Final answer:
The Integrated Communications Access Package (ICAP) is the component of theater deployable communications that serves as the backbone of a deployed communication network.
Step-by-step explanation:
The component of theater deployable communications (TDC) that serves as the backbone of a deployed communication network is the Integrated communications access package (ICAP). ICAP is a suite of modules and accessory kits that provide the necessary infrastructure for establishing a communication network in a deployed theater. It includes equipment such as routers, switches, modems, antennas, and cabling.