TANDBERG E5500, Инструкция по эксплуатации

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Glossary
Instruction Manual: evolution 5000 E5500 Mobile Contribution Encoder Page A-7
ST.TM.E10033.3
PSR (Professional Satellite
Receiver) See also: IRD.
PSU Power Supply Unit.
QAM (Quadrature Amplitude
Modulation) A method of modulating digital signals which uses combined techniques of phase modulation and amplitude
modulation. It is particularly suited to cable networks.
QPSK (Quadrature Phase
Shift Keying) A form of phase shift keying modulation using four states.
Quantising: Quantisation A process in which the continuous range of values that a quantity may assume is divided into a number of
predetermined adjacent intervals and in which any value within a given interval is represented by a single
predetermined value within the interval.
Also:
A restriction of the number of DCT coefficient values, resulting in a limiting of the luminance and chrominance
information.
RAM (Random Access
Memory) A volatile storage device for digital data. Data may be written to, or read from, the device as often as required.
When power is removed, the data it contains is lost.
RF Radio Frequency.
ROM (Read-Only Memory) A non-volatile storage device for digital data. Data has been stored permanently in this device. No further
information may be stored (written) there and the data it holds cannot be erased. Data may be read as often as
required.
RS (Reed Solomon coding) An error detection and correction coding system which is applied to the Transport Stream before transmission to
counter the effects of interference.
RLC (Run Length Coding) Minimisation of the length of a bit-stream by replacing repeated characters with an instruction of the form ‘repeat
character x y times’.
SCPC Single Channel Per Carrier.
Scrambling
Alteration of the characteristics of a television signal in order to prevent unauthorised reception of the information
in clear form.
Also:
A process (in digital transmission) used to combine a digital signal with a pseudo-random sequence, producing a
randomised digital signal, conveying the same information, in order to facilitate transmission.
SDT (Service Description
Table) Provides information in the SI stream about the services in the system; for example, the name of the service, the
service provider, etc.
SELV Safety Extra Low Voltage (EN 60950).
Set-Top Box (STB) The cable equivalent of the IRD (q.v.).
SFN Single Frequency Network.
SI (Service Information)
Digital data describing the delivery system, content and scheduling/timing of broadcast data streams. SI data
provides information to enable the IRD to automatically demultiplex and decode the various streams of
programmes within the multiplex. Specified in ISO/IEC 13818[1].
Smart Card See: Viewing Card.
SMATV (Satellite Mast
Antenna Television) A distribution system which provides sound and television signals to the households of a building or group of
buildings, typically used to refer to an apartment block.
SMPTE Society of Motion Picture and Television Engineers.
SMS (Subscriber Management
System) A system which handles the maintenance, billing, control and general supervision of subscribers to conditional
access technology viewing services provided through cable and satellite broadcasting. The SMS system provided
by NDS links a number of Users on a LAN with Batch Processors and a File Server providing access to a
Database and a separate dedicated Conditional Access Interface Server which communicates with an
Authorisation Control Centre (ACC).
An SMS can be an automatic (e.g. Syntellect) system where subscribers order entitlements by entering
information via a telephone. Alternatively, an SMS can be a manual system which requires subscribers to speak
with an operator who manually enters their entitlement requests. Some systems support multiple SMSs.
SNG Satellite News-Gathering.
SNMP Simple Network Management Protocol.
Spatial Redundancy Information repetition due to areas of similar luminance and/or chrominance characteristics within a single frame.
Removed using DCT and Quantisation (Intra-Frame Coding).
SPI Synchronous Parallel Interface.