Glossary

A

Access Point
A wireless access point (WAP) is a device that allows wireless communication devices to connect to a wireless network using Wi-Fi, Bluetooth or related standards. The WAP usually connects to a router, and can relay data between the wireless devices (such as computers or printers) and wired devices on the network.

AES
The Advanced Encryption Standard (AES) is an encryption standard adopted by the U.S. government. It became effective as a Federal government standard on May 26, 2002 after approval by the Secretary of Commerce. It is available in many different encryption packages. AES is the first publicly accessible and open cipher approved by the NSA for top-secret information.

Amplifier
Generally, an amplifier or simply amp, is any device that changes, usually increases, the amplitude of a signal. The relationship of the input to the output of an amplifier—usually expressed as a function of the input frequency—is called the transfer function of the amplifier, and the magnitude of the transfer function is termed the gain.

Asynchronous
A method of data transmission which allows characters, that are preceded by a start bit and are followed by a stop bit, to be sent at irregular intervals.

B

Band
Another term for spectrum used to indicate a particular set of frequencies. Wireless networking protocols work in either 2.4 GHz or 5 GHz bands.

Bandwidth
A range within a band of frequencies, or an amount of data, that can be transmitted in a preset amount of time. The bandwidth determines the rate at which information can be sent.

Bridge
A connectivity device that operates at the OSI Data Link Layer; it filters and forwards packets by physical addresses. See also router.

Bus network
A network topology in which all the computers connect to a single wire. Bus networks are the simplest way to connect multiple computers, but may encounter collisions when two clients want to transmit at the same time. Bus networks are also sometimes called “daisy-chain” networks, and they aren’t commonly used anymore.

C

Channel
A specific portion of the radio spectrum; for example, the channels allotted to one of the wireless networking protocols. 802.11b and 802.11g use 14 channels in the 2.4 GHz band, only 3 of which don’t overlap (1, 6, and 11). In the 5 GHz band, 802.11a uses 8 channels for indoor use and 4 others for outdoor use, and none of them overlap.

Circuit-switched network
A network in which a virtual circuit is set up for each connection in order to simulate having a physical wire between two points. The telephone system is a circuit-switched network. Circuit-switched networks are generally considered less efficient than packet-switched networks like the Internet because the circuit remains reserved even when no data is being transferred (i.e. when no one is talking).

CLASS features
Acronym for Custom Local Area Signaling Services; consists of number-translation services, such as call-forwarding and caller identification.

CPE
Acronym for Customer Premise Equipment; it includes all telecommunications terminal equipment located on the customer premises, including telephone sets, PBXs, data terminals and customer-owned coin-operated telephones.

D

Daisy-chain network (a.k.a. bus network)
A network topology in which all the computers connect to a single wire. Daisy chain networks are the simplest way to connect multiple computers, but may encounter collisions when two clients want to transmit at the same time. These networks are not commonly used anymore.

Digital divide
A gap between those who have ready access to information and communication technology (Internet access) and the skills to make use of those technologies, and those who do not have the access or skills to use those same technologies within a geographic area, society or community.

E

E911
Enhanced 911, a North American telecommunications based system that automatically associates a physical address with the calling party’s telephone number, and routes the call to the most appropriate Public Safety Answering Point (PSAP) for that address. The caller’s address and information are displayed to the call taker immediately upon call arrival.

Ethernet
A family of frame-based computer networking technologies for local area networks (LANs). The most common networking standard in the world, formally known as IEEE 802.3.

F

Fixed wireless
The operation of wireless devices used to connect two fixed locations (e.g., buildings) with a radio or other wireless link; used to enable data communications between the two sites. This term is usually reserved for devices that derive their electrical power from public utility mains—if it runs off a battery, it’s not fixed wireless.

Four-wire circuit
A two-way circuit using two paths so arranged that the respective signals are transmitted in one direction only by one path and in the other direction by the other path. Late in the 20th century, almost all connections between telephone exchanges were four-wire circuits, while conventional phone lines into residences and businesses were two-wire circuits.

H

Hot spare
Sometimes referred to as hot standby; a failover mechanism to provide reliability in system configurations. The hot spare is active and connected as part of a working system. When a key component fails, the hot spare is switched into operation. More generally, a hot standby can be used to refer to any device or system that is held in readiness to overcome an otherwise significant start-up delay.

Hot spot
A place where you can connect to a public wireless network.

I

IP
Acronym for Internet Protocol. It provides for transmitting blocks of data between hosts identified by fixed-length addresses.

ISDN
Acronym for Integrated Services Digital Network. It is a network architecture that enables end-to-end digital connections. It supports diverse services through integrated access arrangements and defines a limited set of standard, multipurpose interfaces for equipment vendors, network providers, and customers.

L

Last Mile
The last mile or last kilometer is a phrase used by the telecommunications, cable television and internet industries to refer to the final leg of the telecommunications networks delivering communications connectivity to retail customers, the part that actually reaches the customer.

