SACCH

Slow Associated Control Channel; transmits continuous measurements in parallel with operation of TCH or SDCCH; needed for handover decisions.

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SB

Synchronization Burst; used for time synchronization of the mobile.

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SCCP

Signaling Connection Control Part provides connection-less and connection-oriented services and extended functions including specialized routing (FTT Global title Translation) and subsystem management capabilities above MTP3.

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S-CDMA

Synchronous CDMA (see CDMA).

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SCH

Synchronization Channel; downlink only frame synchronization and identification of base station.

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SCP

Switching/Service Control Point.

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SDCCH

Stand-alone Dedicated control Channel; communications channel between the MS and the BTS. Used for signaling during call set-up before a TCH is allocated.

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SDLC

Synchronous Data Link Control.

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SDMA

Spatial Division Multiple Access.

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Sector

A physical coverage area associated with a base station having its own antennas, radio ports and control channels. The concept of sectors was developed to improve co-channel interference in cellular systems and most wireless systems use three sector cells.

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Service Policy

Policy or set of policies set by operators for each different data service in terms of Quality-of-Experience parameters, such as minimum and maximum bit-rate, as well as service availability rates, such as the service blocking and dropping priority. See Service Policy Managerr.

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SGSN

Service GPRS Support Node; the gateway between the RNC and the core network iin a GPRS/UMTS network.

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Shadowing

A phenomenon that occurs when a mobile moves behind an obstruction and experiences a significant reduction in signal power.

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Signaling

Exchange of information concerned with the establishment, management and control of connections in a telecommunications network.

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Signal-to-noise ratio

The ratio of power in a signal to the noise power in the channel. This term is usually applied to lower frequency signals, such as voice waveforms.

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SIM

Subscriber Identity Module; a smart card containing the telephone number of the subscriber, encoded network identification details, the PIN and many other user data such as the phone book. A user's SIM card can be moved from phone to phone s it contains all the key information required to activate the phone.

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SLA

Service Level Agreement. The SLA is a contract between the vendor and the user that specifies the level of service that is expected during its term. SLAs are used by vendors and customers as well as internally by IT shops and their end users. They can specify bandwidth availability, response times for routine and ad hoc queries, response time for problem resolution (network down, machine failure, etc.).

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Slow fading

A long term fading effect changing the mean value of the received signal. Slow fading is usually associated with moving away from the transmitter and experiencing the expected reduction in signal strength.

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SMR

Specialized Mobile Radio; the US term for private mobile ratio (See PMR).

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SMS

Short Message Service a text message service that enables users to send short messages (160 characters) to other users. A very popular service, particularly among young people, with 400 billion SMS messages sent worldwide in 2002. A store and forward message service available on most second-generation digital systems that allows short messages (up to 140 octets) to be sent to the mobile and displayed on a small screen. The control and signaling channels are normally used to deliver these messages.

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SMSC

SMS Center - the-network entity that switches SMS traffic.

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SMSCB

SMS Cell Broadcase.

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SMS-MO

SMS Mobile Originated.

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SMS-MT

SMS Mobile Terminated.

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SMS-PP

SMS Point to Point.

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SNDCP

Sub-network Dependent convergence Protocol. Responsible for transmission and reception of NPDUs in acknowledged and unacknowledged LLC mode according to QoS profile. It also takes card o Segmentation/Reassembly and header/data compression.

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SNR

Signal-to-Noise Ratio (see listing above).

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SoHo

Small Office/Home Office.

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SP

Service Provider.

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SP-Managerr

CellGlide GPRS Service Policy Managerr. This component of the CellGlide GPRS Mobile Traffic Shaperr creates, implements and enforces a predefined default network-wide Service Policy for optimal allocation of resources.

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SQAM

Staggered Quadrature Amplitude Modulation.

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SQPSK

Staggered Quadrature Phase Shift Keying.

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SS7

Signaling System Number 7 (See CCS7). International standard protocol defined for open signaling in the digital public switched network. It is based on a 64 kbps channel and allows for information transfer for call control, database and billing management, and for maintenance functions.

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SSP

Service Switching Point.

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Stateful / Stateless

Stateful and stateless are adjectives that describe whether a computer or computer program is designed to note and remember one or more preceding events in a given sequence of interactions with a user, another computer or program, a device, or other outside element. Stateful means the computer or program keeps track of the state of interaction, usually by setting values in a storage field designated for that purpose. Stateless means there is no record of previous interactions and each interaction request has to be handled based entirely on information that comes with it. Stateful and stateless are derived from the usage of state as a set of conditions at a moment in time.

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STK

SIM ToolKit; specified within the GSM standard, this allows operators to add additional functions to the phone menu in order to provide new services such as mobile banking or email.

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STM

Synchronous Transfer Mode.

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Streaming

An internet derived expression for the one-way transmission of video and audio content.

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Symbian

A company created by Psion, Nokia, Ericsson and Motorola in 1998 with the aim of developing and standardizing an operating system that enable mobile phones from different manufacturers to exchange information.

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