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The following information is provided for your convenience. Hank's Electrical Supply will not be responsible for any content or information provided from the information provided below. Most of the info below was found from different manufacturers sources, web searches and Wiki's. Please use at your own risk. As always Hank's recommends using licensed and/or certified Electricians for any electrical work.

Glossary of Common Electrical Terms

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A Common abbreviation for ampere.

AC Alternating current. An electrical current that continually reverses its direction giving a definite plus and minus wave form at fixed intervals

Amplitude  The distance between high or low points of a waveform or signal. Also referred to as wave “height”.

AWG  American Wire Gauge. Standard measuring gauge for nonferrous conductors (i.e., non-iron and non-steel). Gauge measures the diameter of a conductor (thickness of cable).

AXT  Alien crosstalk (AXT) is electromagnetic noise that can occur in a cable run alongside other signal-carrying cables. The term "alien" arises from the fact that this form of crosstalk occurs between different cables in a group or bundle, rather than between individual wires or circuits within a single cable

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Backbone Wiring  The physical/electrical interconnections between telecommunications closets and equipment rooms. Cross-connect hardware and cabling in the Main and Intermediate Cross-Connects are considered part of the backbone wiring.

Bandwidth  The difference between the highest and the lowest frequencies of a transmission channel (path for information transmission). Identifies the amount of data that can be sent through a given channel. Measured in Hertz (Hz); higher bandwidth numbers mean higher data capacity.

Bend Radius (Fiber)  Radius of curvature that a fiber can bend without breaking. Also see Cable Bend Radius.

BOM Bill of Materials

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Cable Bend Radius  The amount of bend that can occur before a cable may sustain damage or increased attenuation.

Category 3 CAT 3, A category of performance for inside wire and cable systems. Commonly used for voice applications and data to 10Mbps. Defined by FCC Part 68, ANSI/EIA/TIA-568, TIA TSB-36 and TIA TSB-40.

Category 5 CAT 5, A category of performance for inside wire and cable systems. Used in support of voice and data applications requiring a carrier frequency of up to 100 MHz. Defined by FCC Part 68, EIA/TIA-568, TIA TSB-36 and TIA TSB-40.

Category 5e (Enhanced) CAT5e, A category of performance for inside wire and cable. Used in support of signaling rates of up to 100MHz over distances of up to 100 meters. Calls for tighter twists, electrical balancing between pairs and fewer cable anomalies. CAT 5e is intended to support 100Base-T, ATM and Gigabit Ethernet.

Category 6 CAT 6, A cable standard for Unshielded Twisted Pair (UTP) supporting signaling rates up to 250 MHz. Applications include 1000Base-T, ATM, Gigabit Ethernet and applications under development.

Category 6 Augmented  CAT6A, Also referred to as 10G or 10Gigabit Ethernet. A cable standard for Unshielded Twisted Pair (UTP) supporting signaling rates up to 500 MHz. Applications include 10GBase-T, ATM, 10 Gigabit Ethernet, VoIP, and applications under development.

CE  European Compliance (This is not a certification agency, but CE is the European Compliance Mark)

CEC  Canadian Electrical Code

Circuit   A completed path, over which electrons can flow, from the negative terminal of a voltage source to the positive terminal of the same voltage source.

Closed – In terms of circuits or switches. A closed switched or circuit is not open and will be a conductive path. Note: In most cases we speak of open and closed circuits, switches, contacts etc… in their normal non-energized or otherwise influenced state. This is commonly confused as we have a tendency to associate closed with off. However, a closed circuit is a conductive path and may or may not have anything to due with its electrical state. See also Open, N.C. & N.O

Coaxial Cable  A cable composed of an insulated central conducting wire wrapped in another cylindrical conductor (the shield). The whole thing is usually wrapped in another insulating layer and an outer protective layer. A coaxial cable has great capacity to carry vast quantities of information.

Conductor  Any substance, usually a wire or cable, that can carry an electrical current.

Crosstalk  See Near-End Crosstalk.

