Deutsche Telekom keeps its '4G' options open

Deutsche Telekom hasn't yet decided on a technology for its next generation mobile network, even though at Cebit it is demonstrating the LTE (Long Term Evolution) technology for speeding up 3G (third-generation) cellular networks.

Other "fourth-generation" options on the table include Mobile Wimax and UMB (Ultra Mobile Broadband). However, the mobile carrier wants to keep its options open for now, said Philipp Humm, chairman of the carrier's mobile subsidiary T-Mobile Deutschland.

"We will start trials in the middle of the year, and make a decision towards the end of the year," said Humm.

At Cebit, though, it's all about LTE. Together with Ericsson, T-Mobile is demonstrating mobile broadband speeds at 100Mbps download and 50Mbps upload. Applications demonstrated will include high-definition television.

"LTE would be a natural step for us, but we don't want to choose before we know it can perform, both in terms of cost and performance," said Joachim Horn, Chief Technology Officer at T-Mobile International.

When it comes to choosing between the options on the table, "The radio won't be the deciding factor, because they are all based on OFDM," he said, referring to orthogonal frequency-division multiplexing, one of several techniques for sharing limited radio spectrum between multiple simultaneous communications.

Instead, said Horn, other factors like intellectual property, cost and the included ecosystem will make or break a technology.