Glossary
2G (second-generation cellular service)
Based on digital access to cellular networks. GSM and CDMA are 2G cellular technologies.
3G (third-generation cellular service)
3G mobile standards specify techniques that are capable of supporting more voice traffic and broadband mobile multimedia (speech, audio, text, graphics, and video) services. There are three main 3G services, including WCDMA, CDMA2000, and UMTS TDD. See also 3GPP and 3GPP2.
3GPP (3rd Generation Partnership Program)
A collaborative group that is developing an agreement to jointly create technical specifications for maintaining LTE, GSM, GPRS, and EDGE and for evolving WCDMA and LTE networks. European, Asian, and North American telecommunications standards bodies formed the 3GPP.
3GPP2 (3rd Generation Partnership Program 2)
An analogous group to 3GPP, but it is working on evolving technical specifications for CDMA2000 networks.
10base-T
An IEEE specification for unshielded, twisted-pair cabling used for Ethernet LANs that transmit at 10Mbps. The distance limitation for 10base-T networks is 100 meters.
100base-T
An IEEE standard compatible with 10base-T for transmitting at 100Mbps over unshielded twisted-pair cabling on LANs.
802.11
A set of IEEE standards for LANs. 802.11a, 802.11b, and 802.11g are the most common and are used in homes to share Internet access, in enterprises, and in hotspots.
802.15.4
The IEEE standards upon which the ZigBee Alliance tests and certifies equipment, and adds functions to sensor networks.
802.20
A set of IEEE standards for wireless technology based on OFDM. Flarion, which is part of Qualcomm, builds 802.20 equipment.
8YY toll-free numbers
An abbreviation describing the format of the North American Numbering Plan for toll-free numbers. The first three digits of toll-free telephone numbers must be the number 8 followed by 0 or 2 through 9 for the second and third digits. When central office switches see the 8YY format, they request a database check to determine where the toll-free number should be routed.
adaptive bit rate streaming
The capability of equipment (encoders) used to stream video and multimedia content from the Internet to computers and mobile devices to adjust the bit rate dynamically to the user’s processing capabilities and bandwidth availability.
access fees
Carriers pay access fees to local telephone companies for transporting long-distance traffic to and from local customers. The FCC sets access fees for interstate traffic, and state utility commissions set access fees for intrastate traffic. They are intended to offset the costs that local phone companies incur in providing links to local customers, but these fees have been decreasing, and residential and business customers are paying some of the costs in the form of monthly charges called Subscriber Line Charges (SLCs). VoIP traffic is exempt from access fees.
ACD (Automatic Call Distribution)
Equipment and software that distribute calls to agents, based on parameters such as the agent who has been idle the longest. ACDs are part of telephone systems or adjuncts to telephone systems. ACDs are also referred to as contact centers. See also contact centers.
Active Directory
A directory of users on organizations’ LANs. Provides authentication that people are who they claim to be and security by encrypting calls.
ANI (Automatic Number Identification)
The business or residential customer’s billing number. Customers such as call centers pay for callers’ ANIs to be sent to them simultaneously with incoming 800 and 888 and other toll-free calls.
APs (Access Points)
These contain antennas and chips with 802.11a, 802.11b, 802.11g, or 802.11n air interfaces for 802.11 wireless LANs. Access points translate between radio frequencies and Ethernet signals for cabled networks. An access point has similar functions to base stations for cordless home phones.
API (Application Programming Interface)
Software used to translate programming code between two different programs. An API can be used when an application at an enterprise accesses an application on the cloud.
architecture
Defines how computers are tied together. Some vendors refer to the architecture of their equipment in terms of the growth available and the hardware and software needed for their systems to grow.
ASCII (American Standard Code for Information Interchange)
The main 7-bit code personal computers use to translate bits into meaningful language. Most computers now use extended ASCII, which supports 8-bit codes. Each group of 8 bits represents a character. Computers can “read” one another’s binary bits when these bits are arranged in a standard, uniform “language.” ASCII is the most commonly used computer code.
ATM (Asynchronous Transfer Mode)
A high-speed switching technique that uses fixed-size cells to transmit voice, data, and video. A cell is analogous to envelopes that each carry the same number of bits. Used mainly in older networks.
backbone
A segment of a network used to connect smaller segments of networks together. Backbones carry high concentrations of traffic between on and off ramps to networks.
backhaul
A term used mostly to describe the links between antennas at base stations and mobile central offices, and services in the cellular networks core. Traffic and signaling information is backhauled from where it enters the network to the mobile core, and vice versa.
band refarming
The reuse of portions of spectrum for more advanced mobile protocols. Many countries are refarming spectrum originally used only for older second-generation services to newer fourth-generation technologies.
bandwidth
The measure of the capacity of a communications channel. Analog telephone lines measure capacity in hertz (Hz), the difference in the highest and lowest frequency of the channel. Digital channels measure bandwidth in bits per second (bps).
BGP (Border Gateway Protocol)
A routing protocol with more than 90,000 addresses. Used by carriers to route packets on the Internet. BGP enables routers to determine the best routes to various destinations.
bill and keep
A carrier-to-carrier billing method that eliminates the requirement for carriers to bill each other access fees. It is used by billing companies only to bill carriers that carry less traffic than carriers with whom they exchange traffic.
bit error rate
The percentage of bits received in error in a transmission.
blade
Circuit boards are often referred to as “blades” when they are dense, such as when they have many ports (connections) or software for a specialized application such as security.
Bluetooth
A set of standards for special software on low-cost, low-powered radio chips that enables devices to communicate with one another over a short-range wireless link. Bluetooth eliminates cable clutter between computers and peripherals in offices and supports wireless headsets for mobile handsets.
BOC (Bell Operating Company)
One of the 22 local Bell telephone companies owned by AT&T Corporation prior to 1984. Examples of Bell Operating Companies are Michigan Bell, Illinois Bell, and Pac Bell. Bell Operating Companies are now part of AT&T Inc., CenturyLink, and Verizon Communications.
border elements
Another name for media gateways. See also media gateways.
bps (bits per second)
The number of bits sent or received in one second.
BRI (Basic Rate Interface)
The ISDN interface made up of two B channels at 64 kilobits each and a signaling channel with a speed of 16 kilobits.
bridge
A device that connects local or remote networks together. Bridges are used to connect small numbers of networks. Bridges do not have routing intelligence. Organizations that want to connect more than four or five networks use routers.
broadband
A data transmission scheme in which multiple transmissions share a communications path. Cable television uses broadband transmission techniques.
broadcast
A message from one person or device forwarded to multiple destinations. Video and e-mail services have broadcast features whereby the same message can be sent to multiple recipients or locations.
