SAE C102, also known as Society of Automotive Engineers (SAE) Standard J1928 - Wire Processor and Cellular Interface for On-Board Vehicle Networks, is a communication protocol used for in-vehicle applications. It provides a standardized interface between wireless modems or on-board processors and the in-vehicle network, making it easier for different devices to communicate with each other. SAE C102 is commonly used in connected cars to enable remote monitoring and diagnostics, as well as over-the-air software updates.