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CSR launched its sixth generation of BlueCore silicon for Bluetooth. BlueCore6 includes industry-leading radio performance and power consumption, as well as full support for the latest version of the Bluetooth specification (v2.1+EDR).

Included in BlueCore6 is CSR’s AuriStream technology, a radical improvement to the way Bluetooth handles voice traffic. AuriStream provides toll-quality voice calls and is capable of a 40% reduction in power consumption in BlueCore6-ROM as compared with standard Bluetooth voice transmission methods. Production is scheduled for January 2008.

CSR has enhanced the RF performance to give BlueCore6 class 1 Bluetooth range without the need for an external power amplifier. A total 11 dB link margin improvement over BlueCore4 (+4 dBm to Tx, -7 dBm to Rx) makes BlueCore6 the industry’s most efficient Bluetooth radio and helps improve operation across the body, for example when a Bluetooth headset connects to a mobile phone worn on the user’s belt. BlueCore6-ROM is packaged in CSR’s tried and tested wafer-level CSP format and is smaller than competing Bluetooth silicon.

Voice remains the key application for Bluetooth, and users continually demand higher voice quality – but also longer battery life. CSR’s BlueCore6 has inherited all of the features that made BlueCore the world’s leading Bluetooth silicon, plus substantial improvements in voice quality and power requirements.

Bluetooth traditionally relies on a continuous variable slope delta (CVSD) modulation coding scheme to carry voice over a synchronous connection oriented (SCO) link. CVSD is a fairly simplistic binary coding scheme, but was selected because it is highly robust and resistant to bit errors. However, SCO does not allow for retransmission of failed packets. Since v1.2 of the Bluetooth specification, eSCO has supported retransmissions.

With AuriStream, CSR has introduced adaptive differential pulse code modulation (ADPCM) as an enhanced voice-coding method, since it performs the same function at half the rate of CVSD (ADPCM scans at 32 Kbps, CVSD 64 Kbps) saving up to half the Bluetooth power in the handset; ADPCM is more accurate, and provides a much higher voice quality. CSR’s AuriStream boosts quality from a mean opinion score of 2.41 with CVSD to a toll quality score of 4.14, bringing fixed line quality to a Bluetooth connection.

CSR has introduced a range of technologies into BlueCore6 all of which bring important savings on either the Bluetooth or the host device’s power consumption for mobile phone architectures. CSR has reduced the power in standby and restructured how Bluetooth devices scan for other devices. Standby current typically accounts for over half the total power consumption of a Bluetooth system.