480 GHZ. USED IN OTHER WIRELESS TECHNOLOGIES INCLUDING BLUETOOTH AND...

2.480 GHz. Used in other wireless technologies including Bluetooth and cordless phones.Fresnel zone The area of usable RF coverage between a transmitter and receiver. Must be clear of obstacles by at least 60 percent.

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gain An increase in signal strength of an RF signal, caused by an increase in amplitude. See also active gain, passive gain.Greenfield mode (Mode 0) HT protection mode that allows only high throughput (HT) functionality. 802.11a/b/g stations on the same channel are not allowed to connect. These devices will not communicate with a Greenfield access point and transmissions will collide, resulting in errors.grounding rod A metal rod driven into the earth eight feet or more and used to direct electrical currents to earth ground that are caused by lightning strikes.

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half-duplex Allows for two-way communication but in only one direction at a time.Health Insurance Portability and Accountability Act (HIPAA) Legislation that provides standardized mechanisms for electronic data exchange, security, and confidentiality of all health care-related computer information.hidden node In wireless networking, hidden node is the result of client devices connected to an access point and not able to “hear” each other prior to starting a RF transmission. Hidden node results in excessive collisions at the access point.High Rate/Direct-Sequence Spread Spectrum (HR/DSSS) A spread spectrum technol-ogy used in IEEE 802.11b and 802.11b/g with data rates of 5.5 and 11 Mbps set on a spe-cific radio frequency channel.high throughput (HT) protection Protection mechanism that allows for IEEE 802.11n devices to be backward compatible and coexist with 802.11a/b/g devices. There are four HT protection modes.HT mixed mode (Mode 3) HT protection mode used in 802.11n networks if one or more non-HT stations are associated in the BSS.434 GlossaryHT non-member protection mode (Mode 1) HT protection mode used in 802.11n networks if there are non-HT stations or access points using the primary or secondary channels.HT 20 MHz protection mode (Mode 2) HT protection mode used in 802.11n networks only if HT stations are associated in the BSS and at least one 20 MHz HT station is associated.HTTP (Hypertext Transfer Protocol) A Layer 7 protocol used by a server and a client using request/response architecture. By default works at port 80.HTTPS (Hypertext Transfer Protocol Secure) Works with HTTP to provide a Secure Sockets Layer (SSL) mechanism and to provide secure transactions across public networks such as the Internet. By default works at port 443.hot-plug Allows for replacement of computer system components and devices without powering down the system.

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IEEE (formally the Institute of Electrical and Electronics Engineers) A nonprofit orga-nization responsible for generating a variety of technology standards, including those related to information technology.impedance The measurement of alternating current AC resistance, measured in Ohms.independent basic service set (IBSS) A wireless network in which no access points are used and only device-to-device communication takes place. Other terms for this type of net-work are ad hoc and peer-to-peer.Industry Standard Architecture (ISA) Architecture, developed by IBM, which allowed for expansion cards in early models of personal computers.infrastructure mode An operation mode that allows wireless LAN devices to connect to resources on the wired network or to other wireless devices by using an access point.insertion loss A form of signal loss caused by RF connectors. It is minor but can contrib-ute to overall loss in a system, thereby resulting in less signal and less throughput.interference Two or more RF signals interacting with each other and causing a degrada-tion of performance.IP address A logical Layer 3 address that identifies a device on a network. This address must be unique for devices on a common subnet.isotropic radiator Theoretical concept used in reference and calculations. Assumes that RF energy is broad-cast equally in all directions in a spherical manner. An isotropic radiator is an imaginary, perfect antenna.

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last-mile data delivery A common term used in telecommunications to describe the con-nection from a provider to an endpoint such as home or business. Not necessarily a mile in distance.Layer 2 tunneling protocol (L2TP) A Layer 3 VPN security solution. L2TP is the combi-nation of two different tunneling protocols: Cisco’s Layer 2 Forwarding (L2F) and Micro-soft’s Point-to-Point Tunneling Protocol (PPTP). Usually works with IPSec to provide encryption.lightning arrestor Device used to shunt electrical currents from indirect lightning strikes to the ground. Protects electronic devices connected to the system from damage.lightweight access points Work with wireless LAN controllers/switches to provide net-work access for wireless LAN devices. Also known as thin access points.line of sight The ability of a transmitter and receiver to “see” each other (visual line of sight) or to transmit RF energy (RF line of site). RF line of sight is the area of coverage around the visual line of sight.load balancing In wireless networking, a mechanism that prevents wireless client devices from associating to an access point that has already reached the maximum number of client devices to allow for optimal performance.lobe In radio frequency technology terms, the shape of the RF energy emitted from an antenna element and is in the form of main, side, and rear.

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MAC address filtering Allows or denies access to a device based on its Layer 2 Media Access Control (MAC) unique hardware address.MAC spoofing A way of changing (through software) the assigned Layer 2 Media Access Control (MAC) address to something other than what it was intended to be. This may allow gaining access to restricted systems.Media Access Control (MAC) address A 6-byte unique number to identify a device (net-work interface adapter) connected to a computer network.midspan device Usually a single port or multiple port injector, injects DC power into Ethernet cable over the unused pairs of wires to allow power and data at the end (powered)