Straight Talking - What Happened To 3G?
PC World
barryf@pcw.co.uk.
Travelling to freezing Finland to attend the 'launch' of the first real third-generation mobile phone and Internet service, and finding it was no such thing, concentrates the mind. When we should have been roaming Helsinki with Internet mobiles, we were dumped at a local cinema to see Bend it like Beckham with Finnish subtitles. It was then that I vowed to find out how the telecoms industry has got itself in to such deep doodoo over 3G. The unhappy conclusion is that Europe - after the runway success of GSM - may have got it very wrong with 3G and may now be five years behind the US.
The first GSM call was made in Finland in 1991; now there are 400 GSM networks in 180 countries around the world, with over 730 million users and the number is expected to reach one billion next year. Ten years ago the processors in a cellphone ran at 15mips (millions of instructions per second); now it is 300mips, with less battery drain. GPRS builds on GSM to give a faster, always-on connection, charged by the kilobyte, not the minute. Back in 1999 the International Telecommunications Union (ITU) sanctioned five ways of delivering third-generation mobile services, from which two systems, UMTS (Universal Mobile Telephone Service) and CDMA (Code Division Multiple Access) emerged as front runners. Both use spread spectrum technology, developed by US company Qualcomm for military use, and later modified for digital cellphones. Speech and data are put into labelled packets and spread thin like noise over the full width of a carrier frequency.
This is completely different from GSM, which is a TDMA (Time Division Multiple Access) system. Frequencies in the 900 and 1,800MHz bands (1,900MHz in the US) are split into time slots and each time slot is used as a phone channel. Calls are 'circuit-switched' like a home phone; once a time slot is allocated for a call it remains allocated until the caller hangs up.
GPRS (General Packet Radio Service), pools all the GSM time slots and allocates them to different users as and when they become available.
Europe opted for UMTS which is Wideband CDMA; it works at different frequencies (2.1GHz) from GSM and spreads the data over 5MHz carriers. So European GSM operators must build completely new networks. All base stations use the same frequencies and the mobile may have radio links to four cells at the same time. So handover involves switching between groups of cells not just single cells. Things get even more difficult if the phone is also switching between UMTS and GSM/GPRS.
Operators in the US, Korea and Japan opted for 3G CDMA because they have been using the CDMA One system for conventional cellphones. The frequency bands are relatively narrow - 1.25MHz wide - and used in groups. The 3G system is called CDMA 2000 and uses denser packet packing to increase data speeds.
CDMA uses GPS satellite timing signals to keep the base stations synchronised.
The UMTS designers tried to avoid dependence on America's GPS by making the base stations keep each other in step.
Finland was the first country to auction UMTS licences. Over 120 networks in 27 countries then gullibly paid over $ 110b (GBP 71b); Vodafone in the UK alone paid $ 9.4b (GBP 6b). Nokia, Motorola and Ericsson bet their banks on developing the kit. But despite all the huffing, puffing and promotion, no network has yet gone live with a UMTS service for consumers to use.
They are all still at the trial stage because 3G cannot yet offer a service that is better than GSM or halfway as reliable.
3G UMTS was sold with the promise of much higher connection speeds than GPRS. The UK Government's website (www.spectrumauctions.gov.uk/3gindex.htm) still cheerfully talks of 3G arriving in 2002, with 2Mbits/sec for 'high-resolution video and multimedia services on the move, such as video-conferencing and online entertainment'.
At their 3G non-launch, Nokia and network Sonera were talking the new language of 3G speak about the need to 'distinguish between 3G radio technology and 3G services'. Nokia's publicity material now refers to GPRS as 'making possible the first true 3G services like MMS (Multimedia Services)'. Sonera said: 'The 3G services launched this autumn will operate initially in the present mobile network.' The companies making both technologies say it is too late now for Europe to change from UMTS to CDMA 2000, even if the licences could be altered.
'Europe has made a bed and must now lie in it,' said Bob Shukai, director of Motorola's 3G division, which supplies both UMTS and CDMA handsets and network equipment. 'Operators will figure out how to make it all work.
But it will take at least five years.'
Even when UMTS networks start working, data rates will be far below the promised 2Mbits/sec. Nokia now puts the practical limit for UMTS at 384Kbits/sec.
Nokia's new 6650 3G camera-phone has been 'limited' to 128Kbits/sec for downlink reception and 64Kbits/sec for uplink transmission. Sonera, meanwhile, has limited its network to 64Kbits/sec in both directions.
Who, I wonder, will be first to sue their government for selling a 3G licence under false pretences? |
