Hz

1. (Hertz) The measurement of frequency, which previous to 1930 was expressed as cycles per second (cps). See Hertz, Heinrich Rudolf. 2. In analog terms, bandwidth is measured in Hz, specifically as the difference between the highest and lowest frequencies over a circuit or within a channel. For example, a channel operating in the range between 4,000 Hz and 8,000 Hz has a bandwidth of 4,000 Hz, or 4 kHz (kiloHertz). Although some applications operate in very low capacity environments, measured in tens of Hz or hundreds of Hz, analog bandwidth more commonly is measured in kHz or kiloHertz (thousands of Hz), MHz or MegaHertz (millions of Hz), GHz or GigaHertz (billions of Hz), and even THz or TeraHertz (trillions of Hz).

74570c08.qxd 9/11/07 12:22 PM Page 234

74570c09.qxd 9/11/07 12:22 PM Page 235

• AAL2 (ATM Adaptation Layer Type 2)
• AAL3/4 (ATM Adaptation Layer Type 3/4)
• AAL5 (ATM Adaptation Layer Type 5)
• AAL (ATM Adaptation Layer)
• A (Ampere)
• AAV (Alternative Access Vendor)
• abbreviation
• Abilene Project
• Abilene Project
• ABM (Asynchronous Balanced Mode)
• Above 890 Decision
• ABR (Available Bit Rate)
• absorption
• abstruse
• AC-3 (Adaptive Transform Coder 3)
• AC-3 (Adaptive Transform Coder 3)
• AC (Alternating Current)
• A Carrier
• acceptance angle
• Access BPL (Access Broadband over Power Line)
• Access BPL (Access Broadband over Power Line)
• access broadband over power line (Access BPL)
• access broadband over power line (Access BPL)
• access charges
• access circuit