BARCELONA -- Mobile World Congress 2011 -- Vodafone Group plc (NYSE: VOD) is using Long Term Evolution Time Division Duplex (LTE TDD) technology to backhaul an LTE small cell here at a booth demo.

For the demo, the operator is using equipment from Huawei Technologies Co. Ltd. , and it says it is in discussions with other vendors, including Nokia Networks and Ericsson AB (Nasdaq: ERIC), to develop such an LTE TDD backhaul solution. Vodafone is also running a trial of the LTE TDD backhaul technique in Spain.

The LTE TDD gear used here operates in 2.6GHz spectrum and reaches 60 Mbit/s on the downlink and up to 25 Mbit/s on the uplink.

Why this matters
This development could potentially overcome a hurdle that has threatened to thwart Vodafone's long-held vision for a "metrozone" deployment of a layer of small cells to boost capacity, coverage and efficiency of LTE networks. Backhaul for small cells in LTE networks is considered by many to be a significant, unresolved issue. (See Vodafone Dreams of Metro Femto and Backhaul Clouds Metro Femto Vision.)

The demo also illustrates a compelling use for TDD spectrum that many operators will acquire along with FDD spectrum for LTE, as Vodafone Germany has done. In 3G networks, for example, many European operators hold a slice of TDD spectrum, but it is largely unused.

For more
In LTE networks, it is expected that operators will deploy smaller cell sites. And the pequeños cells are big here in Barcelona.

— Michelle Donegan, European Editor, Light Reading Mobile