In this subchapter, the following definitions shall apply:

(1)  9–1–1 services and E9–1–1 services

The terms “9–1–1 services” and “E9–1–1 services” shall have the meaning given those terms in section 942 of this title.

(2)  Multi-line telephone system

The term “multi-line telephone system” or “MLTS” means a system comprised of common control units, telephone sets, control hardware and software and adjunct systems, including network and premises based systems, such as Centrex and VoIP, as well as PBX, Hybrid, and Key Telephone Systems (as classified by the Commission under part 68 of title 47, Code of Federal Regulations), and includes systems owned or leased by governmental agencies and non-profit entities, as well as for profit businesses.

(3)  Office

The term “Office” means the 9–1–1 Implementation Coordination Office established under section 942 of this title.