Ethernet switch controller design for real-time control applications

This paper studies the controller design for the Ethernet switches. The switch controller utilizes the information of network and control performance as well as the switch variables such as queue length and utilization to allocate communication bandwidth for each node connected and to implement dispatching algorithm for the incoming network traffic. The goal is to maintain the quality of services of message transmission provided by the communication medium as well as to guarantee the real-time performance of the control system implemented over the switched Ethernet network. The real-time control requirements are encoded in an Ethernet package. The Ethernet switch adopts the earliest deadline first scheduling algorithm to verify the schedule feasibility and dispatch the incoming packages. When the requested packages is feasibly scheduled, an active queue control law is utilized for adjusting proper allocation of available network bandwidth.