A powerful programming language developed at Bell Labs by Brian Kerninghan and Dennis Ritchie in the early 1970s. C has wide application, including central office switches and voice processing systems. C operates under Unix, MS-DOS, Windows (all flavors) and other operating systems.
Symbol for capacitance. See also Capacitance .
Symbol for Celsius.
A portion of the electromagnetic spectrum used heavily for both terrestrial microwave and non-terrestrial (i.e., satellite) microwave radio transmission. In terrestrial microwave applications, the C Band is in the range of 4-6 GHz. Satellites split the C Band into an uplink channel at approximately 6 GHz and a downlink channel at 4 GHz. Traditionally, C-Band satellites ranged in power from five to 11 watts per transponder , requiring receive antennas of five to 12 feet in diameter. The fleet of C-Band satellites is being gradually replaced by higher- powered (10-17 watt) satellites, which allow the size of the dish to be reduced to 90 inches in diameter. Traditional applications include voice communications, videoconferencing, and broadcast TV and radio. The large dish size and associated high cost of such dishes have contributed to their lack of popularity for TV reception by individuals; Ku band dishes largely have replaced them in support of DBS (Direct Broadcast Satellite) TV reception . Contrast with KU Band and KA Band. See also C-Band.
Large (6- to 10- foot ) satellite dish antenna, usually motorized , used to intercept signals from C band satellites. Many big dish antennas today receive both C band and Ku band signals.
A source of low potential used in the grid circuit of a vacuum tube to cause operation to take place at the desired point on the characteristic curve.
Signaling and control bits used in certain T-carrier systems. Classic M13 multiplexers serve to multiplex 28 T-1s into a T-3 signal. M13 multiplexers accomplish this process by first combining four T-1s, at a signaling speed of 1.544 Mbps, into a T-2, at a signaling speed of 6.312 Mbps. At this stage, 136 Kbps of overhead is added, including justification, or bit stuffing . (Note that 1.544 Mbps x 4 = 6.176 + .136 = 6.312). At the next stage, seven T-2s, are combined into a T-3, at a total signaling speed of 44.736 Mbps, with 552 Kbps of bit stuffing. (Note: 6.312 x 7 = 44.184 + .552 = 44.736) The stuff bits added during this last stage are known as C Bits, as A & B Bits are used in older channel banks for signaling and control purposes at the T-1 level. C Bits are used for a variety of signaling and control purposes, including synchronization, and parity checking for error control. See also A & B Bits.
T-3 framing structure that uses the traditional management overhead bits (X,P,M,F), but differs in that the control bits (C bits) are used for additional functions, e.g. FID, FEAC, FEBE,TDL and CP. See C Bit for a longer explanation.
A type of line conditioning which controls attenuation, distortion and delay so that they lie within specified limits. See Conditioning.
Also called a female amp connector or 25-pair female connector. The male version is called a P connector.
Clamp used to fasten aerial wire to buildings .
The third of three wires which make up trunk lines between central office switches. There are three wires ” positive, negative, and the "c lead." The purpose of the "c lead" is to control the grounding , holding and releasing of trunks.
An SS7 term . Cross links used between mated pairs of Signal Transfer Points (STPs). They are primarily used for STP to STP communications or for network management messages. If there is congestion or a failure in the network, this is the link that the STPs use to communicate with each other. See A, B and D Links.
This definition from James Harry Green, author of the excellent Dow Jones Handbook of Telecommunications. C Message Weighting is a factor in noise measurements to approximate the lesser annoying effect on the human ear of high and low-frequency noise compared to mid-range noise.
The control plane within the ISDN protocol architecture; these protocols provide the transfer of information for the control of user connections and the allocation/deal- location of network resources; C Plane functions include call establishment, call termination, modifying service characteristics during the call (e.g. alternate speech/unrestricted 64 kbps data), and requesting supplementary services.
C Wire is what the phone company calls the last piece of its wire that comes into your house or office. It is typically the piece of underground cable that comes in from its pedestal on the street to your network interface box on the side of your house or building.
Computers and Communications. An NEC slogan which focused on the deployment of computer and telephony elements to create an integrated environment. Later on, NEC changed it to "Computing and Communicating" and expanded it into a "Fusion" strategy. See Fusion.
A high-level programming language developed by Bjarne Stroustrup at AT&T's Bell laboratories. Combining all the advantages of the C language with those of object-oriented programming, C++ has been adopted as the standard house programming language by several major software vendors .
