Thanks alot Sir Bijoy. Now its clear wrt BTS versions.please one more issue, which i hv to discussed, In remote area HSR of 02 cells of different sites (In/Out HSR of Neigbr)degraded. from the same time DCR increased and due to N200 increased.No Hardware/Intf issue.and HO to other sites from these cells are alright.it might be due to BTS out of syn..plz tell me what steps should be taken to reduce and why it happened suddenly?