Reference Manual

Table Of Contents
5. Configure Point-to-MultiPoint Networks
LUM0020CD Rev June-2020 Page 66 of 112 Copyright © 2019FreeWave
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5.6.5. Master Packet Repeat
Master Packet Repeat
Setting Description
Default Setting 2
Options Any number between 0 and 9
Setup Terminal
Menu
(5) Edit Multipoint Parameters > (1) Master Packet Repeat
Description
In a Point-to-MultiPoint network, Slave radios do not acknowledge transmissions
from the Master.
l If Slave radios did acknowledge all data transmissions, in a large network, the
Master would soon become overwhelmed with acknowledgments from the
Slaves.
l Without acknowledgments, 100% confidence every Slave radio has received
every packet cannot be met.
l To address this issue, change the Master Packet Repeat parameter,
assigning a value between 0 (the packet is transmitted once) to 9 (the packet
is transmitted 10 times).
FREEWAVE Recommends: Use a setting of 1 or 2 in a licensed
network.
For networks with solid RF links, this parameter should be set to a low value
(e.g.,1 or 2).
l If a network has some weak or marginal links it should be set with higher
values.
l If a Slave radio receives a good packet from a Master more than once, it
discards the repeated packets.
l Similarly, after a MultiPoint Repeater receives a good packet from the Master,
it discards any further repeated packets.
l In turn, the Repeater sends the packet out to the next Repeater or Slaves the
number of times corresponding to its own Master Packet Repeat setting.
Notes
l Increasing the Master Packet Repeat setting increases the probability of a
packet getting through, but also increases latency in the network because
each packet from the Master or Repeater is being sent multiple times.
l Therefore, it is important to find the optimal mix between network
robustness, throughput, and latency.
l In general, a setting of 2 to 3 works well for most well designed networks.
l The Master Packet Repeat parameter may be set to 0 if the user software is
capable of, or requires acknowledgment.
l In this case, if the Master sends a packet that the Slave radio does not
receive, the user software controls the retries as needed.
LRS455A-C, LRS455A-CE, LRS455-T
User-Reference Manual
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