Service Provider
Any individual or legal person providing Telecommunications Services to others on a commercial scale or for profit.  The TRA may by Guideline or Decision set forth specific criteria concerning the scale of operations sufficient for a person to be considered operating on a commercial scale.

Service Provider with Significant Market Power (SMP)
A Service Provider that has the ability to practically affect the terms of the subscription relevant to the price and supply in a specific market relevant to a telecommunications service due to controlling essential facilities, or using its position in the market. Essential telecommunications facilities means a Public Telecommunications Service or infrastructure that is exclusively or predominantly provided by one or a limited number of Providers and cannot feasibly be substituted, economically or technically, in order to provide the service.

Slamming
When a consumer’s service is switched from one provider to another without the consumer’s permission.

Subscriber
Another term for Customer (See Customer).

SCLS
Submarine cable landing station.
The choke points where international cable and satellite systems linking multiple countries land. These are the facilities that aggregate and distribute international traffic to and from each country.

SDH
Synchronous digital hierarchy:
A standard developed by ITU (G.707 and its extension G.708) that is built on experience in the development of SONET. Both SDH and SONET are widely used today: SONET in the United States and Canada, SDH in the rest of the world. SDH is growing in popularity and is currently the main concern, with SONET now being considered as the variation.

SDR
Software-defined radio.
A radio communication system that uses software for the modulation and demodulation of radio signals.

SDSL
Symmetrical DSL.
A proprietary North American DSL standard. However, the term SDSL is often also used to describe SHDSL.

Server
(1) A host computer on a network that sends stored information in response to requests or queries. (2) The term server is also used to refer to the software that makes the process of serving information possible.

Service neutrality
A general term referring to rules that allow operators to provide any service in the spectrum band that they are licensed to use.

SES
Satellite Earth station

SHDSL
Single pair high-speed DSL. The informal name for ITU-T Recommendation G.991.2 that offers high-speed, symmetrical connectivity over a twisted copper pair.

Signaling gateway
A network component responsible for transferring signaling messages (i. e. information related to call establishment, billing, location, short messages, address conversion, and other services) between Common Channel Signaling (CCS) nodes that communicate using different protocols and transports.

SIM
Subscriber identification module (card).
A small printed circuit board inserted into a GSM-based mobile phone. It includes subscriber details,security information and a memory for a personal directory of numbers. This information can be retained by subscribers when changing handsets.

SIP
Session Initiation Protocol.
A protocol developed by the IETF MMUSIC Working Group and proposed standard for initiating, modifying, and terminating an interactive user session that involves multimedia elements such as video, voice, instant messaging, online games and virtual reality. In November 2000, SIP was accepted as a 3GPP signalling protocol and permanent element of the IMS architecture. It is one of the leading signalling protocols for Voice over IP, along with H.323. The SIP server initiating the call will unambiguously be aware of the time at which the voice session was initiated, and will in general also know the time at which the voice session ended. The VoIP service provider, which is not necessarily the network operator, will generally be the party operating the SIP server.

Site sharing
See Collocation.

SLA
Service level agreement.
An SLA provides a way of quantifying service definitions by specifying what the end user wants and what the provider is committed to provide. The definitions vary at business, application or network level.

SME
Small and medium enterprise(s).

SMP
Significant market power.

SMTP
Simple mail transfer protocol.
The de facto standard for e-mail transmission across the Internet.

Softswitch
A type of telephone switch that uses software running on a computer system to carry out the work that used to be carried out by hardware.

Spam
Unwanted, nuisance e-mail, some of which may contain computer viruses or worms, fraudulent consumer scams or offensive content.

Spectral efficiency
A measure of the performance of encoding methods that code informa- tion as variations in an analogue signal.

Spectrum
The radio-frequency spectrum of hertzian waves used as a transmission medium for cellular radio, radiopaging, satellite communication, over-the-air broadcasting and other services.

Spectrum commons
Spectrum bands reserved for unlicensed use and shared among lowpower devices on an open access basis.

Spectrum reassignment
A spectrum management approach when the regulator decides when and to whom the spectrum authorization will be transferred – and at what price.

Spectrum trading
This spectrum management approach allows parties to transfer their spectrum rights and obligations to another party, in return for a financial or market benefit. The market determines the value.

Spreadspectrum technology
A radio technique that continuously alters its transmission pattern either by constantly changing carrier frequencies or by constantly changing the data pattern.

SS7
Signaling System No. 7 A set of telephony signaling protocols which are used to set up most of the world's public switched telephone network telephone calls

STB
Set-top box.
A device connected to a television that receives and decodes digital television broadcasts and interfaces with the Internet through the user’s television.

Switch
Part of a mobile or fixed telephone system that routes telephone calls or data to their destination.