Scheduling real-time messages in fibre channel arbitrated loop

This paper addresses the problem of delivering real-time messages, both periodic and aperiodic, over fibre channel arbitrated loop. Periodic messages typically have hard real-time constraints whereas aperiodic tasks are delivered based on the best-effort approach. The deadlines of periodic messages are guaranteed by limiting the packet size under the access fairness algorithm defined in fibre channel arbitrated loop or FC-AL. The aperiodic messages are delivered using a global server scheme based on the full duplex communication and transfer state facilitated in FC-AL. The algorithm presented in this paper is optimal in that it guarantees all the deadlines of periodic messages and fully-utilizes network bandwidth. The optimality is expected to apply to many other broadcasting networks, both LANs and field-buses, by considering the global server scheme in their ongoing standardization processes.