These tools provide automated methods for designing and documenting software programming. Computeraided software engineering (CASE) sketches relations between databases, events, and options. It then provides a language in which the computer writes the code, letting programmers develop applications faster. It's new and seems to work in limited instances.
An antenna in which the feed radiator is mounted at or near the surface of a concave main reflector and is aimed at a convex secondary reflector slightly inside the focus of the main reflector. Energy from the feed unit illuminates the secondary, reflects it back to the main reflector, which then forms the desired forward beam. This technique is adapted from optical telescope technology and allows the feed monitor radiator to be more easily supported.
A slow, inefficient method of storing and retrieving data which uses the same technology as audio cassettes ” like the Sony Walkman. Some PBXs use cassette tape to backup their user programming and database.
A series of ribs and metallized indentations that defines edge contact regions .
A billing agreement between the local and long distance company that provides for the local company to bill long distance calls for an IXC made by end users who dial 10XXX. Normally, the IXC does not have an account for the end user.
A long distance telephone user who uses a long distance call around number, e.g.; 10-1xxxx. This person usually does not went to be pic'ed (chose a Primary Interexchange Carrier). See 101xxxx.
As a result of divestiture most long distance companies in the United States have a 10-1X-XXX code. These codes are used for various purposes, one of which is long distance calling. To bypass your local exchange carrier and to bypass your selected long distance carrier, your must dial as follows : 10-1X-XXX + 1 + telephone number. You do this to save money or to make a long distance call if your long distance phone company is kaput. You may also use this service if can't be equal accessed to your preferred long distance carrier. In addition to using the 10-1X-XXX code for long distance calling, the code is also used for the following: Temporary access. While you're waiting for your account to become active, you may use the 10-1X-XXX code to temporarily access the long distance company's network. The bill for these calls typically arrives on the phone bill provided by your chosen local phone company.
You need to watch your phone bills. A class action lawsuit has been filed in the United States District Court for the District of Columbia, in Washington, D.C., on behalf of all MCI subscribers who were charged MCI's "casual calling" rates (in some cases as high as $2.87 for a one-minute call) instead of the lower rates which MCI advertises and which subscribers expected to be charged. The lawsuit alleges that this practice of MCI violates the Communications Act of 1934. MCI has one set of rates for subscriber direct dialing, including its widely promoted "Five Cents Sunday" Calling Plan. MCI also has another, much higher set of rates it charges for non-subscriber or casual calling: $0.38 per minute, plus a surcharge of $2.49 for every call. The lawsuit alleges, however, that MCI has charged many of its own subscribers the higher non-subscriber, casual calling rates.
See Dress-down day.
Want to send something to someone over a network? There are various levels of encryption ” some more hard to crack than others. Remember the harder it is to crack, the harder (and more expensive) it is to administer and work with. PC Magazine describes casual encryption as encoding your documents using compression software such as WinZip and assigning a password to the file ” so that only the person knowing the password could actually unzip the file and read it.
Shortened way of saying "Category," as in Cat 1 cabling. Say Cat 5 or CAT5 and you mean Category 5 wiring. See Category 1 through 5 and Category of Performance.
CAT (concatenate) - a UNIX command that dumps a file to a standard output. If you type 'cat myfile', myfile would be displayed to the screen. If you typed 'cat myfile wc' UNIX would dump the file contents to the program 'wc' (word count) and just print the number of words in the file.
A fine metal thread resembling the arched shape of a cat's whisker, used in early radio wave detecting crystal sets.
A special branch of dynamical systems theory that studies and classifies phenomena characterized by sudden shifts in behavior arising from small changes in circumstances.
CAT 1. An unspecified Category of Performance for inside wire and cable systems. CAT 1 cables can be of various gauges, and are useful in support of applications requiring a carrier frequency less than 1 MHz, which roughly translates into 1 Mbps, depending on the compression scheme employed. Example applications include analog voice, ISDN BRI, and doorbells. CAT 1 is specified in ANSI/ICEA S-80-576 and S-91-661. See also Category of Performance.
CAT 2. A Category of Performance for inside wire and cable systems. CAT 2 cables can be of either 22 or 24 gauge, and are useful in support of applications requiring a carrier frequency of up to 4 MHz; the transmission rate achievable depends on the compression scheme employed. CAT 2 requirements are based on the IBM Type 3 cabling system for low-speed data cable suitable for 4-Mbps Token Ring. Example applications include 4 Mbps Token Ring LANs (802.5), 1Base-5 Ethernet LANs (802.3), and T-1. CAT 2 is specified in ANSI/ICEA S-80-576 and S-91-661.See also Category of Performance.
CAT 3. A Category of Performance for inside wire and cable systems. CAT 3 cables can be of either 22 or 24 gauge, and are useful in support of applications requiring a carrier frequency of up to 16 MHz; the transmission rate achievable depends on the compression scheme employed. Example applications include POTS, ISDN, T-1, 4/16 Mbps Token Ring (802.5), and 10Base-T Ethernet (802.3). Cat 3 technical specifications are defined by FCC Part 68, ANSI/EIA/TIA-568, TIA TSB-36 and TIA TSB-40. CAT 3 safety requirements are defined by UL 1459 (Telephone), UL 1863 (Wire and Jacks) and NEC 1993, Article 800-4. See also Category of Performance.
CAT 4. A Category of Performance for inside wire and cable systems. CAT 4 cables can be of various gauges, and are useful in support of applications requiring a carrier frequency of up to 20 MHz; the transmission rate achievable depends on the compression scheme employed. Example applications include 4/16 Mbps Token Ring (802.3) and 10 Mbps Ethernet (802.3). CAT 4 technical specifications are defined by FCC Part 68, EIA/TIA-568, TIA TSB-36, and TIA TSB-40. CAT 4 safety requirements are defined by UL 1459 (Telephone), UL 1863 (Wire and Jacks) and NEC 1993, Article 800-4. See also Category of Performance.
CAT 5. A Category of Performance for inside wire and cable systems. CAT 5 cables can be of various gauges, and are useful in support of applications requiring a carrier frequency of up to 100 MHz; the transmission rate achievable depends on the compression scheme employed. Example applications include 4/16 Mbps Token Ring, 10/100Base-T, 100VG-AnyLAN, and even 155 Mbps ATM LANs. CAT 5 is now the most common cabling being installed for LAN connectivity. Increasingly, CAT 5 cabling is being installed for both data and voice use, and is the cabling of choice for forward-looking companies. Category 5 technical specifications are defined by FCC Part 68, EIA/TIA-568, TIA TSB-36, TIA TSB-40, and ANSI/ICEA S-91-661. See also Category of Performance.
See Category 5 Enhanced.
CAT 5e. CAT 5e has become the de facto minimum standard for cabling. It supports signaling rates of up to 100 MHz over distances of up to 100 meters . Specifications call for a tighter twist, electrical balancing between pairs, and fewer cable anomalies, such as inconsistencies in the core diameter. CAT 5e supports 100Base- T, ATM, and Gigabit Ethernet, which is 100 million bits per second. By way of comparison, category 3 cable is rated for any application up to 16 Mhz (Frequency) while category 5e is rated for up to 100 Mhz (Frequency) Computer networks and phone systems all operate at one or another frequency. Category 5e will accomodate both analog phones as well as any computer protocol such as Gigabit Ethernet. See also Category of Performance.
CAT 6. Proposed Category 6 standards from the TIA (Telecommunications Industry Association), known as Class E standards at the ISO (International Organization for Standardization), describe a new performance range for unshielded and screened twisted-paid cabling. Category 6/Class E is intended to specify the best performance that UTP and ScTP cabling solutions can be designed to deliver based on current technology. Category 6e will be specified in the frequency range of 1-250 MHz. The cabling system actually will be rated at 200 MHz in consideration of positive PSACR (Power Sum Attenuation-to-Crosstalk Ratio, also known as PS-ACR), although equipment crosstalk cancellation capabilities will allow the system to be characterized to 250 MHz. The ScTP version of CAT 6 comprises four twisted pairs of 100 Ohm wire, with the entire cable being protected from ambient noise by means of a metallic screen. Most CAT 6 cables have a center filler that separates each pair within the cable jacket. The interface at the workstation will be an 8-position modular jack. According to the Telecommunications Industry Association, "Category 6 cabling is the latest addition to the structured cabling standards and has twice the bandwidth of category 5e cabling. This improved bandwidth, together with vastly improved immunity from external noise, provides the potential for category 6 to support multi-gigabit applications. This white paper provides an update on category 6 cabling and applications standards together with references for finding category 6 information and products." See also Category of Performance and PS-ACR.
See Category 6 Enhanced.
Proposed category 6/class E standards describe a new performance range for unshielded and screened twisted-paid cabling. Category 6/Class E is intended to specify the best performance that UTP and ScTP cabling solutions can be designed to deliver based on current technology. Category 6e will be specified in the frequency range of 1-250 MHz. For Category 6e, the 8-position modular jack interface will be mandatory in the work area. See Category 6.
CAT 7. Also known as Category 7/Class F. A developing cabling standard from the TIA (Telecommunications Industry Association) for STP ( Shielded Twisted Pair), intended to support signaling rates up to 600 MHz in support of ATM and Gigabit Ethernet. A corresponding standard under development by the ISO (International Organization for Standardization) is known as Class F. A typical CAT 7 cable is anticipated to comprise four 23 AWG (American Wire Gauge) twisted pairs, each enveloped within a solid metallic foil wrap. An overall braided sheath typically surrounds the four foil-wrapped pairs, and a drain wire will serve to ground the cable in order to reduce electrical noise potential. Such double-shielded cabling systems sometimes are known as SSTP (Double- Shielded Twisted Pair, as in Shielded-Shielded Twisted Pair) and PiMF (Pairs in Metal Foil). See also Category of Performance.