Conventional Wavelength Band. The optical wavelength band from 1490 to 1570nm (nanometers). The C-Band has been used by conventional WDM (Wavelength Division Multiplexing) optical fiber systems since about 1993. Most WDM and DWDM (Dense WDM) systems, therefore, currently make use of this band. According to ITU-T standards, the C-Band will support 8 optical channels at a frequency spacing of 400 GHz, or wavelength spacing of 3.2nm; 16 channels at 200 GHz, or 1.6nm; 40 channels at 100 GHz, or 0.8nm; 80 channels at 50 GHz, or 0.4nm; and 160 at 25 GHz, or 0.25nm. See also C Band, L-Band and S-Band.
A 30-MHz PCS carrier serving a basic trading area in the frequency block 1895-1910 MHz paired with 1975-1990 MHz.
Character mode Data Terminal Equipment. A term to describe most PCs (personal computers) and printer-terminals that use asynchronous signals for data communications.
A signaling link used to connect mated pairs of Signal Transfer Points (STPs). An Ericsson term.
A type of telephone weighting network that allows for equal attenuation of all frequencies within the voice band in the same manner as it appears to be attenuated by the media.
The C-message frequency-weighted noise on a channel with a holding tone that is removed at the measuring end through a notch (very narrow band) filter.
Fremont, California, June 30, 1999 - The Enterprise Computer Telephony Forum (ECTF) announced the release of its latest Interoperability Agreement, C.100. This agreement specifies that certain packages of Java Telephony API (JTAPI) 1.3 constitute a portable, object-oriented, call control API that meet all ECTF interoperability requirements. C.100 (available for downloading from the ECTF web site at www.ectf.org) serves as a formal reference to the core, call center, call control, and private data packages of JTAPI 1.3 ” see Sun Microsystem's JTAPI web site at http://java.sun.com/products/jtapi/index.html. According to Sun, "JTAPI was designed to be simple to implement. Application developers must still be knowledgeable about telephony, but they will not need implementation-specific knowledge to successfully develop their applications. It can be implemented without existing telephony APIs, but it was also designed to allow layering above APIs such as TAPI, TSAPI and others." The specific JTAPI packages covered by C.100 are: JTAPI Core , Call Center, Call Control and Private Data.
The standard Clear/Acquisition GPS (Global Positioning Code) ” a sequence of 1023 pseudo-random, binary biphase modulations on the GPS carrier at the chip rate of 1,023 MHz. Also known as the "civilian code." See GPS.
Command Response. A Frame Relay term defining a 1-bit portion of the frame Address Field. Reserved for the use of FRADs, the C/R is applied to the transport of data involving polled protocols such as SNA. Polled protocols require a command/response process for signaling and control during the communications process.
Command and Control. The exercise of authority and direction by a properly designated commander over assigned forces in the accomplishment of the mission. Command and control functions are performed through an arrangement of personnel equipment, communications, facilities, and procedures employed by a commander in planning, directing, coordinating, and controlling forces and operations in the accomplishment of the mission. See C3.
Command, Control and Communications. The capabilities required by military commanders to exercise command and control of their forces. See C4.
Command, Control, Communications, and Computers. Once it was C2, then C3, now C4. It basically refers to all the computers and telecommunications which the U.S. military needs to run itself.
European equivalent of the North American System Signaling 7. C7 is not 100% compatible with North American System Signaling 7 and that's where gateway and signaling conversion switches come in. These switches convert the signaling between one and the other and do it in real time. See Signaling System 7.
Canada, as in a Web address, i.e. www.Corel.ca. Do not type Corel.com, thinking the CA is a mistake. It's not. See URL and Web address.
Certificate Authority. See Certificate Authority.
Compound Annual Average Growth Rate.
A container that may enclose connection devices, terminations, apparatus, wiring, and equipment.
In telecommunications, an enclosure used for terminating telecommunications cables, wiring and connection devices that has a hinged cover, usually flush mounted in the wall.
May refer to a number of different types of wires or groups of wires capable of carrying voice or data transmissions. The most common interior telephone cable has been two pair. It's typically called quad wiring. It consists of four separate wires each covered with plastic insulation and with all four wires wrapped in an outer plastic covering. Quad wiring is falling into disrepute as it is increasingly obvious that it does not have the capacity to carry data at high speeds. The wire and cable business is immense. The assortment of stuff it produces each year is mind-boggling. In telecommunications, there is one rule: The quality of a circuit is only as good as its weakest link. Often that "weak link" is the quality of the wiring or cabling (we used the words interchangeably) that the user himself puts in. Please put in decent quality wiring. Don't skimp. See Category of Performance.
