Ethernet can be divided into 2 sublayers; MAC and LLC. For WAN protocols like PPP, HDLC and frame relay, it is not discussed in regards to protocol sublayer for media access control. On serial interface, the encapsulation can be chosen from PPP, HDLC, frame relay, etc.
My question is, do WAN protocols like PPP, HDLC and frame relay have their own media access control protocol or do they use the same media access control protocol?