As we try and push more and more data faster and faster down a pair or two of wires, so the quality of the wires and the components they connect to has become increasingly important. You can't push 100 Mbps (Million bits per second) down junky phone lines. As a result, the EIA/TIA (Electronic Industries Alliance/Telecommunications Industry Association) has defined cabling and cabling component standards. The idea is that if your stuff conforms to the standard, users will be able to achieve the data rates and reliability they want, assuming that the cabling system is installed properly. Some standards specify physical characteristics, such as thickness of cable, plastic material used in the outer jacket, etc. In the main, these "Category of Performance" standards specify tests which the cabling and cabling components must pass. There were originally five categories of tests. But now there are effectively only two categories that anyone buys ” Category 3 and Category 5. In simple terms, if all you want is to support voice and data to 10 Mbps (Megabits per second), i.e. standard Ethernet, then Category 3 will do the trick. If you are transmitting at 100 Mbps on your local area network, then you need Category 5. Today, Cat 5 is 20% to 30% more expensive than Cat 3, but it's well worth it. In my unhumble opinion, all cable going to the desktop today should be Cat 5, since it will support both voice and high-speed data. While Cat 5 isn't necessary for either voice or 10 Mbps data, it's easier and ultimately less expensive to install a single wiring system.
Now, let's talk about how they measure Cat 3 and Cat 5. First, you should understand that all the tests are self- certifying , which means that while there are standards, each manufacturer is itself responsible for conforming. No one will put a manufacturer in jail if his Cat 5 stuff doesn't perform to Cat 5 standards. The only thing likely to happen to the manufacturer is that the world will find out his stuff is garbage and he'll go broke.
The concept of the test is simple. The test for cable and components is a swept frequency test. Note: The standards all speak to the carrier frequency supported, which is measured in Hertz, usually in MHz, or MegaHertz. The transmission rate, which is what we ultimately are interested in, is measured in bps (bits per second). The transmission rate relies on the carrier frequency. At a given carrier frequency, the signal is modulated in various ways to allow the impression of one or more bits per Hertz. The bottom line is that the standards address Hz, not bps.
For example, Cat 3 must pass all signals up to 16 MHz. Cat 5 must pass signals from up to 100 MHz. Cat 3 and Cat 5 cables and components are designed to support any applications intended to operate over those frequencies. Interestingly, both Cat 3 and Cat 5 cabling are the same thickness, namely 24 gauge. Cat 5 conductors, however, are manufactured according to tighter specifications, which result in fewer anomalies, such as nicks in the conductor, and variations in diameter. The twist structure on Cat 5 is tighter, and the insulation is better. Connecting hardware is definitely different. Altogether, the standards specify parameters including frequency rating, attenuation (signal power loss), impedance (resistance), crosstalk, structural return loss, and delay skew. The standards also define maximum distances, as attention renders the signal useless beyond a certain distance.
Below is Harry 's quick rule of thumb for what you should buy based on what you want to transmit, as against the swept frequency test:
Application & Speed Supported
Digital Voice, 1 Mbps Data
16 Mbps Data
20 Mbps Data
100 Mbps Data
100 Mbps Data
1000 Mbps Data
1000 Mbps Data
|[a] Proposed standards, at the time of this writing|
Harry's Rules of Thumb: If you want the most flexibly wired office ” the Office of The Future ” install nothing less than Cat 5 cabling to everyone's desk. And put in twice as much cabling as you ever dreamed you will need. When installing cable, never use staples ; never use tie wraps (some idiot will tighten them too tightly); never untwist wire before you punch it down; (the twists should be right up to the termination); never strip more jacket off the wire than is needed to terminate it; never pull too hard on any cable - especially around a corner; never pull on a cable to straighten out a kink or loop (always go back and untwist it); and never stuff too many cables in too small a conduit. See Commercial Building Telecommunications Wiring Standard.
See Category 1 and Category of Performance.
See Category 2 and Category of Performance.
See Category 3 and Category of Performance.
See Category 4 and Category of Performance.
See Category 5 and Category of Performance.
See Category 5 Enhanced and Category of Performance.
See Category 6 and Category of Performance.
See Category 6e and Category of Performance.
See Category 7 and Category of Performance.
As defined by Louis Pouzin in 1974, a catenet is "an aggregate of networks (which would) behave like a single logical network." In other words, an "internetwork" in which networks are interconnected by "gateways," which are known as "routers" in contemporary terminology. Pouzin's concept was later accepted by DARPA (Defense Advanced Research Project Agency) as the goal of the project it was supporting ” that project developed into what we now know as the Internet.
Common Architecture for Next Generation Internet Protocol. One of the three IPng candidates.
The heated element which emits electrons in a vacuum tube. It may be a filament, or may be a separate element, heated by proximity to a filament. It is maintained at a negative potential in respect to the anode or plate. Cathodes have other applications, also.
The beam of electrons emitted by a cathode. See Cathode Ray Tube.
CRT. A TV screen. A CRT is a tube of glass, used in television, oscilloscope and computer terminals, from which air has been removed (i.e. vacuum tube). At the back of the CRT is an electron gun which directs an electron beam to the front of the tube. The inside front of the tube has been coated with fluorescent material which reacts to and lights up once the electron beams hit. CRTs are very reliable if they are vented, since the electron gun gets hot. CRTs have a "memory." They will memorize what's been left on their screen for a while, i.e. the image is burned into the screen. And you'll see it even though the screen is turned off. In short, turn your screen off when you're not using it. Or run a "CRT-saving" program which varies the image on the screen.
A means of controlling corrosion of metal through use of a sacrificial metallic anode. A form of galvanic corrosion protection in which a conductor with a negative charge will repel chlorine ions, rather than attract them, as would be the case with a positive charge. Cathodic protection is the reason that twisted-pair, copper local loops use -48 volts, rather than +48 volts , for "Ring." At least it was in the olden days of uninsulated local loops. It still works. The same principle works to protect bridges, pipelines, and other metallic structures.
Computer Assisted Telephone Interviewing, a market research term for a call center based on the use of a computerized database.
AT&T software standing for Centralized Automatic Trouble Locating and Analysis System. CATLAS is used as a maintenance tool for locating and diagnosing problems in AT&T electronic central offices.
Common Architecture for Next Generation Internet Protocol. One of the 3 IPng candidates.
Consortium for Audiographics Teleconferencing Standards, San Ramon, CA. 510- 831-4760. CATS describes itself as a non-profit corporation dedicated to promoting standards for this technology, which it describes as enhancing audioconferencing by allowing people at different sites to work together in real time to create, manipulate, edit, annotate and reference still images. Now called IMTC.
Calling Card & Third Number Settlement. An RBOC system for ICS processed through CMDS. Similar to BEARS.
In 17th century England, houses had thatched roofs-thick straw- piled high, with no wood underneath. It was the only place for animals to get warm, so all the dogs, cats and other small animals (mice, bugs ) lived in the roof. When it rained it became slippery and sometimes the animals would slip and fall off the roof. Hence the saying "It's raining cats and dogs."
Another American word for ketchup , which people in Australia and England call tomato sauce.
CAble TeleVision. This term originally stood for "community antenna television," reflecting the fact that the original cable systems carried only broadcast stations received off the air; however, as cable systems began to originate their own programming, the term evolved to mean Cable Television. CATV is a broadband transmission facility. It generally uses a 75-ohm coaxial cable which simultaneously carries many frequency-divided TV channels. Each channel is separated by guard channels. See Addressable Programming and Broadband.
Northern Telecom term for Connection Arrangement Unit.
Controlled Access Unit. CAU. An intelligent hub from IBM for Token Ring networks in conjunction with IBM LAN Network Manager software.
Cave Automatic Virtual Environment. A sophisticated virtual reality facility developed by the Electronic Visualization Lab at the University of Illinois at Chicago. CAVE is much like the HoloDeck of "Star Trek: The Next Generation," although a headset and a wand are required to create the illusion. CAVE allows scientists to see, touch, hear and manipulate data in order to do such things as create and test new models of various machines, or to manipulate atoms of a molecule . See also Virtual Reality.
Cellular Authentication and Voice Encryption. An encryption algorithm specified in ANSI-41 (formerly TIA standard IS-41C) to initiate the system of authentication challenges in order to prove the identity of a mobile phone. CAVE is used in conjunction with the A- key (Authentication key), MIN (Mobile Identification Number) and ESN (Electronic Serial Number) in order to prevent cellular fraud artists from capturing the MIN and ESN data. Such data typically is transmitted "in the clear." The A-key is intended to be known only to the phone and the AC (Authentication Center). Once the A-key is transmitted, the phone and the AC generate a second secret key, known as a SSD (Shared Secret Data), the value of which can be updated in the event that the IS-41 network suspects that it has been compromised.
A volume defined by conductor-dielectric or dielectric-dielectric reflective boundaries, or a combination of both, and having dimensions designed to produce specific interference effects (constructive or destructive) when excited by an electromagnetic wave.
An early British innovation in radar systems development during World War II which permitted the use of extremely short waves ( microwaves ) and improved the quality of the information and images possible through radar systems. See Magnetron.
A wall built of solid masonry units arranged to provide air space within the wall.
