The systems engineering process is applied in the development of the preliminary design of a home automation communication protocol. The objective of the communication protocol is to provide a means for a personal computer to communicate with adapted appliances in the home.

A needs analysis is used to ascertain that a need exist for a home automation system. Numerous design alternatives are suggested and evaluated to determine the best possible protocol design. Coaxial cable, fiber optics wire, infrared, and the home power line are each evaluated to determine which would best serve as the communication medium for the communication protocol. A personal computer and a dedicated computer are compared to determine which computer configuration will be used to control the communication protocol. The final design choice which is considered is the LAN protocol type. CSMA/CD and Token Bus are evaluated to determine which protocol type will best support the home automation system.

The results of the system engineering process is a preliminary design for a home communication protocol that will use the home power line, a personal computer, and a CS-WCD LAN protocol to provide a home communication protocol.