电信专业英英词典S-1（在线收听）

　　SAFENET

　　survivable adaptable fiber-optic embedded network

　　Satellite Communications

　　Satellite communications entails microwave radio, line-of-sight propagation from a transmitting earth terminal (i.e., usually ground-based but potentially ship or airborne) through the atmosphere and outer space media to a satellite, and back to earthbound receiving terminals. In essence, satellites are equivalent to orbiting microwave repeaters.

　　Scenario

　　In SWAT, a scenario is an iteration of an RFW project. A scenario holds the design detail work units that are associated with the project. By creating multiple scenarios, you can compare pricing and scheduling options. A scenario has three different statuses. A Working status indicates that the scenario is under reivew. A Posted status indicates that a scenario has been identified as the official design. A Final Posted status indicates that a scenario is the "as-built" version of the project.

　　SDH

　　synchronous digital hierarchy

　　SDN

　　software defined network

　　SECAB

　　Small Exchange Carrier Access Billing

　　Server

　　In a network, a server is equipment that makes available file, database, printing, facsimile, communications or other services to client terminals/stations with access to the network. A gateway is a server that permits client terminal/station access to external communications networks and/or information systems.

　　Service Management System (SMS)

　　In virtual private networks, SMS is a facility used to build and maintain a VPN database allowing customers to program specific functions for unique business applications. The SMS contains complete specifications of customer defined private network specifications including location data, numbering plan, features, screening actions, authorization codes, calling privileges, etc. This information is downloaded (transmitted) to network control points (NCPs) which implement its instructions on a customer-by-customer basis.

　　Service Order (SO)

　　A service order is a record that describes a customer request to establish, change, or terminate a service. The service order contains all information required to meet a customer's needs.

　　SF

　　single frequency

　　Shielded Twisted Pair

　　Shielded twisted pair is twisted copper paired wire cable with an outer metallic sheath surrounding insulated conductors. See unshielded twisted pair.

　　Signal

　　A signal is usually a time-dependent value attached to an energy propagating phenomenon used to convey information, for example, an audio or sound signal in which the data is characterized in terms of loudness and pitch.

　　Signaling

　　Signaling is the process of generating and exchanging information between components of a telecommunications system to establish, monitor, or release connections (call handling functions) and to control related network and system operations (other functions).

　　Signaling System No. 7, SS #7

　　SS#7 is an international common channel signaling system recommendations established by the CCITT.