By C. M. Breevoort, Ph.D.
This paper proposes a flexible architecture for a multi-services cable communications system that not only supports telephony, data, and digital video services, but also potential future services. A unique network interface unit (NIU) at the home entry point functions as a hub to the in-home cable network, isolating the outside cable plant from any possible ingress from the home. It passes high-speed video data uninterrupted in the downstream direction, while remodulating low-speed data to an area in the 5-40 MHz band The NIU always remodulates data flowing in the upstream direction between end terminal devices and the headend Adoption of an in home network protocol based on the Universal Serial Bus (USB) modified for coax cable is an inexpensive way to form a link between the NIU and a plethora of USB devices that are appearing on the market. The USB protocol on the in-home network uses an efficient modulation scheme.