Long Term Evolution - 4G - still has many rivers to cross
Long Term Evolution (LTE), the future 4G system for wireless broadband, is on the way. UMTS – or 3G, as most people call it – is still new and selling well, but its successor is already on the way. LTE will be under development for a while yet and its standardisation hasn't been finalised, but first tests have displayed a level of maturity not available in the early phases of UMTS. Or at least, so T-Mobile and Nortel Networks were claiming when they jointly presented the next generation mobile telecommunications network in action to a crowd of German and international journalists in Bonn.
We three journalists are sitting in the back of a discreet and businesslike blue (rather than a bright neon pink) VW van with smoked windows. In front of us, there's an enormous LCD screen and next to it there is a young helper. The helper patiently explains what is being received and transmitted while, like some sort of near-future cross-channel data ferry, the van keeps shuttling across Bonn's Konrad Adenauer Bridge over the Rhine. T-Mobile and Nortel Networks have co-operated to install two LTE base stations – one on the roof of T-Mobile's headquarters, the other on the roof of its parent company Deutsche Telekom over on the other side of the river. The handover takes place on the middle of the bridge, and so the van goes back and forth.
We are being shown a live presentation of all the things that are possible with LTE mobile technology. Firstly, we watch a political debate about the slapdash disappearance of billions of dollars at Lehman Brothers via internet TV. Then there is a simultaneous live video link into T-Mobile's conference centre, where our colleagues are already tucking into the buffet (blast them – all we road warriors get is biscuits and cheese). Thirdly, a download of 20 GB of hideous holiday snaps has been started in the background. There's also some multiplayer car-racing game in which our Austrian colleague has just used her console to crash her car into an embankment without concrete pillars.
Not only does is the van receiving a huge amount of data, it's transmitting, too: a camera is sending our driver's-eye view to our colleagues at the buffet, so they get the rich experience of spending the whole day going back and forth across the bridge. When we get to the middle of the bridge, the screen jerks a little and a few small "data loss" windows pop up, but it quickly resumes: the critical handover between this side of the stream and the other has been successful, we're told.
The LTE trial installation in Bonn operates in the 2.1 GHz frequency band at a bandwidth of 10 MHz, achieving download rates of 50 to 70 Mbits/s. Technicians have measured up to 170 Mbits/s when the vehicle is stationary. Everyone is openly proud of the field test results. "We started developing in 2005. If anyone had told me then that we'd start showing it all live in 2008 I wouldn't have believed it", explains Nortel's Central European President Wim te Niet in an interview with heise online. They're ahead of schedule: LTE isn't planned to be available to providers until 2010.
T-Mobile intends to be there from the start. According to Joachim Horn, the Chief Technology Officer, the new standard is indispensable because the features of mobile telephony devices will be dominated by gigapixel cameras and e-book readers as well as the much-cited mobile TV via IP. Horn's supporting crown witness during the LTE presentation is the experience T-Mobile had with the iPhone. Apple's mobile generates seven times the data volume and turns over 50 times as many internet links as the latest models by Nokia and co. "Now is the time to build the networks suitable for the iPhones of the future that are currently in development", said Horn, adding that speed is the order of the day. According to the executive, tests with iPhone users under UMTS/HSPA have already shown that network response times with 60 milliseconds of latency are perceived as "slow". With a latency of 10 milliseconds, LTE is to reduce the waiting time to what's acceptable to the iPhone generation, he said.
The LTE mobile devices by LG Electronics are still bulky prototypes. However Kin-Sung Choi, chief developer at LG Electronics' 4G research centre, is positive that consumer devices will have hit the shelves by 2010. In his opinion, the 4G killer apps will be video conferencing facilities, constant access video surveillance systems and, for young users, ceaseless YouTube video entertainment.
There is no intention of repeating the mistakes made with UMTS in the past, when marvellous wonders were reported of consumer devices while billions were squandered at the frequency auctions. "While UMTS was developed by the vendors and then presented to us, with LTE we providers are members of the standardising committees", said T-Mobile's Technology CEO Günther Ottendorfer in an interview with heise online. "We learnt the hard way with UMTS, that should be enough." For LTE it's so far only been about the petrol money for a van going back and forth on a bridge.