Glossary Of Terms

3G:
It stands for 3rd generation mobile telephone systems -- analog cellular was the first generation and digital PCS was the second. 3G combines high-speed mobile access with Internet Protocol (IP) based services, up to 384 Kbps when a user is standing still or walking, 128 Kbps in a car, and up to 2 Mbps in fixed applications. 3G can use a variety of present and future wireless network technologies, including GSM, CDMA, TDMA, WCDMA, CDMA2000, UMTS, and EDGE.
Air Interface
The operating system of a wireless network.  Technologies include AMPS, TDMA, CDMA, GSM and iDEN.
AMPS
Advanced Mobile Phone Service (AMPS) is the original analog “cellular” service transmission standard first deployed in the United States, still used as a default standard for cellular systems in the U.S., and in some regions around the world.
Analog
The traditional method of adapting radio signals so they can carry information. AM (Amplitude Modulation) and FM (Frequency Modulation) are the two most common analog systems.   Analog has largely been replaced by digital technologies, which are more secure, more efficient and provide better quality.
Antenna
A device for transmitting and receiving radiofrequency (RF) signals. Antennas are often camouflaged on existing buildings or other structures.
Antenna Array:
A group of antennas usually located at the same vertical elevation on an antenna support structure.
Base Station
The central radio transmitter/receiver that communicates with mobile telephones within a given range (typically a cell site).
Broadband
 A transmission facility having a bandwidth (capacity) sufficient to carry multiple voice, video or data channels simultaneously.  Broadband is generally equated with the delivery of increased speeds and advanced capabilities, including access to the Internet and related services and facilities “that provide 200 kbps upstream and downstream transmission speeds” (per the FCC’s Fourth Annual Report to Congress on the “Availability of Advanced Telecommunications Capability in the United States,” September 2004).
BTA (Basic Trading Area)
A geographic area designed by Rand McNally to reflect business centers, and adopted by the FCC for the licensing of Personal Communications Services and some other wireless services. BTAs are composed of several neighboring counties associated by business and commuting patterns. The U.S. is divided into 493 BTAs.
Carrier (see also Service Provider)
Also known as service provider or operator, a carrier is the communications company that provides customers service (including air time) for their wireless phones.  
CDMA (Code Division Multiple Access)
A technology used to transmit wireless calls by assigning them codes.  Calls are spread out over the widest range of available channels.  The codes allow many calls to travel on the same frequency and also guide those calls to the correct receiving phone.
CDMA2000 1X
CDMA2000 1X is an IMT-2000 (3G) technology that delivers industry leading circuit-switched voice communications and supports packet data transmissions with speeds of up to 307 kbps.
CDMA2000 1xEV-DO
CDMA2000 1xEV-DO (Evolution - Data Optimized) is an evolution of CDMA2000 that is optimized to deliver data-centric broadband network services. Commercially launched in 2002, 1xEV-DO Release 0 and Revision A offer peak data speeds of up to 2.4 Mbps and 3.1 Mbps, respectively.
CDMA2000 EV-DO
CDMA2000 EV-DO includes EV-DO Revision B that aggregates multiple 1.25 MHz (EV-DO Rev. A) radio channels through a software or hardware (channel card) upgrade to deliver peak data speeds up to 9.3 Mbps or 14.7 Mbps, respectively.
Cell
The basic geographic unit of wireless coverage. Also, shorthand for generic industry term "cellular." A region is divided into smaller "cells," each equipped with a low-powered radio transmitter/receiver.  The radio frequencies assigned to one cell can be limited to the boundaries of that cell. As a wireless call moves from one cell to another, a computer at the Mobile Telephone Switching Office (MTSO) monitors the call and at the proper time, transfers the phone call to the new cell and new radio frequency. The handoff is performed so quickly that it’s not noticeable to the callers.
Cell Site
The location where a wireless antenna and network communications equipment is placed in order to provide wireless service in a geographic area.
