Do we still need Gi Firewall for 3G/UMTS/HSPA network ?

["Lee, Steven (NSG Malaysia)" <kin-wei.lee () hp com>]

Hi all, in most of the existing 2G/2.5G mobile PS-core (Packet Switch) networks have Gi segment (interface between GGSN 
& IP Router/firewall). Due to the IP address constraint, operator usually do NAT on the Gi firewall to NAT the private 
IP to public IP in the past. Looking at the traffic pattern and user access behaviour, does it make sense to have 
firewall between the GGSN & Public Internet if the public IP addresses are sufficient to cater for mobile subscribers? 
Especially with 3G/UMTS/HSPA or even LTE in the future.

Please share your thought and thanks in advance :)

Regards,
Steven Lee