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Daisy Chain  In telecommunications, a wiring method where each telephone jack in a building is wired in series from the previous jack. Daisy chain is NOT the preferred wiring method, since a break in the wiring would disable all jacks “downstream” from the break. See also Home Run.

dB (Decibel)  A dB is a unit of measure of signal strength, usually the relation between a transmitted signal and a standard signal source. Every 3dB equals 50% of signal strength, so therefore a 6dB loss is a loss of 75% of total signal strength.

Decora / Decorator / Designer is a rocker or paddle type rectangular switch as opposed to a more traditional toggle type switch. Most Decorator type devices have a common mounting opening and are universal in regards to fitment of Wallplate's. However their have been some anomalies in which the radius of the device or wall plate corners are not consistent, but this is rare especially among the major manufacturers.

Device  As distinguished from equipment. In telecommunications, a “device” is the physical interconnection outlet. Equipment (a computer, phone, fax machine, etc.) then plugs into the device. See also Equipment and Plug.

Duplex  Allowing communication in opposite directions simultaneously as in duplex telephony. Also a duplex receptacle wallplate, meaning it contains 2 outlets. i.e. A duplex outlet is a single device with 2 electrical outlets

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Electromagnetic Interference (EMI) The interference in signal transmission or reception caused by the radiation of electrical and magnetic fields.

Electronic Low Voltage (ELV) is a type of transformer or lighting control. Electronic transformer are typically small, light, and more efficient. However dimming these types of transformers is usually requires a more expensive dimmer. These also have limits on size and length of wire beyond the transformer that MLV type do not have. Noise is considerably less to none. See Also: Low Voltage, Magnetic Low voltage

Equipment  As distinguished from Device. Telecom equipment (computers, phones, faxes, etc.) plugs into telecommunications outlets or devices. See also Device.

Ethernet  Type of local area network used for connecting computers, printers, workstations, terminals, etc. within the same building. Ethernet is a physical link and data link protocol that operates over twisted pair wire and over coaxial cable at speeds up to 10Mbps.

ETL ETL Testing Laboratories – See Also UL

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Fiber Optics  A technology in which light beams are used to transport digital information from one point to another via thin filaments of glass. Benefits include the ability to transmit enormous amounts of data over long distance, high bandwidth, relatively low cost, low power consumption, small space needs, total insensitivity to electromagnetic interference, and excellent security control.

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Gang – One device or mounting position, used in terms of wall boxes or Wallplate's, i.e. a 3 gang box would have three device mounting location for say three dimmers and require a 3-gang Wallplate.

Gigabit  When used to describe data transfer rates, it refers to 10 to the 9th power (1,000,000,000) bits. Gigabit Ethernet, abbreviated GbE,supports data transfer rates of 1 Gigabit (1,000 megabits) per second. The first Gigabit Ethernet standard (802.3z) was ratified by the IEEE 802.3 Committee in 1998.

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Halogen for our purposes is a more specific type of incandescent light. The process in which the Halogen lamp is made typically results in what most perceive as a brighter, more white (higher color temperature) light. The actual heat of this lamp is also typically much greater than a traditional incandescent lamp. It is a common misconception that Halogen is low voltage. The term 'Halogen lighting' has been used so commonly in referring to types of light fixtures that use it has been become synonymous to most and obviously this is wrong. Most Low Voltage fixtures use Halogen Lamps however Halogen Lamps come in all common voltages. Halogen has other benefits but most of which were exceeded by Xenon based lamps. See also: Incandescent, Xenon

Home Run  Telephone system wiring where the individual cables run from each telephone directly back to the central switching equipment. Home run cabling can be thought of as “star” cabling. Every cable radiates out from the central equipment. See also Star Wiring, Daisy Chain.

Hub  In data communications, a hub is a place of convergence where data arrives from one or more directions and is forwarded out in one or more other directions. Hubs aren't switches as they have very little intelligence, if any, and don't set up transmission paths.

Hub  The point on a network where circuits are connected. Also, a switching node. In local area networks, a hub is the core of a star as in ARCNET, StarLAN, Ethernet, and Token Ring. Hub hardware can be either active or passive. Wiring hubs are useful for their centralized management capabilities and for their ability to isolate nodes from disruption.

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IDC (Insulation Displacement Connection) A type of wire termination where wire is “punched down” into a metal holder which cuts into the insulation wire and makes contact with the conductor, causing the electrical connection to be made.