Why 10-4, good buddy, that stands for Citizens Band. Also known as Children's Band , not because of Radio Shack's toy walkie talkies, but for the inane chatter that sometimes goes on in these channels. In short, CB is low-power (up to four Watts permitted) public radio. You do not need permission from the FCC to transmit or receive at these frequencies. Thus CB's great popularity. CB went through a boom (perhaps a craze?), then it ran out of radio frequencies and public enthusiasm . Its original frequencies were 26.965 to 27.225 Mhz. Now the FCC's given it new frequencies ” 462.55 to 469.95 MHz. These new frequencies are much better, clearer and less congested . If you buy a CB set, make sure you get one that operates in these higher frequencies. In some countries they use different frequencies. CB radio is not allowed in many countries, even some civilized countries , though it will obviously work there.
Your PBX is busted. You call the phone man. He comes. You ask him what's wrong with it? He shrugs his shoulders. "CBA," he answers. What's that? you ask. He says "Could Be Anything." Stupid, but funny .
Context Based Access Control. CBAC is a sophisticated way of managing different types of traffic on a single network. It allows an intelligent network (i.e. one carrying the different types of traffic) to recognize a given traffic and prioritize its movement over the network accordingly . In other words, voice will have greater priority over data, because voice is more sensitive to delays and dropouts, etc. See also QoS (Quality of Service) and RSVP (Resource Reservation Protocol).
Circuit Breaker Bay is a distribution panel used to power equipment in a rack/row of a site.
Cipher Block Chaining. A special DES (Data Encryption Standard) block cipher algorithm for encrypting encryption mode that combines blocks of the message together before encrypting them to provide higher levels of security. Often referred to as DES-CBC.
Connectionless Broadband Data Service: A connectionless service similar to Telcordia Technologies' SMDS defined by European Telecommunications Standards Institute (ETSI). In short, the European version of SMDS.
Computer Business Equipment Manufacturers Association. A lobbying group created to protect the interests of its members . CBEMA is the author of the AC voltage disturbance tolerance specification to which all computing and business equipment is designed.
Specifies overvoltage and undervoltage events that computing equipment must withstand. This standard, for example, provides that all computing and business equipment must withstand a power loss or transfer time of 12ms.
Computer Based Fax.
Cured By F...ing Magic. When the telco carrier takes the circuit for test Wednesday morning and calls you back 2 days later with no reason for the outage ..the circuit problem resolution is CBFM.
See Component Busy Hour .
Class-Based Queuing. A queuing algorithm used in routers to manage congestion. Through user-definable class definitions, incoming packet traffic is divided into classes. A class might include all traffic from a given interface, all traffic associated with a particular application, all traffic intended for a particular network or device destination, or all traffic of a specific priority classification. Each class of traffic is assigned to a specific FIFO (First In First Out) queue, each of which is guaranteed some portion of the total bandwidth of the router. Should some class(es) of traffic not make full use of their allocated bandwidth, CBQ portions out that available bandwidth to other class-specific FIFO queues on a proportionate basis. See also FIFO, RED, Router and WFQ.
Constant Bit Rate. CBR refers to processes such as voice and video that require a constant, repetitive or uniform transfer of information. The ATM Forum defines it as "an ATM service which supports a constant or guaranteed rate to transport services such as video or voice as well as circuit emulation which requires rigorous timing control and performance parameters."
Committed Bit Rate.
Computer Based Training. Also known as CAI (Computer Assisted Instruction), CBT commonly supports self-paced learning through the use of a CD-ROM storage technology. You plug the CD-ROM into the multi-speed CD-ROM drive of your high-performance PC, and begin the course. CD-ROM storage technology provides enough memory to support great graphics, and is fast enough to provide hyperlinks so you can move around the material quickly. At the end of each section, the CBT system will offer you a quiz to test your knowledge, and will present you with your score. CBT was crude prior to the development of CDROM and high-performance PCs. See also CAI and CD-ROM.
Canadian Business Telecommunications Alliance. The largest organization of business telecom users in Canada. According to the CBTA's own literature, the CBTA is a national non-profit organization that has been working on behalf of business telecommunications customers for over 34 years . As a major voice in the Canadian telecommunications industry, the CBTA represents about 400 organizations from all sectors of the Canadian economy including industry, commerce, education, health care, and government. CBTA member organizations have combined annual expenditures of over $4 billion (Canadian dollars). The CBTA strives to facilitate a competitive advantage in Canadian business (where business is understood to include all for-profit, not-for-profit, governmental, educational, and medical institutions), through the strategic application of telecommunications by proactively advocating the common interests of its members and by promoting information exchange and professional development. The main goals of the CBTA are to encourage innovation, quality, and choice in the telecommunications marketplace ; to build a strong, influential, and representative national organization; to provide professional development opportunities and relevant services to its members; to enhance the Alliance's visibility as a leading industry authority. CBTA was at the Canadian Trust Tower, 161 Bay Street, Suite 3650, Toronto, Ontario, Canada M5J 2S1. 416-865-9993 and fax 416-865-0859. www.cbta.ca The CTBA closed its doors in June, 1999 due to lack of funding.
Call Before U Dig. Operational management system for protection of fiber facilities. May have electronic geographic maps of states, counties and city streets where the carrier has buried facilities, upon which reported construction activities are automatically mapped. Human technicians verify that the activities do not pose a danger to the facilities, or dispatch on-site technicians when facilities may be at risk.
Call Control. A wireless telecommunications term. A term used to refer to circuit communications management.
Country Code. The portion of an international telephone number used to identify the country of the called party. That country code may be one, two or three digits. An international phone number consists of a Country Code (CC) and a NSN (National Significant Number). Until December 31, 1996, the CC can be up to three digits and the NSN up to 11 digits ” for a total of no more than 12 digits. After December 31, 1996, the CC stays at up to 3 digits and the NSN goes to up to 14 digits, for a total of no more than 15 digits. See the Appendix for a full list of International Country Codes.
Carbon Copy. That's where it comes from. It refers to the person who received one of the copies of a memorandum or document. Now CC is an electronic mail term that means that someone will receive a copy of the electronic mail.
Company Code. Also called OCN (Operating Company Number). A unique four-place alphanumeric code (NNXX) assigned to all U.S. domestic telecommunications service providers by NECA (National Exchange Carrier Association). See Company Code for a complete explanation.
Dot cc (.cc) is a premium, international top-level domain (TLD) that works worldwide on the Internet just like .com, .net and .org. The ccTLD identifies the country in which the Internet address resides. See Domain Name for a full discussion.
Common Carrier Bureau. One of the largest divisions of the FCC, this Bureau regulates interstate telephone systems ” licensing them, monitoring their charges, the conditions they offer service under, etc. The Common Carrier Bureau opened long distance communications to competition in America.
Came Clear By Magic. This term created (but not contributed ) by Nynex (now part of Verizon). This is pseudo-technical lingo used by Nynex when they repair something that they broke (i.e. the problem was their fault), but they are unwilling to admit it was their fault. They say this "CCBM" to interconnect companies who are trying to get their customers' phone lines fixed.
Clear Coded Channel. A 64 Kbps channel in which all 64 Kbps is available for data.
Clear Channel Capability. The bandwidth of a data transmission path available to end users after control and signaling bits are accounted for.
Communications Competition Coalition. Lobbying organization established to encourage competition in telecommunications in Canada.
Computer Controlled Cable Modem, a host-based device that shares PC resources such as memory and processing.
Charge Coupled Device, a light sensitive chip used for image gathering. CCDs are the "eyes" of a scanner or digital camera ” still or movie. They convert incoming light into bit-map images, which can be stored by the device on digital media ” a flash memory card, a CD, a hard disk. CCDs are small electronic devices with arrays of light-sensitive elements. The number of these elements and their width determine the scanner's or camera's resolution. Light is bounced off the image onto the CCD, which translates the varying intensities of the reflected light into digital data. In their normal condition CCDs are grayscale devices. To create color, a color pattern is laid down on the sensor pixels, using a color mask like RG BG, (Red, Green, Blue and Green). The extra green is used to create contrast in the image. The CCD pixels gather the color from the light and pass it to the shift register for storage. CCD are analog sensors, the digitizing happens when the electrons are passed through the A to D converter. The A to D converter (analog to digital converter) converts the analog signal to a digital file or signal. CCDs are currently the device of choice for digital and consumer imaging devices like camcorders, scanners , and digital cameras .
Corporate Consolidated Data Network. It is the name for IBM's main internal data communications network. It used to be managed by IBM. It's now managed by Advantis, an IBM spin-off company, which is majority-owned by IBM and the rest by Sears.
See Call Carrying Equipment.
See Consumer Consultative Forum.
Cold Cathode Fluorescent Lamp. A technology several laptop computer manufacturers use to light their LCD screens.
Connections per Circuit per Hour. How many phone calls one circuit was able to complete in one hour. Compare to ACH, which is call Attempts per Circuit per Hour. See ACH. CCH and ACH are terms useful in traffic engineering, i.e. figuring out how many trunks you need for your incoming and/or outgoing telephone calls.
Computer and Communications Industry Association. A trade organization of computer, data communications and specialized common carrier services companies headquartered in Arlington VA. It runs seminars , does lobbying and generally tries to take care of the common interests of its members. See CBEMA.
Cisco Certified Internetwork Expert. Cisco's equivalent of Novell's CNE or Microsoft's MCSE. Attend a class. Study. Become a CCIE. A way of giving some certification as to your ability to manage a network.
Comite Consultatif International des Radiocommunications. The agency responsible for the international use of the radio spectrum. Effective in 1993, the CCIR is now known as the International Telecommunications Union ” Radio. ITU-R and ITU-T form the International Telecommunications Union.
