An apparatus includes a first and a second wireless communication modules and a packet traffic arbitration (PTA) module. The first wireless communication module issues a first request for a first transmission or reception operation in a first time period, wherein the first request includes information regarding a first power level for performing the first TX or RX operation. The second wireless communication module issues a second request for a second TX or RX operation in a second time period, wherein the second request includes information regarding a second power level for performing the second TX or RX operation. The packet traffic arbitration module receives the first request and the second request, and grants one or both of the first request and the second request according to the first power level and the second power level when the first time period is overlapped with the second time period.