ZXG10 BS21 (V2.2) Compact Outdoor BTS for GSM Maintenance Manual
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Confidential and Proprietary Information of ZTE CORPORATION
correct. And then use the mobile phone for test to perform on-site
dialing test. Check whether a time slot of a carrier is occupied
constantly and is irrelevant to the specified time slot when
unidirectional get-through occurs. If yes, maybe faults occur at
some time slots of the carrier. Remotely reset the carrier or replace
ETRM.
iv.
If none of the above operations works, consider replacing the AEM
module.
7.
Precautions
None.
SDCCH Occupied too Long
1.
Symptom
Trace and observe the occupancy of the SDCCH channel in OMCR
dynamic data management and find that SDCCH is congested and
occupied for too long.
2.
Source
Find the fault when observing the dynamic data management of the
background O&M system.
3.
Related parts
Parameter settings of OMCR, the ETRM where SDCCH is in, the DIP
setting of the TIC board at the BSC side.
4.
Fault analyzing and locating
The fault is caused by:
i.
SMS problems
Sending too many SMs causes SDCCH congestion.
ii.
Border problems of the location area
When a cell is located on the border of the location area, in which
the traffic may be heavy, resulting in frequent location update and
causing a congested signaling channel.
iii.
Too concentrated traffic
Too heavy traffic in the cell, signaling channels configured too little,
relevant parameters of the C2 algorithm configured improperly,
parameter T3122 (protection period of the access attempt), T3212
(periodic location update timer).
iv.
Hardware fault
Judged from experience, either it is related to the carrier where
SDCCH is in or big bit error exists in the transmission.