Cell Splitting
A means of increasing the capacity of a wireless system by subdividing one cell into two or more smaller cells.
CSD (Circuit Switched Data)
  One technological approach used for the exchange of data. A circuit connection is made that is exclusively reserved for the individual’s use. This can be inefficient, as many communications do not require a dedicated communications channel, but only brief connectivity, for the transmission of short messages.
CMRS (Commercial Mobile Radio Service) Provider:
An FCC designation for any wireless carrier or license owner whose wireless service is connected to the public switched telephone network and/or is operated for profit.  Wireless services that are offered to the public are classified as CMRS, unlike private systems which are classified as “Private Mobile Services.”
Co-Location
Placement of multiple antennas at a common site.  Some companies act as brokers or cell site managers, arranging cell sites and coordinating many carriers' antennas at a single cell site.
Controlled Environment (see “MPE Math”)
Controlled environment refers to regulated RF exposure areas which require both RF awareness and RF training by person(s) working in this environment.
CTIA
Cellular Telecommunications and Internet Association.  The CTIA is the cellular industry’s largest trade organization.
Decibel (dB):
A unit of measure used to express relative difference in power or intensity of sound.
Digital Signal
Technological approach that converts signals (including voice) into the binary digits ‘0’ and ‘1’.  This data is compressed, and then transformed into electronic pulses for a wired network, optical light waves for fiber optic networks or radio waves for wireless networks.  Digital wireless technology has largely superceded analog technology, because digital delivers more capacity and supports more applications, as well as offers better sound quality, and more secure signals.
Dual Band
  A wireless handset that works on more than one spectrum frequency, e.g., in the 800 MHz frequency and 1900 MHz frequency bands.
Dual Mode
A wireless device that works on both analog and digital networks, or different digital modulation schemes (e.g., CDMA and GSM).
Duplex:
As in ordinary telephone service, a characteristic of a communications system where simultaneous transmission and reception is possible.
E-911:
Short for Enhanced 911, a location technology advanced by the FCC that will enable mobile, or cellular phones to process 911 emergency calls and enable emergency services to locate the geographic position of the caller.
EDGE
Enhanced Data Rate for Global Evolution is an evolutionary step in the GSM-development path for faster delivery of data, delivered at rates up to 384 Kbps. The standard is based on the GSM technology platform and uses the TDMA approach (see TDMA, below).
Electromagnetic Energy (EME)
Energy used to transmit radio waves; when we send or receive from our cell phones or any wireless devices we use radio waves which are electromagnetic energy forms. Cell phone users, park rangers, sheriff departments, transportation department workers to name a few, all use radios waves for communication. The transmission and receiving elements are often referred to as antennas or transceivers.
Electromagnetic Radiation
Radiation made up of oscillating electric and magnetic fields and propagated at the speed of light. This includes but is not limited to gamma rays, X-rays, visible light, infrared radiation, and radar and radio waves.
Electromagnetic Spectrum
The range of frequencies of electromagnetic radiation from zero to infinity.
Environmental Protection Agency (EPA)
The EPA is an independent federal agency which was established to facilitate the implementation of environmental regulations.
ESN (Electronic Serial Number)
The unique serial identification number programmed into a wireless phone by the manufacturer. Each time a call is placed, the ESN is transmitted to a nearby base station so the wireless carrier can validate the call.  The ESN differs from the Mobile Identification Number, which identifies a customer’s wireless phone number.  MINs and ESNs are electronically monitored to help prevent fraud.
Federal Communications Commission (FCC)
The FCC is the regulatory agency which sets the regulatory standards for the communications industry.
FDD (Frequency-Division Multiplexing)
Frequency division multiplexing is a method in which numerous signals are combined for transmission on a single communications channel. Each signal is assigned a different frequency (subchannel) within the main channel.
Frequency
A measure of the energy, as one or more waves per second, in an electrical or light wave information signal. A signal’s frequency is stated in either cycles-per-second or Hertz (Hz).
Gigahertz (GHz)
Billions of Hertz (see also Hertz).
GPRS (General Packet Radio Service)
A packet technology approach that enables high-speed wireless Internet and other GSM-based data communications. It makes very efficient use of available radio spectrum for transmission of data. 
GPS (Global Positioning System)
A worldwide satellite navigational system, made up of 24 satellites orbiting the earth and their receivers on the earth’s surface.  The GPS satellites continuously transmit digital radio signals, with information used in location tracking, navigation and other location or mapping technologies.
GSM (Global System for Mobile Communications)
A technological approach also based on dividing wireless calls into time slots.  GSM is most common in Europe, Australia and much of Asia and Africa.  Generally, GSM phones from the United States are not compatible with international GSM networks because the U.S. and many other nations use different frequencies for mobile communications.  However, some phones are equipped with a multi-band capability to operate on such other frequencies.
Handoff
The process when a wireless network automatically switches a mobile call to an adjacent cell site.
Hertz
Hertz is a unit of frequency (of change in state or cycle in a sound wave, alternating current, or other cyclical waveform) denoting “one cycle per second.” In the United States, common electrical supply runs at 60 hertz, or one cycle per second (meaning the current changes polarity from positive to negative 120 times, or 60 cycles per second). Broadcast transmissions are at much higher frequency rates, usually expressed in kilohertz (KHz), which equates to 1,000 Hertz, megahertz (MHz), equal to 1,000,000 Hertz, and gigahertz (GHz), equal to 1,000,000,000 Hertz.
HSCSD (High Speed Circuit Switched Data)
In using HSCSD a permanent connection is established between the called and calling parties for the exchange of data. As it is circuit switched, HSCSD is more suited to applications such as videoconferencing and multimedia than 'bursty' type applications such as email, which are more suited to packet switched data.
HSPA (High Speed Packet Access)
High Speed Packet Access (HSPA) is a WCDMA-based technology (3GPP Release 6) that combines High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA) to deliver both voice communications and broadband data access over the same RF channel.  Peak data rates of up to 3.6, 7.2 or 14.4 Mbps are possible, depending upon the modulation scheme used and its implementation.
HSPA+
High Speed Packet Access Plus (HSPA+) is an evolution (3GPP Release 7) of HSPA that delivers peak data speeds of up to 56 Mbps with the use of MIMO technologies.
iDEN (Integrated Digital Enhanced Network)
A specialized mobile technology that combines two-way radio, telephone, text messaging and data transmission into one digital network.  iDEN is designed to give users quick access to information on a single device.  Introduced by Motorola and used by AirTel Montana, Nextel Communications, Nextel Partners, and Southern LINC Wireless, among others.
IEEE
Abbreviation of Institute of Electrical and Electronics Engineers, pronounced I-triple-E. Founded in 1884 as the AIEE, the IEEE was formed in 1963 when AIEE merged with IRE. IEEE is an organization composed of engineers, scientists, and students. The IEEE is best known for developing standards for the computer and electronics industry. In particular, the IEEE 802 standards for local-area networks are widely followed. The FCC often adopts the IEEE recommended standards.
IMT-2000
The family of third generation (3G) wireless communication standards that were published by the International Telecommunications Union (ITU).
Ionizing Radiation
Ionizing radiation is radiation with enough energy to so that during an interaction with an atom, it can remove tightly bound electrons from their orbits, causing the atom to become charged or ionized and forever changed.
Interconnection
Connecting one wireless network to another, such as linking a wireless carrier's network with a local telephone company’s network.
Intermodulation and Isolation Studies:
Intermodulation and Isolation studies predict possible interference of radio frequencies transmitted from different antennas and provide important information about the isolation levels required for a compatible site environment.
Interoperability
The ability of a network to coordinate and communicate with other networks, such as two systems based on different protocols or technologies.
