Ahead of the 3GSM show next week, Cambridge Silicon Radio has launched a chip that combines WiFi and Bluetooth, but makes sure that both work at the same time efficiently. This is important as both operate in the 2.4GHz band, and other coexistence schemes take lots more power.
It means CSR is now competing with Broadcom and TI, but as it already has over 50% of the Bluetooth handset market when competing against them, that's not too much of a problem.
The trick with UniVox Mobile is there are dedicated hardware lines between the Unifi WiFi chip and the Bluetooth chip, controlling where the two are operating. The two are synchronised in the time domain so they don't clash, and the WiFi notifies the Bluetooth where the Wifi is operating so that the Bluetooth chip can hop around it in the frequency domain.
This is good stuff. The chips also go to sleep between packets to keep the power down, giving standby times for dual mode phones with standard 860mAh batteries of up to 10 days and talk time of 8 hours, which is comparable to existing mobiles.
The UniVox Mobile reference design contains all the additional hardware and software to turn a mobile handset into a wirelessly enabled handset that can take and make Voice over WiFi calls, and CSR is working with two handset makers to do this already. It points to its experience with integrating the software for Bluetooth in minimising the risks.
This chip also includes the G.711 codecs and other software that will make VOIP calls of decent quality (equivalent to wireline, says CSR) rather than the poor codecs in current handsets. That will certainly help to drive the takeup of dual mode phones.
"It’s clear that consumers like the concept of the dual mode phone, however until now it has proved tricky to deliver the power consumption and voice quality that the end customer requires," said Raj Gawera, Marketing Manager for the WiFi Strategic Business Unit at CSR. "With these issues overcome, we believe that dual mode phones present a tremendous opportunity for manufacturers. UniVox Mobile has been designed from the bottom up using power saving and coexistence technologies that we have developed specifically to ensure a smooth user experience.“