Advanced Television Systems Committee (ATSC)

• call supervision
• call trace
• call transfer
• call vectoring
• call waiting
• CamelCase
• CamelCase
• camp-on
• camp-on
• Canadian Radio-television and Telecommunications Commission (CRTC)
• candela (cd)
• candle
• CAN-SPAM Act (Controlling the Assault of Non-Solicited Pornography And Marketing Act)
• CAP
• capacitance (C)
• capacitive reactance (X )
• capacitor
• capacity
• Captioned Telephone Service
• carding
• carrier
• Carrier Access Charge (CAC)
• Carrier Access Code (CAC)
• carrier class
• carrier frequency