Specifications

Introduction
Altitude 35x0 Access Point Product Reference Guide20
defining the days and hours access is permitted. Authentication requests for users belonging to the
group are honored only during these defined hourly intervals.
QBSS Support
Each access point radio can be configured to optionally allow the access point to communicate channel
usage data to associated devices and define the beacon interval used for channel utilization
transmissions. The QBSS load represents the percentage of time the channel is in use by the access point
and the access point’s station count. This information is very helpful in assessing the access point’s
overall load on a channel, its availability for additional device associations and multi media traffic
support.
Reliable Multicast
This feature enables the AP to reliably transmit multicast transmission to those MUs that have
subscribed to them. This is done by converting the multicast packet to unicast packet and then
transmitting them. The received multicast packet is then dropped by the AP to prevent the MUs from
receiving the transmission twice. Up to a maximum of 16 multicast groups can be supported by this
feature. The maximum number of number of simultaneous streams supported is 32.
Configurable WPA Handshake Retry Levels
The AP has been updated to support configurable WPA handshake retry levels. This is to prevent the
MUs from timing out restarting association procedure if it does not receive any of the EAPOL messages
from the AP. The retry timeout can be configured to appropriate value between 100ms to 2 seconds so
that the EAPOL message is retried by AP before the MU can timeout. Also, the number of retries is
configurable in the range of 1 and 10 retries.
Theory of Operations
To understand access point management and performance alternatives, users need familiarity with its
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 a digital modulated RF signal 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 the carriers using an advanced digital modulation technique as specified in the
802.11a/b/g standards. 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 radio) or the 5 GHz