Simplified Block Diagram Showing SDV Architecture, Cable Operator to Subscriber and Return, courtesy of Cisco
Sealing Boot (Sealing Sleeve)
Placed on port threads for outdoor installations. It water seals and corrosion protects the port thread to connector area. [Arr11] SECAM
Système Électronique Couleur avec Mèmoire; a color television system developed by the French and used in the USSR. SECAM operates with 625 lines per picture frame and 50 cycles per second, but is incompatible in operation with the European PAL system or the U.S. NTSC system. [Sat07] SFD
Saturation Flux Density; The power required to achieve saturation of a single repeater channel on the satellite. [Sat07] Second Audio Program (SAP)
In a BTSC-encoded television sound carrier, a monaural audio subcarrier that can be used to transmit supplemental foreign language translation audio or other information.
Secondary Audio Program (SAP)
Secondary audio signal that is broadcast along with a television signal and its primary audio. SAP may be enabled through either the television, stereo VCR equipped to receive SAP signals, or an SAP receiver. SAPs may be used for a variety of enhanced programming, including providing a “video description” of a program’s key visual elements, inserted in natural pauses, that describes actions not otherwise reflected in the dialog, used by visually impaired viewers. This service also allows television stations to broadcast programs in a language other than English, and may be used to receiver weather information, or other forms of “real-time” information. [Fib111] Second Harmonic
A second order beat whose two beating carriers have the same frequency. Second Order Beat
An unwanted carrier created by two separate carriers beating against each other. These beating carriers may have the same or different frequencies.
The cryptographic key used in a symmetric key algorithm, which results in the secrecy of the encrypted data that depends solely on keeping the key a secret; also known as a symmetric key.
Secure Hash Algorithm 1 (SHA-1)
A standards-based method for computing a condensed representation of a message or a data file.
Secured Socket Layer (SSL)
Used to define standard encryption software to pass sensitive information over an unsecured Internet connection. SSL works on encryption of sensitive data using complex techniques and converting them back to original data using keys on the receiving side. Or a public key encryption based protocol for secure communications between client and server.
Security Association (SA)
A one-way relationship between sender and receiver offering security services on the communication flow.
Security Association Identifier (SAID)
Uniquely identifies Security Associations in the DOCSIS Baseline Privacy Plus Interface (BPI+) security protocol.
Security Shield (Security Sleeve)
Protects "F" connections on taps, converters, etc. from tampering. [Arr11] Selective Reception
A characteristic of spatial processing that monitors incoming signals and distinguishes between desirable information and interference; by filtering out interfering signals and appropriately combining the reception from all the antennas in the array, this approach provides significant improvement in signal quality.
A measure of the performance of a radio receiver to respond only to the tuned transmission (such as a radio station) and reject other signals nearby, such as another broadcast on an adjacent channel. Selectivity is usually measured as a ratio in decibels (dB), comparing the signal strength received against that of a similar signal on another frequency. If the signal is at the adjacent channel of the selected signal, this measurement is also known as adjacent-channel rejection ratio (ACRR). Selectivity also provides some immunity to blanketing interference. [Wor11] Self-phase modulation (SPM)
A fiber nonlinearity caused by the nonlinear index of refraction of glass. The index of refraction varies with optical power level causing a frequency chirp which interacts with the fiber’s dispersion to broaden the pulse. [Fib111]
Self-phase Modulation Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/s
Derived from "self-focusing,'' Nippon Sheet Glass Co. (NSG) of Japan's trade name for graded-index fiber rods with parabolic index profile, suitable for use as cylindrical microlenses. [Pho11] Selfoc Lens
A trade name used by the Nippon Sheet Glass Company for a graded-index fiber lens; a segment of graded-index fiber made to serve as a lens. [Fib111] Semiconductor
