Conrad L. Young’s Wired Broadband and Related Industry Glossary of Terms with Acronyms As of 15 February 2012 Open Access This document is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial
STS-n SONET Transport Signal level n. The electrical signal level (rate) of SONET networks
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STS-n SONET Transport Signal level n. The electrical signal level (rate) of SONET networks. (Arris Glossary of Terms)
(Wikipedia) STTR Small Business Technology Transfer Resources STUN Simple Traversal of User Datagram Protocol (UDP) Through Network Address Translators Sub Subscriber; a cable customer. Sub Band The frequency band from 6 MHz to 54 MHz, which may be used for two-way data transmission. Also known as sub-VHF channels, television channels usually between 5.75 and 47.75 MHz or at frequencies lower than channel 2. (Arris Glossary of Terms) Subcarrier A second signal "piggybacked" onto a main signal to carry additional information. In satellite television transmission, the video picture is transmitted over the main carrier. The corresponding audio is sent via an FM subcarrier. Some satellite transponders carry as many as four special audio or data subcarriers whose signals may or may not be related to the main programming. Subflow A unidirectional flow of IP packets characterized by a single source and destination IP address and single source and destination UDP/TCP port. Sublayer A subdivision of a layer in the Open System Interconnection (OSI) reference model. Submarine Cable A cable designed to be laid underwater. (FiberOpticsInfo) 
Submarine Cable Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/s Subnetwork Subnetworks are formed by connecting adjacent nodes physically with transmission links. Subnetwork Access Protocol (SNAP) An extension of the LLC header to accommodate the use of 802-type networks as Internet Protocol (IP) networks. Subsatellite Point The unique spot over the earth's equator assigned to each geostationary satellite. (Satnews) Subscriber A household or business that legally receives and pays for cable and/or pay television service for its own use. Alternate definition is: The entity that is the subject of, and has been issued, a Certificate. The Subscriber is capable of using, and is authorized to use, the private key that corresponds to the public key listed in the Certificate. Also, the telephone or CATV customer. Subscriber Converter See Converter, subscriber. Subscriber Line Charge (SLC) A monthly fee paid by telephone subscribers that is used to compensate the local telephone company for part of the cost of installation and maintenance of the telephone wire, poles and other facilities that link your home to the telephone network. These wires, poles and other facilities are referred to as the "local loop." The SLC is one component of access charges. (Timbercon) Subscriber Loop The part of the telephone network that runs from the Central Office to individual subscribers. (Timbercon) Subscriber Media Gateway (SMG) A media gateway located within the subscriber's network which “bridges” calls between the Internet Protocol (IP) network and the subscribers' telephones (or telephony-type devices). Typically such a media gateway provides an external interface to one or more 2500-type telephony handsets and also supports common standard add-on devices such as caller-id display units and message-waiting lights. Subscriber Unit The fixed, typically wall-mounted equipment used by the subscriber in a wireless local-loop system to send and receive messages; a standard telephone is attached to it by wire to complete the connection to the user. Subscription Television (STV) A special service providing additional programs in encoded form to television viewers who pay a monthly rate. (Timbercon) Subsidiary Communications Services A subcarrier of television and FM stations providing a second audio programming source. (Timbercon) Subsplit A frequency-division scheme that allows bi-directional traffic on a single cable. Reverse path signals come to the headend from 5 to 30 (up to 42 on extended subsplit systems) MHz. Forward path signals go from the headend from 50 or 54 MHz to the upper frequency limit of the cable network. An example of a subsplit HFC network frequency plan is shown below: 
Subsystem An element in a hierarchical division of an open system that interacts directly with elements in the next higher division or the next lower division of that open system. Sun Angle The angle of the Sun above the horizon. Both the quantity (lumens) and the spectral quality of light being reflected to a remote sensor are influenced by Sun angle. Also called Sun elevation and Sun elevation angle. (Timbercon) Sun Synchronous An Earth satellite orbit in which the orbital plane remains at a fixed angle with respect to the Sun, precessing through 360°. (Timbercon) Superband The band of cable television channels J through W lying between 216 MHz and 300 MHz. In satellite communications, the frequency band from 216 to 600 MHz used for fixed and mobile radios and additional television channels on a cable system. (Satnews) Superheterodyne Superheterodyne refers to a method of designing and building wireless communications or broadcast equipment, particularly radio receivers. Sometimes a receiver employing this technology is called a "superheterodyne" or "superhet." (What is ) The superheterodyne (short for supersonic heterodyne) receiver was first evolved by Major Edwin Howard (E. H.) Armstrong. (VK5BR) One of Armstrong's four principal inventions—regeneration, superregeneration, the superheterodyne, and frequency modulation (FM), he devised it during World War I, patented it shortly afterward, sold his patent to Westinghouse, who cross-licensed RCA and the radio industry. (Douglas) , in 1918. It was introduced to the market place in the late 1920s. Superheterodyne Receiver To “heterodyne” means to mix to frequencies together so as to produce a beat frequency, namely the difference between two frequencies. Amplitude modulation is a heterodyne process: the information signal is mixed with the carrier to produce the side-bands. The side-bands occur at precisely the sum and difference frequencies of the carrier and information. These are beat frequencies (normally the beat frequency is associated with the lower side-band, the difference between the two). When you use the lower side-band (the difference between the two frequencies), you are “superheterodyning”. Strictly speaking, the term superheterodyne refers to creating a beat frequency that is lower than the original signal. Although we have used amplitude modulation side-bands as an example, we are not talking about encoding information for transmission. What superheterodying does is to purposely mix in another frequency in the receiver, so as to reduce the signal frequency prior to processing. Why and how this is done will be discussed below. As discussed above, superheterodyning is simply reducing the incoming signal in frequency by mixing. In a radio application we are reducing the AM or FM signal which is centered on the carrier frequency to some intermediate value, called the IF (intermediate frequency). For practical purposes, the superheterodyne receiver always reduces to the same value of IF. To accomplish this requires that we be able to continuously vary the frequency being mixed into the signal so as to keep the difference the same. Here's what the superheterodyne receiver looks like: 
This is essentially the conventional receiver with the addition of a mixer and local oscillator. The local oscillator is linked to the tuner because they both must vary with the carrier frequency. For example, suppose you want to tune in a TV station at 235 MHz. The band-pass filter (which only permits signals in a small range about the center frequency to pass) must be centered at 235 MHz (or slightly higher in single side-band (SSB)). The local oscillator must be set to a frequency that will heterodyne the 235 MHz to the desired IF of 452 kHz (typical). This means the local oscillator must be set to 234.448 MHz (or alternatively to 235.452 MHz) so that the difference frequency will be exactly 452 kHz. The local oscillator must be capable of varying the frequency over the same range as the tuner; in fact, they vary the same amount. Therefore, the tuner and the local oscillator are linked so they operate together. Advantages of Using Superheterodyning Now, we easily see that this type of receiver can be constructed, but for what purpose? All we have accomplished is to reduce the frequency to the IF value. We still must process the signal as before. So why do many receivers use the superheterodyne method? There are three (3) main advantages, depending on the application used for:
Super Shield See quad shield cable. Superstation Originally referred to television station WTBS in Atlanta; now generally used to describe any broadcast TV station that has its signal distributed nationally by satellite. Superstation A North American television broadcast station, other than a Broadcast Network station, licensed by the FCC that is secondarily transmitted by a satellite carrier. (Timbercon) Supertrunk A cable that carries several video channels between facilities of a cable television company. (Arris Glossary of Terms) Supertrunking The application of cable systems to transport television signals with minimum degradation. Wireless point-to-point and point-to-multipoint systems, such as Amplitude Modulated Link (AML) and optical fiber are also used for supertrunking applications. Supertrunking applications include providing headend (HE) to hub transport, extending the cable system to adjacent communities, and transporting signals from an off-air antenna site remote from the cable system. (Hartwick) Supplemental Ordinary Keycodes Keycodes other than the Mandatory Ordinary Keycodes that have not been reserved for special purposes, and thus will be treated the same as the Mandatory Ordinary Keycodes, i.e., will be available to the application that has focus. Surface-emitting Diode A simple and inexpensive LED that emits light from its flat surface rather than its side with emission spread over a wide angle. (FiberOpticsInfo) 
Surface-emitting Diode Diagrams courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/s Surge Protection Optional feature for all line passives (RPI, RLS,RLDC). Shunts voltage surges to ground, protecting the active passive system components. Voltage surges can be from lightning, power sup-ply surges and power grid surges. (Arris Glossary of Terms) Surround Sound More commonly referred to as Dolby Digital, a standard for high-quality digital audio that is used for the sound portion of video stored in digital format, especially videos stored on DVD-ROMs. Dolby Digital delivers 6 channels in the so called “5:1” configuration: left, right, and center screen channels, separate left and right sounds, and a subwoofer channel. (FiberOpticsInfo) SVC Switched Virtual Circuit SVD Subscriber Video Device S-Video High quality video interface, derived from Super VHS signal format. SVOD Subscription Video On Demand Sweep-Test Pertaining to cable, checking frequency response by generating an RF voltage whose frequency is varied back and forth through a given frequency range at a rapid constant rate and observing the results on an oscilloscope. In cable TV applications, the structural return loss sweep-test determines internal reflections in the cable. A high structural return loss is desirable. (Arris Glossary of Terms) Switch 1) In communications systems, a mechanical, electro-mechanical, or electronic device for making, breaking, or changing the connections in or among circuits. 