User's Manual

Chapter 4 - Operation and Administration
BreezeNET B System Manual
4-60
Burst Mode
Burst mode provides an increased throughput by reducing the overhead
associated with transmissions in the wireless media. In a burst
transmission the inter-frame spacing is reduced and data frames are
transmitted without any contention period.
Burst Mode Option
The Burst Mode Option enables or disables the Burst Mode operation.
The default is Enable.
NOTE
When Burst Mode Option is enabled, do not change the SW Retry Support parameter in
the Adaptive Modulation menu from its default setting of Disable.
Burst Period
The Burst Period defines the burst size, which is the time in which data
frames are sent immediately without contending for the wireless
medium.
The range is 1 to 10 milliseconds.
The default is 5 milliseconds
Adaptive Modulation Algorithm (Multi Rate)
The Adaptive Modulation Algorithm enables adapting the modulation
level of transmitted data to the prevailing conditions of the applicable
radio link.
Link quality fluctuates due to various environmental conditions.
Dynamically switching between the possible modulation levels increases
the probability of using the maximum modulation level suitable for the
current radio link quality at any given moment.
The decisions made by the Adaptive Modulation algorithm relate to the
modulation level selected for transmission of new frames (first trial
attempt) as well as the modulation level for retransmissions. The
decisions are based on multiple parameters, including information on
received signal quality (SNR) that is received periodically from the
destination unit, the time that has passed since last transmission to the
relevant unit, and the recent history of successful and unsuccessful
transmissions/retransmissions.
The transmission/retransmission mechanism operates as follows: