We can't make communications technology as simple as A-B-C, but we can translate some of the most confusing terminology into simple English.
Talk to someone outside the trucking industry about dollies, hotshots and bobtails, and it's likely you'll get some strange looks. Every business has its own specialized vocabulary, terms that carry specific meaning for those in the know. But when it comes to insider jargon, few areas are as confusing as communications, especially wireless data communications.
With cellular, satellite, PCS, packet-radio and other competing systems, the wireless industry is fertile ground for acronyms and buzz words, sometimes making it hard for outsiders to understand just what's going on when the discussion really gets rolling.
As you attempt to evaluate you fleet's wireless options, the following glossary offers short, non-technical definitions of the terms you're likely to encounter as you wade through literature, sales presentations and vendor conversations. It could never be complete, since wireless communications is changing daily; and in some cases we've sacrificed technical accuracy in order to provide a clearer non-technical explanation. It should, however, help you translate the jargon and make it a good deal easier to understand just what it is you're being offered.
Airtime: Actual time spent transmitting data over a wireless network. Packet-type wireless data systems charge by the amount of data transmitted.
Air interface: The standard operating system of a wireless network; technologies include AMPS, TDMA, CDMA and GSM.
Alphanumeric: Message or other type of data that contains both letters (alphas) and numbers (numerics).
AMPS (advanced mobile phone service): Although the term specifically refers to cellular standards developed by the former AT&T Bell Laboratories in 1984, today it indicates the common analog cellular technology used throughout the U. S.
Analog: Traditional method for carrying data over radio waves. Whether using AM (amplitude modulation) or FM (frequency modulation), analog sends data in a continuous stream and can be susceptible to interference. Digital signals break data into separate bits of information that are reassembled by receiver and can be more resistant to errors caused by interference.
Analog-to-digital conversion (ADC): Process of converting an analog signal to a digital signal. DAC represents the reverse translation.
ASCII (American standard code for information interchange): Standard computer system text coding format
Asynchronous communications: Data moves through a network as it is generated, rather than in organized message blocks.
ATM (asynchronous transfer mode): A high-speed, high-bandwidth transmission technology.
Bandwidth: The frequency "pipe" used to carry data transmissions.
Base station: The central radio transmitter/receiver that maintains communications with mobile units.
Bit: A single digital unit of information
Bit rate - Digital transmission speed measured in bits per second.
Bluetooth: A new proprietary wireless technology that is expected to provide data connections between a wide range of electronic devices, including desktop computers, handheld devices, wireless phones, and printers. As Bluetooth chips needed for sending and receiving information come down in price, it could become the de facto standard for communicating data wirelessly.
Broadband: A wide-bandwidth channel that offers fast transmission speeds for high-volume data applications.
C-Band: One of the frequencies used for communications over satellite systems. Motient operates and uses a C-Band satellite.
CDMA (code division multiple access): A proprietary approach developed by Qualcomm for digital voice and data transmission that allows systems to carry more traffic. CDMA was originally used by Qualcomm's Omnitracs satellite communications system and is now expanded to many digital voice and data systems, including Sprint PCS.
CDPD (cellular digital packet data): A system for transmitting and receiving data over idle cellular channels not being used for voice. Unlike circuit-switched systems such as dial-up modems, packet data systems are always connected. Usage is billed by number of data packets transmitted rather than by airtime.
Cellemetry: Brand name for Cellemetry LLC's wireless data service, which carries short data messages over the unused control channel of cellular telephone networks. Low service cost may make it especially popular for vehicle or trailer tracking. Microburst is a similar control-channel technology developed by Aeris.net.
CMRS (commercial mobile radio service): A Federal Communications Commission designation for any commercial wireless service provider whose network is connected to the public switched (i.e., wired) telephone network.
Common Carrier: In telecommunications, this is any organization that operates communications systems used by other people, including telephone companies and operators of communications satellites. They are required to file fixed tariffs for specific services.