An Act passed by Congress that deregulated most of the CATV industry including subscriber rates, required programming and fees to municipalities. The FCC was left with virtually no jurisdiction over cable television except among the following areas: (1) registration of each community system prior to the commencement of operations; (2) ensuring subscribers had access to an A-B switch to permit the receipt of off-theair broadcasts as well as cable programs; (3) carriage of television broadcast programs in full without alteration or deletion; (4) non-duplication of network programs; (5) fines or imprisonment for carrying obscene material; and (6) licensing for receive-only earth stations for satellite-delivered via pay cable. The FCC could impose fines on CATV systems violating the rules. This Act was superseded by the Cable Reregulation Act of 1992.
A completed cable that typically is terminated with connectors and plugs. It is ready to install.
Lots of cable arranged like bays in a harbor.
Cable bend radius during installation infers that the cable is experiencing a tensile load. Free bend implies a small allowable bend radius since it is at a condition of no load.
In the telephone network, multiple insulated copper pairs are bundled together into a cable called a cable binder. Each binder group contains 25 cable pairs, which are color -coded in order to make it easier to splice and terminate them properly. That way you won't get the tip and ring reversed , or connect your boss' phone to his administrative assistant's cable.
See Denial of Service Attack.
A local area network term. The overall length of cable allowed between the DTEs located farthest apart within a common collision domain.
A magazine on cabling run by Steve Paulov and family in Mesquite (Dallas), TX. A great magazine. 214-270-0860.
The number assigned to a television channel carried by a cable television system. Cable channels 2 through 13 are assigned to the same frequencies as broadcast channels 2 through 13; cable channels above Channel 13 are not. Cable channel assignments are specified in EIA Interim Standard EIA/IS-132, and are incorporated by reference into the FCC's cable television rules.
Equipment often provided by a cable company in a subscriber's home that allows access to cable TV services.
Service outage caused by cutting or damaging a cable.
For a cabled single-mode optical fiber, Cable Cutoff Wavelength specifies a complex inter-relation of specified length, bend, and deployment conditions. It is the wavelength at which the fiber's second order mode is attenuated a measurable amount when compared to a multimode reference fiber or to a tightly bent single-mode fiber.
Expressed in millimeters or inches. Affects space occupied, allowable bend radius, reel size, length on a reel and reel weight. Also affects selection of pulling grips.
The interchange point between the regional fiber network and the cable plant. At the hub, the cable modem termination system (CMTS) converts data from a wide-area network (WAN) protocol, such as packet over SONET (POS), into digital signals that are modulated for transmission over HFC plant and then demodulated by the cable modem in the home or business. The CMTS provides a dedicated 27 Mbps downstream data channel that is shared by the 500 to 1,000 homes served by a fiber node, or group of nodes. Upstream bandwidth per node typically ranges from two Mbps to ten Mbps.
Slang expression. In the West, lifelong cable installer who seeks no upward mobility. In the East, worker who deals with underground cable.
An amplifier , usually in a gain of 2, suitable for driving the low resistance of a double terminated cable. Load resistance = 150 ohms for video, 100 ohms for instrumentation.
The segment of cable that typically runs from the street or a telephone pole into the home.
A type of connector. I cannot describe it. Go to this web site. There's a photo of one type of cable gland connector. www.josef-schlemmer.com/1PRODUCT.html.
The point where a marine cable connects to terrestrial facilities.
The cable headend connects the cable network with dishes that receive both satellite and traditional broadcast TV signals, and with cable modems linking to the Internet.
This forum is a organization of the cable television, telephone, computer and switching network industries. The Forum was created to promote greater communication between vendors in the information technology industry, cable television companies and CableLabs, the research and development consortium serving most of the cable operators in North America. The Convergence Forum, based in Louisville, CO, was conceived and sponsored by CableLabs. Companies that have agreed to join the Forum include Apple Computer, Bay Networks, Cisco Systems, Compaq, Digital Equipment Corporation, Fore Systems and LANCity. See also CableLabs.