BTA (Basic Trading Area)
A relatively small area in which the FCC allocates spectrum. There are 491 basic trading areas in the United States.
CAP (Competitive Access Provider)
Originally provided midsize and large organizations with connections to long-distance providers that bypassed local telephone companies. CAPs are now often referred to as Competitive Local Exchange Carriers (CLECs) or competitive providers.
CCIS (Common Channel Interoffice Signaling)
A signaling technique used in public networks. Signals such as those for dial tone and ringing are carried on a separate path from the actual telephone call. CCIS allows for telephone company database queries used in features such as caller ID, call forwarding, and network-based voicemail. CCIS channels are also used for billing and diagnosing public network services.
CDMA (Code-Division Multiple Access)
An air interface used to transmit digital cellular signals between handheld devices and cellular carriers’ networks. CDMA assigns a unique code to every voice and data transmission by using a channel of a particular carrier’s airwaves. CDMA is a spread-spectrum technology that is used by Verizon Wireless, Sprint, and South Korean carriers such as SKT.
CDMA2000 (Code-Division Multiple Access 2000)
A 3G technology for carrying high-speed data and multimedia traffic on cellular networks.
CDMA2000 1X (Code-Division Multiple Access 2000)
The earliest version of the CDMA2000 3G technology for carrying high-speed data and multimedia traffic on cellular networks.
CDMA2000 1xEV-DO (Code-Division Multiple Access 2000 Data Optimized or Data Only)
A later, higher-data-rate version of CDMA2000 1X 3G technology for carrying high-speed data and multimedia traffic on cellular networks.
central office
The site in the Public Switched Telephone Network with the local telephone company’s equipment that routes calls to and from customers. It also has equipment that connects customers to Internet service providers and long-distance services.
channel
A path for analog or digital transmission signals. With services such as ISDN, T1, and T3, multiple channels share the same one or two pairs of wires or fiber.
CIC (Carrier Identification Code)
The four-digit code (previously three digits) assigned to each carrier for billing and call-routing purposes. AT&T’s CIC is 0288. If someone at a pay telephone dials 1010288 and then the telephone number she is calling, the call is routed over the AT&T network.
CIR (Committed Information Rate)
A term used in frame relay MPLS networks to indicate the speed of the transmission guaranteed for a customer. See also MPLS.
circuit switching
The establishment—by dialing—of a temporary physical circuit (path) between points. The circuit is terminated when either end of the connection sends a disconnect signal by hanging up.
CLEC (Competitive Local Exchange Carrier)
A competitor to incumbent local telephone companies that has been granted permission by the state regulatory commission to offer local telephone service. CLECs compete with the incumbent telephone company. CLECs are also simply called local telephone companies.
CLID (Calling Line ID)
The number that identifies the telephone number from which a call was placed. For most residential customers, the calling line ID is the same as their billing number, their Automatic Number Identification (ANI).
CO (Central Office)
The location that houses the telephone company switch that routes telephone calls. End offices are central offices that connect end users to the Public Switched Telephone Network.
compression
The reduction in size of data, image, voice, or video files. This decreases the capacity needed to transmit files.
concatenation
The linking of channels in optical networks so that voice or video is transmitted as one stream. This is done to ensure that there are no breaks in the transmission.
connectionless service
The Internet protocol is connectionless. Each packet travels through the network separately. If there is congestion, packets are dropped. Packets are reassembled at their destination.
contact center
Another term for automatic call distribution. The term contact center implies that call centers have the capability to respond to e-mail and facsimile as well as voice calls.
containers
Application programs surrounded by software that enables a group of programs in the same container to work together.
convergence
The use of one network for voice, data, and video.
CORD (Central Office Re-architected as a Data Center)
Telephone companies that deploy CORD architect their central offices as data centers rather than as typical central offices. They use open source software and commodity servers and switches and software-defined networking. The goal is to be able to quickly add and delete features and services used by customers.
cordless
Cordless telephones provide portability, mainly within homes and apartments.
core networks
The portions of carrier and enterprise networks that carry the highest percentage of traffic, and where switches and routers connect to other switches and routers rather than to customers. High-speed core routers are located in core networks.
CPE (Customer Premises Equipment)
Telephone systems, modems, terminals, and other equipment installed at customer sites.
CSU/DSU (Channel Service Unit/Data Service Unit)
A digital interface device that connects customer computers, video equipment, multiplexers, and terminals to T1/E1 and T3/E3 lines.
CTI (Computer Telephony Integration)
CTI software translates signals between telephone systems and computers so that telephone systems and computers can coordinate sending call routing and account information to agents in contact centers.
CWDM (Coarse Wavelength-Division Multiplexing)
A multiplexing technology standard that enterprises and carriers deploy to connect corporate sites to public networks and to bring the capacity of fiber closer to residential neighborhoods. It carries up to eight channels of traffic on a single fiber pair.
dark fiber
Fiber-optic cables without any of the electronics (that is, multiplexers and amplifiers). Carriers can lay dark fiber and add SONET, Gigabit Ethernet, and wavelength-division multiplexers later.
DCE (Data Circuit-Terminating Equipment)
A communications device that connects user equipment to telephone lines. Examples include modems for analog lines and CSUs for digital lines.
dedicated line
A telephone line between two or more sites of a private network. Dedicated lines are always available for the exclusive use of the private network at a fixed, monthly fee.
de-duplication
A method of compression that removes changes in files sent between two sites where each site has a copy of the file as it was originally sent. De-duplication sends only changes each time after the original transmission. The receiving end adds the changes and puts the file back together.
DID (Direct-Inward Dialing)
A feature of local telephone service whereby each person in an organization has his own ten-digit telephone number. Calls to DID telephone numbers do not have to be answered by onsite operators. They go directly to the person assigned to the ten-digit DID telephone number.
DiffServ (Differentiated Services)
Used in routers to tag frames. The tags request a particular level of service on the Internet and other IP-based networks.
disk mirroring
The process of simultaneously writing data to backup and primary servers.
divestiture
In January 1984, divestiture deregulated long-distance service in the United States. It separated the former AT&T from its 22 local Bell telephone companies. Agreement on divestiture was reached by the Justice Department, which negotiated an antitrust settlement with the former AT&T, called the Modified Final Judgment.
DLC (Digital Loop Carrier)
Used to economically bring fiber closer to customers. Carriers run fiber cabling from central offices to DLCs and they lay twisted-pair copper cabling from DLCs to customers.
DNIS (Dialed-Number Identification Service)
The service used to identify and route toll-free and 900 numbers to particular agents or devices within a customer site. For example, if a customer has multiple 800 numbers, the network provider routes each toll-free number to a different four-digit number at the customer’s telephone system. The onsite telephone system then routes the call to a particular group of agents, voice response system, or department.
