TDM (Time-Division Multiplexing)

A multiplexing method by which multiple low-speed incom-

ing transmissions can share a single high speed outgoing digital circuit. An analog voice conversation requires bandwidth of 4 kHz.Although there are a considerable number of methods for converting an analog voice signal into a digital signal, the fundamental standard is pulse code modulation (PCM), which requires 64 kbps. A voice grade digital channel, therefore, is 64 kbps wide, which forms the fundamental building block for digital switching and transmission of not only voice, but all forms of data. A typical digital voice application is multi-channel in nature and involves a four-wire circuit with a TDM multiplexer, or mux, placed on each end of the circuit, as illustrated in Figure T-3.

• Table E-4: Frequency Spectrum: Band Designations, Nominal Frequency Ranges, Nominal
• Table E-5: Endianess
• Table G-1: G-Series Recommendations
• Table H-1: H.320 Related Standards Recommendations
• Table H-2: SDTV Scanning Formats
• Table H-3: Notation Comparison
• Table H-4: Selected ITU-T H-Series Recommendations
• Table I-1: Frame Relay Implementation Agreements
• Table I-2: Index of Refraction (IOR)
• Table I-3: IPv4 Address Classes
• Table I-4: Selected ITU-T I-Series Recommendations
• Table I-4: Selected ITU-T I-Series Recommendations (continued)
• Table I-5: ITU-T Series Recommendations
• Table J-1: Japanese Digital Hierarchy: J-carrier
• Table L-1: Longitudinal Redundancy Check (LRC)
• Table M-1: International Morse Code
• Table O-1: OSI Reference Model Layers
• Table O-2: G.709 Line Rates and Corresponding SDH/SONET Line Rates
• Table P-1: Evolution of PBX technology
• Table P-2: Military and Aviation Phonetic Alphabet
• Table Q-1: Selected ITU-T Q-Series Recommendations
• Table R-1: Before and After: Bell Operating Companies (BOCs) and Regional Bell Operating
• Table R-1: Before and After: Bell Operating Companies (BOCs) and Regional Bell Operating
• Table R-2: Coaxial Cable Types
• Table S-1: SDTV Scanning Formats