LAN (Local Area Network)
Local Area Network (LAN) is a small data network covering a limited area, such as a building or group of buildings. Most LANs connect workstations or personal computers.  This allows many users to share devices, such as laser printers, as well as data.  The LAN also allows easy communication, by facilitating e-mail or supporting chat sessions.
Lock-out/Tag-out:
Lock-out is the placement of a locking device on a transmission site or antenna that ensures the equipment cannot be operated until the lockout device is removed. Tag-out is the placement of an attachable tag to indicate that the equipment may not be operated until the tag out device is removed.
LTE – Long Term Evolution
Long Term Evolution (LTE) is a fourth generation IP network technology based on OFDM slated for rollout in 2010. With peak data rates of 100 Mbps down and 50 Mbps up, LTE is a highly attractive technology for network operators and is currently being tested by Verizon Wireless and AT&T Mobility.
MicroCell:
Very small cell in a cellular network, typically employed in high-traffic urban environments with tall buildings or rural areas with limited coverage.
Microwave
A form of communication transmission constituting a narrow beam (usually five degrees) which can be separated into multiple channels. Transmission is limited in the distance signals can travel before requiring re-transmission through a repeater station. Thus repeater stations are typically placed approximately thirty miles apart on towers, the tops of tall buildings or hilltops to provide line of sight paths.
(MPE) Maximum Permissible Exposure
Maximum Permissible Exposure is a radio frequency radiation human exposure limit standard adopted by the FCC.
MPE “Maps of the Invisible”®
MPE Maps of the Invisible® contain the site specific RF graphic representation of the controlled and uncontrolled areas of a wireless site. These downloadable maps can help the carriers with FCC compliance by providing a mitigation tool for RF emission above the public exposure limit. They will also assist employers with OSHA compliance by informing their employees of the location of the RF emissions and allowing them to exercise control over the potential hazard.
MPE Math
Thermal harm from RF exposure occurs at 4W/kg. The FCC adopted a factor of safety which is ten times less at .4W/Kg (four tenths of one watt per kilogram) as the limit for worker exposure. At this level, a worker must use time exposure limits to minimize the potential heating affects from the thermal RF as follows:
.4W/kg = 100% MPE (6 min. exposure/hour)
.8W/kg = 200% MPE (3 min. exposure/hour)
1.2W/kg = 300% MPE (1.5 min. exposure/hour)
Megahertz
Megahertz (MHz) is a unit of frequency equal to one million hertz or cycles per second.  Wireless mobile communications within the United States generally occur in the 800 MHz, 900 MHz and 1900 MHz spectrum frequency bands.
MIN (Mobile Identification Number)
The MIN, more commonly known as a wireless phone number, uniquely identifies a wireless device within a wireless carrier's network. The MIN is dialed from other wireless or wireline networks to direct a signal to a specific wireless device. The number differs from the electronic serial number, which is the unit number assigned by a phone manufacturer.  MINs and ESNs can be electronically checked to help prevent fraud.
MIMO (Multiple Input, Multiple Output)
Multiple Input, Multiple Output (MIMO) is the use of multiple antennas at both the transmitted (base station) and receiver (wireless device) to improve radio communication performance.
MSA (Metropolitan Statistical Area)
One of the 306 urban-centered cellular service areas based on the largest urban markets as designated by the U.S. government in 1980. Two “cellular” service operators are licensed in each MSA.
MTA (Major Trading Area)
A geographic area designed by Rand McNally to reflect business centers, and adopted by the FCC for the licensing of Personal Communications Services and some other wireless services.  MTAs are composed of neighboring basic trading areas (BTAs) associated with major business centers. The U.S. is divided into 51 MTAs, which do not reflect state boundaries.
MTSO (Mobile Telephone Switching Office)
The central computer that connects wireless phone calls to the public telephone network. The MTSO controls the series of operations required to complete wireless calls, including verifying calls, billing and antenna handoffs. 