DNSSEC (Domain Name Service Security Extensions)
An Internet security standard for preventing users from using other organizations’ domain names, which is also known as spoofing. Disguising domain names makes it more difficult to track the origin of traffic.
domain name
Everything after the @ sign in an e-mail address. It includes the host computer, the organization’s name, and the type of organization (for example, .com for commercial and .edu for educational). Both .com and .edu are top-level domain names. The domain name can also designate the country, such as .bo for Bolivia. A domain name is part of the TCP/IP addressing convention.
DoS (Denial-of-Service) attack
An attack by which hackers bombard networks with thousands of packets intended to disrupt the capability of the attacked network to function.
downlink (DL)
On broadband and mobile networks, the downlink portions are those that carry traffic from the carrier to the customer.
downloading
Receiving an entire file from another location. When music is downloaded, the entire music file must be downloaded to the computer’s hard drive before it can be played.
DS-0 (Digital Signal level 0)
A transmission rate of 64Kbps. This refers to one channel of a T1, E1, E3, T3, fractional T1, or fractional T3 circuit.
DS-1 (Digital Signal level 1)
The T1 transmission rate of 1.54Mbps. There are 24 channels associated with DS-1 or T1.
DS-3 (Digital Signal level 3)
The T3 transmission rate of 44Mbps over 672 associated channels. (T3 is equivalent to 28 T1s.)
DSP (Digital Signal Processor)
Compresses (shrinks the number of bits required for) voice and video, performs digital-to-analog and analog-to-digital voice conversions, and packetizes voice and video in real time for IP networks.
DTE (Data Terminal Equipment)
Devices that communicate over telephone lines. Examples include multiplexers, PBXs, key systems, and personal computers.
DVB (Digital Video Broadcasting)
A standard approved by the European Telecommunications Standards Institute (ETSI). It has lower resolution than HDTV.
DWDM (Dense Wavelength Division Multiplexing)
A way of increasing the capacity of fiber-optic networks. DWDM carries multiple colors of light, or multiple wavelengths, on a single strand of fiber. Also known as Wavelength Division Multiplexing (WDM).
E1
The European standard for T1. E1 has a speed of 2.048 megabits with 30 channels for voice, data, or video, plus one channel for signaling and one for diagnostics.
E3
The European standard for T3. E3 has a speed of 34.368Mbps with 480 channels. It is equivalent to 16 E1 circuits.
E-911 (Enhanced 911)
The capability for agents who answer 911 calls to receive the callers’ phone numbers and locations.
EDGE (Enhanced Data Rates for Global Evolution)
EDGE mobile services offered by cellular carriers have higher data rates than second-generation cellular networks. EDGE is often used by carriers as they transition to higher-data-rate, third-generation mobile service.
end offices
The central offices connected to end users and to tandem central offices. Most end offices are based on circuit switching, but they are slowly being converted to softswitch technology to carry VoIP.
endpoint
Any device connected to LANs, such as computers, printers, and VoIP telephones.
Ethernet
Based on the 802.3 standard approved by the IEEE. It defines how data is transmitted on and retrieved from LANs. It is used by devices such as personal computers to access the LAN and to retrieve packets carried on the LAN.
exabyte (EB)
A unit of measurement to indicate the number of bytes in storage networks. An exabyte is equal to 1,000,000,000,000,000,000 bytes or 1 billion gigabytes. A byte is equal to 8 bits, or one character.
FDDI (Fiber-Distributed Data Interface)
An ANSI-defined protocol in which computers communicate at 100Mbps over fiber-optic cabling. FDDI can be used on backbones that connect LAN segments together. It is not widely used.
fiber-optic cable
A type of cable that is made from glass strands rather than copper wire. The key advantage of fiber-optic cabling is that it is non-electric. Thus, it is immune from electrical interference and interference from other cables within the same conduit. Fiber-optic cabling can be used for higher-speed transmissions than twisted-pair copper cabling.
Fibre Channel protocol
Used in storage area networks and data centers for gigabit-speed, highly reliable, short-distance access to devices such as disks, graphics equipment, video input/output devices, and storage devices that hold massive amounts of data.
firewall
Software and hardware that prevents unauthorized access to an organization’s network files. The intention is to protect files from computer viruses and electronic snooping.
firmware
Special software embedded in hardware (routers, printers, cellular phones etc.) containing instructions that control the hardware on which it’s installed. Firmware is non-volatile. It isn’t lost when power is lost.
fixed mobile convergence
The capability to use the same handset or portable computer for Wi-Fi as well as mobile voice and data sessions. For voice calls, it is the capability to continue the call when moving; for example, from a hotspot or home to a cellular network, and vice versa.
fixed wireless
Wireless service between fixed points. Generally, these are between an antenna on a tower and a dish on a business or residential customer’s building. It is also used to connect two buildings together as a lower-cost option than running cabling. Used most often in rural or hard-to-cable areas.
fixed wireless access
Provides similar data rates as Gigabit Ethernet technologies using wireless media rather than cabling. LTE and 5G can be used for broadband wireless access service.
fractional T3
A less expensive T3 access scheme in which the customer pays for a fraction of the 672-channel capacity of T3 lines. For example, it might have the capacity of 6 T1s or 144 channels. Fractional T3s are cheaper than a full T3 line.
FTP (File Transfer Protocol)
A part of the TCP/IP suite of Internet protocols. It is software that lets users download files from a remote computer to their computer’s hard drive.
gateway
Allows equipment with different protocols to communicate with one another. For example, gateways are used when incompatible video systems are used for a video conference.
Gigabit Ethernet
A high-speed service used for site-to-site carriers’ backbone networks, metropolitan area networks, Internet access, and in enterprise internal networks. These networks operate at 1- or 10Gbps.
gigabits per second
Billions of bits per second (Gbps). Fiber-optic cables carry signals at this speed.
GPRS (General Packet Radio Services)
A cellular data-packet network service. Upgrades to digital cellular networks are required to provision the service. This is an “always on” data service that users do not have to dial into to access. Its data rates are lower than EDGE and 3G protocols.
GPS (Global Positioning System)
Used for locational tracking purposes. For example, many wireless E-911 systems are based on GPS satellites along with equipment at a carrier’s cell stations and special handsets.
GPU (Graphic Processing Unit)
Specialized computer chips able to manipulate graphics. GPUs are used in mobile phones, game consoles, and computers.
GSM (Global System for Mobile Communications)
The most widely deployed cellular service, worldwide. It is a digital service that was first used in Europe in the 1990s.
H.320
The standard for enabling video conference equipment from multiple vendors to communicate with each other by using ISDN service.
