S

[This is preliminary documentation and subject to change.]

satellite receiver card: A broadcast receiver card that receives and processes data sent by satellite.
satellite uplink: 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 also NTSC.
Secure Electronic Transaction: (SET) The Microsoft standard for safely transmitting Visa or Mastercard information to support electronic commerce over the Internet.
server: On a network, a computer running software that provides data and services to clients over the network. The term server can also apply to a software process, such as an Automation server, that similarly sends information to clients and that appears on the same computer as a client process, or even within the same application.
server lookup: The process by which a content server application finds for a specified data service the names of the appropriate Microsoft Multicast Router, address reservation server, and bandwidth reservation server, along with the Internet Protocol (IP) multicast addresses reserved for global and local announcements for that data service. Because there are likely to be backup machines for the servers and the router, these names can each resolve to more than one actual IP address. For more information, see the MSBDN Services Overview section of the Broadcast Architecture Programmer's Reference. See also IP multicast address assignment.
service provider: In Broadcast Architecture, a business that provides a broadcast data service.
Session Announcement Protocol: (SAP) An Internet protocol for announcements that 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 produced by the Internet Engineering Task Force (IETF). See also Session Announcement Protocol.
session key: A Triple DES key used to encrypt broadcast data content.
SET: See Secure Electronic Transaction.
set-top box: 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.
show reference: Information about a television show in a text data format that specifies such things as the time the show is broadcast, the channel the show is broadcast on, and the show's duration. Show references allow software based on Broadcast Architecture to exchange references to television shows.
show reminder: Tasks in Task Scheduler that remind a user to watch or record a television broadcast. Show reminders can be set by Microsoft WebTV for Windows and by applications developed by independent software vendors.
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.
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.
S/N: See signal-to-noise ratio.
source filter: A filter that receives 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. A thread waiting for the spin lock loops, attempting to acquire the spin lock, until it is released by the thread that holds the lock.
SRB: See stream request block.
station: 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 subscribe to continuously broadcast sports scores.
string: Data composed of a sequence of characters, usually representing human-readable text.
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.
SVGA: See super VGA.
S-video: 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.