The system that transports a signal to a satellite for broadcast. Signals usually come to the uplink through multiplexers.
SECAM
(Sequential Couleur á Memoire, or Sequential Color with Memory) The television standard for France, Russia, and most of Eastern Europe. As with PAL, SECAM is based on a 50-hertz power rate, but it uses a different encoding process. Devised earlier than PAL, its standards reflect earlier technical limitations. See alsoNTSC.
Secure Electronic Transaction
(SET) The Microsoft standard for safely transmitting Visa or MasterCard information to support electronic commerce over the Internet.
service provider
In Broadcast Architecture, a business that provides a broadcast data service.
Session Announcement Protocol
(SAP) An Internet protocol for announcements. This protocol defines a header in binary format that precedes the Session Description Protocol (SDP) portion of an announcement. A draft document about SAP has been produced by the Internet Engineering Task Force (IETF).
Session Description Protocol
(SDP) A textual Internet protocol for the announcements intended to announce and initiate multimedia sessions. Currently a work in progress, SDP is defined in a draft document (RFC 2327) produced by the Internet Engineering Task Force (IETF). See alsoSession Announcement Protocol.
In standard cable or satellite systems, this device converts and decodes the incoming signal into a form that can be received by a standard television set. The device usually sits on top of the viewer's television.
signal-to-noise ratio
(S/N) The amount of power by which a signal exceeds the amount of channel noise at the same point in transmission. This amount is measured in decibels and indicates the clarity or accuracy with which communication can occur.
sleeping state
A state of low power consumption in a computer or device that supports power management.
smart card
A circuit board the size of a credit card with built-in logic, memory, or firmware that gives it storage and decision-making ability, generally for purposes of purchasing, funds transfer, or identification and validation.
SMPTE time
A broadcast time standard defined by the Society of Motion Picture and Television Engineers. It is formatted as hh:mm:ss;ff where hh is hours, mm is minutes, ss is seconds, and ff is a frame number between 00 and 29. In this format, the television frame rate is 30 frames per second. To compensate for the actual NTSC frame rate being 29.97 frames per second rather than 30, the 00 and 01 frames are dropped at the start of each minute, except for minutes that are numbered as even multiples of 10.
A filter that represents data from a source, such as an MPEG file, and introduces it into a filter graph. Source filters have one or more output pins.
spin lock
A data type that provides a synchronization mechanism for protecting resources shared by kernel-mode threads. A thread acquires a spin lock before accessing protected resources. The spin lock keeps any thread but the one holding the spin lock from using the resource. While waiting for the spin lock, a thread loops, attempting to acquire the spin lock, until the lock is released by the thread that holds it.
An establishment equipped for radio or television transmission.
stream
A collection of data sent over a data channel in a sequential fashion. The bytes are typically sent in small packets, which are reassembled into a contiguous stream of data. Alternatively, the process of sending such small packets of data.
stream request block
(SRB) Information necessary for a vertical blanking interval (VBI) minidriver to process data and control requests for the streams it works with. An SRB comprises a command and data associated with that command. A HW_STREAM_REQUEST_BLOCK structure contains all information relating to a specific SRB.
streaming architecture
A model for interconnection of stream-processing components, in which applications dynamically load data as they output it. Dynamic loading means data can be broadcast continuously. See also WDM streaming.
streaming data
Data continuously broadcast to an application. For example, a broadcast client's user might receive continuously broadcast sports scores.
stub network
A network that carries packets only to and from local devices. Even if a stub network has paths to more than one network, it does not carry traffic for other networks.
subgenre
In Broadcast Architecture, a subset within a genre; for example, science fiction, Western, or soap opera.
super VGA
(SVGA) A video standard established by the Video Electronics Standards Association (VESA) to provide high-resolution color display on IBM-compatible computers. SVGA supports the Video Graphics Array (VGA) standard.
Video in which chrominance and luminance signals are sent separately. This separate transmission produces a sharper video image than composite video, because it has no color artifacts. For example, S-video has no traveling dots or shimmering along color-change lines.