Many vendors are proposing an integrated SGW/PGW platform approach for operators, who just started rolling out LTE Networks. Combining both SGW+PGW in same hardware platform ( more specifically, the ever promising ATCA) has advantages over dedicated platforms.
The operator should decide whether to deploy the combined/dedicated platform according to their own projected traffic over their planned coverage.
For some operators who don't want piggyback their LTE traffic on existing 3G/2G platforms can opt for a dedicated infrastructure for LTE GWs (May be from different vendors). But in future if they decide to Upgrade their existing GGSN platform to have GW potentialities then they should be careful in choosing their combined SGW+PGW Node for the present situation.
The important part is that integrated node should be able to offload part of the traffic on S5 interface to the upgraded GGSN (to PDN-GW) node. This is in a way will ensure the investment protection for existing infrastructure.
What is your view ?....
