pulsAR
radio Operator's Manual
node, which will become the source of the heartbeat. The other radios at that site must be hubs or
roots. In this situation choose an even cycle split of 50/50.
5. Make sure that all radios have the
tdd sync-mode
set to
auto
(default).
If you follow these guidelines the radios will send the synchronization information across the network
and completely avoid self-interference. Use the
“>show
” command to find which radio is the source
for the heartbeat at that site and also whether there are any conflicts in the configuration.
2.4.4
Heartbeat suppression
There are situations when the multicast of heartbeat packets may not be necessary, and would put an
unnecessary burden on the Ethernet. The radios detect these situations automatically and suppress the
multicast of the heartbeat packets when there is no co-located device to receive them.
You may have situations where you do not wish the radios to try and synchronize to each other. For
example, the Ethernet LAN may be extended with fiber or a third party wireless bridges resulting in
the Afar radios assuming that they are co-located when indeed they are not. In these cases you can
turn off the radio participating in the synchronization protocol by setting the
tdd sync-mode
to
off
.
This is also the appropriate setting if multiple co-located radios get synchronization over RF and
therefore cannot accept a heartbeat over the Ethernet. In these cases you need to avoid self-
interference with the more traditional methods of increasing the separation between antennas, and/or
reducing transmit power
2.4.5
Synchronization with NetCrossing Gateways
The Afar NetCrossing Gateway devices convert between a synchronous serial data stream and
Ethernet packets. They can be paired with the
pulsAR
radios to establish wireless point to point serial
synchronous links. When you have multiple such links and need to co-locate radios, the gateways
can participate in the heartbeat negotiation and site synchronization. The gateways are equipped with
a SYNC port through which they propagate the synchronization information, without having to
connect the radio LANs together.
Figure 2.6 shows a network with mixed radios and gateways (NxG) and illustrates how the SPAN
synchronization is achieved.
In the gateways the
tdd sync-mode
can be set to three different values:
off
(which is the default)
,
auto
, and
master
. The figure shows the appropriate setting of each gateway. All radios should have
the tdd sync-mode configured to the default
auto
setting.
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Summary of Contents for AR-24010E
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