Motorola P-7131N-FGR Product Reference Manual page 641

Configuring Mesh Networking 9-25
NOTE Ensure AP#1 and AP#2 use the same channel for each 802.11a/n radio, or
the APs will not be able to "hear" each other over different channels.
9.3.1.3 Configuring AP#3
To define the configuration for AP#3 (a client bridge connecting to both AP#1 and AP#2
simultaneously):
1. Provide a known IP address for the LAN1 interface.