A Novel Centralized Flow Control Scheme for ABR Service in Wireless ATM Networks

In this paper, we propose a novel Centralized Flow Control Scheme (CFCS) for ABR service in WATM network. The goal is to provide Quality-of-Service (QoS) guarantee to the users and to reduce the computational complexity at switches. A novel concept of monitoring the network status in the centralized controller in the form of rate allocation tables for flow control is the main theme of our algorithm. CFCS operates in ATM switches placed in the backbone of WATM network. The Network Controller Switch (NCS) monitors the current status of VC and bandwidth availability as well as tracking the current number of active sessions contending for capacity, to adjust the explicit bound in the source transmission rates. The simulation results show that the scheme is stable and efficient in achieving maximum utilization of bandwidth occupancies, enhancing average throughput and achieving robustness under continuously varying network conditions. The simulation experiments also demonstrate the superiority of the proposed scheme to the other schemes in dealing with switch complexity.