Bluetooth picks Wi-Fi as UWB drags along
Wi-Fi becomes a fast Bluetooth option as UWB is too, er, slow
By Peter Judge | Techworld | Published: 17:25, 31 October 2007
The Bluetooth community has decided to make a fast version of Bluetooth running over the Wi-Fi protocol, because handset makers and operators are increasingly frustrated by the wait for ultra-wideband (UWB) to finally appear in handsets.
"We have got to be realistic," said John Barr, chairman of the Bluetooth Special Interest Group (SIG) board of directors, and director of standards realisation at Motorola. "Ultra-wideband silicon vendors are not delivering anything close to what they have promised."
Ultra-wideband promises speeds of 480Mbit/s currently and potentially beyond that, over distances around ten metres. The Bluetooth SIG decided in March 2006 to use UWB as an optional very fast transport for Bluetooth, which would allow users to download movies or albums to mobile devices in seconds - and use much less power than Wi-Fi.
However, with UWB products slow to arrive and UWB-enabled handsets still around two years away. The technical committees of the Bluetoth SIG have decided to develop protocols that will allow Bluetooth to use Wi-Fi alongside UWB as a fast connection - and it appears to be happening because the handset makers have run out of patience.
"Delays in ultra-wideband have caused Motorola to switch its focus," said Barr at the Bluetooth Evolution conference in London. "There is an increasing demand for Wi-Fi in mobile devices."
"We want to use the radio that is already there," agreed Patric Lind, senior specialist in local connectivity at Sony Ericsson. "We want to use Wi-Fi first, but we aren't excluding UWB. It takes a while before a technology works properly." Wi-Fi might use more power, but there are other costs involved with changing to a new technology, he said.
UWB vendors disputed this. "There will be UWB handsets in Asia, within the next six months, said Mark Moore, chief technology officer of Artimi - though these handsets (including one announced by Korea's SK Telecom) will use the Wireless USB variant of UWB.
"It's actually good to work on two alternative transports at the same time," said Robin Heydon, who works on global standards at Cambridge Silicon Radio. It proves the value of the SIG's strategy of supporting multiple transports, he said.
"It won't work on existing dual-mode phones," said Nick Hunn, CTO of Ezurio, questioning whether Bluetooth on Wi-Fi would actually be quicker. "You have two chips that need to talk at the baseband level and Bluetooth and Wi-Fi have completely different security models."
Read more in our analysis here.