User's Manual

pulsAR radio Operator’s Manual
2-10
Figure 2.5 shows an example of a mixed network with multiple topologies. When the whole network
is synchronized each radio runs its TDD in one of two timings, A or B, as shown in the figure. All
radios at a single site run on the same cycle.
The following are guidelines you need to follow to achieve a successful synchronization in a complex
network:
1. At any site with multiple radios ensure that all radios are connected to the same LAN. The LAN
connection between radios must be FULL DUPLEX. Use the “>ether” command to check that
the radio Ethernet port is in full duplex (see also section 2.4.5 for synchronizing a site where the
radios are paired with NetCrossing Gateways).
2. You need to use a fixed TDD cycle split throughput the network. If you are co-locating multiple
hubs or roots in a point-to-multipoint or tree configurations, choose any split appropriate for the
traffic in your network. You must use the same value in all co-located radios.
3. When you co-locate all hubs or all roots, you may use a cycle period of either 20 or 40 ms, but it
must be the same in all co-located devices. You can mix hub and root radios at the same site, but
in that case you must set the hubs cycle periods to 20 ms and the roots to 40 ms.
4. You can also co-locate a remote (or a leaf or branch) with other radios. However children nodes
have their cycles synchronized to their parents. So at one given site there can only be one child
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 spread the synchronization 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.