Abstract: A building management system controller (10) is provided. The building management system controller may be configured to detect electro-magnetic interference on a plurality of frequency channels of a narrow band frequency, and select one of the plurality of frequency channels having a detected electro-magnetic interference which less than a predetermined electro-magnetic interference threshold as a communication channel for communicating with at least one device (12, 14). The building management system controller may also be configured to communicate wirelessly with at least one device (12, 14), to determine a communication reliability for communications between the controller and the at least one device, and to determine a communication route between the controller and the at least one device in dependence on the determined communication reliabilities. Devices 12, 14 together make up a network 8 of controllers/sensors for the building management system.