An internationally agreed-upon standard for the digital encoding of component color television that was derived from the SMPTE RP125 and the EBU 324E standards. It uses the 4:2:2 sampling scheme for Y, U and V with luminance sampled at 13.5 MHz and chrominance (U and V components) sampled at 6.75 MHz. After sampling, 8-bit digitizing is used for each channel. These frequencies are used because they work for both 525/60 (NTSC) and 625/50 (SECAM and PAL) television systems. The system specifies that 720 pixels be displayed on each line of video. The D1 digital videotape format conforms to CCIR 601. See CCIR 656. The CCIR is now known as the ITU-R. See ITU-R.
The international standard defining the electrical and mechanical interfaces for digital TV operating under the CCIR 601 standard. It defines the serial and parallel interfaces in terms of connector pinouts as well as synchronization, blanking and multiplexing schemes used in these interfaces. The CCIR is now known as the ITU-R. See ITU-R.
Coordinating Committee for Intercontinental Research Networks. A committee that provides a forum for North American and European network research organizations to cooperate and plan. The CCIR is now known as the ITU-R. See ITU-R.
Common Channel Interoffice Signaling. A way of carrying telephone signaling information along a path different from the path used to carry voice. CCIS occurs over a separate packet switched digital network. CCIS is separate from the talk path. A special version of CCIS is called Signaling System #7. SS#7 is integral to ISDN. CCIS offers basically two benefits: first, it dramatically speeds up the setting up and tearing down of phone calls. Second, it allows much more information to be carried about the phone call than what is carried on in-band (old-fashioned) signaling. That information can include the calling number, a message, etc.
Signaling for a group of voice telephone circuits is done on CCIS by encoding the information digitally on one of the voice circuits. In the previous method of signaling ” the one replaced by CCIS ” multi-frequency tones were sent down the same talkpath that the conversation would eventually travel. By taking the signaling information out of the talkpath, the "phone phreak" community could no longer get free calls by using so-called "blue boxes" which duplicated the multi-frequency tones used by switching machines. CCIS is a much more efficient method of signaling, since it doesn't require a full voice grade channel just to check if the called party in LA is free and whether the call coming in from New York should be put through. See also Common Channel Signaling, Signaling System 7, ISDN and Common Channel Interoffice Signaling.
Comit consultatif international t l graphique et t l phonique, which, in English, means the Consultative Committee on International Telegraphy and Telephony. The CCITT is now known as the ITU-T (International Telecommunications Union-Telecommunications Services Sector), based in Geneva, Switzerland. The scope of its work is now much broader than just telegraphy and telephony. It now also includes telematics , data, new services, systems and networks (like ISDN). The ITU is a United Nations Agency and all UN members may also belong to the ITU, represented by their governments. In most cases the governments give their rights on their national telecom standards to their telecommunications administrations (PTTs, or TOs). But other national bodies (in the US, for example, the State Department) may additionally authorize Recognized Private Operating Agencies (RPOAs) to participate in the work of the ITU. After approval from their relevant national governmental body, manufacturers and scientific organizations may also be admitted, as well as other international organizations. This means, says the ITU, that participants are drawn from the broad arena. The activities of the ITU-T divide into three areas:
Study Groups (at present 15) to set up standards ("recommendations") for telecommunications equipment, systems, networks and services.
Plan Committees (World Plan Committee and Regional Plan Committee) for developing general plans for a harmonized evolution of networks and services.
Specialized Autonomous Groups (GAS, at present three) to produce handbooks, strategies and case studies for support mainly of developing countries.
Each of the 15 Study Groups draws up standards for a certain area - for example, Study Group XVIII specializes in digital networks, including ISDN. Members of Study Groups are experts from administrations, RPOAs, manufacturing companies, scientific or other international organizations - at times there are as many as 500 to 600 delegates per Study Group. They develop standards which have to be agreed upon by consensus. This, says the ITU, can sometimes be rather time-consuming , yet it is a democratic process, permitting active participation from all ITU member organizations.
The long-standing term for such standards is "CCITT (ITU-T) recommendations." As the name implies, recommendations have a non-binding status and they are not treaty obligations. Therefore, everyone is free to use ITU-T recommendations without being forced to do so. However, there is increasing awareness of the fact that using such recommendations facilitates interconnection and interoperability in the interest of network providers, manufacturers and customers. This is the reason why ITU-T recommendations are now being increasingly applied ” not by force, but because the advantages of standardized equipment are obvious. ISDN is a good example of this. NOTE: ISDN and other standards recommendations include options which allow for multiple "standards," in recognition of differing national and regional legacy "standards;" as a result, international standards recommendations do not necessarily yield evenly applied standards options.
The ITU-T has no power of enforcement, except moral persuasion. Sometimes, manufacturers adopt the ITU-T specs . Sometimes they don't. Mostly they do. The ITU-T standardization process runs in a four-year cycle ending in a Plenary Session. Every four years a series of standards known as Recommendations are published in the form of books. These books are color-coded to represent different four cycles. In 1980 the ITU published the Orange Books, in 1984 the Red Books and, in 1988, the Blue Books. See ITU Study Groups and ITU V.XX below.
The ITU has now been incorporated into its parent organization, the International Telecommunication Union (ITU). Telecommunication standards are now covered under Telecommunications Standards Sector (TSS). ITU-T (ITU-Telecommunications) replaces ITU. For example, the Bell 212A standard for 1200 bps communication in North America was referred to as ITU V.22. It is now referred to as ITU-T V.22. See ITU.
Complementary Code Keying is a modulation technique used by IEEE 802.11b compliant wireless LANs for transmission at 5.5 and 11 Mbps. CCK is compatible with the DSSS (Direct Sequence Spread Spectrum) spreading technique specified in the IEEE 802.11 standard for wireless Ethernet LANs, and uses complementary codes to spread the data frames across the assigned spectrum. CCK codes are defined by a set of 256 8-chip code words, which work well in an indoor multipath environment and which can be demodulated efficiently . See also 802.11b, Chip, DSSS, and Spread Spectrum.
Configuration Control Link, works with ACD.
Carrier Common Line. A usage-sensitive charge billed to IXCs by the local telephone company to recover costs for the portion of the telephone company facility, normally to the end user location, that is used to complete a call.
Call Centre Management Association, an association based in the United Kingdom. The CCMA is run by a Committee made up of elected representatives who have an interest in Call Centres. The annual subscription is stlg95.00 and a joining fee of 30 English pounds sterling. One of CCMA's primary goals is to set up an educational program where members can attend courses and have those attributed to a recognized qualification.
Computer Controlled Cable Modem.
Customer's Carrier Name Abbreviation. Identifies the common language code for the IXC providing the interLATA facility. This code reflects the IXC to be contacted for provisioning whereas the ACNA reflects the IXC to be billed for the service. See ACNA.
Cisco-Certified Network Associate.
Cisco-Certified Network Engineer.
Customer Control Routing, works with ACD. See ACD.
An ATM term. Current Cell Rate: The Current Cell Rate is an RM-cell field set by the source to its current ACR when it generates a forward RM- cell . This field may be used to facilitate the calculation of ER, and may not be changed by network elements. CCR is formatted as a rate.
Centi Call Seconds. One hundred call seconds or one hundred seconds of telephone conversation. One hour of telephone traffic is equal to 36 CCS (60 x 60 = 3600 divided by 100 = 36) which is equal to one erlang. CCS are used in network optimization. See also Erlang and Traffic Engineering.
Common Channel Signaling: A high-speed, packet switched communications network that is separate from the public packet switched and message networks. It is used to carry addressed signaling messages for individual trunk circuits and/or database- related services between signaling points in the CCS network. *A form of signaling in which a group of circuits share a signaling channel. See Signaling System 7.
Custom Calling Services was changed a few years ago to "Custom Calling Features". These services include speed calling, call forwarding, 3-way calling, etc.
A network element or a network system connected to the CCS network via SS7 links.
A Telcordia Technologies term for Common Channel Signal/Signaling System 7. See Signaling System 7.
Common Channel Signaling 7. See ISDN and Signaling System 7.
Common Control Switching Arrangement. A private network set up by AT&T for very large users and using parts of the public switched network. One important feature of a CCSA is that any user anywhere in a CCSA network can reach any other user by dialing only seven digits. Only very large customers subscribe to this service. It's expensive. AT&T has fewer than 100 customers.
A PBX feature which allows a PBX user to get into a CCSA network. See CCSA.
Command Communications Service Designator; control communications service designator JP 1-02. It's a circuit designator. Also used as a circuit order number. A U.S. military term somewhat like USOC code in the civilian world.
Continuity Check Tone.
Country Code Top Level Domain. Eg: firstname.lastname@example.org. The uk shows it's from the United Kingdom. See Top Level Domain, Country Code, Domain Name, gTLD, and TLD.
Closed Circuit TV.
Communication Control Unit. A processor, often a minicomputer, associated with a host mainframe computer that performs a number of communications-related functions. Compare with cluster control unit.
Camera Control Unit.
Call Control eXtensible Markup Language. CCXML is a new software language to allow developers to program telephone switches and computer telephony devices. It is designed to address call management and event processing. It is not finished and is at this point a project of a W3C working group, called the Voice Browser Working Group. CCXML has been designed to complement and integrate with a VoiceXML system. The two languages are separate and are not required in an implementation of either language. For example CCXML could be integrated with a more traditional IVR (Interactive Voice Response) system and VoiceXML could be integrated with some other call control system. According to the working group, "There are a number of needed features that VoiceXML currently can't supply:
Support for multi-party conferencing, plus more advanced conference and audio control. Any large conference application requires such features.
Ability to give each active call leg its own dedicated VoiceXML interpreter. Currently, the second leg of a transferred call lacks a VoiceXML interpreter of its own, limiting the scope of possible applications.
Sophisticated multiple-call handling and control, including the ability to place outgoing calls. Multiple-party conferences mean VoiceXML needs a more effective way of handling telephony resources.
