A potential problem with DQDB network is the achievement of fair sharing of bandwidth in terms of the location of the access node. For the sake of compensating this unfairness, the IEEE 802.6 Standard recommends to utilize a Bandwidth Balancing (BWB) Mechanism. This paper deals with the implementation of BWB mechanism using the modified DQDB method. We focus on the behavior of this protocol when the network is Heavy load. The effect of BWB mechanism on the fairness problems suffered by a DQDB network with two stations for three different scenarios is investigated analytically through using a graph model which is based on the space time diagram. Simulation is used when the number of active stations is larger than two. Our results provide a deep insight into the equilibrium access of data channel by all the active stations. They also show that the station throughputs are independent on the state of the network when overload occurs.