H.323
An ITU-based standard for sending voice via IP. H.323 was originally developed for video conferencing.
H.324
An ITU standard for sending video, voice, and data between devices over a single analog, dial-up telephone line using a 28.8Kbps modem. Compression is used on the voice, video, and data.
HBA (Host Bus Adapter)
Used to connect Ethernet switches to networks running Fibre Channel protocols. See also Fibre Channel protocol.
HDTV (High-Definition Television)
A standard for digital high-resolution television video and surround sound audio.
headend
The control center of a cable television system where incoming video signals are received and converted into a format compatible for transmission to subscribers and combined with other signals onto the cable operator’s fiber infrastructure.
home page
The default first page of an Internet web site. A home page is analogous to the first page and table of contents of a book.
hotspot
A public area where people with Wi-Fi equipped laptops or personal digital assistants can access the Internet. Access might be free or available for monthly or daily rates.
HTML5 (Hypertext Markup Language 5)
A language for structuring browsers and web sites. The World Wide Web Consortium (W3C) specifies the standard. Its goal is to make browsing the Web from mobile devices faster, particularly for accessing video and other applications directly from browsers without using specialized plug-in languages. Apple uses it on its mobile devices in competition with the proprietary Adobe Flash.
HTTP (HyperText Transfer Protocol)
The protocol used to link Internet sites to one another. For example, HTTP provides links to servers containing text, graphical images, and videos.
hub
Prior to the use of switches on LANs, each device (such as a computer or printer) was wired to the hub, generally located in the wiring closet. Hubs enabled LANs to use twisted-pair cabling rather than more expensive, harder-to-install and move coaxial cabling. Hubs are sometimes referred to as concentrators. In wide area network architectures, the hub is the headquarters, the central site, in the network of connected locations.
hyper convergence
Software to simplify data center architecture by tightly integrating computing devices, storage, network, and virtualization.
hypervisor
Software that monitors and supervises software on servers with virtual machines.
ILECs (Incumbent Local Exchange Carriers)
The former Bell and independent telephone companies that sell local telephone service. This term differentiates incumbent telephone companies that were the providers of telephone service prior to 1996 from competitors such as Paetec, XO Communications, and tw telecom.
IMS (Internet Protocol Multimedia Subsystem)
Enables applications for voice, video, and online games to be stored, billed for, and accessed on a common IP platform available from mobile as well as wired networks.
Indefeasible Right of Use (IRU)
Long-term lease for fiber-optic cable runs. IRUs are analogous to condominium arrangements. One organization lays the cable and leases it to another carrier for its exclusive use.
independent telephone company
An incumbent local telephone company that was never a part of the former AT&T’s Bell system. Examples of independent telephone companies are Frontier Corporation and Cincinnati Bell, Inc.
instant messaging
The ability to exchange e-mail in near-real time without typing in an address. Users merely click an icon representing the user to whom the message is intended, type a message, and then click Submit (or press the Return key) to send the message.
intermodal competition
Competition between services based on different media and technology. For example, mobile services compete with wireline services for local and long-distance calling. Cable TV companies compete with telephone companies such as AT&T and CenturyLink.
Internet
The Internet—with a capital I—is an entity composed of multiple worldwide networks, tied together by a common protocol, TCP/IP.
intranet
The use of web technologies for internal operations. Intranets are used by organizations as a way to make corporate information and applications readily accessible by employees. An example is a corporate telephone directory that can be accessed by a browser.
inverse multiplexer
Instead of combining individual channels into one “fat” pipe, which is what a multiplexer does, an inverse multiplexer separates out channels into smaller “chunks.” Inverse multiplexers are used for video conferencing, where the 24 channels might be transmitted in groups of 6 channels at a speed of 386Mbps.
IPsec (Internet Protocol Security)
A protocol that establishes a secure, encrypted link to a security device at the carrier or the enterprise. It is used for remote access to corporate services (such as e-mail) in conjunction with VPNs.
IPv4 (Internet Protocol version 4)
An older addressing format for networks. Each device on an Internet network is assigned a 32-bit IP address. This limits the total number of addresses available.
IPv6 (Internet Protocol version 6)
A newer Internet protocol format that specifies 32-bit IP addresses. This increases the number of addresses available in networks and on the Internet. IPv6 also has additional security.
ISDN (Integrated Services Digital Network)
A digital network standard that lets users send voice, data, and video over one telephone line from a common network interface.
ISP (Internet Service Provider)
An organization that connects end users to the Internet via broadband, mobile networks, and dial-up telephone lines. ISPs often own Internet backbone networks. ISPs supply services such as voicemail, hosting, and domain name registration.
IXCs (Interexchange Carriers)
The long-distance companies that sell toll-free 800, international, data networking, and outgoing telephone service on an interstate basis. They now also sell local telecommunications services.
Java
A programming language created by Sun Microsystems. Multiple types of computers can read Java programs. They increase the power of the Internet because programs written in Java (called applets) can be downloaded temporarily by client computers. They do not take up permanent space on the client hard drive. Interactive games can use Java programs.
LAN (Local Area Network)
Enables computer devices such as personal computers, printers, alarm systems, and scanners to communicate with one another. Moreover, LANs allow multiple devices to share and have access to expensive peripherals such as printers, firewalls, and centralized databases. A LAN is located on an individual organization’s premises.
LATA (Local Access And Transport Area)
Upon divestiture in 1984, LATAs were set up as the areas in which Bell telephone companies were allowed to sell local telephone services. LATAs cover metropolitan statistical areas based on population sizes. For example, Massachusetts has two LATAs and Wisconsin has four, but Wyoming, which has a small population, has one LATA. LATAs are sometimes used for billing telephone calls in the United States.
Layer 4
One of the seven layers of the OSI model. Layer 4 is the Transport layer that routes and prioritizes packets, based on the source of the packet, the destination port number, the protocol type, and the application. For example, Layer 4 devices can prioritize voice and video so that networks using IP for voice and data can handle voice without the delays and lost packets associated with lower-level protocols.
LDAP (Lightweight Directory Access Protocol)
A directory protocol that describes a uniform way of organizing information in directories. Examples of LDAP directories include the address books in e-mail systems. LDAP enables companies to use one central directory to update multiple corporate directories. They also facilitate single sign-on to access different applications on corporate intranets.
leased line
Analogous to two tin cans with a string between two or more sites. Organizations that rent leased lines pay a fixed monthly fee for the leased lines that are available exclusively to the organization that leases them. Leased lines can be used to transmit voice, data, or video. They are also called private or dedicated lines.
LEC (Local Exchange Carrier)
Any company authorized by the state public utility commission to sell local telephone service.
local loop
The telephone line that runs from the local telephone company to the end user’s premises. The local loop can use fiber, copper, or wireless media.
