Upstream US

© 2004 Cisco Systems, Inc. All rights reserved. BCRAN v2.1—4-10

The following key terms are commonly used to describe cable technology basics:

Broadband: Refers to the ability to frequency-division multiplex (FDM) many signals in a wide RF bandwidth over an HFC network and the ability to handle vast amounts of information.

Coaxial cable: The principal physical medium with which cable TV systems are built. Coaxial cable is used to transport RF signals. Coaxial cable signal loss (attenuation) is a function of the diameter of the cable, dielectric construction, ambient temperature, and operating frequency (f).

Headend: The location where the cable company aggregates, combines, mixes, and modulates all signals to send them downstream. Upstream signals usually are received in the headend.

■ Downstream: RF signal flow from headend toward subscribers. Also called forward path.

■ Upstream: RF signal flow from the subscribers to the headend. Also called the return or reverse path.

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