mania,
paging coordination is a feature that allows CS Paging to reach MS which are in Packet Transfer Mode.
Paging coordination can be done with Gs interface, or with a special feature in the BSC. In ALU, the Gs is supported since B10 or B9, while the “BSC Paging Coordination” is supported in B11 only.
I think all details are in the previous posts, but if you need anything more, let me know 🙂
regards
pix