IEC  International Electrotechnical Commission

Impedance  The total opposition (i.e. resistance and reactance) a circuit offers to the flow of alternating current. It is measured in ohms, and the lower the ohmic value, the better the quality of the conductor.

Incandescent or Incandescent Light Bulb A general term for heat-driven light emissions. Basically all common types of light bulbs including Halogen can be generally classified as incandescent. For our purposes this term is used to differentiate between various types of recessed or other lighting assemblies. In a very vague sense we refer to 'line voltage' recessed lighting as incandescent to differentiate it from fluorescent, LED, or Low Voltage.

Insertion Loss  The difference in the amount of power received before and after something is inserted into the circuit. In optical fiber, insertion loss is the optical power loss due to all causes, usually expressed as decibel/kilometer.

Internet Gateway  Internet Gateways typically sit on a local area network and convert IP (Internet Protocol) packets to IPX, AppleTalk or some other non-IP formats (protocols found on LANs) and vice versa. It is used to connect non-IP networks to the Internet.

IP Address  Each machine that is on a network (a local network, or the network of the Internet) has a unique address known as an Internet Protocol address (IP address). The IP address takes the form of four numbers separated by dots, for example: If a machine does not have an IP address it cannot be on a network.

ISDN  Integrated Services Digital Network. A set of international standards for a circuit switched digital network that supports access to any type of service such as voice, data or video over a single integrated local loop from the customer premises to the network edge.

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Jack  A receptacle used in conjunction with a plug to make electrical contact between communication circuits. Jacks and their associated plugs are used for connecting hardware applications including cross connects, interconnects, information outlets, and equipment connections. Jacks are used to connect cords or lines to telephone systems. A jack is the female component of a plug/jack connector system, and may be standard, modified, or keyed.

Jacket  Also Cable Jacket or Sheath. The outer covering applied over internal cable elements for protection.

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LAN  Local Area Network. A short distance network (typically within a building or campus) used to link together computers and peripheral devices (such as printers) under some form of standard control.

L.E.D. is an emerging type of lighting historically reserved for electronics applications. Current progress has LED lamps in excess of 14watts providing some promising alternatives for a more efficient future. Light Emitting Diodes previously had limitations on color and intensity. Today they are currently available in most primary colors and several shades of white, colored in a similar fashion as fluorescent lamps are colored. You will also find and RGB LED which essentially 1 Red, 1 Green and 1 Blue LED combined in a single chip, used in conjunction with an RGB controller combines to make just about any perceived color. You will soon see LED based televisions as well. Although LED's are DC by nature is some replacement LED type lamps and fixtures are available in AC/DC applications and typically have built in rectification. Although raw LED's are dimmable simply by varying the voltage, common dimmers don't work this way, so most 120vac LED retro lamps & Fixtures don't dim with conventional dimmers. Also most lighting transformers are AC and LED's requiring DC use a DC power supply or driver. LED's are also susceptible to over voltage and can be easily damaged in this manner. Otherwise they are fairly durable. See also LED Driver

Loop  1. Typically a complete electrical circuit. 2. In computer software, a loop repeats a series of instructions until a pre stated event has happened or test has been passed.

Low Voltage Lighting- Common reference to 12vac low voltage lighting. Also commonly misconceived that low voltage lighting is safer and energy efficient. Though the operating voltage is lower, the current is ten times that of a 120vac lamp. Most people also think they can use smaller gauge wire on low voltage, however this couldn't be further from the truth. The wire size is more dependant on the current than the voltage for the common voltages we use for lighting. As far as the energy efficiency, this type of lighting is less efficient. than it's 120vac counter part because we have a loss in the transformer to account for. So why do we use them? Because of the excellent quality and control of light and their small size. They should also be further classified to Magnetic Low Voltage (MLV) or Electronic Low Voltage (ELV) depending on the transformer supplying the low voltage. Although most residential and commercial low voltage lighting is 12vac we will see other voltages as well, and with the emergence of LED lighting it's important to note DC vs. AC as most prior low voltage lighting systems were AC based and depending on the LED product you have, it maybe current specific or some have built in rectification and claim to be AC/DC rated. More on this in the LED Section. Incandescent and/or halogen types of low voltage lighting are not typically current dependant, in other words they will work on AC or DC. See also: Halogen, MLV, ELV, Incandescent and LED

