What is spliced into the hardline coaxial cable to combine AC power with the RF signal in an HFC network?

In an HFC (Hybrid Fiber-Coaxial) network, a power inserter is utilized to combine AC power with the RF (radio frequency) signal. The purpose of the power inserter is to inject the necessary power into the coaxial cable, allowing devices such as amplifiers or nodes to operate effectively without needing a separate power source.

This integration is crucial, especially in outdoor or remote installations where electrical outlets may not be readily accessible. By using a power inserter, the network maintains efficiency while ensuring that the RF signals and power are transmitted over the same coaxial line.

The other options do not perform this function in the same way. A signal booster amplifies the RF signal to improve weak signal strength but does not add power; an RF splitter divides the RF signal into multiple outputs for distribution without incorporating power; whereas a termination box is used to properly terminate coaxial cables to prevent signal leakage and maintain system integrity. These distinctions reinforce the role of the power inserter as the correct answer for this query.