A method and apparatus for improving performance in communication systems is provided. In order to maintain the real time constraints of the communication systems, time intervals and indication signals are used in various implementations to indicate and/or force subsequent transmissions of encoded data. An indication signal can include, for example, modulation modification information for subsequent transmissions. In various other implementations, a quality metric is computed for the communication channel and is used to provide modified modulation scheme information to be subsequently used on the communication channel.