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Magnetic Low Voltage or MLV Is a term referred to when describing a type of transformer or lighting control. MLV transformer work on an inductive principal and are also called core and coil. Typically in lighting this is a large heavy encapsulated core and coil or Torodial type. All Magnetic transformer have a noticeable hum, more pronounced depending on their quality, encapsulation and type. Torodial tend to be the least prone to make noticeable levels of noise. See also Low voltage, Torodial, and Magnetic Low Voltage

Mbps  Megabits Per Second. One million bits per second. (Different from MBps, or a million bytes per second.)

MHz  Megahertz. A unit of frequency denoting one million Hertz (i.e., 1,000,000 cycles per second).

Motion Sensor this one sounds fairly straight forward but California Energy Commission and their Title 24 standards complicated the issue in or around 2005. For our purposes a motion sensor is a device typically used to replace a wall switch that senses motion and upon lack of motion these generally have a timer which time out and shut off the lighting circuit or connected load. Along came Title 24 energy standards and now we have 2 basic types of sensors: Occupancy and Vacancy. Please click on either for a better description. It should be noted that there are also a couple different types of motion sensing methods, PIR and Ultrasonic or a combination thereof. Most sensors are of the PIR type and range in quality and performance usually respective of their price. Ultrasonic or combinations, also known as dual-tech, are typically of a better quality and higher price designed primarily for commercial use.

Multimode  Optical fiber with either 50 micron or 62.5 micron core size, designed to allow light to carry multiple signals distinguished by frequency or phase, at the same time. Can be used with LED or LASER light sources. Contrasts with single-mode. Common in Local Area Networks.

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NAED  National Association of Electrical Distributors

N.C. / N.O. – Normally Closed / Normally Open. Description of circuit, switch, contact, etc.. in it’s normal, non-energized or otherwise influenced state. See also Open and Closed

Near-End Crosstalk (NEXT)  Electrical noise coupled from one pair of wires to another within a multi-pair cable.

NEC  National Electric Code

NEMA  National Electrical Manufacturers Association

Network  A network ties things such as communications or computer equipment together. Computer networks connect computers and computer- related things— terminals, printers, modems, door entry sensors, temperature monitors, etc. Local Area Networks (LANs) to connect computer equipment within a building or campus. Wide area networks extend beyond metropolitan areas.

NFPA  National Fire Protection Agency

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Occupancy Sensor as opposed to Vacancy Sensor. This is the 'Full Auto', or 'Auto On / Auto Off'. The occupancy sensor is just that it senses, or tries to, the occupancy of the room. Depending on how nice of a sensor you bought this is a great or possibly frustrating little thing & how well it is adjusted. You should take a moment to familiarize your self with the different technologies used so you better understand their applications and get one that works right the first time. See Also Motion Sensors, Vacancy Sensors, PIR and Ultrasonic Sensors.

OEM  Original Equipment Manufacturer

Open (Fault)  Means that the circuit is not complete or the cable/ fiber is broken

OPEN – In terms of circuits or switches. An Open switch or circuit is not closed and will not be a conductive path. Note: In most cases we speak of open and closed circuits, switches, contacts etc… in their normal non-energized or otherwise influenced state. This is commonly confused as we have a tendency to associate open with on. However, a open circuit is a break in the conductive path and may or may not have anything to due with its electrical state. See also Closed, N.C. & N.O

OSHA  Occupational Safety and Health Administration

Outlet  Also referred to as a receptacle or sometimes plug. A telecommunications outlet is a single-piece cable termination assembly (typically on the floor or in the wall), containing one or more modular telecom jacks. Such jacks might be RJs, coaxial terminators, fiber optic couplers, etc. See also Device and Equipment.

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Patching  A means of connecting circuits via cords and connectors that can be easily disconnected and reconnected at another point. May be accomplished by using modular cords connected between jack fields or by patch cord assemblies that plug onto connecting blocks.

