UniLINK as a media access protocol for community cable TV

UniLINK is a media access control (MAC) protocol optimized for community area networking over new and existing hybrid fiber-coax cable (HFC) infrastructures. It is designed to operate on the tree and branch topology prevalent in the cable industry at distances up to 100 miles from the Head End or Central Office. UniLINK is based on modified TDM concepts, supporting a mix of fixed, contention, and reservation bandwidth concurrently. It dynamically adjusts the mix as offered load changes. The protocol is used in the LANcity family of products. This implementation, with a frequency agile QPSK modem is deployed at over 200 customer sites and provides a packet oriented interface with a high speed, symmetrical, 10 Megabit per second connection. This paper provides an overview of the UniLINK protocol, its operating environment, test results, and possible future enhancements.