Xfinity by Comcast offers Internet, TV, and phone service to consumers primarily via their hybrid fiber coaxial (HFC) network. They are also rolling out fiber-to-the-home (FTTH) installations in some regions.
Hybrid Fiber Coaxial (HFC) networks are used globally by cable providers to deliver broadband internet access to consumers. In short, HFC networks deliver a fiber optic connection to a node within a neighborhood, which then branches off to service 25-2000 homes. By using this network structure, Comcast and other cable providers are able to take advantage of their existing coaxial infrastructure to offer competitive broadband speeds at a lower up-front installation cost to the company.
In the case of FTTH installation, fiber optic cable is run directly to consumers residences or businesses. This network structure is preferred over hybrid networks. Unfortunately, they aren’t widely available due to the high costs associated with running fiber optic cable.