Toto, one LAC per BSC … it’s normally not recommended. The PCH in your cells are going to be overloaded, with normal assumptions regarding paging load.
There is some remark i should about the assumption I used in my previous post : putting 130 cells per LAC works in european networks (with a “european” call mix).
In other countries (Africa, Middle East), it’s highly probable that a LAC should contain less cells, because the amount of paging is much higher. (a lot of fixed-to-MS calls, a lot of “beeping”, etc)
Well, anyway, i’m just giving guide lines, you have to use them carefully and thoughtfully.