A material whose resistivity is between that of conductors and insulators, and whose resistivity can sometimes be changed by light, electric field , or a magnetic field. Current flow is sometimes by movement of negative electrons, and sometimes by transfer of positive holes. Used in transistors, diodes, photodiodes, photocells, and thermistors. Some examples are: silicon, germanium, selenium, and lead sulfide. [Arr11] Semiconductor Optical Amplifier (SOA)
A specialized laser diode, without end mirrors, with fiber attached to both ends. SOAs amplify any optical signal that comes from either fiber and transmit an amplified version of the signal out of the second fiber. SOAs are typically constructed in a small package and work for 1310 nm and 1550 nm systems. In addition, they transmit bidirectionally, making the reduced size of the device an advantage over regenerators or EDFAs. However, the drawbacks to SOAs include high-coupling loss, polarization dependence, and a higher noise figure. Modern optical networks utilize SOAs in the following ways: (1) Power Boosters: Many tunable laser designs output low optical power levels and must be immediately followed by an optical amplifier. (A power booster can use either an SOA or EDFA). (2) In-Line Amplifier: Allows signals to be amplified within the signal path. (3) Wavelength Conversion: Involves changing the wavelength of an optical signal. (4) Receiver Preamplifier: SOAs can be placed in front of detectors to enhance sensitivity. [Fib111]
The sensitivity of an electronic device, e.g., a communications system receiver, or detection device, e.g., PIN diode, is the minimum input signal required to produce a specified output signal having a specified signal-to-noise ratio (SNR), or other specified criteria. Note 1: The sensitivity of a microphone is usually expressed as field strength in dB re 1 V/Pa (Pa = N/m²) or as millivolts per pascals (mV/Pa) into an open circuit or into 1 kilo ohms load.
Note 2: "Sensitivity" is sometimes improperly used as a synonym for "responsivity."
Source: from Federal Standard 1037C and from MIL-STD-188. [Wor11] Serial
One bit at a time, along a single transmission path. [Fib111] Serial Digital
Digital information that is transmitted in serial form. Often used informally to refer to serial digital television signals. [Fib111] Serial Digital Interface (SDI)
A 10-bit, scrambled, polarity independent interface, based on a 270 Mb/s data rate, with common scrambling for both component ITU-R 601, composite digital video, and four channels of (embedded) digital audio. Most new broadcast digital equipment includes SDI. [Fib111] Serial Digital Transport Interface (SDTI)
Another name for Society for Motion Picture and TV Engineers (SMPTE) 305M. Allows faster-than-real-time transfers between various servers and between acquisition tapes, disk-based editing systems and servers. Supports both 270 Mb/s and 360 Mb/s data rates. [Fib111] Server
A computer and/or software that provides and controls resources for clients on a network. These resources can include hardware devices such as printers and storage systems, or files as in the case of a Web server. Service
A service is a sequence of programs under the control of a broadcaster which can be broadcast as part of a schedule.
Service Access Point (SAP)
The point at which services are provided by one layer, or sublayer to the layer immediately above it.
An application is service-bound if, and only if, it is associated with one or more broadcast services.
A set of queuing and scheduling attributes that is named and that is configured at the cable modem termination system (CMTS). A Service Class is identified by a Service Class Name. A Service Class has an associated QoS Parameter Set.
Service Class Name
An ASCII string by which a Service Class may be referenced in modem configuration files and protocol exchanges.
Service Control Point (SCP)
A SCP is a node within a signaling system number 7 (SS7) network that provides centralized service logic and data, such as call routing information.
Service Data Unit (SDU)
The information that is delivered as a unit between peer service access points (SAPs).
Service Flow (SF)
A unidirectional flow of packets on the RF interface of a DOCSIS system. Or a MAC-layer transport service which provides unidirectional transport of packets from the upper layer service entity to the RF. It also shapes, polices and prioritizes traffic according to QoS traffic parameters defined for the Flow.
Service Flow Identifier (SFID)
A 32-bit integer assigned by the CMTS to each DOCSIS Service Flow defined within a DOCSIS RF MAC domain. Any 32-bit SFID must not conflict with a zero- extended 14-bit SID. SFIDs are considered to be in either the upstream direction (USFID) or downstream direction (DSFID). USFIDs and DSFIDs are allocated from the same SFID number space.