Handling for richer and more asynchronous events. Advanced telephony operations involve substantial amounts of signals, status events, and message-passing . VoiceXML does not currently have a way to integrate these asynchronous "external" events into its event-processing model.
Ability to receive events and messages from external computational entities. Interacting with an outside call queue, or placing calls on behalf of a document server, means the VoiceXML must be contacted by an outside party." Says the group, "We originally intended to see if we could add new tags to VoiceXML to support the new features here. However, we repeatedly encountered conflicts between the design goals for VoiceXML, and the requirements we list here. Most of these conflicts came from trying to reconcile two very different event models. Event generation and handling in VoiceXML are focused on specific user interface transactions (e.g., within a given field, the filled, noinput, nomatch, or help events are thrown and handled). However, events from telephony networks or external networked entities are non-transactional in nature; they can occur at any time, regardless of the current state of VoiceXML interpretation. These events could demand immediate attention. We could either abandon VoiceXML's admirably simple single-threaded programming model, or delay event- servicing until the VoiceXML program explicitly asked to handle such events. Instead of making either of these bad choices, we instead move all call control functions out of VoiceXML into an accompanying CCXML program. VoiceXML can thus focus on being effective for voice dialogs, while CCXML tackles the very different problems we described above.
An implementation of VoiceXML is not required to support CCXML. Such implementations may choose to support proprietary methods of call control, and still be deemed compliant with the W3C VoiceXML Recommendation.
An implementation of CCXML is not required to support VoiceXML. Such implementations may choose not to support interactive dialogs at all, or may do it in a proprietary way, and still be deemed compliant with the W3C CCXML Recommendation."
For more information, email@example.com.
Carrier Detect. CD is a signal generated by a dial-up modem. CD indicates its connection status. If your CD light is on, then your modem is speaking to another modem.
Compact Disc. A 12 centime diameter (around 4 3/4 inches) disk containing digital audio or digital computer information, which can be played back and (now recorded) on a laser-equipped player. It was introduced by Sony and Philips in 1982. Philips (the inventor ) chose the diameter of a Dutch 10-cent coin for the diameter of the hole in the CD. A compact disc originally came in only one flavor ” read only. And most music tapes can only be listened to, not recorded to. For music it was a major breakthrough . It recorded music digitally (that is, coded as the zeros and ones of computer-speak) instead of trying to make an electrical copy of the sound waves themselves as devices like audiocassettes and LP records had. The Economist described the CD well. It said, "Instead of using a needle, the sound was plucked from the CD's surface by a tiny beam of laser light and then processed by a microcomputer. To the ear, the leap in performance between a compact disc and a long-playing record was even greater than the difference between color and black and white TV was to the eye."
A CD can typically hold up to 650 megabytes of information. That is the equivalent of 1,500 floppies or 250,000 pages of print. Most computer CD-ROM drives can play audio CD disks ” if they have the software and the speakers . Audio CD players, though, cannot play computer CD-ROM discs. But most computer CD-ROM players can play CD audio discs. As CD-ROM have become more popular and their makers have tried to do more and more with them, so CD-ROM formats have proliferated and some are not compatible with each other. See CD-R, CD-ROM, CD-I, CD-V, DVD and WORM.
Cell Delineation. An ATM term. See Cell Delineation.
See Campus Distributor.
See CD-I below.
This format defines specifications for a unified logical file format for CDRecordable. The new format, known as CD UDF, defines a common scheme of "packet writing" to assure interchangeability of CD-R (CD Recordable) discs and to greatly increase performance and flexibility when storing large and small files on recordable disc media. As a result, CD-Recordable drives can be integrated into computer systems to behave much like other removable disk storage products. www.osta.org
Sometimes called "Redbook audio," is the digital sound representation used by CD-ROMs. CD audio is converted to analog sound output within the CD-ROM drive. The sampling frequency for CD audio is 44.1 KHz.
Compact Disc Interactive. Geared toward home entertainment, the drive connects to a television.
A format for CDs created by Sony and Philips Electronics which makes the multimedia track on CDs invisible to CD players. The problem: there are few enhanced CDs ” discs for both CD players and CD-ROM drives. The reason: the format prior to CD-Plus puts the multimedia data on track one, which listeners must skip over on their CD players. Thus the new format.
CD-Recordable. A standard and technology allowing you to write to and read from a Compact Disc, but not erase or change what you record. This technology is compatible with existing CDs, i.e. you are able to read these discs in existing CD-players, and often in both PC and Macintosh machines. See CD-ROM and Multi-Session.
CD-ReWritable discs are erasable and can be used again and again, such as an audio cassette.
Compact Disc Read Only Memory. Also called CD or CD-ROM. The familiar five inch diameter Compact Disc which you see in the audio stores, but now made for computers. These discs hold huge amounts of data ” as much as 700 megabytes per disk, or 300,000 pages of ASCII text. But CD-ROMs are catching up. Most of today's newer CDROMs can now be used in multimedia applications and virtually all CD-ROM drives available today support the Multimedia PC or MPC standard. See CD, CD-ROM XA, CD-V, CD-WO and Shovelware. See also DVD for an update on what CD-ROMs are becoming.
CD Recordable. A compact disc you can write once to but read many times from. The disc has a spiral track which is preformed during manufacture, onto which data is written during the recording process. This ensures that the recorder follows the same spiral pattern as a conventional CD, and has the same width of 0.6 microns and pitch of 1.6 microns as a conventional disc. Discs are written from the inside of the disc outward. The spiral track makes 22,188 revolutions around the CD, with roughly 600 track revolutions per millimetre. Instead of mechanically pressing a CD with indentations, a CD-R writes data to a disc by using its laser to physically burn pits into the organic dye. When heated beyond a critical temperature, the area "burned" becomes opaque (or absorptive) through a chemical reaction to the heat and subsequently reflects less light than areas that have not been heated by the laser. This system is designed to mimic the way light reflects cleanly off a "land" on a normal CD, but is scattered by a "pit", so a CD-R disc's data is represented by burned and non-burned areas, in a similar manner to how data on a normal CD is represented by its pits and lands. Consequently, a CD-R disc can generally be used in a normal CD player as if it were a normal CD. CD-R's real advantage is that the writing process is permanent. The media can't be erased and written to again. Only by leaving a session " open " - that is, not recording on the entire CD and running the risk of it not playing on all players - can data be incrementally added to a disc. The most recent solution is CD-RW. See CD-RW.
CD Rewritable, also spelled rewriteable. It's a compact disc that allows repeated recordings. CD-RW drives can write both CD-R and CD-RW discs and can read any type of CD. Like regular CDs, CD-Rs and CD-RWs are composed of a polycarbonate plastic substrate, a thin reflective metal coating, and a protective outer coating. CD-R is a write once, read many (worm) format, in which a layer of organic polymer dye between the polycarbonate and metal layers serves as the recording medium. The composition of the dye is permanently transformed by exposure to a specific frequency of light. In a CD-RW, the dye is replaced with an alloy that can change back and forth from a crystalline form when exposed to a particular light, through a technology called optical phase change. The patterns created are less distinct than those of other CD formats, requiring a more sensitive device for playback. Only drives designated as "MultiRead" are able to read CD-RW reliably. Similar to CD-R, the CD-RW's polycarbonate substrate is preformed with a spiral groove to guide the laser. The alloy phase-change recording layer, which is commonly a mix of silver, indium, antimony, and tellurium, is sandwiched between two layers of dielectric material that draw excess heat from the recording layer. After heating to one particular temperature, the alloy will become crystalline when it is cooled; after heating to a higher temperature it will become amorphous (won't hold its shape) when it is cooled. By controlling the temperature of the laser, crystalline areas and non-crystalline areas are formed . The crystalline areas will reflect the laser, while the other areas will absorb it. The differences will register as digital data that can be unencoded for playback. To erase or write over recorded data, the higher temperature laser is used, which results in the non-crystalline form, which can then be reformed by the lower temperature laser. CD-RW discs usually hold 74 minutes (650 MB) of data, although some can hold up to 80 minutes (700 MB) and, according to some reports , can be rewritten as many as 1000 times.
Stands for Compact Disc - Read Only Memory eXtended Architecture. Microsoft's extensions to CD-ROM that let you interleave audio with data. Though it is not a video specification, limited video can be included on disc. Demand for multimedia applications is increasing use of CD-ROM XA. To use it, you must have a drive that reads the audio portions of the disc and audio card in your computer that translates the digital into sound. Not all drives can recognize the extensions. See CD-R, CD-RW, CD-WO.
Compact Disc Video. A format for putting 5 minutes of video on a 3-inch disc. This format has come and gone. Video is shifting towards CD-ROM XA.
Compact Disc Write Once. A CD-ROM version of the WORM (Write Once Read Many) technology. For companies performing all CD-ROM publishing in-house, this format is useful for creating test discs before sending the master for duplication. CD-WO discs conform to ISO 9660 standards and can be played in CD-ROM drives.
See Communications Decency Act.
Customer Dialed Account Recording.
Customer Data Change.
Continuous Dynamic Channel Selection.
Copper Distributed Data Interface is a version of FDDI (Fiber Distributed Data Interface ” a 100 million bit per second local area network) that runs on unshielded twisted-pair cabling rather than optical fiber.
Common Desktop Environment. A graphical user interface which is common and consistent across UNIX platforms. CDE is designed to make UNIX systems easier to use, simpler to support and more cost-effective to target for application development. CDE is defined to converge the major components of the desktop (X Window System, OSF/Motif, and CDE), adding basic features such as printing APIs (Application Programming Interfaces), and providing a competitive, common approach to delivering on-line information access and on-line publishing technology. A major initiative of The Open Group, CDE sponsors include Digital Equipment Corporation, Fujitsu Limited, Hewlett-Packard, Hitachi, IBM, Novell, and Sun.
