(1) In a network, a wire protocol is the mechanism for transmitting data from point a to point b. The term is a bit confusing, because it sounds like layer 1 of the network, which physically places the bits "onto the wire." In some cases, it may refer to layer 1; however, it generally refers to higher layers, including Ethernet and ATM (layer 2) and even higher layer distributed object protocols such as SOAP, CORBA or RMI. See OSI model, communications protocol, data link protocol and distributed objects.
(2) In an electronic system, a wire protocol refers to the control signals (start and stop data transfer) and architecture (serial, parallel, etc.) of the bus or channel.