Service Identifier (SID)
An identifier appearing in the DOCSIS media access control (MAC) allocation map message, which identifies the entities which may make use of a particular upstream bandwidth assignment. A cable modem may have one or more unicast SIDs. A group of cable modems may share a multicast SID.
Service Information (SI)
That information that describes the broadcast services available on the network.
Service Profile Identifier (SPID)
A number that the telephone company switching equipment uses to keep track of configuration information for each terminal adapter connected to an ISDN telephone line. The telephone company should give you your SPIDs at the time they assign you your ISDN directory numbers.
Automatic device for regulating. [Fib111] Session Description Protocol (SDP)
A DDE-1 protocol that defines a multicast session that may or may not be concurrent with a TV program. Or IETF protocol that describes multimedia sessions for the purposes of session announcement, session invitation, and other forms of multimedia session initiation. Session Initiation Protocol (SIP)
An Internet protocol used for negotiating multimedia sessions across the network.
A cryptographic key intended to encrypt data for a limited period of time, typically between a pair of entities.
Set-Top Box (STB)
Any of several different electronic devices that may be used in a customer's home to enable services to be on that customer's TV. If the “set-top” device is used only for extending the channels available, it is called a converter. If it restores scrambled or otherwise protected signals, it is a descrambler.
Short Haul; a classification of video performance under RS-250B/C. Higher performance than long-haul or medium-haul. [Fib111]
SHA-1 Secure Hash Algorithm 1 Shadow Mask
A metal plate filled with holes that perfectly match the phosphor groupings in a color television. The shadow mask, or aperture grill as it’s sometimes known, is used to keep the electron beams from straying into other phosphor groupings in a color cathode ray tube. Often the shadow mask is installed as part of the phosphor addition process because the tiny holes need to be perfectly aligned. A slight variance in the position of the shadow mask can greatly affect screen performance. [Glo07] Shannon's Law
An arithmetic proof that defines the maximum data rate an analog device can achieve when sending information over a sampled, analog-to-digital connection when the analog device has no control over the timing of each individual sample. For the North American telephone system, which has a sample rate of 8,000 samples per second with a range of up to 128 sample values, Shannon's Law shows the maximum data rate that can be achieved over voice grade lines to be about 36Kbps.
The percent of television households tuned to a particular program or category of programming.
Shared Wired Network
A topology where multiple households connect to a common piece of wire.
An outer protective layer of a fiber optic cable. Also called the cable jacket. [Fib111]
Sheath Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/s
A grooved wheel or pulley used when installing cable in underground plant. [Arr11]
A sheet, screen or braid of metal, usually copper, aluminum or other conducting material placed around or between electric circuits or cables or their components, to contain any unwanted radiation, or to keep out any unwanted interference. [Arr11] Shield Coverage (Shield Percentage)
The physical area of a circuit or cable actually covered by shielding material, expressed in percent. [Arr11] Shop-At-Home
Programs allowing customers to view products and/or order them by cable TV, including catalogues, shopping shows, etc.