Control panel DEVice. An Apple Macintosh term.
An ATM term. Cutoff Decrease Factor: CDF controls the decrease in ACR (Allowed Cell Rate) associated with CRM.
Channel Definition Format. A term used in Internet/Intranet push technology.
See Combined Distribution Frame.
Centrex Data Facility Pooling.
Compact Disc File System, which controls access to the contents of CD-ROM drives in PCs.
The CDMA Development Group (CDG), according to its Web site, is an industry consortium of companies who have come together to develop the products and services necessary to lead the adoption of CDMA wireless systems around the world. In working together, the 100 member companies will help ensure interoperability among systems, while expediting the availability of CDMA technology to consumers. The CDMA Development Group is committed to the definition of CDMA features, services, technical requirements and other activities that promote the availability and evolution of CDMA (IS-95 based) wireless systems worldwide. Specific objectives include:
Leading the adoption of CDMA based systems around the world.
Maintaining a forum to address issues impacting manufacturers and carriers actively involved in CDMA deployments.
Developing next-generation CDMA systems.
Minimizing the time required to implement CDMA services and features. www.cdg.org.
An interface once required by the Bell System to protect their phone lines from "foreign" (i.e. non-AT&T) phone equipment. CDH devices were eventually ruled a total waste of money and the phone companies refunded the money ” at least to the subscribers who asked. If you still have the stuff installed, you may be due a huge refund. Watch out for the statute of limitations.
Coded Digital Locator.
Cellular Data Link Control. A public domain data communications protocol used in cellular telephone systems. In other words, you can attach a data terminal to a cellular telephone and send and receive information. There are more 5,000 modems using CDLC on the Vodaphone Cellular System in the UK, where it is the de facto standard for cellular data communications. Features like improved synchronization field, forward error correction, bit interleaving, and selective retransmission make CDLC ideal for cellular transmissions, according to Millidyne who makes the CDLC modems in the US.
Confirming Design Layout Report Date. The date a common carrier accepts the facility designed proposed by the Telco.
Code Division Multiple Access is a digital, spread spectrum, packet-based access technique generally used in RF (Radio Frequency) radio systems. Perfected and commercialized by Qualcomm, CDMA is used in certain cellular phone systems and in some WLANs (Wireless Local Area Networks). CDMA organizes the data to be transmitted into discrete packets of various lengths. Prior to it being packetized, the data may be converted from analog to digital format by a vocoder, as would be the case in a voice transmission over a cellular network. Once in a digital format, the data may be compressed in order to reduce the raw number of bits to be transmitted and, therefore, make more efficient use of limited RF spectrum. In a CDMA-based cellular voice network, for example, each transmission comprises a stream of data packets, which stream is assigned a unique 10-bit code sequence known as a PN (PseudoNoise) sequence. That PN code is prepended (i.e., added to the front of) each packet in the packet stream, enabling each receiver to separate that specific transmission from both the inherent background noise and the other transmissions that share the RF channel. Thereby, multiple packets associated with multiple conversations can share the same spectrum, overlapping in both frequency and time, without mutual interference. The major benefit of CDMA is increased capacity (up to 20 times analog cell service) through more efficient use of spectrum. CDMA also provides three features that improve system quality: 1) The "soft hand-off" feature ensures that a call is connected before handoff is completed, as the cellular phone moves from cell-to-cell; this reduces the probability of a dropped call. 2) Variable rate vocoding allows speech bits to be transmitted at only the rates necessary for high quality, which conserves the battery power of the subscriber unit. 3) Multipath signal processing techniques combines power for increased signal integrity. Additional benefits to the subscriber include increased talk times for portable units, more secure transmissions and special service options such as data, integrated voice and data, fax and tiered services. See also FDMA, OCDMA, Spread Spectrum, TDMA, and Vocoder.
Code Division Multiple Access 2000. A third generation (3G) wireless system, cdma2000 is a trademark of Qualcomm, the company that commercialized CDMA. cdma2000 essentially is the CDMA approach to IMT-2000, the ITU's concept for a single, global standard for 3G wireless technology. Based on earlier CDMA versions (also known as TIA/EIA IS-95a and IS-95b), cdma2000 (also known as IS-2000) has been approved by the ITU. The initial version, known as cdma2000 1xMC (one times Multi-channel), offers 3G capabilities within a single standard 1.25 MHz channel, effectively doubling the voice capacity of the predecessor cdmaOne systems and offering data speeds up to 307 Kbps. The high-speed version is known officially as cdma2000 3xMC (Three times Multi- Carrier), as it makes use of three standard 1.25 MHz channels within a 5 MHz band to deliver data speeds up to 2 Mbps in support of integrated voice, data and video. cdma2000 runs in the 800 MHz and 1.8-2.0 GHz spectrum.
CDMA2000 IXEV-DO is a third-generation wireless protocol that is a stepping stone in the evolution of cdma2000. 1 XEV-DO "data optimized"is a data only overlay that uses a 1.25 MHz channel to provide a peak rate data throughput of 2.4 Mbps. UBS Warburg believes a lx-EV DO network is better suited for the enterprise. Several Korean mobile operators have rolled out I x-EV DO networks.
A brand name, trademarked and reserved for the exclusive use of the member companies of the CDMA Development Group (CDG). cdmaOne describes a complete wireless system that incorporates the IS-95 CDMA air interface, the ANSI-41 network standard for switch interconnection and many other standards that make up a complete wireless system. As of the end of second quarter 2002, there were approximately 127 million total global CDMA subscribers (according to the CDMA Development Group). , cdmaOne is basically a brand name. That's it. Nothing more. See also CDMA, and CDG.
Cellular Digital Messaging Protocol.
Control Directory Number.
Content Data Network. A network that bills the end user on the basis of the specific content accessed, rather than on either a flat-rate or usage-sensitive basis. The emerging concept of the CDN centers on the Internet and World Wide Web, and has application in both the wired and wireless domains.
Community Dial Office. A small automatic central office switching system that is completely unattended. Routine maintenance is provided by a traveling technician once or twice each year, or as troubles develop. Such an office usually serves a small community with a few hundred lines in a rural area.
Customized Dial Plan.
See Capture Division Packet Access.
Cellular Digital Packet Data. A radio technology that supports the transmission of packet data at speeds of up to 19.2 Kbps over the existing analog AMPS (Advanced Mobile Phone Service) cellular network, with appropriate CDPD upgrades. The data is structured in packets that are transmitted during pauses in cellular phone conversations, thereby avoiding issues of developing an overlay cellular network for data communications. Estimates suggest that as much as 20%-30% of an AMPS network is idle, even during periods of peak usage. This idle capacity is due to short pauses between the point in time at which you disconnect your circuit-switched cellular telephone conversation and the time when someone else seizes that same radio channel to place a call. Idle capacity also is created when you are "handed-off" from one cell to another as you travel through the area of coverage in your vehicle. While 19.2 Kbps transmission rates are possible, throughput commonly drops to 2.4 Kbps or so during periods of peak usage.
Connectionless protocols such as IP (Internet Protocol) and the OSI CLNP (Connectionless Network Protocol) are employed to accomplish this minor miracle . The contention method employed is DSMA/CD (Digital Sense Multiple Access/Collision Detection), which is much like CSMA/CD used in Ethernet LANs. CDPD offers a number of advantages over competing wireless mobile data technologies. Among those advantages is the fact that CDPD packets use forward error correction (FEC) to reduce the impacts of noise and interference over the air link. Additionally, CDPD incorporates authentication and encryption to yield much improved security.
CDPD uses a full 30-KHz voice channel, but it can move your connection from one channel to another to avoid congesting voice communications. The drawbacks to CDPD are that it requires you to have a CDPD modem to access your upgraded cellular network, and not all cellular service providers are willing their to upgrade their cellular equipment to CDPD. On July 21, 1993, the group of cellular carriers that supports the Cellular Digital Packet Data (CDPD) project released the complete version 1.0 of its open specification designed to enable customers to send computer data over an enhanced cellular network. The group said the packet data approach is ideally suited to those applications that require the transmission of short bursts of data, for example, authorizing a credit card number, exchanging e-mail messages or making database queries. The cellular networks deploying CDPD will enable mobile workers to use a single device to handle all of their voice and packet data needs. This version of the specification includes input from parties that reviewed the earlier release (0.8 and 0.9). The new version provides details of the CDPD architecture, airlink, external network interfaces, encryption and authentication, network support services, network applications services, network management, radio resource management and radio media access control.
CDPD was originally developed by IBM and is backed by the CDPD Forum. Carriers offering CDPD in the U.S. include Ameritech, AT&T Wireless, Bell Atlantic NYNEX Mobile, and GTE Mobilnet (now Verizon Wireless). Those carriers offer the service in over 60 markets. Limited CDPD coverage also is provided in Canada, Ecuador, Indonesia and Mexico. Pricing generally is on the basis of a monthly fee, plus a usage charge calculated on the number of kilobytes of data transmitted. Terminal equipment can be in the form of a laptop which plugs into your cellular phone through an adapter, or which has its own CDPD modem and antenna. Recently developed are CDPD terminals which look much like a cellular telephone, although with enhanced display capabilities. The original scope of the CDPD specifications was expanded in July 1995 to include CS-CDPD (Circuit Switched CDPD), which operates on a connection-oriented basis, much like a cellular voice call. This approach supports longer file transmissions and yields improved throughput, as a radio channel is seized and maintained for the duration of the transmission. CDPD has application beyond AMPS, as it can be run over TDMA and CDMA networks, as well. See CDPD Forum.
