An apparatus and method for controlling wireless communication signals is provided, in which a wireless transmitter in a communication network generates a signal carrying data for wireless transmission, and is capable of varying the data carrying capacity of the wireless transmission channel in response to the quantity of data received for wireless transmission. A monitor is provided to monitor the quantity of received data and the capacity of the communication channel is increased if the monitored quantity exceeds a predetermined threshold. The capacity of the communication channel can be varied by varying the level of modulation and/or by varying the level of code inserted into the data stream. The output power of the wireless transmission signal may be varied in response to the quantity of received data.