A medical sensor system comprises a gateway comprising a wideband receiver and a narrow band transmitter, the each gateway configured to receive a wideband positioning frame using the wideband receiver from one or more wearable sensors and to transmit acknowledgement frames using the narrow band transmitter that include timing and control data for use by the sensors to establish timing for transmission of the positioning frame; and at least one wearable sensor comprising a wideband transmitter and a narrow band receiver, the sensor configured to transmit a sensor data frame to the gateway using the wideband transmitter and to receive an acknowledgement frame from the gateway using the narrow band receiver, extract timing and control information from the frame, and adjust the timing and synchronization of the wideband transmitter using the timing and control information.