Bluetooth SCO / CVSD 뜻

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 32Kbps, CVSD 64Kbps) saving up to half the Bluetooth power on 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.