PIR Sensor or Passive Infra-Red (as opposed to Ultrasonic). This is by far the most common technology of motion sensor used on the market. PIR sensors can be fairly simple and inexpensive, but this is one of those items that you really get what you pay for. PIR sensors work on heat motion. So this sensor will 'see' a somewhat significant change in ambient temperature moving past its senor and triggers. The tricky part to the best PIR performance is realizing how it works. If the motion senor is aimed at a wall and it just so happens there is a heat register or possibly even a window with direct sunlight heating that wall it may not see you if the wall is close to the same temperature as the passer by. Location is KEY and to the opposite effect a cool sensation from an air conditioner may trigger it. I may have better stated it as needing to see a difference in heat. So back to our wall scenario if it's staring at a wall all day that may become 80 degrees through a sunny exposure, it may not see you until the wall temperature drops significantly from your body temperature. Lets use another analogy by saying it's a camera or video recorder instead of a sensor, but only see's heat. It take that heat 'picture' into memory and when that picture quickly & significantly changes it triggers. I think I've way over stated this, but when you've sold as many of these as I have and gotten several call backs saying why doesn't work, well there is just no simple answer and another reason I prefer the Ultrasonic, less call backs... see also Occupancy and Vacancy Sensors

Plug  Misnomer often referring to an outlet or receptacle. A plug is a male cord end typically. A male component of a plug/jack connector system. In premises wiring, a plug provides the means for a user to connect communications equipment to the communications outlet.

PoE  Power Over Ethernet technology describes any system to transmit electrical power, along with data, to remote devices over standard twisted-pair cable in an Ethernet network. This technology is useful for powering IP telephones, wireless LAN access points, webcams, Ethernet hubs, computers, and other appliances where it would be inconvenient or infeasible to supply power separately.

Polarity  A term describing positive and negative sides of an electrical circuit. Positive and negative wires must be wired correctly to support touchtone phones and video.

POTS  Plain Old Telephone Service. The basic service supplying standard single line telephones, telephone lines and access to the public switched network with no added features such as call waiting or forwarding.

Punchdown  Refers to the use of an impact tool that enables installers to make efficient IDC style connections.

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Return Loss A measure of the similarity of the impedance of a transmission line and the impedance at its terminations. It is a ratio, expressed in decibels, of the power of the outgoing signal to the power of the signal reflected back.

RFQ  Request for Quotation

Ring  As in Tip and Ring. One of the two wires needed to set up a telephone connection. See Tip

RJ  Registered Jack. RJs are telephone and data jacks registered with the FCC. Numbers, like RJ-11, RJ-45, etc. are widely misused in the telecommunications industry. A much more precise way to identify a jack is to specify the number of positions (width of opening) and number of conductors. Example: “8-position, 8-conductor jack” or “6-position, 4-conductor jack”.

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Series Wiring  Also referred to as Daisy Chain. In telecommunications, a wiring method where each telephone jack in a building is wired in series from the previous jack. It is NOT the preferred wiring method, since a break in the wiring would disable all jacks “downstream” from the break. See also Home Run.

Service Loop  When a device is terminated to the wire in the communications outlet, a fair amount of “slack” should be left on the wire and wound in the box to accommodate future trimming when devices are changed out.

Singlemode  Optical fiber with an 8.3-9.5 micron core size, optimized for LASER light sources which transmit only one mode or path of light. This eliminates modal dispersion, the main limitation to bandwidth. Typical in long-haul networks and outside plant applications due to increased bandwidth.

Splice  The joining of two or more cables together by connecting the conductors pair-to-pair.

Switch  A mechanical, electrical, or electronic device which opens or closes circuits, completes or breaks an electrical path or selects paths or circuits. A switch looks at incoming data to determine the destination address, then sets up a transmission path.

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T&M  Time and Material

T1  A standard for digital transmission in North America. A digital transmission link with a capacity of 1.544 Mbps (1,544,000 bits per second.) T1 lines are used for connecting networks across remote distances. Bridges and routers are used to connect LANs over T1 networks.

TCP/IP  Transmission Control Protocol/Internet Protocol A protocol for communication between computers, used as a standard for transmitting data over networks and as the basis for standard Internet protocols.

Telco  An Americanism for Telephone Company.