Noise caused by current fluctuations arising from the discrete nature of electrons. [Fib111] Shrink Tubing
A plastic-based tubing which, when heated to a critical temperature, will shrink and form a weatherproof seal. Applied to connectors to protect the connection from any possibility of water infusion. Also known as heatshrink. [Arr11]
Silicon; generally used in optical photo detectors. Good for short wavelengths only (e.g., < 1000 nm). [Fib111] SI Service Information
SI System Integrators SI Units
Système Internationale (in English, International System of Units), commonly known as the metric system. [Fib111]
Silicon Carbide; a bluish-black crystalline compound, SiC, one of the hardest known substances, used as an abrasive and heat-refractory material and in single crystals as semiconductors, especially in high-temperature applications. [Ans11]
Read more: http://www.answers.com/topic/silicon-carbide#ixzz1H3gIp6VO SID Service Identifier Sideband
Frequencies distributed above and below the carrier that contain energy resulting from amplitude modulation. The frequencies above the carrier are called upper sidebands, and the frequencies below the carrier are called lower sidebands. [Fib111] Side Lobe
A construct used to describe an antenna's ability to detect off-axis signals. The larger the side lobes, the more noise and interference a dish can detect. High side lobe rejection is a desirable antenna characteristic. [Arr11] SiGe
Silicon Germanium; a semiconductor material made from silicon and germanium. Germanium is very similar to silicon, but when one layer is grown on top of the other to form the base of the transistor, the resulting transistor can switch faster and yield higher performance. SiGe transistors are compatible with standard fabrication processes and are built on the same chip with silicon transistors to create high-frequency circuits. Only a handful of SiGe transistors are used in mobile phones, while tens of thousands are used in optical switches, DACs and ADCs. [PCm11] Signal
Any visible or audible indication which can convey information. Also, the information conveyed through a communication system. [Arr11] Signal Leakage
Undesired emission of signals out of a cable television system. Signal Level
The RMS voltage signal level, usually expressed in dBmV. [Arr11] Signal Level Meter (SLM)
A tuned radio frequency voltmeter, usually calibrated in decibels per millivolt (dBmV) as well as voltage. [Arr11] Signal Switching Point (SSP)
SSPs are points within the signaling system number 7 (SS7) network that terminate SS7 signaling links and also originate, terminate, or tandem switch calls.
Signal-to-Noise Ratio (S/N)
The ratio of usable signal power to extraneous noise power in a specified bandwidth, indicating picture quality, usually expressed in decibels. Also referred to as SNR. [Arr11] Signal Transfer Point (STP)
A STP is a node within signaling system number 7 (SS7) network that routes signaling messages based on their destination address. It is essentially a packet switch for SS7. It may also perform additional routing services such as Global Title Translation.
The process by which an end system notifies a network that it wants service.
Signaling Connection Control Part (SCCP)
This is a protocol within the signaling system number 7 (SS7) suite of protocols that provides two functions: (1) The ability to address applications within a signaling point. (2) Global Title Translation.
Signaling Gateway (SG)
A signaling agent that receives/sends switched circuit network (SCN) native signaling at the edge of the Internet protocol (IP) network. In particular the signaling system number 7 (SS7) SG function translates variants ISUP and TCAP in an SS7-Internet Gateway to a common version of ISUP and TCAP.
Signaling System Number 7 (SS7)
SS7 is an architecture and set of protocols for performing out-of-band call signaling with a telephone network.
Signal-to-Noise Ratio (SNR)
The sensitivity of a communications receiver is generally specified in terms of the audio signal-to-noise ratio that results from an input signal of a certain number of microvolts.
Signed and Sealed
An “envelope” of information which has been signed with a digital signature and sealed using encryption.
Glass made mostly of silicon dioxide, SiO2, used in conventional optical fibers. [Fib111] SILVO
An organization formed in the mid 1980's to monitor frequency re-use. [Sat07] Simple Gateway Control Protocol (SGCP)
A call signaling protocol used for controlling media gateways from a call agent (or Call Management Server) within the network. SGCP was the precursor to the PacketCable Network-based Call Signaling (NCS) protocol.
Simple Mail Transfer Protocol (SMTP)
A TCP/IP protocol used to send e-mail on a network or to route e-mail on the Internet.
Simple Network Management Protocol (SNMP)
SNMP allows a TCP/IP host running an SNMP application to query other nodes for network-related statistics and error conditions. The other hosts, which provide SNMP agents, respond to these queries and allow a single host to gather network statistics from many other network nodes.
A circuit which can carry information in only one direction; for example, broadcasting. [Arr11]
A term sometimes used for a single-fiber cable. [Fib111] Simplex Transmission
Transmission in one direction only. Also referred to as half-duplex transmission. [Fib111]
Simplex Transmission Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/s