Table R-1: Before and After: Bell Operating Companies (BOCs) and Regional Bell Operating

Companies (RBOCs) (continued)

Bell Operating Companies (Primary

Regional Bell Operating Companies

States of Operation), Pre-divestiture

(Headquarters), Post-divestiture

New England Telephone (Massachusetts,

NYNEX (New York). Acquired by Bell Atlantic (August 1997);

Maine, New Hampshire, Rhode Island,

now Verizon Communications.

and Vermont)

New York Telephone (New York)

Pacific Bell (California)

Pacific Telesis (California). Acquired by SBC (April 1997);

now AT&T.

Nevada Bell (Nevada)

Southwestern Bell (Arkansas, Kansas,

Southwestern Bell Corporation (Texas), then SBC Communica-

Missouri, Oklahoma, and Texas)

tions; now AT&T (November 2005).

Mountain Bell (Arizona, Colorado, Idaho,

US West (Colorado). Acquired by Qwest (June 2000).

Montana, New Mexico, Utah, and Wyoming)

Northwestern Bell (Iowa, Minnesota, North

Dakota, Nebraska, and South Dakota)

Pacific Northwest Bell (Oregon and Washington)

• 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
• Table S-2: SONET/SDH Signal Hierarchy
• Table T-1: North American Digital Hierarchy: T-carrier
• Table T-2: TCP/IP Protocol Suite
• Table V-1: Electromagnetic Signal Propagation Velocity (Approximate)
• Table V-2: Vertical Redundancy Check (VRC)
• Table V-3: Selected ITU-T V-Series Recommendations
• Table W-1: ITU-T Transmission Windows
• Table X-1: DSL Technology Comparisons
• Table X-2: ITU-T X Series Recommendation Groups
• Table X-3: Select X Series Recommendations
• TACS (Total Access Communications System)