The invention provides a mobile communication device having a first wireless communication module with a strong driving circuit, and a second wireless communication module with a weak driving circuit. The first wireless communication module is coupled to the second wireless communication module via only one wire. The first wireless communication module sends a first traffic pattern of a first wireless transceiving to the second wireless communication module via the wire, and receives a second traffic of a second wireless transceiving from the second wireless communication module via the wire. The second traffic pattern indicates whether the second wireless communication module decides to use a remaining period of time, in which the first wireless communication module is not required to perform wireless transceiving, for the second wireless transceiving.