I am working for an operator overseas and we are using siemens switch. i will give u some information based on the our network. We have installed Power CP in all our MSCs, the static capacity of VLR is 180K, with 1.7 BHCA.
400k sub 1ith 1.5 BHCA, total BHCA will be 600k. Assuming 180k VLR in one MSC, u need atleast 3 MSCs.
Any more clarrification u can write back.