MVNO (Mobile Virtual Network Operator)
A company that buys network capacity from a network operator in order to offer its own branded mobile subscriptions and value-added services to customers.
National Institute for Occupational Safety and Health (NIOSH)
NIOSH is the federal agency responsible for conducting research and making recommendations for the prevention of work-related disease and injury.
National Telecommunications and Information Administration (NTIA)
The federal government's spectrum management authority.
Non-Ionizing Radiation
Non-ionizing radiation is radiation without enough energy to remove tightly bound electrons from their orbits around atoms. Examples are micro waves, visible light, and radio waves as shown in the electromagnetic spectrum chart.
Non-Thermal RF
Any effect of electromagnetic energy absorption not associated with a measurable rise in temperature.
NAM (Number Assignment Module)
The NAM is the electronic memory bank in the wireless phone that stores its specific telephone number and electronic serial number.
Number Portability:
  The ability of a customer to retain their telephone number when changing service providers in a specific area, whether changing from one wireless company to another, one wireline company to another, or between wireless and wireline companies.
Occupational Safety and Health Administration (OSHA)
OSHA establishes and enforces safety standards for workers and employers as required by the federal government.
OFDM (Orthogonal Frequency Division Multiplexing):
A system for the transmission of digital message elements spread over multiple channels within a frequency band, in order to achieve greater throughput while minimizing interference and signal degradation through the use of multiple antennas. 
Packet
A piece of data sent over a packet-switching network, such as the Internet.  A packet includes not just the data comprising the message but also address information about its origination and destination.
Packet Data
Information that is reduced into digital pieces or ‘packets’, so it can travel more efficiently across networks, including radio airwaves and wireless networks.
Frequency Partitioning
Parceling a spectrum license into two or more geographic areas.
PCS (Personal Communications Services)
Defined by the FCC as a broad family of wireless services, commonly viewed as including two-way digital voice, messaging and data services.  One set of “PCS” licenses established by the FCC operates in the 1900 MHz band. 
Personal Protection Monitors
Personal protective monitors are used as a warning device to alert site workers of certain levels of RF radiation at transmission sites.  These devices are limited in their ability to adequately protect an individual.
PIN (Personal Identification Number)
An additional security feature for wireless phones, much like a password.  Programming a PIN into the Subscriber Information Module (SIM) on a wireless phone requires the user to enter that access code each time the phone is turned on.
POPs
  For wireless, POPs generally refers to the number of people in a specific area where wireless services are available (the population).  For traditional ‘landline’ communications, a “Point of Presence” defines the interconnection point between the two networks.
Protocol
  A standard set of definitions governing how communications are formatted in order to permit their transmission across networks and between devices.
PSD (Packet Switched Data)
A technological approach in which the communication “pipe” is shared by several users, thus making it very efficient. The data is sent to a specific address with a short delay. This delay depends on how many users are using the pipe at any one time as well as the level of priority requested for your information. PSD is the technology used for data communication across the Internet and makes more efficient use of the network.
Radiation
Energy in transit in the form of high speed particles and electromagnetic waves. Examples include visible light, radio and television waves, ultra violet light (UV), and microwaves.
Radio Frequency (RF)
Any frequency within the electromagnetic spectrum normally associated with radio wave propagation. Radio stations transmit at the frequency indicated on the dial. FM radio stations transmit in the bandwidth between 88--108 MHz/sec (megahertz/sec) while cell phones (depending upon type and manufacture) can transmit at 880 MHz/sec in the cellular range or 1910 MHz/sec in the PCs range.
Radio Frequency Radiation (RFR)
Radio Frequency Radiation is another term for “radio frequency” (RF).
Radiation Pattern Maps
The Radiation Pattern Maps or MPE “Maps of the Invisible®” contain site specific graphic representation of the thermal (red) and non-thermal (yellow) radio frequency emissions. These RF pattern maps make it simple for a person to identify the areas where RF exposure training is required by federal mandate.
