Wireless Jargon

Ripped stright from Seattle Wireless.

• 802.11b - The current standard for 11 Mbps wireless data exchange between computers. May soon be eclipsed by newer and faster standards like 802.11a and 802.11g.
  
• Access Point (aka 'AP') - AccessPoint
  
• Ad-Hoc Mode - Most wireless network cards support this mode 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 Distribution', 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.

Explanations

Ripped from Glenn's 802.11b Weblog

• Configuration. Most gateways use a Web-based interface to configure, reboot, and install firmware (internal software) updates. A few require proprietary Macintosh or Windows software to manage them, needlessly limiting their market. Some Web-based gateways use Windows tools for firmware upgrades, or have limitations that keep Web tools from performing upgrades under Linux or Mac OS. See notes accompanying each gateway.
• DHCP Server. All units surveyed except the Xircom offer a DHCP server to hand out IP addresses to local machines on request. These servers almost always work in bridge mode to offer DHCP over both a wired LAN and the wireless network.
• Firewall. Most gateways have firewall features that block ports and attacks. Most gateways offer separate a WAN (Wide Area Network or broadband) Ethernet port and one or more LAN (Local Area Network) ports that a firewall protects as well: the LAN traffic is sent via the firewall before heading out over the WAN port. The amount of customization varies, as does the difficulty of allowing certain kinds of traffic to pass throgh. Some units monitor for pattern attacks and/or log firewall violations.
• NAT. Almost all gateways support NAT (network address translation), which is a firewall-like service that masks internal machines by assigning them private addresses. The NAT software sorts out which machines packets need to be sent to and from, but the internal network is invisible to the outside world.
• Punch through or virtual servers. Most units that offer NAT and/or firewall support also let you create a path between the gateway and a specific port on a specific machine on the network. This allows you to run a Web server without using a static IP or exposing the entire machine or network to the Internet.
• DHCP Client. Almost all the gateways sport a DHCP client to request an address from a broadband provider. The gateway requires this client in order to route traffic through the provider.
• PPPoE. PPPoE (PPP over Ethernet) is used by some broadband companies as a security measure and/or as a session-length-control tool. Practically all the gateways support this as well.
• WEP encryption. Although the encryption built into 802.11b has been compromised, WEP (Wireless Equivalent Privacy) is still a first line of defense and a reasonable way to prevent casual users from peeking into your network, especially for home users who don't create enough traffic to allow crackers to extract the key. Most gateways now support full 128-bit WEP encryption keys; older gateways only supported the shorter key, known variously as 40, 56, and 64 bits long, but all compatible with each other. Note that some gateways require you to manually make up and enter 14 pairs of hex digits to create a 128-bit key while hiding the values from you as you type them (SMC Networks, for instance). This can be an exercise in frustration, as a single slip of the pinky and you've rendered your unit inaccessible.
• Cloning address for gateway. Some broadband providers use a MAC address (the unique Ethernet Media Access Control layer address) to limit access to a single machine on a network. The gateway may need to clone or replicate the MAC layer address of a machine on the network in order to connect to the remote broadband service.
• Simultaneous Users. The number of machines supported by each gateway varies, and manufacturers' recommendations aren't necessarily the guide to follow; I've tried to indicate the numbers of users claimed, at least. There's a sharp distinction between the number of NAT addresses a unit can feed out (usually 252 or 253) and the number of users it can actually cope with simultaneously. Many companies are employing a sort of marketing cloud by stating the NAT limit, not the user limit. If you see a number like 35 to 50, it's more likely to be a true count of users.
• VPN. VPNs or Virtual Private Networks use end-to-end encryption to make sure that traffic can't be sniffed or intercepted in legible form between a user's machine and the end goal inside a company network. There are two protocols for VPN in wide use, PPTP and IPSec, and a third, L2TP, gaining in popularity. If you need to use VPNs via a home gateway, make sure it can pass the protocol your company uses. Support varies widely and changes constantly, so check the current specs or call the company to be sure.
• Ethernet. All the gateways surveyed include an Ethernet port. Some also include one to four additional ports for the LAN. One port is dedicated to the WAN connection, such as a DSL modem. Just because a unit offers multiple LAN Ethernet ports does not mean that it has a firewall between the LAN and WAN. Most of these Ethernet ports are 10/100 Mbps and many gateways with hubs are switched (separate channels for each port offering full network bandwidth); see details by access point below.
• AppleTalk and NetBEUI. Mac OS and Windows have their own filesharing and printer protocols which not all access points will pass. For instance, only Apple, Asante, and Proxim gateways pass AppleTalk and note this in their documentation; SMC Networks's gateway also passes AppleTalk but doesn't mention it. If you're using a wireless network just for Internet traffic (TCP/IP), this doesn't affect you. But if you're trying to build an internal wireless network and the gateway can't handle the protocols you need, it's a showstopper. Read the tech specs very carefully and compare notes with other users.
• Modem. The Apple and Agere models have a built-in 56K modem for dial-up routing. A few others have an RS-232C port to connect to an external modem or ISDN device that use PPP.
• Print spooling. Many gateways have - as a default or as one of their model options - a parallel port to allow the unit to function as a print spooler for Windows machines; the Asanté claims to work for Macs as well. (An alert reader pointed out that many of these spoolers support Unix LPR style printing as well as Windows's print system. Macs can print to LPR by using the Apple Printer Utility to set up an LPR device. That application is installed by default - search your system for it.)