The core network requirements for next-generation Long Term Evolution (LTE) are so demanding that vendors have revamped their products and strategies, Unstrung has found.

As vendors jostle for position to prove they have what it takes in LTE and the Evolved Packet Core (EPC), Ericsson AB (Nasdaq: ERIC) is so far the only vendor with more than one operator customer for EPC equipment. Telia Company and Verizon Wireless have both selected Ericsson, not only for LTE radio access equipment, but also for EPC gear. (See TeliaSonera: We'll Do 4G in 2010 and MWC 2009: Verizon Picks LTE Vendors.)

Other vendors have clocked up important early wins, too: Verizon has chosen Alcatel-Lucent (NYSE: ALU) and Starent Networks Corp. (Nasdaq: STAR), along with Ericsson, to supply EPC equipment. TeliaSonera has picked Huawei Technologies Co. Ltd. and Ericsson for its LTE core network. (See After Verizon, What's Starent's Next Move? and MWC 2009: Starent Dines on LTE.)

In Japan, NTT DoCoMo Inc. (NYSE: DCM) has selected NEC Corp. (Tokyo: 6701), as well as Nokia Networks , in partnership with Fujitsu Ltd. (Tokyo: 6702; London: FUJ; OTC: FJTSY), to supply EPC equipment. And even Nortel Networks Ltd. announced a partnership with Hitachi Ltd. (NYSE: HIT; Paris: PHA) to supply KDDI Corp. 's EPC equipment. (See DoCoMo Picks NEC for Super 3G, Fujitsu Wins 'Super 3G' Deal , and Nortel Snares LTE Core Deal.)

In addition, mobile core specialist Starent has sealed 3G network deals with U.S. cable operator Cox Communications Inc. and Austrian operator Mobilkom Austria AG & Co. KG , to supply equipment that is software upgradeable to support the operators' planned LTE core networks. (See Mobilkom Picks Starent and Starent at Core of Cox's 3G Push.)

The LTE core challenge
LTE networks are not just about ramping up the mobile access network to theoretical peak rates of 150 Mbit/s [ed. note: emphasis on theoretical there]. It will also require a major overhaul in the packet core network. The role of the EPC in next-generation mobile networks will be more critical than in 3G networks, because the new packet core will have to handle a much heavier data traffic load and deliver real-time rich media services, such as VoIP and video, over an all-IP packet architecture.

To meet these capacity and service delivery challenges, equipment suppliers will have to introduce new platforms for their EPC network elements.

"The EPC needs more capacity and more features, which calls for a new platform," says Heavy Reading senior analyst Gabriel Brown. "The packet core market has been a bit under-invested historically. But with all the growth in HSPA traffic and expectations for LTE, operators are looking for a new generation of equipment, and vendors are stepping up their investments."

The packet core market is low volume in terms of units shipped, but racks up around $1.4 billion in annual revenues, according to Brown. Given how critical and strategic the equipment is to carriers, Heavy Reading believes the EPC market is set for sustained revenue growth, according to its recent white paper, "LTE/SAE & the Evolved Packet Core: Technology Platforms & Implementation Choices."

There are four network elements in the EPC: a Mobility Management Entity (MME), Policy and Charging Rules Function (PCRF), the Serving Gateway, and the Packet Data Network (PDN) Gateway. LTE rivals have been hard at work on revamping the underlying platforms for these EPC elements, and the resulting choice for carriers is varied, ranging from edge routers to ATCA platforms and in-house solutions.

Here's a snapshot of vendors' EPC platform choices:

— Michelle Donegan, European Editor, Unstrung