Despite the unprecedented global support for proto-4G Long-Term Evolution (LTE), network deployment strategies and equipment designs vary widely, finds a new report from Heavy Reading.

Operators face a 4G network dilemma over whether to roll out LTE as an overlay network alongside existing 2G and 3G networks, or deploy a multi-standard radio access network (RAN) that integrates LTE with 2G and 3G technologies in the same base station.

This decision is still up in the air for most operators, and that shows in the diversity of today's LTE base station designs, according to the new report, "LTE Base Stations and the Evolved Radio Access Network." But the best RAN product portfolios support both approaches.

The overlay strategy is the "fastest, cheapest, and easiest" way to roll out LTE, and this approach will likely lead in early deployments, according to Gabriel Brown, Heavy Reading senior analyst and author of the report.

On the plus side, there would be no impact on legacy 2G or 3G networks, the systems would be less complex, and best of breed equipment could be deployed. On the down side, however, this approach would have higher overall opex costs and long-term higher capex costs.

In contrast, the multi-standard RAN approach has lower opex, better coordination among the 2G, 3G, and 4G systems, a single backhaul pipe, and one operations, administration, and maintenance (OA&M) to manage.

Among the cellular infrastructure vendors, Ericsson AB (Nasdaq: ERIC), Huawei Technologies Co. Ltd. , and to some extent ZTE Corp. (Shenzhen: 000063; Hong Kong: 0763) are in the integrated, multi-standard base station camp with their LTE RAN product designs, while Nokia Networks product integrates WCDMA and LTE (but not GSM). And Alcatel-Lucent (NYSE: ALU)'s current LTE equipment is designed for overlay network implementation but will integrate 3G over time. (See LTE Base Station Strategies.)

NEC Corp. (Tokyo: 6701) and Nortel Networks Ltd. products will be LTE focused, but will look to align with 3G as appropriate.

Fujitsu Ltd. (Tokyo: 6702; London: FUJ; OTC: FJTSY) and Motorola Inc. (NYSE: MOT) are developing dedicated LTE products targeted for overlay deployments and hope to take market share with early contract wins.

“Operators need to take a view on how their overall RAN requirements might evolve as they evaluate LTE and will be significantly influenced by the capabilities of these new base station platforms and eNodeB products,” says Brown.

The operators leading the LTE charge are China Mobile Communications Corp. , NTT DoCoMo Inc. (NYSE: DCM), and Verizon Wireless , and they have the most urgency to move to 4G. China Mobile may be driven to deploy the Chinese version of LTE (TD-LTE) as quickly as possible, given the technical and regulatory delays to its 3G TD-SCDMA network deployment. In Japan, DoCoMo faces capacity constraints on its high-speed packet access (HSPA) network. And in the U.S., there will come a point where Verizon's 3G CDMA2000 EV-DO network will not be competitive with the HSPA or mobile WiMax networks in the country. T-Mobile International AG is also an LTE enthusiast and is pushing to deploy LTE rather than upgrade its 3G network with Evolved HSPA. (See China Mobile Preps LTE Network, T-Mobile Beefs Up LTE Plans, AT&T, Verizon Plot Faster Futures, and AT&T & Verizon to Use 700 MHz for 4G .)

— Michelle Donegan, European Editor, Unstrung

In-depth profiles of the eNodeB product strategies of all these LTE vendors are provided in the new Heavy Reading report "LTE Base Stations & the Evolved Radio Access Network." For additional information, or to request a free executive summary of this report, please contact: