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
Download 2.22 Mb.
|
They are sometimes known as Bowditch curves after Nathaniel Bowditch, who studied them in 1815. They were studied in more detail (independently) by Jules-Antoine Lissajous in 1857 (MacTutor Archive). Lissajous curves have applications in physics, astronomy, engineering, and other sciences. The curves close if  is rational.
Lissajous curves are a special case of the harmonograph with damping constants  .
Examples of Lissajous Curves, courtesy of Weisstein, Eric W. "Lissajous Curve." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/LissajousCurve.html Special cases are summarized in the following table, and include the line, circle, ellipse, and section of a parabola.
The line, circle, ellipse, and section of a parabola; all special cases of the Lissajou Curve courtesy of Weisstein, Eric W. "Lissajous Curve." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/LissajousCurve.html REFERENCES:
(Weisstein) LLC Logical Link Control LLID Logical Link Identifier; an optical network assignable address given to passive optical network (xPON) optical network units (ONUs) by the optical line termination (OLT) during the discovery process. Discovery is the process whereby newly connected or off-line ONUs are provided access to the PON. The process is driven by the OLT, which periodically makes available Discovery Time Windows during which off-line ONUs are given the opportunity to make themselves known to the OLT. The periodicity of these windows is unspecified and left up to the implementer. The OLT signifies that a discovery period is occurring by broadcasting a discovery gate message, which includes the starting time and length of the discovery window. Off-line ONUs, upon receiving this message, wait for the period to begin and then transmit a Register_Req message to the OLT. Discovery windows are unique in that they are the only times where multiple ONUs can access the PON simultaneously, and transmission overlap can occur. In order to reduce transmission overlaps, a contention algorithm is used by all ONUs. Measures are taken to reduce the probability for overlaps by artificially simulating a random distribution of distances from the OLT. Each ONU shall wait a random amount of time before transmitting the Register_Req message that is shorter than the length of the discovery time window. It should be noted that multiple valid Register_Req messages can be received by the OLT during a single discovery time period. Included in the Register_Req message is the ONU’s MAC address and number of maximum pending grants. Upon receipt of a valid Register_Req message, the OLT registers the ONU, allocating and assigning new port identities (LLIDs), and bonding corresponding MACs to the LLIDs. (FreeDictionary dot com) LMDS Local Multipoint Distribution System LNA Low Noise Amplifier LNB Low Noise Blockdown Converter; a device within a satellite dish which converts C-Band, X-Band, Ku-Band, or Ka-Band satellite communications downlink frequencies (IF) to lower L-Band intermediate frequencies (FiberOpticsInfo) 
LNB Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/l
Local Access and Transport Area Switching Systems Generic Requirements (LSSGR) A very large set of documents published by Telcordia (formerly Bellcore) that describes the local telephone network. Local Area Network (LAN) A LAN is a collection of computing equipment at a single location (e.g., an office building or campus) that communicate with each other to share resources and information, such as disk storage and files, printers, and e-mail. See also WAN. Or a non-public data network in which serial transmission is used for direct data communication among data stations located on the user's premises. Local Area Network A communications network that is restricted to a small geographical area, usually within a building or on a campus, and that has cabling normally installed and/or controlled by the organization that operates the network. (Arris Glossary of Terms) Local Distribution System (LDS) A wide band microwave system or cable system which is capable of transporting a number of television signals simultaneously. Used to interconnect cable system headends. Local Exchange An exchange where telephone subscriber lines connect. Local Exchange Carrier (LEC) Telephone company lingo for your local telephone company. See also RBOC. Local Loop An access circuit from the network edge to the customer premises, a local loop is a short haul circuit for access to a local exchange. The most common example of a local loop is an electrically based, two-wire, copper access circuit between a telephone company central office (CO) switching center and a residential or small business premises. Such a circuit is provisioned over a single unshielded twisted pair (UTP), within which two wires are required to complete the electrical circuit, with the current in one wire opposite to the current in the other, and with both wires carrying the information signal. The two conductors comprise an electrical loop, with one wire carrying the go signal and the other carrying the electrical return signal. In the broader contemporary sense, any access circuit between the customer premises and the edge of the telco network, or that of any other service provider, is termed a local loop, whether it is electrically based or employs optical or radio energy. (Dictionary, Your Dictionary) Local Loop This portion of the telecommunications network physically connects end users to the central office network facilities and generally is dedicated to that particular user. Twisted pairs of copper wire form the traditional medium of the telephone network local loop, although other connections now are used in some cases. Local Multipoint Distribution System (LMDS) A fixed wireless technology that is one solution for bringing high-bandwidth services to homes and offices within the “last mile” of connectivity. Local Number Portability (LNP) A system that allows local telephone numbers to be transferred to competitive local exchange carriers. This allows the subscriber to change local phone companies without experiencing a change in phone numbers. Local Origination Programming developed by an individual cable TV system specifically for the community it serves. Local Oscillator A device used to supply a stable single frequency to an upconverter stage of a downconverter. The local oscillator signal is mixed with the carrier wave to change its frequency. (Arris Glossary of Terms) Local Signals Television signals that are received at locations that are within the station's Predicted Grade B Contour. Cable systems must carry all commercial local signals in their areas. Locator This term has different definitions depending on the application format: A DVB- HTML locator is a link, expressed in the syntax in IETF RFC 2396 [40], which provides an unambiguous pointer to a DVB-HTML document accessible to the MHP in a specific transport stream. The scheme specified should resolve to one of the available transports signaled for the DVB-HTML application. For signed DVB-HTML applications, the schemes HTTP and HTTPS may use the return channel. This version of the specification does not include a scheme for transporting independent locators; future versions are expected to do so. This term in the DVB-HTML context should not be confused with the DVB-J class of the same name. Locking Nut A component of a connector, used to seize and retain the cable outer conductor. (Arris Glossary of Terms) Locking Terminator A theft-proof connector used in a cable system where it becomes necessary to terminate both RF signal and 60 Hz AC power. (Arris Glossary of Terms) Log-Periodic Antenna A directional antenna in which the size and spacing of the elements increase logarithmically from one end of the antenna to the other. (Arris Glossary of Terms) Logical Link Control (LLC) The LLC network protocol sublayer is the part of the data link layer that uses the services of the Medium Access Control (MAC) Layer to provide services to the Network Layer. See also Logical Link Control Procedure. Logical Link Control Procedure In a local area network (LAN), or a metropolitan area network (MAN), that part of the protocol that governs the assembling of data link layer frames and their exchange between data stations, independent of how the transmission medium is shared. Long-Distance Service This term refers to a communication terminating outside the local telephone service area of the originating party. Since 1984 in the U.S., the term generally has meant service across local access and transport areas (LATAs). Long Form Video Content A type of video content that has a content arc with a beginning, middle, and end which in its entirety typically lasts longer than ten (10) minutes. It may include professionally produced content from television and cinema that has migrated online, as well as personal videos shared online. If the content is ad supported, it typically contains breaks (mid-roll). (Fain) Long Form Video Portal A Web site that provides access to a variety of video sources. Individual video content providers such as Amazon, Hulu and Netflix host their own Web sites, but portals such as Zinc and Boxee provide access to multiple video sources. (P. M. Encyclopedia) Long-haul Telecommunications 1. In public switched networks, regarding circuits that span long distances, such as the circuits in inter-LANA, interstate, and international communications. 2. In military use, communications among users on a national or worldwide basis. Long-haul communications are characterized by a higher level of users, more rigorous performance requirements, longer distances between users, including worldwide distances, higher traffic volumes and densities, larger switches and trunk cross sections, and fixed and recoverable assets. Usually pertains to the U.S. Defense Communications System. (FiberOpticsInfo) Longitude The distance east or west of the prime meridian, measured in degrees. (Arris Glossary of Terms) Longitudinal Mode An optical waveguide mode with boundary condition determined along the length of the optical cavity. (FiberOpticsInfo) Loose-tube A type of fiber optic cable construction where the fiber is contained within a loose tube in the cable jacket. (FiberOpticsInfo) 
