You have Abis pool for the whole cell (3 sectors), part of it could be reserved for each sector the rest is dynamically allocated regarding the instant needs.
As you know 1 TS is not mapped to 1 Abis subslotq instead concatenated subslots are used – up to 5 for MCS 9 i think, and 2 for CS 2 if you enable CS 3 and 4.
Regards