WiFoo..The.Secrets.of.Wireless.Hacking [Electronic resources] نسخه متنی

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adjacent cell

A coverage area of an AP that is physically located next to an existing AP's coverage area.

adjacent channel

A channel or frequency that is directly above or below a specific channel or frequency.

AES

Advanced Encryption Standard. A next-generation encryption function approved by the National Institute of Standards and Technology (NIST) for use with WLAN. The encryption mechanism to be used in 802.11i and is likely to replace DES and 3DES.

aggregate throughput

A measure of the maximum amount of data a network or other communications system can carry in a given timeframe. Basically a total summation of all data rates of all simultaneous transmissions possible at one instance on the system. If a system could support five simultaneous transmissions of 2 Mbps, for example, it would have an aggregate throughput of 10 Mbps.

amplitude

The magnitude or strength of a varying waveform.

amplitude modulation (AM)

A technique whereby the voltage level or amplitude of a carrier is varied to transmit digital or analog information.

antenna

The part of a radio communications system intended to radiate and/or collect RF energy.

dBi and dBd.

AP

access point. The central point of communications for all stations in a WLAN. An AP provides connection between wireless devices as well as between the wired network and the wireless network.

attenuation

A reduction in strength or deterioration of a radio signal as it passes through a transmission medium. Attenuation generally increases with frequency, cable length, and the number of connections in a circuit. Attenuation is measured in decibels (dB).

attenuator

A device that reduces the level of a transmitted signal, in terms of current, voltage, or power.

authentication

In WLAN usage, a process by which a user must present some form of identifying credentials to be permitted access to a resource. In mutual authentication, a user must validate his identity to the network and the network's identity must be validated by the client.

bandwidth

The frequency range necessary to convey a signal, measured in units of hertz (Hz). For example, voice signals typically require approximately 7 kHz of bandwidth, and data traffic typically requires approximately 50 kHz of bandwidth, but this depends greatly on modulation scheme, data rates, and how many channels of a radio spectrum are used.