synchronous connection oriented (Bluetooth) (SCO)
A Synchronous Connection Oriented Link (SCO) is a synchronous point-to-point connection between two Bluetooth devices. This type of connection is mainly used for time-related transmission of voice data. It works with fixed time slots reserved by the master station in which the voice is transmitted in real time.
The voice transmission is connection-oriented and takes place in a protected transmission channel, thus achieving a high quality standard. Master and slave communicate via a fixed time slot reserved for them.
An extended variant of Synchronous Connection Oriented is Extended Synchronous Connection Oriented (e-SCO), which supports optimal voice transmission between headset and cell phone.
In addition to the Synchronous Connection Oriented Link (SCO), data can also be transmitted asynchronously in Bluetooth. The corresponding link is the Asynchronous Connectionless Link( ACL).