A coax network is an extension of the existing home network onto the coax cable network in the home. Just like Wi-Fi is the ubiquitous standard for wireless home networks, MoCA is the nearly ubiquitous standard for coax networks. MoCA stands for the Multimedia over Coax Alliance. If your cable service provider offers a service called Multi-Room DVR, they are almost certainly using MoCA to enable it.
The current standard for MoCA is 1.1 and the equipment used in this project is standards compliant.
A MoCA network is broadcasted roughly between 500MHz and 1.5GHz (1500MHz). The technology is designed so that it does not interfere with the broadcasts of traditional cable TV service. However, satellite TV, which runs on different spectrum, is not compatible with the 1.1 MoCA standard. For their respective multi-room DVR services, they use a proprietary coax networking technology. The MoCA 2.0 standard in development is expected to work for all service providers.
To get the most detailed and updated information about this technology, visit the MoCA website