Internet access via traditional cable television networks with upstream capability supported by either telco return (in nonupgraded one-way cable plants) or RF return (in upgraded two-way cable plants).
Just what it sounds like. The buildings where undersea cables begin and end.
The amount of radio frequency (RF) signal attenuated (lost) while it travels on a cable. There are many reasons for cable loss, including the cable's shape, its type, its size, its length and what it's made of. For coaxial cable, higher frequencies have greater loss than lower frequencies and follow a logarithmic function. Cable losses are usually calculated for the highest frequency carried on the cable. See Attenuation.
Companies have oodles of telephone cables in and around their buildings. Cable management is the science and art of managing those cables. Typically, cable management covers keeping track of where the cables are (maps are useful), what type and quality the cable is, and what is attached to either end of it. Cable management for corporations is critical, since stringing, laying and snaking of new cable can be inordinately expensive.
Cable mapping is the task of trying to track every single pair of wire or circuit from beginning to end. You will need to know where all cables reside, not just the circuits that are in use. Cable mapping is critical for any organization ” from company to university ” which has a lot of cables floating around. Installing more of it ” when there are plenty of spare pairs ” is stupid and expensive. Thus, the need for cable mapping.
Also known as sheath mile. The measurement, in miles, of fiber optic cable that is deployed. Contrast with fiber mile and route mile.
A cable modem is a device that will let you transmit and receive computer information over your cable TV line ” just as a phone modem will let you transmit and receive computer information over your dialup telephone line. A dial-up modem on your local analog phone line will provide online Internet access through the public telephone network at up 53,000 bits per second. A cable modem will give you Internet access through your cable TV network at more than one million bits per second, or about 20 times faster. When a cable modem unit is installed next to your computer, a splitter is placed between the coaxial cable coming in from CATV provider. One side of the splitter will go to your cable set-top box and the other to your cable modem. Your cable modem will connect to your computer through a standard 10Base-T Ethernet RJ-45 interface. Data is transmitted between the cable modem and computer at standard Ethernet local area network speeds of 10 million bits per second. You connect your cable modem directly to your computer using a standard Ethernet NIC (network Interface card) card ” the exact same card you use to connect to your office's local area network. Here's how it works. A cable television system typically has 60 or more TV channels. Most of them are used for receiving channels like ABC, CBS, NBC, CNN, ESPN and HBO. In a typical installation, the cable company chooses one TV channel and sets it aside for data transmission. That one channel can deliver 27 million bits per second downstream and and 10 mbps of upstream capacity. Typically the cable company organizes that that capacity is shared by a cluster of homes or apartments. Because data traffic is bursty , several hundred cable modem users can surf roughly at the same time. If speeds begin to fall off due to heavy traffic (we're all sharing one line), the cable operator will eventually allocate more channel space. A device called a cable modem termination system (CMTS) is located at the local cable operator's network hub and controls access to cable modems on the network. Each of the cable modems have their own network numbers ” just as each NIC card has its own network number. Your carrier's access software can turn off or on service to the your cable modem. Traffic is routed from the CMTS to the backbone of a cable Internet service provider (ISP), such as @Home or Road Runner, which, in turn , connects to the Internet. With newer cable modem systems, all traffic from the CMTS to the cable modem is encrypted to ensure privacy and security for users. Some cable modem ISPs, such as @Home and Road Runner use proxy and caching servers to store copies of popular Web sites closer to their subscribers. The upshot: A customer with a cable modem connection isn't forced to travel across the Internet. The problem: sometimes a cable modem subscriber can be fed an old web site. Several million cable modems have been installed in the U.S. and Canada. The hardware and software supporting those connections aren't always completely interoperable, or able to work together. If, for example, a cable company uses Motorola network equipment, at one stage only a Motorola modem can be plugged into it. To try to promote cable modem rollouts, as well as relieve technological confusion, CableLabs, an industry trade organization, drafted a standard for cable modem products in 1996 called DOCSIS, which stands for Data Over Cable Service Interface Specification. The standard was developed to ensure that cable modem equipment built by a variety of manufacturers is compatible, as dial-up modems are. CableLabs tests DOCSIS cable modems, stamping the products that pass the test "CableLabs Certified." My personal experience with cable modems has been excellent ” far better than my experience with DSL lines. I've learned two things about getting cable modems to work. First, when you first install your cable modem, it's best to replace the entire cable from and within your house to the pole coming in from the cable company. The fewer splitters in that line the better and the newer the cable the better. Second, your cable modem and attached router will occasionally lock up. Before you call Repair, unplug the cable modem and the router from electricity, count to ten, then plug them back in again. 99% of the time, your system will then work fine. See DOSCIS and the next definition also.
