Vodafone R&D chief backs LTE, still watching WiMax closely

Vodafone R&D chief backs LTE, still watching WiMax closely

by Keith Dyer

The head of the networks division of Vodafone’s group R&D function has said that LTE is currently the most likely candidate technology to meet the operator’s needs for 4G, but he added that the operator is still watching WiMax “closely” to see if it might still have something to offer.
Speaking at the Next Generation Network & Basestations conference in Bath, UK, Trevor Gill said that through its work with other operators in the Next Generation Mobile Network group, Vodafone is currently outlining its demands for any 4G technology – in terms of spectral efficiency, ease of rollout and minimising complexity and cost.

NGMN is also setting the terms for standard comparisons that would allow it to objectively assess competing technologies is a like for like manner, in terms of traffic conditions, use cases network demands.
Those results show that in terms of spectral efficiency (bits per second per Hertz per sector) LTE, with extra antennas, shows the potential to achieve NGMN’s demands. Tests also show that future evolution of HSPA will make HSPA technology as efficient as the first iterations of LTE, he added.

This meant that the move to 4G is unlikely to happen any time soon, as HSPA is likely to provide mobile broadband coverage “for many years to come.”
Gill pointed out that Vodafone still has only two million 3G data customers across the world, which he described as a “fairly small proportion.” Clearly this means mobile operators still have a distance to travel before they can earn back their investment in event their existing 3G networks, never mind investments in 4G.

He added that one of the big future moves would be to take UMTS to 900MHz, giving greater coverage for 3G. Only Elisa, in Finland, has done this on a commercial basis, and Gill said the results from Elisa show that the performance was good enough to support the move to higher orders of modulation.
France is the only other country with regulatory approval for 3G at 900mHz, but Gill forecast that would change over time.
As for 4G development, Gill said that LTE would need to offer operators a greater degree of automisation in the actual roll out of the networks.
“There’s still a great degree of manual configuration in mobile base stations,” he said. “We’re a long way from plug and play.”
Gill also said the aim of the NGMN was to make sure there is one physical layer across TDD and FDD and a common architecture, meaning vendors would focused on developing the technology in a common direction, rather than engaging in technology battles.
Researchers and developers hoping to catch Gill’s eye would also be advised to concentrate on backhaul, Gill bemoaned the lack of research and innovation in this area. “Research in the universities and labs is almost exclusively focused on the air interface,” he said, “and nobody seems to be talking about backhaul.”