Which protocol primarily uses the powerline system within customer premises to communicate with connected devices?

The correct answer is that HomePlug primarily uses the powerline system within customer premises to communicate with connected devices. HomePlug enables the transmission of data over existing electrical wiring, allowing devices in a home or office to communicate without the need for additional cabling. This protocol is particularly advantageous in environments where wireless signals may be weak or where running new Ethernet cables is impractical.

Other options, while useful in their respective contexts, do not utilize powerline communications in the same manner as HomePlug. For example, Z-Wave is designed for low-power devices within home automation networks but relies on radio frequency signals rather than powerlines. Similarly, X10 is also a powerline communication protocol but is largely considered outdated and less efficient compared to modern solutions like HomePlug. Lastly, Wi-Fi Direct establishes connections between devices wirelessly, unrelated to powerline communication systems.