CMTS. To deliver data services over a cable network, one six-MHz television channel (in the 50-750 MHz range) is typically allocated for downstream traffic to homes and another channel (in the 5-42 MHz band) is used to carry upstream signals. A head end CMTS communicates through these channels with cable modems located in subscriber homes to create a virtual LAN connection. See also Cable Modem, CableLabs Certified, and DOCSIS.
A mechanism incorporated into a consumer television receiver which allows the user to select the channel assignment plan. In older receivers, this mechanism is usually a physical switch; in newer receivers, it is usually incorporated as an option in the setup menu. All cable/normal switches allow two choices: "standard" (some- times called "normal" or "off air") which tunes to the channel assignments used by broadcast stations for over-the-air transmission; and "cable" (sometimes called "CATV" or "STD") which tunes to cable channels. Many receivers also include a third option called HRC or Harmonically-Related Carriers.
As defined by the Cable Act, a cable operator is a CATV (Community Antenna TeleVision) system operator that provides video programming using closed transmission paths and using public rights-of-way. Not included are open video systems, MMDS (Multichannel Multipoint Distribution Systems), or DBS (Direct Broadcast Satellite). See also Cable Act of 1984.
A term which refers to the physical connection media (optical fiber, copper wiring, connectors, splicers, etc.) in a local area network. It is a term also used less frequently by the telephone company to mean all its outside cables ” those going from the central office to the subscribers' offices.
Any tier of cable television programming except: - The basic tier (see Basic Cable Television Service). - Any programming offered on a per-channel or per-program basis.
There are three basic types of protection in addition to standard plastic cladding:
ElectroMagnetic (EM) Shielding: Prevents passive coupling. EM shielding can be a metallic conduit or metal wrapping-with appropriate grounding-on the wires.
Penetration-Resistant Conduit: Used to secure the cable from cutting or tapping. Note, however, not all penetration-resistant conduits provide EM shielding.
Pressurized Conduit: Detects intrusion by monitoring for pressure loss. Fiber optic cable is extremely difficult to tap and if tapped, the intrusion can be detected through signal attenuation. But since fiber optic cable can be cut, penetration-resistant conduit is recommended to protect the cable.
Framework fastened to bays to support cabling between them.
Cable Reregulation Bill 1515 passed Congress in October 1992, forcing the FCC to reregulate cable television and cable television rates (after the Cable Act of 1984 effectively de- regulated the cable TV industry). After the Act was passed, the FCC forced the industry to reduce its rates by 10% in 1993 and then again by 7% in 1994.
A fancy way of saying that you have a communications system which can pump a lot of bits over some cables that weren't originally meant to carry that many bits. For example let's say you put digital subscriber line electronics on a standard phone line. That would be called a "cable relief system."
Cable running vertically in a multi-story building to serve the upper floors.
Conduit used to run cables through a building. Also, path taken by a cable or group of cables.
A device which tests coaxial, twisted-pair, and fiber-optic cable. It measures the length of a cable segment, tests for opens and shorts, and can report on the distance to the problem so the problem can be found and fixed. Many scanners also indicate if a cable segment has RFI or EMI.
A covering over the conductor assembly that may include one or more metallic members, strength members , or jackets. See Cable Shield.
A metallic component of the cable sheath which prevents outside electrical interference and drains off current induced by lightning.
Excessive levels of radio frequency (RF) energy that leak from cable television systems. Leak can cause interference to communications users, including safety service users such as aviation, police and fire departments. FCC rules specify the maximum RF leakage, and require that cable television systems be operated within certain guidelines.
Tool used to strip the jackets off ALPETH and lead-jacketed telephone cable. Cable strippers include cable knives and snips.
A professional or amateur stripper who appears on X-rated, or community access channels. Quality varies widely. Pay is often non-existent.
Cable Telephony is transmitting anything other than TV pictures over a cable TV system. That "anything" might be anything from a data connection to the Internet to simple, standard, analog voice phone calls ” local, long distance and international. Typically transmitting anything other than TV over the standard coaxial cable CATV providers install at your house requires a cable modem. See Cable Modem.