Terminate  To connect a wire conductor to something, typically a piece of equipment.

Tip 1 . The first wire in a pair of wires, the tip is the conductor in a telephone cable pair which is usually connected to positive side of a battery at the telco. It is the telephone industry’s equivalent of Ground in a normal electrical circuit. 2. The transaction internet Protocol ensures that multi vendor transaction monitors will work with one another to complete transactions over the Internet.

Token Ring  An old topology for a local area network (LAN) in which a supervisory frame, or token, must be received by an attached terminal or workstation before that terminal or workstation can start transmitting.

Tone Dial  A push-button telephone dial that makes a different sound (in fact, a combination of two tones) for each number pushed. The technically correct name for tone dial is Dual Tone Multi Frequency, or DTMF.

Twisted Pair  Two insulated copper wires twisted around each other to reduce induction (thus interference) from one wire to the other. The twists, or lays, are varied in length to reduce the potential for signal interference between pairs. Several sets of twisted pair wires may be enclosed in a single cable. In cables greater than 25 pairs, the twisted pairs are grouped and bound together.

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UL  Underwriters Laboratories Inc

UL  Underwriters Laboratories, a privately owned company that tests to make sure that products meet safety standards. UL also administers a program for the certification of Category-Rated Cable.

Ultrasonic Motion Sensor - without getting overly technical this type of motion sensing is basically an inaudible acoustic sensor. It sends out an ultra sonic sound waves as when those are interrupted it assumes motion. This is personally my favorite type of sensor from a sales point of you, because these almost always get the job done when a PIR senor cannot. Say like a closed bathroom stall or even around certain corners or other minor obstructions. This is also used in combination with a PIR for some manufacturers as a means of checks and balances, to avoid false triggering. Both PIR and Ultrasonic are prone to false triggering if set very sensitive, but if this is a problem you may whish to consider a Vacancy Sensor vs. an Occupancy Sensor.

UPS  Uninterruptible Power Supply, a power supply that includes a battery to maintain power in the event of a power outage, especially important in data center applications.

UTP  Unshielded Twisted Pair. See Twisted Pair.

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Vacancy Sensor as opposed to Occupancy Sensor. This is the Title 24 type Manual On / Auto Off Sensor. The Vacancy sensor contrary to your normal perception of motion sensors. It does nothing unless you tell it to. That is to say you have to manually turn it on and it instantly turns on and starts sensing motion and like the Occupancy sensor will time out and shut off when motion is no longer sensed. Although most of the Vacancy sensors are of the PIR type you should take a moment to familiarize your self with the different technologies used so you better understand their applications and get one that works right the first time. See Also Motion Sensors, Occupancy Sensors, PIR and Ultrasonic Sensors.

VoIP  Voice over Internet Protocol allows voice calls to be encoded and transmitted over the data network. Benefits are cost-savings, the ease of managing just one network, and lots of new services including integrated messaging, voice emails, number portability, and phone account management via Internet.

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WAN  Wide Area Network- a public voice or data network that extends beyond the metropolitan area.

WAP  Wireless Access Point. WAP also refers to the Wireless Application Protocol, a carrier independent, transaction oriented protocol for wireless data networks.

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1000BASE-T  This IEEE standard defines an Gigabit Ethernet local area network running 1000Mbps baseband over unshielded twisted-pair cabling. Throughput over 10Base-T is improved by decreasing bit latency periods and increasing packet speeds.

100BASE-T  This IEEE standard defines an Ethernet local area network running 100Mbps baseband over unshielded twisted-pair cabling. Throughput over 10Base-T is improved by decreasing bit latency periods and increasing packet speeds.

10BASE-T  This IEEE standard defines an Ethernet local area network running 10Mbps baseband over unshielded twisted pair cabling, typically Category 5.

10GBASE-T  This proposed IEEE standard defines 10 Gigabit Ethernet running 10GMbps over unshielded twisted-pair cabling. Positioned as high speed technology to support Metropolitan Area Networks and other high-demand applications.

802.11 a/b/g IEEE standards for wireless LANs. An 802.11a/b/g compatible Wireless Access Point works interchangeably with all three (802.11a, 802.11b, and 802.11g).

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