Some of the world's largest mobile operators and vendors are working on a European Telecommunications Standards Institute (ETSI) specification for a base-station equipment interface that will ultimately help operators reduce cell site costs and energy consumption.

The requirements for the specification were created by the operator group, Next Generation Mobile Networks (NGMN) Ltd. , which then selected ETSI to write the spec.

The new ETSI group, under the name Open Radio Equipment Interface (ORI), will write a standard for an open interface that goes between a base station's baseband unit and remote radio head, which are the basic elements in a distributed base-station architecture.

Operators already deploy remote radio heads today because such a distributed setup is more energy efficient than traditional base stations. But the interface between the baseband unit and the remote radio head, which typically uses a fiber optic physical connection, has not been standardized, and the equipment has not been interoperable.

Operators want the opposite -- standardized, interoperable equipment, according to Ultan Mulligan, director of strategy and new initiatives at ETSI.

"This is a way of making sure the openness on interfaces is more industrialized," says Franck Emmerich, senior program manager at the NGMN group.

The spec is important because it will increase the flexibility and decrease the cost when operators need to deploy basebands or remote radio heads.

Part of the specification will rely on work already done by the Common Public Radio Interface (CPRI) group, which is a cooperation among six companies: Alcatel-Lucent (NYSE: ALU), Ericsson AB (Nasdaq: ERIC), Huawei Technologies Co. Ltd. , NEC Corp. (Tokyo: 6701), Nokia Networks , and Nortel Networks Ltd.

Another group of vendors, the Open Base Station Architecture Initiative (OBSAI) , also defines interfaces between among base station elements. But its contribution to ETSI's ORI group is not clear.

It is understood that all three groups -- CPRI, OBSAI, and now ORI -- will coexist, but not compete with each other.

The first ORI specification is expected to be published in September and will cover both the UMTS and Long Term Evolution (LTE) standards. A second version with added features, including GSM support, is planned for release in the first quarter of 2011.

The participants in ETSI's ORI group are:

— Michelle Donegan, European Editor, Light Reading Mobile