Alvarion BreezeNET B System Manual page 179

Chapter 4 - Operation
4.2.6.5.5 Multicast Modulation Level (BU only)
The Multicast Modulation Level parameter defines the modulation level used for
transmitting multicast and broadcast data frames. Multicast and broadcast
transmissions are not acknowledged; therefore if a multicast or broadcast
transmission is not properly received there is no possibility of retransmitting. It is
recommended that you set a lower modulation level for broadcast and multicast
frame transmissions to increase the probability that they are received without
errors.
The Multicast Modulation Level parameter is applicable only to data frames
intended to unknown recipients. Beacons and other wireless management and
control frames are always transmitted at the lowest modulation level according to
the Sub Band.
The minimum and maximum values for the Multicast Modulation Level parameter
are defined by the Sub Band in use.For information on how to view the Sub Bands
supported by the unit and the supported parameters' values and options, refer to
Section
For BU-B14/28, the maximum modulation with 40 MHz is 5, while for BU-B100
the Maximum Modulation is 8.The default is the lowest supported modulation
level (modulation level 1).
4.2.6.5.6 Control Modulation Level
This feature controls the modulation for ACK frames sent by the unit. The ACK
modulation can either be set dynamically based on the modulation of the frame it
acknowledges or it can be enforced to modulation level 1. The latter is particularly
useful for asymmetric links.
For instance, if one unit in the link is capable of receiving frames in modulation 8,
while the other can only receive in modulation 2, in theory one of the units should
send its data traffic using modulation 8. However, unless it receives the
corresponding ACK feedback in modulation 2 or 1, it will not be able to
synchronize and will bring its own Tx modulation down as a result. Setting the
ACK modulation to level 1 at the other side of the link will fix this, allowing the
unit to acknowledge that frames sent in modulation 8 are successfully received.
The available options are:
Basic Rate - Sets 3 modulation thresholds for the sent ACK frames depending

on the modulation of the received frame:
BreezeNET B
4.2.2.4.
155
Menus and Parameters
System Manual