Broadcom launches 802.11n chip for cell phones

IDG News Service - Broadcom Corp. has announced a single chip that combines 802.11n wireless LAN, Bluetooth and FM radio for use in phones and other handheld devices.

The BCM4329 chip was announced at Broadcom's analyst day.

The 802.11n draft standard's best-known feature is the ability to support multiple streams of data on a single radio channel using multipath reflections, but this can't be easily supported on mobile phones, which do not have room for the widely spaced antennas the feature requires. There is, however, a single-stream option, which increases transfer rates using other parts of the 802.11n standard.

"Single-stream 802.11n can give up to 50Mbit/sec. of real throughput," said Chris Bergey, director of Broadcom's embedded wireless line of business. "In particular, space-time block codes give improved diversity and eliminate dead spots inside a building."

The combo chip will be in volume production in 2009 and available in products by the end of 2009, according to the company. After that, Bergey expects 802.11n to become widespread in phones because the chip will be cheaper and more power-efficient than existing 802.11g chips.

"It will use less energy in joules per bit, as it can do transfers faster," Bergey said. "802.11n aggregates packets, so the devices have more time to go to sleep between transactions."

"Wireless LAN is becoming popular in phones thanks to full HTML browsers as seen on the iPhone," said Bergey, who added that there was also interest in using it for a personal-area network in which Bluetooth uses Wi-Fi as an "alternative MAC/PHY," or AMP, to transmit media files quickly. "Bluetooth does a great job of setting up a piconet, whereas wireless LAN is difficult to set up ad hoc," Bergey said.

As well as the usual 2.4-GHz band, the chip can support Wi-Fi in the 5-GHz band, which is less crowded and likely to become increasingly important.

The module can also share media using an FM transmit function allowing it to stream audio to nearby radio receivers such as car stereos.