Window-based token ring network supporting two priority traffic streams with bounded delay

A window-based token ring protocol supporting two priority traffic streams is proposed. This protocol uses the circulating window to limit the packet transmissions of a token holding station. Packets arrived during a window period are always transmitted before those arrived during subsequent window periods. Nonpreemptive priority service discipline is used to service high priority packets. A call admission control policy based on delay bound is then employed to guarantee QoS such as the packet delay, delay jitter, and the packet loss-free requirement for both priority traffic streams. Under such window-based token ring operation and the call admission control, packet arrivals within a window period is guaranteed to be transmitted in the next window period and the network output traffic characteristics become predictable.