Im facing high SDCCH Allocation and Assignment Failure in one cell. In the trace im getting “Immediate Assgnment Reject”. There is no SD congestion or over flow in that cell. Please if anyone can let me know with the reason why it happens and whats the solution for it.
immediate assignment reject is caused by sdcch congestion : if no SDCCH resource is availble in the BTS, the BSC sends an immediate assignment reject.
Can you give, at the busy hour, the following QOS indicators:
1. nb of SDCCH requests
distribution of types of sdcch requests (loc upd, ms orig, ms term, sms, etc.)
2. nb of SDCCH rejected due to congestion
3. nb of SDCCH allocated
4. SDCCH erlang at busy hour
5. SDCCH capacity of the cell
My problem is solved after giving hard reset to the BCCH TRM. Also this problem was arised because of the cell break tht comes because of the media flicks couple of days back. IS this happens in ur network also.
Yes, it can happen that a cell has a weird behaviour at some point, and needs to be restarted.
Actually, every time one measures a sudden change of QoS, the first step to do is to reset TRMs and the SUM, and possibly the TCU at BSC side.. Just to rule out a possible software failure and not spend too much time trying to find a logical cause to the problem 🙂