TCH Blocking

When TCH is not allocated to the user after SD allocation, it is TCH Blocking.

It is the failed call attempts which the MS user can notice.
It takes place due to lack of TCH Resource.

Reasons for TCH Blocking:

Some of them are-
High Utilization of TCH
Time slot faulty.
Lock TRXs.
HW Problem.

Solutions for removal of TCH Blocking:

Implement half rate or Dual rate.

Check FRL & FRU.
Add another TRX. If TRX addition not possible, try to share the traffic of that cell with the neighboring cell by changing tilt or orientation.

Useful Report for TCH Blocking:
135 TCH Congestion.