A base station selects and assigns uplink segments to specific wireless terminals. The base station estimates potential system interference levels, selects, assigns, and transmits a maximum uplink rate indicator value to a wireless terminal indicating the maximum uplink dat rate that the wireless terminal is permitted to use. The wireless terminal receives the maximum data rate indicator and selects an uplink data rate to use which is less than or equal to the maximum data rate indicator level. The selection includes consideration of data amounts, data importance, communications channel quality, changes affecting the channel and/or power information. The wireless terminal encodes information indicative of the selected used rate wit the user data/information to be transmitted by placing additional energy on a subset of the uplin signals. The base station receives the uplink signals including user data/information and data rate. The base station extracts the data rate used and utilizes the data rate to demodulate and decode the uplink user data/information.