Radio Frequency Interference
An undesired radio signal that interferes with a radio communications signal causing extraneous noise and/or signal dropouts.
Repeater
Devices that receive a radio signal, amplify it and re-transmit it in a new direction. Used in wireless networks to extend the range of base station signals and to expand coverage.  Repeaters are typically used in buildings, tunnels or difficult terrain.
Roaming
When traveling outside their carrier's local service area, roaming allows users to continue to make and receive calls when operating in another carrier’s service coverage area. 
Rogue Broadcaster
Rogue broadcasters utilize unlicensed frequency spectrum and are often difficult to locate. These rogue broadcasters can cause potential interference problems with wireless carriers.
RSA (Rural Service Area)
One of the 428 rural markets across the United States, as designated by the FCC for the delivery of cellular service outside of the initial 306 MSAs.
Specific Absorption Rate (SAR)
A measure of the rate of RF radiation absorption by a mass such as biological tissue during a specific time period. It is expressed in watts/kilogram or milliwatts/kilogram. The FCC’s safety limits for human exposure to RF radiation are expressed using SAR.
Spectrum Allocation
Federal government designation of a range of frequencies for a category of use or uses. For example, the FCC allocated the 1900 MHz band for personal communications services. Allocation, typically accomplished in years-long FCC proceedings, tracks new technology development. However, the FCC can shift existing allocations to accommodate changes in spectrum demand. As an example, some UHF television channels were recently reallocated to public safety.
Spectrum Assignment
Federal government authorization for use of specific frequencies or frequency pairs within a given allocation, usually at stated a geographic location(s). Mobile communications authorizations are typically granted to private users, such as oil companies, or to common carriers, such as cellular and paging operators. Spectrum auctions and/or frequency coordination processes, which consider potential interference to existing users, may apply.
Smart Phone
  Wireless phones with advanced data features and often keyboards. What makes the phone "smart" is its ability to manage and transmit data in addition to voice calls.
SMS
Short Messaging Service enables users to send and receive short text messages (usually about 160 characters) on wireless handsets. Sometimes referred to as “text messaging.”
Spectrum Allocation
Process whereby the federal government designates frequencies for specific uses, such as personal communications services and public safety.  Allocation is typically accomplished through lengthy FCC proceedings, which attempt to adapt allocations to accommodate changes in spectrum demand and usage.  
Spectrum Assignment
Federal government authorization for the use of specific frequencies within a given spectrum allocation, usually in a specific geographic location.  Mobile communications assignments are granted to both private users such as businesses, and commercial providers such as wireless and paging operators.  Spectrum auctions and/or frequency coordination processes, which consider potential interference to existing users, may apply.
Spread Spectrum
A method of transmitting a radio signal by spreading it over a wide range of frequencies.  This reduces interference and can increase the number of simultaneous users on one radio frequency band.
TCP/IP (Transmission Control Protocol/Internet Protocol)
A protocol permitting communications over and between networks, the TCP/IP protocol is the basis for the Internet communications.
TDMA (Time Division Multiple Access)
A technological standard that permits the transmission of information by dividing calls into time slots, each one lasting only a fraction of a second. Each call is assigned a specific portion of time on a designated channel.  By dividing each call into timed ‘packets,’ a single channel can carry many calls at once.    
Telecommunications Act of 1996
Legislation intended to spur competition among wireless and wireline carriers. Signed into law by President Clinton February 8, 1996.
Thermal RF
Radio frequency radiation exposure that results in an increase in temperature of a specific amount of biological tissue. Usually measured in W/kg (watts/kilogram) or mw/kg (milliwatts/kilogram) RF radiation has been scientifically proven to produce thermal effects at a power level of 4 Watts on 1 kilogram of biological tissue. At this level scientists can measure the increase in body temperature over a period of time, thus denoted it as “Thermal.”