Compression Algorithms: Software that reduces the number of bits required to transmit a data message, reducing transmission cost.
Conus: The 48 contiguous United States, which excludes Hawaii and Alaska.
CPE (customer premises equipment): Telephones, terminals, and other communications equipment maintained by the communications service customer.
Delay: The time it takes in a satellite system for a message to go from the sending transceiver through the satellite to the receiving station.
Digital: Information created as, or translated into, bits of data for transmission. Digital data is the native language of computer software.
Dual band: A wireless device that communicates over both the standard cellular network and newer digital PCS systems.
Earth etation: The facility used to send and receive signals to and from a satellite.
ESMR (enhanced specialized mobile radio): Digital SMR networks. Nextel Communications provides dispatch, voice, messaging, web-access and data services over ESMR.
FCC (Federal Communications Commission): The U.S. government regulatory agency telecommunications
Footprint: Although the term does have a specific technical definition, it is now generally used to describe the operating area of a wireless system.
Forward error correction (FEC): A technique that adds unique codes to a digital signal so errors can be detected and corrected by receivers.
Frequency reuse: A technique that allows both satellite and land-based wireless systems to increase transmission capacity.
Geostationary: A satellite orbit that keeps the satellite over one area of the earth, providing dedicated communications coverage to that region. Qualcomm and Motient use geostationary satellites.
Globalstar: A proposed satellite system that would deploy a network of 48 satellites to create a global wireless voice and data service. Qualcomm is among the major backers.
GPS (global positioning system): A network of satellites that allows low-powered, mobile receivers to calculate position with great accuracy. If fleets want to track vehicles with GPS, they need a complementary two-way wireless service to send that location data to a dispatch system.
GSM (global system for mobile communications): The digital cellular standard common throughout most parts of the world except the U.S.
Handoff: The process of automatically switching a wireless transmission to an adjacent cell site.
Hub: A central facility for handling all communications to and from a satellite or land-based system. Service subscribers use landline or Internet connections with the hub to communicate with mobile units.
iDEN (integrated digital enhanced network): A Motorola Inc. enhanced specialized mobile radio network (ESMR) technology that combines two-way radio, telephone, text messaging and data transmission into one network. Nextel uses iDEN technology.
IMT-2000: The new third-generation GSM
Interface: Hardware or software that allows different systems to share or trade data.
Interoperability: The ability of a wireless network to operate with two or more systems based on different protocols or technologies.
ISDN (integrated services digital network): A high-capacity wireline technology used for high-speed data transfer now being displaced by DLS technology.
ITU (International Telecommunication Union): A United Nations agency headquartered in Geneva, charged with monitoring global allocation of wireless spectrums for future uses.
Ku-Band: Radio spectrum used by Qualcomm's OmniTRACS satellite communications systems.
Leased line: A dedicated landline typically used for high-speed data transfers.
LEO (low-earth orbit): A mobile communications satellite that does not remain in a geostationary orbit above one region. Instead, multiple LEO satellites are networked so that one or more is always over a given region providing constant coverage. Orbcomm is one LEO system offering service to the trucking industry.
Message alert: A light or other indicator on a wireless device that indicates a message has arrived.
Modem: Any device that allows data to be communicated over wireless or wired systems.
MSA (metropolitan statistical area): The 306 largest urban population markets as designated by the U.S. government. Often used by wireless data providers to indicate range of service coverage.
Multiplexing: Technology that allows multiple simultaneous transmissions over a single circuit. TDMA and CDMA are the most common modes in wireless communications.
NAMPS (narrowband advanced mobile phone system): Combines cellular voice with digital signaling, increasing the capacity of AMPS systems.
Narrowband PCS: The next generation of paging networks designed to provide advanced services such as two-way, acknowledgment, and "wireless answering machine" paging.
NTIA (National Telecommunications and Information Administration): Dept. of Commerce agency responsible for U.S. government telecommunications policy, standards setting and radio spectrum allocation.
Off-peak: Low volume periods for communications systems, usually before or after common business hours. Some wireless providers offer discounted airtime charges during off-peak periods.