LTE (Long-Term Evolution)
A 4G mobile protocol that uses packet switching to carry voice, data, and multimedia traffic more efficiently than earlier protocols. It will eventually support broadband speeds of up to 100Mbps. LTE was developed by the 3rd Generation Partnership Project.
LUN (Logical Unit Number)
An identifier in Storage Area Networks (SANs). It identifies the particular database stored in a computer disk. LUNs are part of the Fibre Channel protocol used in SANs.
MAN (Metropolitan Area Network)
A network that covers a metropolitan area such as a portion of a city. Hospitals, universities, municipalities, and large corporations often have telephone lines running between sites within a city or suburban area.
Mbps (millions of bits per second)
A transmission speed at the rate of millions of bits in one second. Digital telephone lines measure their capacity or bandwidth in bits per second.
media gateways
Contain Digital Signal Processors (DSPs) that compress voice traffic to make it smaller so that it can be carried more efficiently. In addition, media gateways are equipped with circuit packs with ports for connections to traditional circuit-switched analog and T1 trunks. Thus, they are used to link converged IP networks to Public Switched Telephone Networks.
media servers
Specialized computers that play announcements and generate ring tones in corporate telephone systems and converged public networks. In corporate VoIP systems, they control call processing.
media servers for homes (home servers)
PCs or separate devices that store content, music, photos, movies, or TV shows that can be distributed over home networks to home entertainment equipment.
mesh networks
Networks in which every device is connected to every other device. Community wireless networks and sensor networks often use variations of mesh networks, as does the military when it sets up communications facilities in war zones. Mesh networks are also referred to as multipoint-to-multipoint networks.
microwave wireless services
Wireless services with short wavelengths operating in the frequency range of about the 890MHz to 60GHz bands. It is a fixed point-to-point wireless technology used to connect two points. Line of sight is required between microwave towers. For example, if there is a tree blocking the view between the towers, the service is inoperable.
middleware
Software used to translate between disparate systems. It translates between the hardware (set-top devices) and network protocols and the applications in satellite TV and cable TV networks. Middleware also enables interactive television applications from different developers to work with set-top box hardware from a variety of manufacturers. Thus, applications don’t have to be designed differently for each type of device with which they interact.
millimeter wireless services
Operate at microwave and higher frequencies. Millimeter refers to the very short wavelengths of high-frequency services. Some next-generation, 5G, mobile services are implemented on millimeter airwaves. The wavelength is the distance from the highest or lowest point of one wave to the highest or lowest point of the next wave.
MIMO (Multiple-Input Multiple-Output) antennas
MIMO antennas simultaneously transmit multiple streams at different frequencies within a single channel. This improvement is analogous to the increased capacity on a multilane highway vs. a road with a single lane. MIMO antennas are used on 802.11n (Wi-Fi) WLANs, LTE, and WiMAX networks.
mobile wireless services
Provide mobility over wide areas by using services such as cellular, as in cities, states, countries, and in some instances, internationally.
MPLS (Multi-Protocol Label Switching)
Used to increase router speeds and prioritize packets. Short, fixed-length “labels” instruct routers how to route each packet so that the router does not have to examine the entire header of each packet after the first point in the carrier’s network. Voice and video can have tags that classify them with a higher priority than data bits.
MSOs (Multiple System Operators)
Large cable TV operators, such as Comcast and Time Warner Cable, with cable franchises in many cities.
MTA (Major Trading Area)
A region that includes multiple cities or states. They are made up of some of the 491 BTAs. The FCC auctions off spectrum in both BTAs and MTAs.
MTSO (Mobile Telephone Switching Office)
A central office used in mobile networks. They connect cellular network calls to the PSTNs, and vice versa.
multicasting
The transmission of the same message from a single point to multiple nodes.
multicloud
Using more than one cloud provider to avoid dependence on a single provider or because a particular provider meets a customer’s specific requirement, for example, using both Amazon and Microsoft.
multiplexing (muxing)
A technique in which multiple devices can share a circuit. With multiplexing, carriers do not have to lay cabling for each computer that communicates. T1 multiplexers and fiber multiplexers enable many devices to share strands of fiber, air waves, and copper cabling.
MVNOs (Mobile Virtual Network Operators)
MVNOs such as Tracfone and cable TV operators resell cellular service on cellular carriers’ networks.
NAS (Network Attached Storage)
The use of servers for storing files that can be accessed directly by computers located on the LAN. NAS is less costly than traditional SANs.
NAT (Network Address Translation)
Translates external IP addresses to internal IP addresses, and vice versa. Carriers and enterprises use different internal and external IP addresses to conserve public addresses and to shield IP addresses from outside sources.
NFC (Near Field Communications)
A low-power, short-range protocol used for contactless payments via smartphones at retailers and at subway systems instead of tokens and credit cards.
NEBS (Network Equipment Building Standards)
Requirements published in a Bellcore (now Telcordia) technical reference for products placed in a central office environment. Bellcore is the former Bell Telephone central research organization. There are eight standards referring to issues such as environmental, electrical, and cabling requirements, as well as resistance to natural disasters such as earthquakes.
network
An arrangement of devices that can communicate with one another. An example of a network is the PSTN over which residential and commercial telephones and modems communicate with one another.
NFV (Network Function Virtualization)
Virtualizes the functions of devices such as switches, routers, load balancers, and firewalls and installs these functions as virtual machines in servers. Is used as an adjunct to software-defined networks (SDNs).
non-blocking
Switches that have enough capability for each connected device to communicate at the same time up to the full speed of the port to which it is connected.
number pooling
Allows local carriers to share a “pool” of telephone numbers within the same exchange. Number pooling is a way to allocate scarce telephone numbers more efficiently. Without pooling, a single local telephone company has rights to the entire 10,000 block of telephone numbers, but it might only use a portion of the block.
OSS (Operation and Support Service)
Hardware and software that carriers use for billing, maintenance, and changes to customer features.
packet switching
A network technique that routes data in units called packets. Each packet contains addressing and error-checking bits as well as transmitted user data. Packets from a transmission can be routed individually through a network such as the Internet and be assembled at the end destination.
PAN (Personal Area Network)
Operates over small areas within rooms and buildings. Bluetooth and RFID are examples of PANs.
PBX (Private Branch Exchange)
Computerized, onsite telephone system located at an organization’s premises. PBXs route calls both within an organization and from the outside world to people within the organization, and vice versa.
