58 #66516billGuest
i need advice on a critical issue. Vendor is Siemens, there are a few cells in my network having high PDTCH blocking (count of REJPDASS due to no radio resources is high) though the payload is very low. Also voice traffic and TCH_BLK on the cell is high but within limits. I increased the dedicated packet timeslots but still the packet radio blocking is not reduced. What can i do, any parametric changes, from where should i start :S26th June 2011 at 09:09 #66517billGuest
dear experts, kindly reply 🙁26th June 2011 at 13:05 #66518pixGuest
I don’t know anything about siemens, so I cannot help you.
If the same thing was happening in ALU (a system that I pretend to know), i would check all parameters related to the sharing of PDCH and TCH.
The number of ts allocated as PDCH is not a static value, but dynamic. I would check thresholds and margins that dynamically define how many PDCH are set when there is a high load of TCH.
Some indicators show how many PDCH are allocated at the busy hour.
Anyway, since you are already in TCH high load (as soon as you have TCH blocking means that there is 0 TCH available –> therefore the number of PDCH is restricted !) then it proves that you wouldn’t be able to anything more..
if you add more PDCH, then the TCH blocking will sky-rocket !
pix29th June 2011 at 04:57 #66519billGuest
pix, there was a single static pdch on the cell, then we added one more, but despite low traffic the situation remained same. in siemens the gprs/edge operates only on bcch trx.30th June 2011 at 18:16 #66520pixGuest
Ok, but 2 static PDCH is not enough to handle all the traffic. What matters most is the dynamic PDCH’s.
What are your parameters to control those dyn PDCH ? And what are their values ?
also, ensure that you can put at least 4 TBF per PDCH, in both directions. This is a way to multiplex several users on the same PDCH.
also, you can try decreasing the number of PDCH per TBF. Instead of 4, you put 3. (not less…)