This invention relates to radio communication networks and more particularly, but not exclusively, to radio communication networks using multiple access techniques. A system and method for adaptively changing the characteristics of a signal transmitted across a network is provided. In one embodiment, the communications network comprises at least two stations for transmitting and receiving; wherein at least one of the stations is capable of sending a control signal to the other station after receiving a signal transmitted over the network from the other station after analysis of the transmitted signal, which control signal is transmitted as a data packet independent of the other data and overhead signals.