Triangulation
The lengthy process of pinning down a caller's location using radio receivers, a compass and a map.
Tri-Band Handset
Phones that work on multiple frequencies, typically in the 1900 MHz, 800 MHz, and 900 MHz frequencies used in the U.S. and elsewhere.
Tri-Mode Handset
  Phones that operate in different modes, such as the CDMA, TDMA, and analog standards.
UMTS (Universal Mobile Telecommunications Systems)
This is third generation technology generally based on W-CDMA (Wideband Code Division Multiple Access). UMTS promises a communications speed between 384 Kbps and up to about 2 Mbps.
Uncontrolled Environment
Uncontrolled environment refers to regulated RF exposure areas which require both RF awareness and RF training by person(s) working in this environment.
VoIP (Voice over Internet Protocol)
VoIP is not simply capable of delivering voice over IP, but is also designed to accommodate two-way video conferencing and application sharing as well. Based on IP technology, VoIP is used to transfer a wide range of different type traffic.
Voice Recognition
The capability for wireless phones, computers and other devices to be activated and controlled by voice commands.  
WAN (Wide Area Network)
A general term referring to a large network spanning a country or around the world. The Internet is a WAN. A public mobile communication system such as a cellular or PCS network is a WAN.
WAP (Wireless Application Protocol)
Wireless Application Protocol is a set of standards that enables wireless devices, such as phones, pagers and palm devices, to browse content from specially-coded Web pages. 
W-CDMA(Wideband Code Division Multiple Access)
One of two 3G standards that makes use of a wider spectrum than CDMA and therefore can transmit and receive information faster and more efficiently. 
WiFi (Wireless Fidelity): 
WiFi provides wireless connectivity over unlicensed spectrum (using the IEEE 802.11a or 802.11b standards), generally in the 2.4 and 5 GHz radio bands. Wi-Fi offers local area connectivity to WiFi-enabled computers.
WiMAX
An OFDMA-based wireless technology based on the IEEE 802.16 standard providing metropolitan area network connectivity for fixed and mobile wireless access at broadband speeds.
Wireless
Technology that uses the radio-frequency spectrum for transmitting and receiving voice, data and video signals for communications rather than telephone lines.
Wireless Internet
  A general term for using wireless services to access the Internet, e-mail and/or the World Wide Web.
Wireless Local Area Network (WLAN)
Using radio frequency (RF) technology, WLANs transmit and receive data wirelessly in a certain area.  This allows users in a small zone to transmit data and share resources, such as printers, without physically connecting each computer with cords or wires.
Wireless Private Branch Exchange (PBX)
Equipment that allows employees or customers within a building or limited area to use wireless devices in place of traditional landline phones.
WLL (Wireless Local Loop)
WLL is a system that connects wireless users to the public switched telephone network (PSTN) using wireless technology and other circuitry to complete the "last mile" between the wireless user and the exchange equipment.  Wireless systems can often be installed faster and cheaper than traditional wired system.

A Sample of Uses of the Electromagnetic Spectrum:

Frequency Band
10 kHz to 30 kHz Very Low Frequency (VLF)
30 kHz to 300 kHz Low Frequency (LF)
300 kHz to 3 MHz Medium Frequency (MF)
3 MHz to 30 MHz High Frequency (HF)
30 MHz to 144 MHz
144 MHz to 174 MHz
174 MHz to 328.6 MHz
Very High Frequency (VHF)
328.6 MHz to 450 MHz
450 MHz to 470 MHz
470 MHz to 806 MHz
806 MHz to 960 MHz
960 MHz to 2.3 GHz
2.3 GHz to 2.9 GHz
Ultra High Frequency (UHF)
(Cell Phones 800-900MHz
and1.8-2 GHz)
2.9 GHz to 30 GHz Super High Frequency (SHF)
30 GHz and above Extremely High Frequency (EHF)
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