What is the difference between ACL and SCO Link in Bluetooth?

Question

ACL= Asynchronous Connection-Less. SCO = Synchronous Connection Oriented.

SCO is Point to Point Connection between only one master and only one slave.

ACL is multipoint connection between one master and many slaves.

What are the other differences?

Answer 1

SCO is for real-time narrow band signal which does not require retransmission. Voice data in Bluetooth hands free kit is an example for this. This narrow band audio is called "Bluetooth voice" type. Where as ACL is for all other BT data transfer including High quality audio/video data. Example is music playback through A2DP. This is high bandwidth data and hence called "Advanced Audio". SCO is fixed bandwidth channels and can have maximum 3 channels per device, but throughput of ACL varies with other active connections(SCO and ACL) at that time.