An interesting article on LTE EPC market.http://telephonyonline.com/3g4g/news/mobile-core-wars-1221/
Here is the summary.
Alcatel-Lucent: Starting from scratch with 4G, designing its LTE evolved packet core using its IP division 7750 Service RouterCisco: Cisco has built P-gateways and S-gateways using its router platforms, but with the acquisition of Starent Networks it will likely focus on its purpose-built ST40 platform for both 3G and 4G
Ericsson: It's partnership with Juniper ends at 3G. Instead it's using Redback SmartEdge technology to build its gateways.
NSN: While evolving its 3G technology for the LTE core, it is redesigning on the Advanced Telecom Computing Architecture to give it extra kick on the control plane
Tellabs: Bought WiMax gateway specialist WiChorus and plans to use its technology to enter LTE market as well as use augment its backhaul products.