A system and method for avoiding mutual interference between two communications system is disclosed. One embodiment of the invention provides a system that includes a fixed unit and a portable unit. The fixed unit has a fixed transceiver. The portable unit has a portable transceiver. The fixed transceiver and the portable transceiver are members of a first RF system of the first RF system. The portable transceiver is configured to communicate with the fixed transceiver via a first RF link of the first RF system. The system further includes an additional transceiver. The additional transceiver is configured to communicate with a headset via a second RF link of a second RF system. The system further includes a processor that is coupled to one of the fixed transceiver, the portable transceiver, and the additional transceiver. The processor is configured to avoid interference between the first RF link and the second RF link. The interference can be avoided by coordination between the first RF system and the second RF system. Alternatively, the interference can be avoided using signal or timing information from the second RF system. For example, RSSI obtained by the first RF system can be used to estimate or derive timing information of the second RF system, which can then be used by the first RF system to avoid interference with the second RF system.