PCS (Personal Communications Service)
Originally referred to 2G digital mobile services that use spectrum in the higher frequencies. PCS (or DCS in Europe) is now used in the industry to refer to all 2G cellular access technologies.
peer-to-peer network
Distributes intelligence over devices in the network instead of relying on central computers. Peer-to-peer networks are often used to download free music and movies from the Internet. In addition, companies such as Skype use the technology for voice calls and other services.
petabyte (PB)
A unit of measurement. One petabyte equals 1,000,000,000,000,000 bytes or 1,000 gigabytes. A byte equals 8 bits.
photonics
All of the elements of optical communications. This includes fiber, lasers, and optical switches and all elements involved in transmitting light over fiber.
ping (Packet Internetwork Groper)
A software protocol used to test communications between devices. To “ping” means to send a packet to another device or host to see if the device sends back a response. The ping also tests round-trip delay, the time it takes to send a message to another device.
plug-in
A small program that adds capabilities to a parent, usually larger, program. Plug-ins are used in browsers and in software defined networks and MANO (Management and Organization).
PoE (Power over Ethernet)
A standard that defines how power can be carried from wiring closets on floors to the computers and other LAN-connected devices using the same cabling that transmits packetized voice and data. Thus, every device does not need its own power or backup power.
PON (Passive Optical Network)
Technologies deployed to extend fiber to homes, businesses, and neighborhoods. PONs use non-electrical devices located in the access network that enable carriers to dynamically allocate capacity on a single pair of fibers to multiple homes, buildings in a campus, apartments, and small and medium-sized businesses.
POP (Point of Presence)
A long-distance company’s equipment that is connected to the local telephone company’s central office. The POP is the point at which telephone and data calls are handed off between local telephone companies, long-distance telephone companies, and the Internet.
POTS (Plain Old Telephone Service)
Telephone lines connected to most residential and small-business users. POTS lines are analog from the end user to the nearest local telephone company equipment. People using POTS for data communications with modems are limited in the speed at which they can transmit data.
presence
The ability of users to know when someone within their community of users is available for real time or near real time messaging.
PRI (Primary Rate Interface)
A form of ISDN with 23 paths for voice, video, and data and 1 channel for signals. Each of the 24 channels transmits at 64Kbps.
protocol
Defines how devices and networks communicate with one another. For example, a suite of protocols known as TCP/IP spells out rules for sending voice, images, and data across the Internet and in corporate networks.
proxy server
Authenticates callers to ensure that they are who they say they are before they are sent to their destination. They serve as intermediaries between callers and applications or endpoints, telephones, and other devices connected to the LAN. For instance, a proxy server in a VoIP environment ensures that external devices requesting to communicate with an IP telephone are who they say they are.
PSAP (Public Safety Answering Point)
Groups of agents that answer and dispatch 911 and E-911 calls for their town, county, or cluster of towns. They are often located at police stations.
PSTN (Public Switched Telephone Network)
The global network of circuit-switched telephone services that telephone companies operate. The PSTN comprises traditional copper-based telephone lines, central office switches, fiber-optic cabling, undersea cable systems, cellular systems, microwave connections, communications satellites, and any other system connected via public telephone switching centers. It does not include the Internet or carriers’ private data networks.
push-to-talk
A walkie-talkie type of service pioneered by Nextel (now part of Sprint) in which customers reach one another by pushing a button on the side of their phone. They also dial an abbreviated telephone number. Push-to-talk is used to reach individuals or predefined groups. Walkie-talkies are used on non-mobile spectrum between people that perhaps hike together or for parents to monitor children in other rooms of a house.
QoS (Quality of Service)
The ability to offer a number of priorities for various types of communications including voice, e-mail, and video on LANs and WANs.
radio
A wireless device with an antenna that converts signals to and from formats compatible with the airwaves. Wireless handsets are radios.
ransomware
A type of security attack where hackers encrypt organizations’ files, and then demand payment to decrypt the files to make them readable again.
RBOC (Regional Bell Operating Company)
At Divestiture in 1984, the Justice Department organized the 22 Bell telephone companies into seven Regional Bell Operating Companies. As a result of mergers and name changes, the former RBOCs are now part of AT&T, CenturyLink, or Verizon.
reverse channel
In cable TV systems, this carries signals from the customer to the cable operator’s equipment. Reverse channels are required for Internet access, on-demand TV, and VoIP.
RFID (Radio Frequency Identification)
A non-line-of-sight wireless technology used to control, detect, and track objects. Two common applications are merchandise tracking and automated tollbooth collection.
roaming
The capability in mobile networks to use the same handset on another carrier’s network. Carriers set up roaming agreements to define terms such as per-minute fees that carriers charge one another.
router
A device with routing intelligence that connects local and remote networks together. Routers are also used to forward packets in the Internet.
RPKI (Resource Public-Key Infrastructure)
An Internet security protocol for routing packets on the Internet. It adds encryption between databases called Internet registries (centralized databases with Internet addresses) and network operators. Encryption is the use of mathematical algorithms to scramble data.
RSS (Really Simple Syndication)
A series of software standards that automates feeding updates from news sites such as Forbes.com and blogs to other sites and users. The use of RSS means that people don’t have to continually check to see news headlines or updates to blogs.
RTMP (Real-Time Messaging Protocol)
A realtime streaming protocol developed by Adobe for using Flash servers to improve streamed audio, video, and data over the Internet. It is now used with other Adobe programs. According to Adobe, most of the RTMP specifications are open to developers to create applications compatible with Adobe Flash Player.
RTP (Real-Time Transport Protocol)
An IETF standardized protocol for transmitting multimedia in IP networks. RTP is used for the “bearer” channels, the actual voice, video, and image content.
SDH (Synchronous Digital Hierarchy)
A world standard of synchronous optical speeds. The basic SDH speed starts at 155Mbps, also called STM-1 (Synchronous Transport Mode-1) in Europe. SONET is a subset of SDH.
server
A specialized, shared computer on the LAN or in a carrier’s network containing files such as e-mail or applications. It can be used to handle sharing of printers, e-mail, and other applications.
set-top box
A device connected to a television that allows access to various content, including pay-per-view programming. Set-top boxes can be used to distribute content to other TVs and devices. Newer models contain hard drives and multiple tuners. They can be used to watch one program while recording a different show, and to pause and rewind programs.
signaling gateway
A type of media gateway that converts signaling from IP networks to that compatible with traditional, circuit-switched networks, and vice versa.
SIM (Subscriber Identification Module)
A clip-on or internal card with microchips in mobile handsets that stores user identity and other information such as speed-dial lists and e-mail addresses. CDMA phones do not have SIM cards.
SIP (Session Initiation Protocol)
A signaling protocol used to establish sessions over IP networks, such as those for telephone calls, audio conferencing, click-to-dial from the Web, and instant message exchanges between devices. It is also used to link IP telephones from different manufacturers to SIP-compatible IP telephones. It is used in landline and mobile networks.
