Wireless Networking Terminology
Note: Also see the Units and Definitions section in WirelessFrequentlyAskedQuestions.
802.11b - The current standard for 11 Mbps wireless data exchange between computers. May soon be eclipsed \for communication between wireless network clients without using an AccessPoint in between. A good example of where you might use ad-hoc mode would be to enable file sharing between two 802.11b wireless-capable computers in a plane or in an office where no AccessPoint is available.
Amplifier (aka 'Amp') - Device that boosts both the transmitted and received signal strength for a wireless network card. Wireless amps are often quite expensive due to the need to switch very quickly between increasing the transmitted and received signal and the preference in using some type of inline power delivery system so that the amplifier can be placed as close to the antenna as possible. Manufacturers often rate their amplifiers in terms of the signal strength increase in milliwatts, for example, 100mW. Note that amplifiers are most often used with quasi-directional or omni-directional antennas; line-of-sight installations often do not require the use of amplifiers. Also note that in the United States 802.11b systems must not radiate over 1 watt in total energy due to the unlicensed part of the spectrum that they operate in.
Bandwidth - A measure of data transfer capacity. An 802.11b wireless card, under ideal conditions, has a potential bandwidth of 11 Mbps. In real-world situations the actual data transfer speed is often much lower then the rated bandwidth due to protocol overhead, lost transmissions, noise and other issues.
Bluetooth - Newer standard for inter-device, wireless networking. Sometimes refered to as a PAN (Personal Area Network). Different from 802.11b in that Bluetooth is intended to be used in very short range applications, for example, to update a PDA form a desktop computer or to attach a wireless keyboard. Widely believed to be a competing standard with 802.11b because they use the same portion of the frequency spectrum to operate in.
BSD - Refers to 'Berkeley Systems Distro', a popular version of UNIX. BSD has a reputation for being very secure making it useful in network applications.
CPE - Stands for 'customer premises equipment', the device(s) that a WISP would install at a customer site that facilitates communication with the WISP's wireless network backbone. Reliability and low cost are key issues. Bandwidth management and remote access are other important factors in considering CPE equipment.
dBm - This is the amount of power, in decibel milliwatts, your radio provides at the antenna connector. This is the same exact figure as a mW, but it uses the dB logarithm. This is just like scientific notation, and a way to cut down on the size of numbers. 15dBm = 30mW and 20dBm = 100mW. [provided by CaseyHalverson]
EIRP/ERP effective (isotropic radiating power) - When you take the power, in watts, out of a radio and put it into an antenna, it then is focused to a certain degree. This is like the reflector in a flashlight, the headlights on your car, or a magnifying glass in the sun. Focus power is measured in dB as well. Every 3dB, the focus power doubles. Higher dB antennas will, naturally, have less "coverage" area than low dB antennas. The two measurements are dBi and dBd. Most people use dBi nowdays. [provided by CaseyHalverson]
Infrastructure Mode - The wireless network mode that wireless network cards use when communicating with an AccessPoint. Wireless clients without an AccessPoint in between them would use ad-hoc mode for communication.
Line of Sight (aka 'LOS') - LOS
Linksys - A manufacturer of wireless network cards and AccessPoints, among other products. The LinksysWap11 is a well known and often talked about Linksys product in wireless networking circles.
Linux - The UNIX-like operating system created by Linus Torvalds and made extremely popular on the Internet due to the large number of distributions available. RedHat, Caldera, Mandrake, SuSE are all Linux-based operating systems. Linux is popular in networking circles because of the similarity to UNIX and the comparative strength of UNIX networking tools in relation to other platforms and also due to it's cost (none - its free).
Lucent - A popular manufacturer of wireless networking equipment. Also known as Orinoco and Agrere due to corporate splits and spin-offs. A large number of wireless devices, such as Apple Computer's AirPort, are simply re-branded and re-built Lucent products.
Lucent Pigtail (aka 'pigtail') - A connector used with Lucent/Orinoco wireless network cards to attach the cards to an external antenna. Most often has either a male or a female 'N' type connector at one end. Must be purchased separately, often at a comparatively high price. See PigTail for pictures and more information.
Mbps - Megabits per second, a measure of data transfer speed. Usually, the higher the number the more data that can be exchanged in a given period of time. Note that 8 bits make up one byte, therefore 11 Mbps equals 1.375 Megabytes per second (11 Mbps divided by 8). Historically, bits are used instead of bytes when referring to data transfer rates between computer systems.
mW - This is the amount of power, in milliwatts, your radio provides at the antenna connector. 1000mW is a full watt. Most radios out there are either 30mW or 100mW (0.03 watts and 0.1 watts). [provided by CaseyHalverson]
NetStumbler - Windows software that detects and logs 802.11b wireless AccessPoints. Can only be used with Lucent/Orionco wireless network cards. Popular in war driving. See http://www.netstumbler.com for more information.
Omni-directional antenna - Type of wireless antenna that has an energy radiation pattern that looks similar to a doughnut and does not require line-of-sight to operate. Omni directional antennas often appear as short pieces of white or black tubing sticking up vertically although they can come in many different sizes and shapes. The built-in antennas in most wireless network cards and AccessPoints are omni-directional antennas.
PoE - Stands for 'Power over Ethernet', a method of using CAT5 cable to inject electrical energy needed to power AccessPoints, amplifiers and other equipment. Using the same cabling for both power and data transfer can greatly simplify installation of a wireless network node, particularly in the case of CPE. Some wireless network equipment comes with the necessary equipment to do POE while other equipment can be modified to operate this way. An interesting Do-It-Yourself guide to PoE is at http://www.nycwireless.net/poe/
SOM - Same as 'Fade Margin', see WirelessFrequentlyAskedQuestions
ViewShed - Formed like watershed. Basically what I can see is in my ViewShed.
Wacking (aka 'War Driving') - Popular pastime for wireless network enthusiasts, consists of driving around with a computer and a wireless network card looking for wireless AccessPoints. Netstumbler is program often used by those doing wacking due to its ease of use although there are several other methods of detecting and logging wireless AccessPoints.
WAP11 - A type of wireless AccessPoint made by Linksys that offers some unique and desirable features not often found in lower-cost equipment. One important feature in the WAP11 is the ability to place multiple WAP11s into a specific mode where they will talk with each other as well as with wireless clients, thereby forming a network backbone. See the LinksysWap11 page for more information.
Wireless Client (aka 'Node') - Usually a computer system equiped with a wireless network card and associated with a wireless AccessPoint.
Wireless Routing Protocol - Wired networks often use routing protocols to help routers determine where data packets should be sent on to so that they can reach their final destination. Wireless networks have several special issues, such as mobile roaming, that make routing protocols developed for wired networks unsuitable for their wireless counterparts. A holy grail of large, metropolitan wireless networks is to develop a wireless routing protocol that offers the ease and convenience of routing protocols used for wired networks while supporting and overcoming the unique issues of wireless networks.
WISP - Stands for 'wireless Internet service provider', just like a regular ISP but one that also offers wireless Internet connectivity.
Yagi - Type of antenna commonly used in wireless networking for point-to-point links. A yagi antenna at the frequencies used in 802.11b looks similar to a long tube capped at one end. Yagi antennas can be quite expensive if purchased from a manufacturer but homemade antennas can be very inexpensive. A popular type of homemade yagi starts out with an ordinary can of Pringles potato chips and can cost as little as $10 to build. See BuildingYagiAntennas for more information on homemade yagi antennas.
