Abbreviation for pulse-time modulation.

Precision Time Protocol

Presentation Timestamp

Packet Technologies and Systems Committee

1. postal, telegraph, and telephone (organization),
2. push-to-talk (see push-to-talk operation).

Abbreviation for precise time and time interval.

Presence User Agents

1. Any telecommunication which the offices and stations must, by reason of their being at the disposal of the public, accept for transmission. [NTIA] [RR]
2. Any telecommunication which the offices and stations, by reason of their being at the disposal of the public, must accept for transmission. [47CFR]

[The] Body of cryptographic and related knowledge, study, techniques, and applications that is, or is intended to be, in the public domain. [INFOSEC-99]

A network established and operated by a telecommunications administration, or a recognized private operating agency, for the specific purpose of providing data transmission services for the public.