NK,
but congestion is usually on the air interface, not both air and abis.
so where is your congestion air, or abis ? 🙂
so what you can do next is to check the TCH mean holding time in each TRX (and if possible in each timeslot).
Can you write also a table from hour 00 to hour 23, with (for which hour) tch congestion rate, tch mean holding time, tch erlang, number of tch seizure requests, number tch seizure success.
Thank you 🙂