The locus of points at which a Mobile End System (M-ES) should no longer access service by using the transmission of a particular cell. See CDPD.
The CDPD Forum Inc. is an not-for-profit special interest group formed in 1994 to promote the development, deployment and use of CDPD. The forum comprises companies that develop, deliver or use CDPD products or services. companies with an interest in CDPD. www.cdpd.org. See CDPD.
Cellular Digital Packet Data (CDPD) SubNetwork Department Convergence Protocol. See CDPD.
Call Detail Recording (as in Call Accounting) or Call Detail Record, as a record generated by customer traffic later used to bill the customer for service. See Call Accounting.
Clock/Data Recovery. An technique used in Local Area Networks (LANs) whereby a data octet is subdivided, scrambled, and encoded into an expanded form. The expanded expression of the data value includes bits which are used for clock recovery (i.e., synchronization) and data recovery (i.e., error detection) between the LAN hub or switch, and the attached terminal device. See also 4B5B, 5B6B, 8B6T, and 8B10B.
A table listing local central office codes which are not monitored (i.e. ignored) by a call accounting system.
Common Data Security Architecture. A security framework for developing security and authentication application programs.
Consumer Digital Subscriber Line (also called Consumer DSL) service, introduced and trademarked by Rockwell in the fall of 1997. CDSL is a one megabit modem technology. The key difference between it and ADSL is that ADSL requires a splitter installed at each home to divide voice and data traffic onto separate lines. CDSL doesn't. According to Rockwell, customers would simply buy a CDSL modem at the local electronics store and call the phone company to have the service turned on. See ADSL.
Compression Labs Compressed Digital Video, a compression technique used in satellite broadcast systems. CDV is the compression technique used in CLI's SpectrumSaver system to digitize and compress a full-motion NTSC or PAL analog TV signal so that it can be transmitted via satellite in as little as 2 MHz of bandwidth. (A normal NTSC signal takes 6 Mhz.)
An ATM term. Cell Delay Variation: CDV is a component of cell transfer delay, induced by buffering and cell scheduling. Peak-to-peak CDV is a QoS delay parameter associated with CBR and VBR services. The peak-to-peak CDV is the ((1a) quantile of the CTD) minus the fixed CTD that could be experienced by any delivered cell on a connection during the entire connection holding time. The parameter "a" is the probability of a cell arriving late. See CDVT.
CD Video. A small videodisc (5" diameter) that provides five minutes of video with digital sound plus an additional 20 minutes of audio.
Cell Delay Variation Tolerance-ATM layer functions may alter the traffic characteristics of ATM connections by introducing Cell Delay Variation. When cells from two or more ATM connections are multiplexed, cells of a given ATM connection may be delayed while cells of another ATM connection are being inserted at the output of the multiplexer. Similarly, some cells may be delayed while physical layer overhead or OAM cells are inserted. Consequently, some randomness may affect the inter-arrival time between consecutive cells of a connection as monitored at the UNI. The upper bound on the " clumping " measure is the CDVT.
An ATM term. Connection endpoint: A terminator at one end of a layer connection within a SAP.
Conformite Europeene (French) Mark; the English translation is European Conformity Mark. CE Mark is a type of pan-European equipment approval which indicates that the manufactured product complies with all legislated requirements for regulated products. Obtaining the CE Mark allows a product to be sold into 18 European countries without any further in-country testing. Several country regulatory bodies are set up to do the testing and thus the certification. These "notified bodies" comprise CEN, CENELEC and ETSI. CEN is responsible for European standardization in all fields except electrotechnical (CENELEC) and telecommunications (ETSI). The CE Mark is now a requirement for all telecommunications terminal equipment (TTE) products sold into the European Union (EU), effective January 1, 1996. Countries covered are Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Spain, Sweden, and the United Kingdom. CE marking confirms that a product has been tested and meets the essential requirements of the European Telecom Directive to market it throughout the EU. The European TTE Directive 91/263/EEC specifies approved products to meet appropriate telecommunications technical standards. These include personal safety, protection of public networks, interoperation with public network equipment, and electromagnetic compatibility.
Several country regulatory bodies are set up to do the testing and thus the certification. These bodies are called "notified bodies." When one company, Larscom, reported one of its NDSUs had been granted a CE Mark, it said that the European "notified body" issuing the approval for its product was the British Approval Board for Telecommunications (BABT).
Customer edge router. A router that is part of a customer network and that interfaces to a provider edge (PE) router.
CeBIT is the world's largest computer and office automation show. It attracts 600,000 plus people to Hannover, Germany in March each year. It is also called the Hannover Fair. It is about five times the size of Comdex, which is North America's largest computer show. Many of the "booths" at Hannover are really small buildings , which are used year round. Many of the "booths" are three stories high, with an open air restaurant on the top floor. Space at the show is sometimes rented for four years.
Consumer Electronics Bus. EIA IS-60 (Electronics Industry Association Interim Standard-60), known as the home automation standard, includes specification of the CEBus. Essentially a Home Area Network (HAN) standard, CEBus allows connectionless, peer-to-peer communications over a common electrical bus, using standard electrical wiring rather than special voice/data cabling. CEBus employs a CSMA/CD contention protocol similar to that used in Ethernet LANs. Each CEBus has two channels. One channel is for real- time, short-packet, control-oriented functions; the other channel is dedicated to intensive data transfer. The standard includes error detection, automatic retry , end-to-end acknowledgement , and duplicate packet rejection , as well as authentication to ensure the identity of the user and encryption to provide for data security. For more information, contact the CEBus Industry Council in Indianapolis, Indiana.
Canadian Electrical Code. The Canadian equivalent of the US National Electrical Code (NEC).
CallEd station iDentification. A 2100 Hz tone with which a fax machine answers a call. See CNG.
Capacitance Electronic Disc. System of video recording a grooved disc, employing a groove-guided capacitance pickup.
Caller-Entered Digits. Digits entered by a caller on a touch-tone phone in response to prompts. Either a peripheral (ACD, PBX, or VRU) or the carrier network can prompt for CEDs.
CED Compression. A method of compression used in faxing.
Comparable Efficient Interface. The idea is that the telephone industry will let all its information providers have this interface ” defined by technical specs and pricing ” and, if it does, then the phone companies can themselves use this information to become information providers themselves. The concept has merit. Implementation has been agonizingly slow.
An ATM term. Connection endpoint Identifier: Identifier of a CE that can be used to identify the connection at a SAP.
Cable distribution systems that use the space between a suspended or false ceiling and the structural floor for running cable. Methods used in ceiling distribution systems include zone, home-run, raceway, and poke-through.
A method of routing communications and/or power cabling vertically from the ceiling/plenum to a cluster of workstations.
Centrex Electronic Key Set.
The basic geographic unit of a cellular system. It derived its name "cell" from the honeycomb pattern of cell site installations. Cell is the basis for the generic industry term "cellular." A city or county is divided into smaller "cells," each of which is equipped with a low- powered radio transmitter/receiver. The cells can vary in size depending upon terrain, capacity demands, etc. By controlling the transmission power, the radio frequencies assigned to one cell can be limited to the boundaries of that cell. When a cellular phone moves from one cell toward another, a computer at the Mobile Telephone Switching Office (MTSO) monitors the movement and at the proper time, transfers or hands off the phone call to the new cell and another radio frequency. The handoff is performed so quickly that it's not noticeable to the callers . For a longer explanation, see CMTS.
The basic unit of a battery, consisting of plates, electrolyte and a container. A chemical device that produces electricity through electrolysis.
A unit of transmission in ATM and SMDS. A fixed-size packet consisting of a 48-octet payload and 5 octets of control overhead in the form of a header in the case of ATM, and a header and trailer in the instance of SMDS. See also Cell Switching, ATM and SMDS.
The smallest component of a table. In a table, a row contains one or more cells.
In cellular and PCS systems, a grouping of physically proximate cells in which each cell uses a different subset of the total spectrum allocated for the wireless service, but the grouping or cluster of cells represents the total allocated spectrum. For example, in AMPS cellular a frequency re-use pattern of seven is usually used. Thus, a cell cluster consists of seven proximate cells, each of which uses a different subset of the AMPS spectrum.
CD. An ATM term. Cell Delineation is accomplished at the Transmission Convergence (TC) sublayer of the ATM Physical Layer (PHY), working in tight formation with the Physical Medium (PM) sublayer. It is at the TC sublayer that the responsibility is assumed for Physical Layer operations that are not medium independent. For example, it is at this sublayer that the ATM cell switch interfaces with a SONET transmission system. Cell Delineation is responsible for defining the cell boundaries at the originating endpoint (e.g., ATM cell switch or ATM workstation) in order that the receiving endpoint can reassemble (i.e., identify and recover) all cells associated with a data payload that has been segmented (i.e., cut up into ATM cells). Cell Delineation is achieved by the receiving endpoint's locking onto the 5-octet cell headers. A failure in this process is known as Loss of Cell Delineation (LCD).
An AMPS (Advanced Mobile Phone System) phenomenon in which a mobile cellular terminal moving away from the current serving cell penetrates deeply into or passes through a neighboring cell before the signal weakens to the point of reaching a predetermined signal level threshold, thereby becoming a candidate for handoff. The phenomenon is caused by irregularities of terrain and various other factors affecting radio propagation.
A cell header precedes payload data (user information) in an ATM or SMDS cell. The header contains various control data specific to the cell switching protocol.
