Tri-band chip aids mobility

Low-power 802.11a/b/g adapter is designed for mobile devices

Chipmaker Cambridge Silicon Radio (CSR) last week announced the first single-chip tri-band wireless LAN (WLAN) adapter specifically for mobile devices. The chip is designed to add 802.11a/b/g capability to smartphones and PDAs without significantly reducing the battery life of such mobile kit, the firm said.

The CSR UniFi-1 chips, due to go into production in the first half of 2005, will feature in future smartphones and handhelds that will be able to browse the internet through wireless hotspots, and they may boost adoption of voice-over-WLAN for phone calls across corporate networks. Products using UniFi chips are not expected for 12 to 18 months, however.

CSR is best known for its Bluetooth silicon, and the firm said it has brought its experience with Bluetooth handsets to WLAN adapters. "Phones are battery powered and don't have the processing power of a Pentium chip behind them, plus they already have GSM and Bluetooth radios, so any extra wireless solution has to be tiny," said CSR chief technical officer James Collier. "You can't just take something designed for the PC and shove it in a phone - it won't work."

The firm's UniFi-1 Consumer chip measures just 6x6mm and contains a hardware MAC layer processor to handle authentication and encryption - tasks frequently offloaded to the Pentium chip in PC WLAN adapters, Collier said.

CSR said its design saves power by only turning on the radio circuitry when it is transmitting. "It consumes about six times the power of a Bluetooth chip, but you get up to 50 times the bandwidth," Collier said.

Because the chip supports all three major WLAN standards, devices equipped with it should be able to connect to any wireless LAN. Devices such as Nokia's forthcoming 9500 Communicator already have built-in WLAN, but only support the 802.11b standard.

CSR declined to name any handset makers looking to use its UniFi-1 chips, but Collier said the chip will add less than $10 (£6) to the cost of a handset.