Latency
The length of time between a packet being sent and the response to that packet being returned.

Leased line
A symmetric telecommunications line connecting two locations. It is sometimes known as a “Private Circuit” or “Data Line” in the UK. Unlike traditional PSTN lines it does not have a telephone number, each side of the line being permanently connected to the other. Leased lines can be used for telephone, data or Internet services. Some are ringdown services, and some connect two PBXes.

Long haul
The transmission of data over long distances, potentially many miles. Traditionally, wired networks have been necessary for long haul, but with 802.16, also known as WiMax, long haul via wireless will become more feasible.

LongHaul
A microwave Ethernet bridge designed and manufactured by Carlson.

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M

Mbps
Megabits per second, or millions of bits per second, a measure of bandwidth.

Megahertz (MHz)
A measure of electromagnetic wave frequency equal to one million (1,000,000) hertz, used to specify the radio frequency used by wireless devices.

Modem
A device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used over any means of transmitting analog signals, from driven diodes to radio.

Multi-point
A configuration or topology designed to transmit data between a central site and a number of remote terminals on the same circuit. Individual terminals are not able to send data to each other.

Multiplexing
A process where multiple analog message signals or digital data streams are combined into one signal over a shared medium. The aim is to share an expensive resource. For example, in telecommunications, several phone calls may be transferred using one wire. It originated in telegraphy, and is now widely applied in communications.

N

Network adapter
The card or built-in hardware used in a computer or handheld device to connect to a network, either by using cables or wirelessly.

Network interface card
Commonly abbreviated to NIC. See network adapter.

P

PLAR
Private Line Automatic Ringdown is a type of analog signaling often used with telephone based intercom systems. When a device is taken off-hook, it applies a ringing voltage to the circuit. Other devices on the same pair will ring. Then, when another device is answered, a call will be maintained over the circuit at normal voltage. The telephone company switch is not involved in the process, making this a private line.

Plain old telephone service (POTS)
The voice-grade telephone service that remains the basic form of residential and small business service connection to the telephone network in most parts of the world. POTS has been available almost since the introduction of the public telephone system in the late 19th century, in a form mostly unchanged to the normal user despite the introduction of Touch-Tone dialing, electronic telephone exchanges and fiber-optic communication into the public switched telephone network (PSTN).

Point-to-point
Is a type of communications link that connects a single device to another single device, such as a Base unit to a CPE unit.

Power over Ethernet (POE)
PoE technology describes a system to safely pass electrical power, along with data, on Ethernet cabling. Power can come from a power supply within a PoE-enabled networking device such as an Ethernet switch or from a device built for “injecting” power onto the Ethernet cabling, dubbed Midspan.

Private branch exchange (PBX)
A telephone exchange that serves a particular business or office, as opposed to one that a common carrier or telephone company operates for many businesses or for the general public. PBXs are also referred to as:
• PABX – private automatic branch exchange
• EPABX – electronic private automatic branch exchange

Private line
A service that involves dedicated circuits, private switching arrangements, and/or predefined transmission paths, whether virtual or physical, which provide communications between specific locations.

Public switched telephone network (PSTN)
The network of the world’s public circuit-switched telephone networks. Originally a network of fixed-line analog telephone systems, the PSTN is now almost entirely digital in its core and includes mobile as well as fixed (plain old telephone service, POTS) telephones.

R

Remote access point
One of a number of secondary access points in a wireless network that uses WDS to extend its range. Remote access points, sometimes also called “relay access points,” connect to a master access point.

Remote configuration
A feature that allows the CPE unit to be configured from the Base unit or VT-100 compatible terminal.

Ring network
A network topology similar to a bus network, but with the ends of the wire connected to form a ring. Ring networks are uncommon today.

Ringdown
A method of signaling an operator in which telephone ringing current is sent over the line to operate a lamp or cause the operation of a self-locking relay known as a drop. Ringdown (a) is used in manual operation, as distinguished from dialing, (b) uses a continuous or pulsed ac signal transmitted over the line, and (c) may be used with or without a switchboard.

RJ-11
As a registered jack, this is plug type used by telephones, using a 6-position 4-conductor (6P4C) modular plug and jack, not to be confused with the larger RJ-45 plug type used in Ethernet networks.

RJ-45
As a registered jack, RJ45 specifies both the physical connector and wiring pattern, and uses a special, [1][2] keyed 8P2C modular connector, with pins 5 and 4 wired for tip and ring of a single telephone line and pins 7 and 8 connected to a programming resistor. It was developed for use with a high-speed modem, and is obsolete today.

Roaming
A general term that refers to the extending of connectivity service in a location that is different from the home location where the service was registered. Roaming ensures that the wireless device keeps connected to the network, without losing the connection.

Router
A device that supports LAN-to-LAN communications. IT reads logical addressing information and directs data across a network to its destination. See also bridge.