SLA (Service-Level Agreement)
Often provided to customers by carriers that sell MPLS. The SLA defines service parameters such as uptime and response time.
smart grids
Upgraded utility networks for metering that can carry two-way messages on cellular networks between customers and electric utilities. A goal is to use energy more efficiently by monitoring usage patterns.
SMS (Short Message Service)
Short, 160-character (including header address information) text messages that can be transmitted between digital cellular telephones.
SMTP (Simple Mail Transfer Protocol)
The e-mail protocol portion of TCP/IP used on the Internet. Having an e-mail standard that users adhere to enables people on diverse LANs to send e-mail to one another.
SNMP (Simple Network Management Protocol)
The Internet Engineering Task Force (IETF) protocol standard used to monitor devices on IP networks. SNMP is used on most LAN monitoring software packages.
softphone
Telephone functionality on a personal computer in VoIP systems. People with softphone-equipped laptops can use their VoIP remotely.
softswitch
Used in converged enterprise and carrier networks that carry VoIP traffic. Softswitches are built on standard computer processors and use standards-based protocols, which makes them less costly than proprietary switches based on circuit-switched technology. Softswitches manage and control traffic in IP networks.
SONET (Synchronous Optical Network)
An older standard for multiplexing high-speed digital bits onto fiber-optic cabling. SONET converts electronic impulses to light impulses, and vice versa. Telephone companies use SONET to transmit data from multiple customers over the same fiber cables.
spectrum
Made up of frequency bands or airwaves that carry either analog or digital wireless signals. Spectrum consists of the multitude of invisible electric energy in frequency bands that surround the Earth and are used to transmit segregated radio waves. Radio waves carry signals as electrical energy on unseen waves.
SSAD (Solid State Drive)
Contains integrated circuits that store memory. SSDs are for the most part used as non-volatile storage where data is not lost in power outages.
SSL (Secure Sockets Layer)
A newer type of security for VPNs than IPsec. It is embedded in browsers so that organizations aren’t required to install special client software in each user’s computer.
statistical multiplexing
Assumes that not all devices are active all the time. A statistical multiplexer does not save capacity for each device connected to it. It operates either on a first-come, first-served basis or on a priority basis in which certain streams of traffic have higher priority than others.
streaming video and audio
A means of starting to play a message while the rest of it is being received. Streaming uses compression to make the voice, video, and data files smaller so that they can be transmitted in less time. Streaming video and audio is used in broadcasting video and audio over the Internet.
switching
Equipment with input and output ports that transmits traffic and sets up paths to destinations based on digits dialed or addressing bits.
T.120
The ITU-defined standard for document sharing and white boarding. People using T.120-adherent software can participate in document-sharing conferences with one another over the Internet. For example, vendors can demonstrate their products to potential customers via computers connected to the Internet at dispersed sites.
T1
A North American and Japanese standard for communicating at 1.54Mbps. A T1 line has the capacity for 24 voice or data channels.
T3
A North American standard for communicating at speeds of 44Mbps. T3 lines have 672 channels for voice and/or data. Fiber-optic cabling or digital microwave is required for T3 transmissions.
tandem offices
Used in the core of traditional, traditional Public Switched Telephone Networks (PSTNs). Tandem central offices switch traffic between central offices. End users are not connected to tandem offices. Tandem central offices are being replaced by lower-cost, more efficient softswitches.
TCP (Transmission Control Protocol)
Includes sequence numbers for each packet so that the packets can be reassembled at their destination. The sequence numbers ensure that all of the packets arrive and are assembled in the proper order. If some packets are discarded because of congestion, the network retransmits them. The numbering and tracking of packets make TCP a connection-oriented protocol. Router-based LAN internetworking uses TCP.
TCP/IP (Transmission Control Protocol/Internet Protocol)
The suite of protocols used on the Internet and also by organizations for communications among multiple networks.
TD-SCDMA (Time-Division Synchronous Code-Division Multiple Access)
China Mobile uses TD-SCDMA, which is a homegrown version of UMTS TDD (3G mobile protocol), for its 3G mobile service.
tether
The ability to connect laptop or tablet computers that don’t have Internet access to the Internet via a mobile handset’s Internet connection. This is generally done by connecting the computer and mobile handset together through USB ports via USB-compatible cables.
throughput
The actual amount of user data that can be transmitted on a telecommunications link or on wireless networks. Throughput does not include headers, for example, bits used for addressing, error correction, or prioritizing packets with voice and data bits.
tier 1 provider
A loosely defined term for Internet service providers that own Internet backbone fiber-optic facilities in addition to ISP services such as hosting and e-mail. Examples include AT&T, Level 3, Sprint Nextel, and Verizon.
TDM (Time-Division Multiplexing)
TDMs, such as T1/E1 equipment, save capacity for each device that is connected to the multiplexer. This is less efficient than other methods such as statistical multiplexing because capacity is unused when the device is not transmitting.
topology
The geometric shape of the physical connection of the lines in a network—or, the “view from the top”—which is the shape of the network, the configuration in which lines are connected to one another.
traffic shaping
A way for carriers to manage traffic to control congestion. Techniques include providing better QoS for particular types of traffic such as video, prioritizing traffic for higher fees, and throttling traffic (decreasing speeds) for subscribers who exceed allotted amounts.
transponder
Fiber-optic transponders receive, amplify, and retransmit optical signals on different wavelength channels on fiber cabling. They also convert electrical signals to optical signals and optical signals back to electrical signals where they connect to twisted-pair copper or coaxial cabling.
trunking gateway
Converts packet network circuits (such as T1/E1 and T3/E3), to those compatible with the Public Switched Telephone Network (PSTN), and vice versa, so that voice traffic can be transferred between IP networks and traditional, circuit-switched networks.
trunks
The circuits (electrical or fiber paths) between telephone companies and enterprise telephone systems and between central office switches. A T1 is a trunk.
tuner
Used in televisions, radios, and set-top boxes to filter out all channels (frequencies) except the particular one at the frequency the tuner is designed to accept. The tuner then adapts the frequency to ones compatible with the TV or radio. Newer set-top boxes are equipped with multiple tuners so that one channel can be recorded while another is being viewed.
tunneling
A method of securely transferring data between sites connected by networks such as a VPN, the Internet, an intranet, or an extranet. Tunneling puts a new header in front of the data. This is a way of separating data from multiple companies using the same network.
UDP (User Datagram Protocol)
Part of the TCP/IP suite of protocols. UDP has less overhead because it does not have bits with packet numbers and acknowledgments. UDP is considered a connectionless protocol because packets arrive at their destination independently from various routes without sequence numbers. There is no assurance that all of the packets for a particular message arrive. UDP is suited for applications such as database lookups, voice, and short messages.
