spectrum reuse—CATV’s most fundamental concept. Historically, the over-the-air spectrum has been assigned to many purposes other than that of carrying TV signals. This has resulted in an inadequate supply of spectrum to serve the needs of viewers. Cable can reuse spectrum that is sealed in its aluminum tubes.
subscriber unit (SU)—An alternate term for cable access router. See cable access router.
upstream—The set of frequencies used to send data from a subscriber to the headend.
Configuring the Cisco uBR900 Series Cable Access Routers 137