CIV. An ATM term. "Jitter" in common parlance, CIV measures how consistently ATM cells arrive at the receiving end-station . Cell interarrival time is specified by the source application and should vary as little as possible. For constant bit rate (CBR) traffic, the interval between cells should be the same at the destination and the source. If it remains constant, the latency of the ATM switch or the network itself (also known as cell delay) will not affect the cell interarrival interval. But if latency varies, so will the interarrival interval. Any variation could affect the quality of voice or video applications.
A cellular radio term. A color code assigned to a set of cells. Each member of the set is adjacent to at least one other member of the set and no two members of the set are allocated the same Radio Frequency (RF) channel for Cellular Digital Packet Data (CDPD) use. Each cell is assigned exactly one Cell Group Color Code.
One of three main location-based service (LBS) technologies, Cell ID fixes the location of the user by identifying which cell in a network is carrying the user's call and translates that information into latitude and longitude. Best used in less dense, rural areas, Cell ID is less accurate than competing technologies such as E-OTD and GPS, and is not well suited to commercial applications such as location-based advertising, which requires fixing the user's exact location. See Location Services.
A bit in an Asynchronous Transfer Mode header, used to indicate a cell's priority level. A cell set with a CLP bit to zero has higher priority than a cell with the CLP bit set to one. In the case of congestion, cells with a CLP bit set to one may be discarded. See Cell Loss Priority Field.
CLP. A single priority bit in the ATM cell header; when set, it indicates that the cell may be discarded should the network suffer congestion. Voice and video data do not tolerate such loss; therefore, such cells would not carry a set CLP bit.
A negotiated Quality of Service parameter in an Asynchronous Transfer Mode network. This parameter indicates a ratio of lost cells to total transmitted cells.
The space between the contents and inside edges of a table cell.
A cellular telephone. In Austria and Germany, it's called a "Handy," in China a "da ge da" (big brother), in Finland a "kanny" (extension of the hand), in France "le portable" or "le mobile", in Greece "kinito" (movable), in Australia a "mobile," in Israel "pelephone" ( wonder phone), in Italy "telefonino" (little phone), in Japan "keitai" (portable), and in Turkey "cep" (pocket). See also GSM and SIM card.
A form of packet switching using fixed length packets which results in lower processing and higher speeds. Cell relay is a generic term for a protocol based on small fixed packet sizes capable of supporting voice video and data at very high speeds. Information is handled in fixed length cells of 53 octets (bytes). A cell has 48 bytes of information and 5 bytes of address. The objective of cell relay is to develop a single high- speed network based on a switching and multiplexing scheme that works for all data types. Small cells (like 53 bytes) favor low-delay, a requirement of isochronous service. The downside to small cells is that the address information is almost 10 percent of the total packet. That equates to high overhead and raw inefficiency. See ATM and SMDS.
The reversal of the polarity of the terminals of a battery cell as the result of discharging.
A transmitter/receiver location, operated by the WSP (Wireless Service Provider), through which radio links are established between the wireless system and the wireless unit. The area served by a cell site is referred to as a "cell". A cell site consists of an antenna tower, transmission radios and radio controllers. The cell site of an analog cellular radio system handles up to 5,000 users (but not all at once).
The cellular radio unit which manages the radio channels within a cell.
COW. A portable cell site positioned to fill in or increase coverage, as a backup for emergency use.
The amount of space between cells in a table. Cell spacing is the thickness, in pixels, of the walls of each cell.
A technique used by cellular operators to improve capacity. Involves splitting cells to create smaller cells to enable frequencies to be re-used. more often. Cell splitting in the city of London, for example, has resulted in cell sizes measuring less than 100 yards.
A term that refers to how cellular calls are switched. Cellular systems are built to accommodate moving phones ” ones in cars , buses, etc. These phones are low-powered. The "moving-ness" and the low power of the phones pose major design constraints on the design of cellular switching offices, which are called Mobile Telephone Switching Offices (or MTSOs). First, you have to build many cellular switching sites. That way each phone is close to a cell site. Thus there's always a cell site which can pick up the transmission. Second, because of the closeness of the cell sites, any phone conversation may be simultaneously heard by several MTSOs. As a result, the MTSO constantly monitors signal strength of both the caller and the receiver. When signal strength begins to fade, the MTSO locates the next best cell site and re-routes the conversation to maintain the communications link. The switch from one bcell site to another takes about 300 milliseconds and is not noticeable to the user. All switching is handled by computer, with the control channels telling each cellular unit when and where to switch.
The Cellular Mobile Telephone System is a low-powered, duplex, radio/telephone which operates between 800 and 900 MHz, using multiple transceiver sites linked to a central computer for coordination. The sites, or "cells", named for their honeycomb shape, cover a range of three to six, or more, miles in each direction. Their range is limited only by certain natural or man-made objects.
The cells overlap one another and operate at different transmitting and receiving frequencies in order to eliminate cross-talk when transmitting from cell to cell. Each cell can accommodate up to 45 different voice channel transceivers. When a cellular phone is activated, it searches available channels for the strongest signal and locks onto it. While in motion, if signal strength begins to fade, the telephone will automatically switch signal frequencies or cells as necessary without operator assistance If it fails to find an acceptable signal, it will display an "out of service" or "no service" message, indicating that it has reached the limit of its range and is unable to communicate.
Each mobile telephone has a unique identification number which allows the Mobile Telephone Switching Office (MTSO) to track and coordinate all mobile phones in its service area. This ID number is known as the Electronic Security Number (ESN). The ESN and Telephone Number are NOT the same. The ESN is a permanent number engraved into a memory chip called a PROM or EPROM, located in the telephone chassis. This number cannot be changed through programming as the telephone number can, although it can be replaced. Each time the telephone is used, it transmits its ESN to the MTSO by means of DTMF tones during the dialing sequence. The MTSO can determine which ESN's are good or bad; thus individual numbers can be banned from use within the system. See Cellular Radio.
A reference to the demands that ATM (Asynchronous Transfer Mode) places on bandwidth. ATM is a cell-switching technology which segments a data stream into cells, each of which comprises 48 octets of payload (data) and 5 octets of overhead (control information). Therefore, each cell is approximately 10.4% overhead. ATM signaling adds another 5%-10% in overhead. While ATM is wasteful of bandwidth, its benefits are significant. See also ATM and Cell.
Wireless Integration/Interface Device. Also referred to as a "Proctor" box (name of the vendor), Cell Trace Box (US West's name for it), and protocol converter.
A cellular radio term. Cell Transfer is the procedure of changing the channel stream in use to a channel stream originating at a different cell.
Cell yell is the tendency of many cellphone users to speak into their phones more loudly than necessary and it has created a subculture of cell-yell haters.
The syntax used to control the "padding" or area around the contents of a table's cell. In HTML tables are used as a layout tool which allows an HTML author to render text and graphics on a Web page in columns and rows. There are many options available with tables and cellpadding is one of them. The syntax looks something like this: <table border=0 cellpadding=5 cellspacing=10>. This syntax would produce a table with a cellpadding of 5 pixels in width.
Social etiquette for using your cell phone. Don't use them in theaters. Don't talk loudly in the presence of others, etc.
A British term for a cellular telephone ” whether car-based or handheld.
Mobile cellular towers that are used temporarily until a permanent tower is operational.
COW. A trailer with antenna and transmitting/receiving hardware used to provide temporary cell phone service in emergencies, special events, remote testing and repair, until a normal, permanent tower can be erected. A cow comes with climate control, diesel generator, and self-supporting wind-resistant antenna mast. Both full- size COWs and mini-COWs are available. The COW is especially useful in system change- outs and to get service where a permanent building may be a while in coming and plans call for a Self Contained Cell Site (SCCS) in the future. See also COLT and COW (for a larger explanation).
CDLC is a public domain data communications protocol used in cellular telephone systems. In other words, you can attach a data terminal to a cellular telephone and send and receive information. There are more than 5,000 modems using CDLC on the Vodaphone Cellular System in the UK, where it is the de facto standard for cellular data communications. Features like improved synchronization field, forward error correction, bit interleaving, and selective retransmission make CDLC ideal for cellular transmissions, according to Millidyne who makes the CDLC modems in the US.
CDPD is an open standard developed by a group of cellular carriers led by McCaw. The specification provides a standard for using existing cellular networks for wireless data transmission. Packets of data are sent along channels of the cellular network. See CDPD for a much more detailed explanation.
In the summer of 1993, a group of cellular carriers that supports the Cellular Digital Packet Data (CDPD) project released the complete - version 1.0 - of its open specification designed to enable customers to send computer data over an enhanced cellular network. According to the group, the packet data approach is ideally suited to those applications that require the transmission of short bursts of data, for example, authorizing a credit card number, exchanging e-mail messages or making database queries. The cellular networks deploying CDPD will enable mobile workers to use a single device to handle all of their voice and packet data needs. The 1.0 specification provides network and customer equipment manufacturers the parameters for building to this nationwide approach that sends packets of data over existing cellular networks. This version of the specification includes input from parties that reviewed the earlier release (0.8 and 0.9) and provides details of the CDPD architecture, airlink, external network interfaces, encryption and authentication, network support services, network applications services, network management, radio resource management and radio media access control. Copies of the specification can be had from CDPD Project Coordinator Tom Solazzo at Pittiglio Rabin Todd & McGrath, 714-545-9400 extension 235.
A floor distribution method in which cables pass through floor cells, constructed of steel or concrete, that provide a ready-made raceway for distributing power and communication cables.
CGSA. The geographic area served by the wireless (cellular) system within which a WSP is authorized to provide service.
See Cellular Radio.
A device that combines data modem and cellular telephone transceiver technologies in a single unit. This allows a user to transfer data on the cellular network without the use of a separate cellular telephone.