Behind every good LTE there's an EPC

Stuart Corner
Monday, 22 March 2010 09:01

Opinion and Analysis

The press has been full of Telstra's upcoming LTE trials and the names of its chosen vendors. LTE is sexy because it promises us downloads of YouTube videos and lots of other good stuff at speeds undreamt of a few years ago, but it is only one part of the story, and not even the most important part.

LTE is only one component - the radio access component - on the mobile broadband roadmap towards 4G. That roadmap, as specified by 3GPP, contains many other components all of which are necessary to deliver the services promised.

In many ways LTE on its own is not the most important part of the picture. As was made clear in Telstra's briefing last week HSPA+ will be able to deliver comparable bandwidths to LTE and Telstra's plan is that the transition will be seamless: user's won't even know whether they are using HSPA+ or LTE.

Of much more importance - and mentioned only in passing by Telstra execs at the briefing - is the technology that connects LTE base station to the rest of the world, including the applications that users will access over LTE. That technology is the Evolved Packet Core (EPC).

Its importance is summed up by this explanation from an Alcatel Lucent White Paper. "EPC promotes the introduction of new innovative services and the enablement of new applications'¦EPC is essential for end-to-end IP service delivery across LTE. As well, it is instrumental in allowing the introduction of new business models, such as partnering/revenue sharing with third-party content and application providers."

Together LTE and EPC form the Evolved Packet System (EPS): an end-to-end all-IP network the stretches from mobile handsets and other terminal devices with embedded IP capabilities, over IP-based evolved NodeBs (LTE base stations), across the EPC and into the application domain.

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