RS-232
Recommended Standard 232 is a standard for serial binary data signals connecting between a DTE (Data Terminal Equipment) and a DCE (Data Circuit-terminating Equipment). It is commonly used in computer serial ports. A similar ITU-T standard is V.24.

RuralConnect
Wireless radio designed by Carlson Wireless to deliver extended coverage, non-line-of-sight (NLOS) broadband connectivity by transmitting over TV white space (TVWS) frequencies, 470 to 698 MHz, which offer superior signal propagation characteristics. 

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S

Signal strength
The strength of the radio waves in a wireless network or the magnitude of the electric field at a reference point that is a significant distance from the transmitting antenna.

SMTP
Simple Mail Transfer Protocol (SMTP) is an Internet standard for e-mail transmission across Internet Protocol (IP) networks. 

Synchronous
A method of data transmission in which timing information is sent along with the transmitted data. Synchronous communication is achieved when timing shares a single clock.

Synchronous Optical Networking (SONET) and Synchronous Digital Hierarchy (SDH)
Standardized multiplexing protocols that transfer multiple digital bit streams over optical fiber using lasers or light-emitting diodes (LEDs). Lower rates can also be transferred via an electrical interface. The method was developed to replace the Plesiochronous Digital Hierarchy (PDH) system for transporting larger amounts of telephone calls and data traffic over the same fiber wire without synchronization problems.

T

T-1, T-3
Transmission systems commonly used in the Internet. T-1 provides a continuous, dedicated transmission rate of up to 1.5 Mbps, T-3 44.7 Mbps. T-1 and T-3 lines are expensive and generally for business or science use, not consumer use.

Time-division multiplexing (TDM)
A type of digital or (rarely) analog multiplexing in which two or more signals or bit streams are transferred apparently simultaneously as sub-channels in one communication channel, but are physically taking turns on the channel. The time domain is divided into several recurrent timeslots of fixed length, one for each sub-channel. A sample byte or data block of sub-channel 1 is transmitted during timeslot 1, sub-channel 2 during timeslot 2, etc. One TDM frame consists of one timeslot per sub-channel. After the last sub-channel the cycle starts all over again with a new frame, starting with the second sample, byte or data block from sub-channel 1, etc.

TDMA
Time division multiple access (TDMA) is a channel access method for shared medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using his own time slot. This allows multiple stations to share the same transmission medium (e.g. radio frequency channel) while using only a part of its channel capacity.

Trailblazer
A microwave radio with integrated channel bank that can interface with POTS, four-wire E&M, and/or Ethernet. Trailblazer can operate in point-to-point and point-to-multipoint configurations.

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Twisted pair
A wiring type in which each pair of wires twists in a certain way to reduce electromagnetic interference. 10Base-T, 100Base-T, and Gigabit Ethernet all use twisted pair wires. Compare twisted pair to silver-satin telephone wire, in which the pairs don’t twist, and which thus cannot be used for networking.

V

V.35
An ITU-T standard located on layer 1 on the OSI model. Max speed is 2 Mbit/s. Withdrawn ITU-T recommendation for 48kbit/s data transmission over wideband circuits. The physical and electrical characteristics of this interface are now specified in ITU-T recommendation V.11.

VoIP
Voice over Internet Protocol (VoIP) is a general term for a family of transmission technologies for delivery of voice communications over IP networks such as the Internet or other packet-switched networks. Other terms frequently encountered and synonymous with VoIP are IP telephony, Internet telephony, voice over broadband (VoBB), broadband telephony, and broadband phone.

W

WEP
Wired Equivalent Privacy, an encryption system for preventing eavesdropping on wireless network traffic. WEP is easily broken, and has been replaced by WPA on newer Wi-Fi products.

Wi-Fi
A certification mark managed by a trade group called the Wi-Fi Alliance. Wi-Fi certification encompasses numerous different standards, including 802.11a, 802.11b, 802.11g, WPA, and more, and equipment must pass compatibility testing to receive the Wi-Fi mark.

WiMAX
Worldwide Interoperability for Microwave Access, a telecommunications technology that provides wireless transmission of data using a variety of transmission modes, from point-to-multipoint links to portable and fully mobile internet access. The technology provides up to 20 Mbps [1] in real world end-user throughput without the need for cables. The technology is based on the IEEE 802.16 standard (also called Broadband Wireless Access).

Wireless Internet service provider (WISP)
Wireless Internet Service Providers (WISPs) are Internet service providers with networks built around wireless networking. Technology may include commonplace Wi-Fi wireless mesh networking, or proprietary equipment designed to operate over open 900 MHz, 2.4 GHz, 4.9 GHz, 5.2 GHz, 5.4 GHz, and 5.8 GHz bands or licensed frequencies in the UHF or MMDS bands.

WLAN
A wireless local area network links devices via a wireless distribution method (typically spread-spectrum or OFDM radio), and usually provides a connection through an access point to the Internet. This gives users the mobility to move around within a local coverage area and still be connected to the network.

Carlson gratefully acknowledges Wikipedia: The Free Encyclopedia for several of the above definitions.