Loose-tube Fiber Construction Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/l LORAN C Long Range Navigation mode C. Provides navigation and very accurate time information via radio. (Arris Glossary of Terms) LOS Line Of Sight Loss Power dissipated in a device, cable, or network expressed in decibels. See attenuation. (Arris Glossary of Terms) Loss Budget An accounting of overall attenuation in a system. See optical link loss budget. (FiberOpticsInfo) Lossless Compression 1) Reduction of the storage size of digital data by employing one or more appropriate algorithms in such a way that the data can be recovered without losing integrity. 2) Reduction of the amount of data that needs to be transmitted per unit time though an analogous real-time process that does not compromise the ability to completely restore the data. (FiberOpticsInfo) Lossy Compression Reduction of the bit-rate for an image signal by using algorithms that achieve a higher compression than lossless compression. Lossy compression presents loss of information and artifacts that can be ignored when comparing to original image. Lossy compression takes advantage of the subtended viewing angle for the intended display, the perceptual characteristics of the human eye, the statistics of image populations, and the objective of the display. 2) Removal of redundant bits from an image in video technology producing a minor loss of image quality. (FiberOpticsInfo) Low Band That portion of the electromagnetic spectrum from 54 to 88MHz, NTSC television channels 2 to 6. (Arris Glossary of Terms) Low Noise Amplifier (LNA) An electronic device that amplifies weak satellite signals while keeping any received noise and interference to a minimum. The unit is mounted on a feedhorn and is rated in degrees Kelvin. (Arris Glossary of Terms) Low Noise Block Downconverter (LNB) An electronic device used on satellite antennas that amplifies and converts weak satellite signals to a lower band of frequencies. The unit is mounted on a feedhorn and is rated in degrees Kelvin. (Arris Glossary of Terms) Low Noise Converter (LNC) A combination Low Noise Amplifier and down converter built into one antenna-mounted package. (Satnews) Low Orbit At an altitude of 200 to 300 km this orbit is used for certain types of scientific or observation satellites, which can view a different part of the Earth beneath them on each orbit revolution, as they overfly both hemispheres. (Satnews) Low Pass Filter (LPF) Replaces the regular filter (used for one-way transmission) on a drop, and enables a subscriber to have 2-way service. The LPF allows low frequencies to pass, but blocks out higher frequencies. Low Power Satellite Satellite with transmit RF power below 30 watts. (Satnews) Low Power Television Broadcast medium that is similar to commercial TV but limited in broadcast coverage area by its low power signal. Low-Split Common HFC frequency assignment in which upstream (to head-end) is below 42MHz and downstream (to customer) is above 54MHz. Low VHF Band The part of the frequency band allocated by the FCC for VHF broadcast television, including NTSC television channels 2 through 6, or 54 through 108 MHz. LPF Low Pass Filter L/R Left/Right baseband audio outputs from stereo system LSSGR Local Access and Transport Area Switching Systems Generic Requirements LTCC Low Temperature Co-fired Ceramic Luminance Signal That portion of the NTSC color television signal which contains the luminance or brightness information.
M2M A three-letter abbreviation with multiple meanings, as described below:
mA Milliamp (Arris Glossary of Terms) MA Monitor Application MAC Media Access Control MAC Medium Access Control MAC Message Authentication Code MAC (A, B, C, D2) Multiplexed Analog Component color video transmission system. Subtypes refer to the various methods used to transmit audio and data signals. (Satnews) A video standard developed by the European community. An enhanced version, HD-MAC delivers 1250 lines at 50 frames per second, HDTV quality. (FiberOpticsInfo)
Macrobend Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/m Macrocell Cellular telephone network term describing an architecture that provides the largest area of coverage within a mobile network. The antenna for macrocells can be mounted on ground-based masts, rooftops or other existing structures. They must be positioned at a height that is not obstructed by terrain or buildings. Macrocells provide radio coverage over varying distances depending on the frequency used, the number of calls made and the physical terrain. Macrocell base stations have a typical power output in tens of watts. (TETRA) Mail Server A computer responsible for processing and/or storing e-mail. It is the electronic equivalent of a post office. E-mail accounts exist on a mail server, where e-mail messages are stored until retrieval by the e-mail client. Main Trunk The major link from the headend to feeder lines. Male Adapter A male adapter has a pin which inserts on a female receptacle. (Arris Glossary of Terms) Male Splice Adapter A housing to housing coupling connector designed to eliminate the need for coaxial jumpers and permit cascadability of taps, etc. (Arris Glossary of Terms) MAN (Metropolitan Area Network) A network covering an area larger than a local area network. A series of local area networks, usually two or more, that cover a metropolitan area. (FiberOpticsInfo) 
Network Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/m Management Information Base (MIB) An SNMP-defined data structure used for storing and retrieving information to and from network elements. Mandatory Ordinary Keycodes The Mandatory Ordinary Keycodes are guaranteed to always be available to the application that has focus. The set of mandatory keycodes includes keycodes required by the MHP specification in the minimum platform capabilities section as the minimum set of input events. Man-Machine Interface (MMI) Another term for User Interface. MAP Manufacturing Automation Protocol; computer programs that run manufacturing automation systems. (FiberOpticsInfo) Margin Download 2.22 Mb. Share with your friends:
|
, 
, 
, 
, 