In a video display, that form of edge busyness that is characterized by spatially varying distortion that occurs in close proximity to the edges of objects.

See coherent.

Session Protocol Data Unit

In the Defense Switched Network, an access line specially conditioned, usually by providing amplitude and delay equalization, to give it characteristics suitable for handling special services, such as reducing data signaling rates (DSR) to a rate between 600 b/s and 2400 b/s.

In the Defense Switched Network, a network-provided service in which specially conditioned interswitch trunks and access lines are used to provide secure voice, data, and facsimile transmission.

A tone that comprises three precise sequential frequencies used to identify recorded announcements. [After T1.207-1998]

See community of interest, interest group, forum, SIG.

A computer that is designed to operate on a restricted class of problems.

A radiocommunication service, not otherwise defined in this Section [of the Radio Regulations], carried on exclusively for specific needs of general utility, and not open to public correspondence. [RR with editor's note in brackets]

All services other than message telephones, e.g., teletypewriter exchange service (TWX), private line services. [47 CFR Pt.36-A]