The authors consider a communication channel which is shared by two classes of stations, the dominating class (DC) and the nondominating class (NDC). The DC stations transmit at a higher power than the NDC stations. Due to the capture effect, a transmission will be received successfully if no other transmissions at the same or higher power is transmitted at the same time. It was found that, in order to maximize the total channel throughput, the DC stations have to send at a rate which is lower than the optimal rate (in the absence of the NDC stations). However, if the NDC stations use the channel at a time-varying rate, due to changes in their traffic requirements, the DC stations will adjust their rates accordingly. The authors have studied this problem under three different assumptions for the arrival process of the NDC stations. The model is illustrated by an example, and it is shown that the strategy increased the total channel throughput.link_to_subscribed_fulltex