A communications device and receiver system and method to efficiently distribute functions among radio frequency (RF), analog front end (AFE) and baseband modules for ultra-low power consumption comprising a wideband receiver subsystem selectively coupled to a signal input receiving a first frequency band, a narrowband received subsystem selectively coupled to the signal input receiving a second frequency band and, a controller configured to monitor the first frequency band using the first receiver subsystem and if a wake up signal is detected using the first receiver subsystem, connect the second receiver subsystem to the signal input and tune the second receiver subsystem to a channel transmitting the wake up signal, the wake up signal including channel selection information defining the channel for subsequent communications. Wherein, the two frequency bands overlap and center on different frequencies.