Cambium Networks cnReach N500, User Manual

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cnReach N500 User Guide System Configuration
phn-4673_003v000 (November 2018)
2-26
MMS
Refer to Chapter 3 Technical Reference for examples and background on multiple master
synchronization (MMS)
Attention
For ISM bands, MMS should be configured with FHSS modulations 57 MSK, 114 MSK, 153
MSK & 229 MSK OR DTS modulations 884 BPSK, 1768 QPSK, 2651 8PSK, 3535 16QAM and
3535 16PSK. It is not recommended to mix FHSS and DTS modulations.
MMS may operate in one of two modes;
1. Generate; the system Access Point internally “generates” the 1Hz timing signal for all other radios in
the network(s).
2. External; a 1PPS “external” trigger signal from a GPS receiver is used to synchronize the 1Hz timing
signal for all other radios in the network(s). See IO Connections in Chapter 3 for wiring info. The
Cambium Networks uGPS is an option for providing the 1PPS sync signal.
MMS Access Point Specific Settings
Generate
When the Access Point radio is set to Generate, it will internally generate a timing signal that can be
used in two ways;
1. For timing downstream radios in any number of interconnected sub-networks.
2.
For timing a co-located Access Point (and any number of interconnected sub-networks
downstream of that Access Point).
Note
If co-locating Access Points connect Pin2 – Pin2 and Pin4 – Pin4 so that one Access
Point will “generate” the timing signal and the other will receive it on the MMS Pins of
the External IO connector.