4G inches closer with Nokia Siemens tests

Nokia Siemens Networks said it had completed the world's first multiuser field trial of Long Term Evolution technology in an urban environment.

The fourth generation of mobile broadband has moved closer to reality, following fresh trials by Nokia Siemens Networks.

Nokia Siemens Networks' tests, announced last week, involved Long Term Evolution (LTE), a potential successor to 3G. Offering theoretical data rates of up to 173 megabits per second, LTE is in something of a race to market with mobile WiMax, which only promises around 70Mbps but has a significant head start. The fastest currently available mobile broadband, HSDPA, offers around 7.2Mbps.

Both LTE and mobile WiMax use the OFDM modulation scheme and multiple-input multiple-output (Mimo) technology, which is based on the use of multiple antennae. Mobile WiMax's recent inclusion to the 3GPP family of standards has raised the possibility of both technologies becoming part of what will be known as 4G.

In its announcement, Nokia Siemens Networks said it had completed the world's first multiuser field trial of LTE in an urban environment. The trial, which was in Berlin, utilized 20MHz of bandwidth in the 2.6GHz spectrum, which is set for a hotly contested auction in the U.K. next year.

"(The trial confirmed) that LTE performance requirements can be met using 3GPP standardized technologies and it realized data rates of more than 100Mbps over distances of several hundred meters, while maintaining excellent throughput at the edge of typical urban mobile radio cells," the company's statement read.

Calling the trial an "important initial proof of concept for LTE," Nokia Siemens Networks' chief technology officer, Stephan Scholz, said that LTE would further the company's goal of connecting 5 billion users by 2015, due to LTE's efficient use of spectrum.

"We can demonstrate that LTE meets the high expectations set for this new technology," said Matthias Reiss, head of LTE at Nokia Siemens Networks. "Most importantly, we now have evidence that future LTE networks can run on existing base station sites and mobile operators can build LTE networks without requiring new antenna sites."

U.K. telecommunications regulator Ofcom announced the keenly anticipated auction of the 2010-2025MHz and 2500-2690MHz bands on Wednesday. The auctions will take place in mid-2008, and the deadline for applications by mobile operators is January 16. It is expected that the use of these bands will pave the way for a multitude of new mobile broadband services.

Although it is theoretically slower than LTE, mobile WiMax has the advantage of currently being in existence, albeit in just a few products. Fixed WiMax, which is in some cases upgradeable to mobile WiMax, is available as a commercial service in some parts of the U.K. today.

David Meyer of

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