A communication device is provided. The communication device includes a measurement device and a controller. The measurement device is configured to measure operation parameters and noise parameters corresponding to Wi-Fi channels used by the communication device. In response to the controller determining that a wireless transmitter/receiver unit (WTRU) is to connect to the communication device, the controller calculates a signal-to-noise ratio and a user ratio corresponding to each Wi-Fi channel according to the operation parameters and noise parameters, and calculates a congestion traffic value corresponding to each Wi-Fi channel according to the signal-to-noise ratio and the user ratio of each Wi-Fi channel. The controller selects a first Wi-Fi channel having the smallest congestion traffic value from among the plurality of Wi-Fi channels to communicate with the WTRU.