2) Synonym for central office, switching center or switched hub, a device used for connecting Ethernet LANs. 3) In communications systems, to transfer a connection from one circuit to another. (FiberOpticsInfo) Switched Circuit Network (SCN) Synonym for the Public Switched Telephone Network. Switched Network Any network in which switching is present and is used to direct messages from the sender to the ultimate recipient. Usually switching is accomplished by disconnecting and reconnecting lines in different configurations in order to set up a continuous pathway between the sender and the recipient. Switched Service A cable communications service in which each subscriber has a terminal and may communicate with any other subscriber. Switched Virtual Circuit (SVC) Allow an end-user to establish on-demand data connections between two end points on an ATM, Frame Relay, or X.25 network. See also Permanent Virtual Circuit (PVC). Switcher A control which permits the selection of one image from any of several cameras to be fed into the television display or recording system. Switcher/Fader A device permitting gradual, overlapping transition from the image of one camera to another. Sometimes incorporated as part of a special effects generator. Symmetric Key The cryptographic key used in a symmetric key algorithm—an algorithm for cryptography that uses the same cryptographic key to encrypt and decrypt messages. Sync An abbreviation for the words “synchronization”, “synchronizing”, etc. Applies to the synchronization signals, or timing pulses, which lock the electron beam of the picture monitors in step, both horizontally and vertically, with the electronic beam of the pickup tube. The color sync signal (NTSC) is known as the color burst. Sync Compression The reduction in the amplitude of the sync signal, with respect to the picture signal, occurring between two points of a circuit. Sync Generator A device used to supply a common or master sync signal to a system of several cameras. This ensures that their scanning pulses will be in phase. Scanning pulses out of phase produce distortion or rolling, sometimes called “sync loss.” Sync Level The level of the tips of the synchronizing pulses. Synchronization Pulse 1) A signal derived from the composite or combination of the horizontal and vertical drives. 2) A pulse used to achieve or maintain synchronism, usually applied to analog signals. (The term “synchronization bit” is usually applied to digital data streams.) Commonly called the sync pulse. See also composite sync. (FiberOpticsInfo) Synchronizing Pulses Pulses imposed on the composite baseband video signal used to keep the television picture scanning in perfect step with the scanning at the television camera. (Channel Vision) Synchronous A data signal that is sent along with a clock signal. A system in which events, such as signals, occur at evenly spaced time durations. Opposite of asynchronous. (FiberOpticsInfo) 
Synchronous_Asynchronous Diagrams courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/s Synchronous Code Division Multiple Access (S-CDMA) A multiple access physical layer technology in which different transmitters can share a channel simultaneously. The individual transmissions are kept distinct by assigning each transmission an orthogonal “code.” Orthogonality is maintained by all transmitters being precisely synchronized with one another. S-CDMA is one of the physical layer technologies included in DOCSIS® 2.0. Synchronous Digital Hierarchy (SDH) SDH and SONET are standardized multiplexing protocols that transfer multiple digital bit streams over optical fiber using lasers or light-emitting diodes (LEDs). Lower data rates can also be transferred via an electrical interface. The method was developed to replace the Plesiochronous Digital Hierarchy (PDH) system for transporting larger amounts of telephone calls and data traffic over the same fiber without synchronization problems. SONET generic criteria are detailed in Telcordia Technologies Generic Requirements document GR-253-CORE.[1] Generic criteria applicable to SONET and other transmission systems (e.g., asynchronous fiber optic systems or digital radio systems) are found in Telcordia GR-499-CORE.[2] SONET and SDH, which are essentially the same, were originally designed to transport circuit mode communications (e.g., DS1, DS3) from a variety of different sources, but they were primarily designed to support real-time, uncompressed, circuit-switched voice encoded in PCM format.[3] The primary difficulty in doing this prior to SONET/SDH was that the synchronization sources of these various circuits were different. This meant that each circuit was actually operating at a slightly different rate and with different phase. SONET/SDH allowed for the simultaneous transport of many different circuits of differing origin within a single framing protocol. SONET/SDH is not itself a communications protocol per se, but a transport protocol. Due to SONET/SDH's essential protocol neutrality and transport-oriented features, SONET/SDH was the obvious choice for transporting Asynchronous Transfer Mode (ATM) frames. It quickly evolved mapping structures and concatenated payload containers to transport ATM connections. In other words, for ATM (and eventually other protocols such as Ethernet), the internal complex structure previously used to transport circuit-oriented connections was removed and replaced with a large and concatenated frame (such as OC-3c) into which ATM cells, IP packets, or Ethernet frames are placed. (Wikipedia)
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