Glossary of Terms and acronyms

C-Band:
This is the band between 4 and 8 GHz with the 6 and 4 GHz band being used for satellite communications. Specifically, the 3.7 to 4.2 GHz satellite communication band is used as the downlink frequencies in tandem with the 5.925 to 6.425 GHz band that serves as the uplink.

Cable Telephony:
Basic switched telephone service offered to consumers and business by local cable companies.

Carrier:
The basic radio, television, or telephony Center of frequency transmit signal. The carrier in an analogue signal. It is modulated by manipulating its amplitude (making it louder or softer) or its frequency (shifting it up or down) in relation to the carrier centre frequency. Satellite carriers operating in the analogue mode are usually frequency modulated.

Carrier Frequency:
The main frequency on which a voice, data, or video signal is sent. Microwave and satellite communications transmitters operate in the band from 1 to 31 GHz (a GHz is one billion cycles per second).

CDMA:
Code Division Multiple Access. Refers to a multiple-access scheme where stations use spread-spectrum modulations and orthogonal codes to avoid interfering with one another.

Channel:
A frequency band in which a specific broadcast signal is transmitted. Channel frequencies are specified in the United States by the Federal Communications CommissionError! Bookmark not defined.. Television signals require a 6-7 MHz baseband frequency band to carry all the necessary picture detail. In the digital environment, a single channel can carry several TV channels, the number being dependent on the required final quality of video on the screen.

C/N:
Carrier-to-noise ratio measured either at the Radio Frequency (RF) or Intermediate Frequency (IF)

Co-Location:
Ability of multiple satellites to share the same approximate geostationary orbital assignment frequently due to the fact that different frequency bands are used.

Common Carrier:
An economic concept dating from the 18th century to describe an organisation that is required by law to provide a transportation (physical or electronic) service to anyone who wants it. The requirement implicitly means that such common carriers are rate regulated to prevent them discriminating against customers they do not want. Common carrier status is usually imposed on organisations because they have a natural monopoly. The first common carriers were canal companies and turnpike operators but the first really big common rate regulated common carriers were the railway networks. Today most national telephone companies are rate regulated, rate capped or rate of return capped common carriers.

Conditional Access:
Method by which consumers can access an encrypted and scrambled TV service (and, in the future, multimedia services). The "conditional" element of the term refers to the fact that consumers can gain access on condition of having paid a subscription fee. Usually the technology involves the consumer having possession of a smart card that has been instructed by the broadcaster through a data stream within the satellite (or cable) TV signal to de-scramble the video stream.

Conus:
Contiguous United States. In short, all the states in the U.S. except Hawaii and Alaska.