UMTS (Universal Mobile Tele-communications System)
A European standard for 3G mobile wireless networks that GSM networks generally use when they are upgraded. WCDMA is a UMTS technology.
UMTS TDD (Universal Mobile Telecommunications System/Time-Division Duplexing)
A high-speed wireless technology used for 3G cellular and broadband wireless access to the Internet. It is also referred to as TD-CDMA. It uses the same channel for sending and receiving, with small time slots to separate the sending and receiving streams rather than the larger guard band used in other 3G technologies.
UNE (Unbundled Network Element)
Parts of the incumbent local telephone company infrastructure required to lease out to other local exchange carriers. Examples of UNEs are the copper lines to customers’ premises. Many UNE requirements have been eliminated.
unicasting
The transmission of one message from a single point to another point. This is also referred to as point-to-point communications.
unified messaging
Computing platform that contains voicemail, facsimile, e-mail, and sometimes video mail on a single system. Users can access all of these services from their computer inbox.
unlicensed spectrum
Governments specify portions of the airwaves for unlicensed services at no charge to companies; 802.11 services are an example. Most governments issue certification, signal-spreading, and power-limitation rules to protect adjacent licensed spectrum bands from harmful interference from transmissions within the unlicensed spectrum.
Uplink (UL)
On broadband and mobile networks, the uplink carries traffic from the customer to the carrier’s equipment.
URL (Universal Resource Locator)
An address on the World Wide Web. The address is made up of strings of data that identify the server, the folder location, and other information indicating the location of information on the Internet.
USF (Universal Service Fund)
Used to fulfill the commitment made by the United States government to affordable universal telephone service to all residential consumers. The Telecommunications Act of 1996 expanded universal service to rural healthcare organizations, libraries, and educational institutions for Internet access, inside wiring, and computers. The library and educational subsidies are a part of universal service known as the e-rate. Every interstate carrier, cell phone, and paging company must pay a percentage of its interstate and international revenues to the fund. A separate fund, The Connect America Fund, has been established for residential broadband.
UTP (Unshielded Twisted-Pair)
Most inside telephones and computers are connected to one another via unshielded twisted-pair copper cabling. The twists in the copper cables cut down on the electrical interference of signals carried on pairs of wire near one another and near electrical equipment.
UWB (Ultra-Wideband)
A wireless service that supports higher data rates than RFID and can be used for some of the same applications. However, widespread adoption is held up by a lack of an agreed-upon standard. It is also used by the military and by governments for tracking and for finding people trapped under rubble.
VLANs (Virtual Local Area Networks)
Groups of devices programmed in Layer 2 switches for special treatment in enterprise networks. They are not grouped together in physical networks; rather, they are grouped together in software for common treatment and programming purposes. They are “virtual” networks that act as if they were separate LANs.
VoIP (Voice over Internet Protocol)
The process of sending voice traffic in packets on IP-based data networks. VoIP digitizes analog voice, compresses it, and puts it into packets at the sending end. The receiving end does the reverse. Unlike circuit switching, no path is saved for the duration of the voice session. However, voice packets can be prioritized.
VoLTE (Voice over LTE)
A 3rd Generation Partnership Program protocol used to carry packetized voice (VoIP) on LTE networks.
VPN (Virtual Private Network)
Provides the functions and features of a private network without the need for dedicated private lines between corporate sites or between corporate sites and remote users. Each site connects to the network provider’s network rather than directly to another corporate location.
VRU (Voice Response Unit)
Provides information to callers based on their touch-tone or spoken commands. VRUs query computers for responses and “speak” them to callers. For example, people often can call their bank or credit card company to find out their balance or to learn if a payment has been received.
WAN (Wide Area Network)
Connects computers located in different cities, states, and countries.
WAP (Wireless Application Protocol)
A protocol that defines how Internet sites can be displayed to fit on the screens of cellular devices and how devices access and view these sites.
WCDMA (Wideband Code-Division Multiplexing)
The 3G service that most GSM operators install.
WDM (Wavelength-Division Multiplexing)
Also known as dense wavelength division multiplexing, this enables multiple colors or frequencies of light to be carried on single pairs of fiber. WDM greatly increases the capacity of network providers’ fiber-optic networks.
WebRTC (Real-Time Communications)
A set of IEEE and World Wide Web Consortiums (W3C) protocols for embedding software based codecs in applications and browsers for real time voice, video, and chat among disparate devices and operating systems.
Wi-Fi (Wireless Fidelity)
Wireless networks based on 802.11 IEEE standards. The Wi-Fi Alliance tests and certifies that products meet IEEE 802.11 standards.
WiMAX (Worldwide Interoperability for Microwave Access)
A forum whose goal is to facilitate interoperability of equipment based on 802.16 standards for high-speed fixed wireless service using the 2GHz to 11GHz frequency bands. Newer versions are used for mobile wireless service. WiMAX fixed wireless service is used for Internet access and for backhaul networks, which connect cellular towers to mobile central offices.
WiMAX 2
A 4G mobile protocol developed by the IEEE. It is not as widely used as LTE, but was available earlier.
wire speed
The capability of switches to forward packets equal to the full speed of their ports. Ports are the interfaces to which cabling is connected. Wire speed is achieved with powerful switch processors, the computers that look up addresses and forward packets.
wireless local loop
Uses wireless media to bring telephone service to a customer’s premises rather than copper or fiber cabling.
WISP (Wireless Internet Service Provider)
Provides Internet access using non-cellular wireless technology.
WLAN (Wireless Local Area Network)
Local Area Network (LAN) in which devices are connected to other devices or the LAN wirelessly rather than with cabling; 802.11-based Wi-Fi networks are WLANs.
worms
Viruses that are programmed to start infecting networks and other computers at a predetermined future time and date. These time-released viruses are also referred to as bots.
WWW (World Wide Web)
Connects users from one network to another when they “click” links. It was developed in 1989 to make information on the Internet more accessible. A browser is required to navigate and access the World Wide Web.
XML (Extensible Markup Language)
A software language that was developed to make it easy for disparate computers to exchange information. XML uses tags to identify fields of data. XML is like a data dictionary in that uniform tags are attached to elements so that diverse programs can read the tags. For example, tags can be used to identify elements such as prices, model numbers, product identities, or quantities ordered.
ZigBee
Based on the IEEE 802.15.4 standard for wireless networks with devices that operate at low data rates and consume small amounts of power. The ZigBee Alliance is developing specifications for higher-level services to be used in sensor networks such as those that monitor and control heating and electrical systems in businesses.