Companies (RBOCs)

Bell Operating Companies (Primary

Regional Bell Operating Companies

States of Operation), Pre-divestiture

(Headquarters), Post-divestiture

Illinois Bell (Illinois)

Ameritech (Illinois). Acquired by SBC Communications

(October, 1999); now AT&T.

Indiana Bell (Indiana)

Michigan Bell (Michigan)

Ohio Bell (Ohio)

Wisconsin Telephone (Wisconsin)

Bell of Pennsylvania (Pennsylvania)

Bell Atlantic (Pennsylvania); now Verizon Communications.

Diamond State Telephone (Delaware)

The Chesapeake and Potomac Companies

(District of Columbia, Maryland, Virginia,

and West Virginia)

New Jersey Bell (New Jersey)

South Central Bell (Alabama, Kentucky,

BellSouth (Georgia). Acquired by AT&T (January 2007).

Louisiana, Mississippi, and Tennessee)

Southern Bell (Florida, Georgia, North

Carolina, and South Carolina)

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• 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
• 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