Theory of operations, Wireless coverage – Brocade Mobility 7131N-FGR Access Point Product Reference Guide (Supporting software release 4.0.0.0-35GRN and later) User Manual
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Brocade Mobility 7131N-FGR Product Reference Guide
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Theory of operations
1
For information on enabling QBSS and defining the channel utilization transmission interval,
see
“Configuring the 802.11a/n or 802.11b/g/n radio”
Theory of operations
To understand access point management and performance alternatives, users need familiarity
with functionality and configuration options. The access point includes features for different
interface connections and network management.
The access point uses electromagnetic waves to transmit and receive electric signals without
wires. Users communicate with the network by establishing radio links between mobile units (MUs)
and access points.
The access point uses DSSS (direct sequence spread spectrum) to transmit digital data from one
device to another. A radio signal begins with a carrier signal that provides the base or center
frequency. The digital data signal is encoded onto carriers using a DSSS chipping algorithm. The
radio signal propagates into the air as electromagnetic waves. A receiving antenna (on the MU) in
the path of the waves absorbs the waves as electrical signals. The receiving MU interprets
(demodulates) the signal by reapplying the direct sequence chipping code. This demodulation
results in the original digital data.
The access point uses its environment (the air and certain objects) as the transmission
medium.The access point can either transmit in the 2.4 to 2.5-GHz frequency range (802.11b/g/n
radio) or the 5 GHz frequency range (802.11a/n radio), the actual range is country-dependent.
Brocade devices, like other Ethernet devices, have unique, hardware encoded Media Access
Control (MAC) or IEEE addresses. MAC addresses determine the device sending or receiving data.
A MAC address is a 48-bit number written as six hexadecimal bytes separated by colons. For
example: 00:A0:F8:24:9A:C8 Also see the following:
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Direct-sequence spread spectrum
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Wireless coverage
An access point establishes an average communication range with MUs called a Basic Service Set
(BSS) or cell. When in a particular cell, the MU associates and communicates with the access point
supporting the radio coverage area of that cell. Adding access points to a single LAN establishes
more cells to extend the range of the network. Configuring the same ESSID (Extended Service Set
Identifier) on all access points makes them part of the same Wireless LAN.