Bandwidth Control Protocol in WiMAX Network

In WiMAX network, service flows with different priorities are defined. The priority of real time traffic is higher than that of non real time traffic. As bandwidth is limited, the resource must be allocated in advance to guarantee the delay time of real time traffic in WiMAX network. For this, the proposed algorithm must respond quickly to the sudden shortage of resource. In this paper, we will propose a Bandwidth Control Protocol (BCP). This algorithm evolves from the traditional bandwidth allocation protocol. When the bandwidth assigned to the real time traffic in advance is insufficient, it should be increased in following frames. With this, the bandwidth allocated to the non real time traffic must be reduced accordingly. In this way, the assigned bandwidth can be adapted to the real load of real time traffic. Also, the belonging bandwidth for non real time traffic can be borrowed by real time traffic if the load of real time traffic is fluctuated. The borrowed bandwidth will not be returned unless the allocated resource to the real time traffic is enough. With this mechanism, the delay time of real time traffic will be reduced effectively. Also, the bandwidth will be allocated more correctly.