Texas Instruments unveils coexistence package

Texas Instruments has found a way to limit interference between the two wireless technologies in handheld devices, by combining...

Texas Instruments has found a way to limit interference between the two wireless technologies in handheld devices, by combining software with its existing chips for 802.11b wireless Lans (WLans) and Bluetooth networks.

Bluetooth and 802.11b both send their signals across the 2.4GHz frequency, which is also used for a variety of common products like baby monitors or garage door openers.

In order to use Bluetooth and 802.11b in the same device effectively, the company needed to develop software that monitors wireless traffic on a packet level to route high-priority traffic and avoid packet collisions, said Matthew Shoemake, director of advanced technology in Texas Instruments'  WLan business unit.

This coexistence package of chips and software is designed for mobile phones, smart phones and PDAs. It can also be used in laptop computers, but was designed for small, handheld devices more prone to interference problems.

"Texas Instruments has been shipping millions of Bluetooth chips through Nokia mobile phones, and has captured a reasonable percentage of the WLan market," said Will Strauss, principal analyst at market researcher Forward Concepts.

Bluetooth is a short-range wireless technology that is used primarily for PC peripherals, such as keyboards, or voice connections between a mobile phone or smart phone and a wireless headset. The 802.11b standard is used mainly in notebook computers for connections to the internet or corporate networks.

Texas Instruments software gives the highest priority to Bluetooth voice traffic, because customers want clear voice connections without static or dropped calls, Shoemake said. But the user doesn't notice the prioritisation, and can use a Bluetooth headset while checking their e-mail on a 802.11b network without any problems, he said.

Users might see a slight performance degradation in internet connection speeds while using their Bluetooth headsets, but most probably would not even notice, Strauss said.

802.11b networks have an effective connection speed of about 6mbps, which is much faster than home broadband connections. But every user would notice static or problems with the voice connection, which is why that transmission deserves priority, he said.
The two chips and the coexistence software will cost less than $20 (£12) to the device manufacturers when purchased in volume, he said.

Future devices with the coexistence technology might resemble the Wanda (wireless any network digital assistant) reference design that Texas Instruments showed at the CTIA show in March.

Wanda features Bluetooth, 802.11b and GSM/GPRS wireless chips, and products based on the design are expected in the third or fourth quarters

Tom Krazit writes for IDG News Service

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