A mobile station for receiving delay-sensitive data from a wireless communications network is provided with a data buffer and cell reselection controller. If both the first and the second CRE are larger than 0, a first modified CRE is set based on the first CRE and a second modified CRE is set based on the second CRE. Furthermore, APs can perform automatic power adjustment so that multiple APs can operate on the same channel while minimizing interference with each other. The pressure charge is released into a chamber which contains a soft projectile. The first output of the first MMI coupling device is optically coupled to the first input of the second MMI coupling device through the first optical coupler. A movable member is sleeved onto the battery set inside the bottom cover and held in a first position by spring members to block side holes of the bottom cover and movable from the first position to a second position to open the side holes of the bottom cover for ventilation to dissipate heat upon insertion of the battery module in a battery charger for charging.