Packet switching: Digital data transmission method that divides messages into standard-sized packets. Often considered more efficient and more robust for data than circuit switching, which maintains a single, constant flow of data between two devices.
PCS (personal communications services): A two-way digital voice, messaging and data service competing with AMPS cellular service.
PDA (personal digital assistant): Any portable computing device that provides data storage for applications such as address books, data bases, and scheduling. When equipped with a wireless modem, PDAs can also be used for paging, messaging, electronic mail, and other mobile information communications.
PSTN (public switched telephone network): The wired public voice telephone system.
PTT (Post Telephone and Telegraph): Any government or government-controlled agency in charge of a country's telecommunications services.
RBOC (regional Bell operating company): Smaller telecommunications companies created by the federal government's breakup of Bell Telephone.
Repeater: Device that receives a radio signal, amplifies it and re-transmits it in a new direction. Used in wireless networks to economically extend the range of base station signals within buildings, tunnels or other difficult locations.
Roaming: Wireless connections made outside a service provider's own coverage area.
Smart antenna: Antenna technology that can focus on a desired signal to reduce interference
Smart phone: Wireless phones that can handle data as well as voice transmissions. The "smartest" also provide limited web browsers for Internet services.
SMR (specialized mobile radio): Trucking's traditional dispatch radio service for businesses. In many areas, SMR frequencies are now being used for digital iDEN services.
Spectrum allocation: Federal government designation of radio frequencies for a category of use or uses. For example, the FCC allocated the 1900 MHz band for personal communications services.
Spectrum assignment: Federal government authorization for use of specific frequencies within a given allocation, usually limited to a specific geographic region. Mobile communications authorizations can be granted to private users for services such as SMR dispatch or to public service providers such as cellular and paging companies.
Spread spectrum: Transmission technology that spreads data packets Sover a wide range of frequencies. Symbol Technologies has a proprietary spread spectrum system that is used for wireless local and wide-area networks like those found in warehouses or terminal yards.
Subcarrier: A second signal piggybacked onto a main signal to carry additional information. Terrion (TKTK) uses an FM subcarrier network for one leg of its wireless wireless message service.
TDMA (time division multiple access): A coding system for digital wireless communications transmission that allows multiple users on a single channel. Competes with CDMA as a technology for increasing wireless capacity.
Telematics: The use of wireless communications to retrieve vehicle operating and location information.
Third-Generation (3G): A new wireless communications standard designed to offer high-speed data capability while also allowing global roaming.
Triangulation: Older radio-based system for determining vehicle location that has largely been supplanted by GPS.
Tri-mode handset: Phones that work on three frequencies, typically using 1900 MHz, 800 MHz digital or reverting to 800 MHz analog cellular when digital is not available.
Triple band: A wireless device designed to operate in three frequency bands.
Turnkey: A system from one vendor that includes mobile communications hardware, wireless service, and at least basic fleet management software applications.
UMTS (universal mobile telecommunications system): Standardized European third-generation cellular system.
Uplink: The communications channel from earth to a satellite.
Voice activation: Feature that allows mobile communications devices to be controlled by spoken commands instead of a keypad.
W-CDMA (wideband code division multiple access): A third-generation standard for GSM systems.
Wireless Internet: Service that provides wireless access to Internet e-mail and/or the World Wide Web.
Wireless IP: The packet data protocol standard for sending wireless data over the Internet. It is becoming increasingly important in developing fleet management systems that can use a variety of wireless communications services.
Wireless LAN (local area network): Systems that replace wired network connections with radio transmissions to send and receive data.
Wireless PBX: Cordless phones connected to a company's internal telephone system (PBX or private branch exchange).
X.25: A commonly used standard for packet switching.
X.400: Widely used standards for global messaging. (CHECK)
xDSL: Another acronym for DSL (digital subscriber line), a technology that allows simultaneous two-way transmission of voice and high-speed data over ordinary copper phone lines.