Prof. Dr. Young-yeol Choo

"Guaranteeing Periodic Communication Service on Multiple Access Neworks for Hard Real-Time Systems"

The topic of this talk is about a novel algorithm for guaranteeing periodic communication support in real-time system. An overview of real-time system and the role of periodic communication in real-time systems will be introduced briefly. As a basis of proposed algorithm, the operation of timed token protocol and related protocols will be reviewed. Timed token medium access protocols are widely adopted in real-time multiple access networks because of bounded access time. However, timed token protocols inadequately provide periodic communication service, although this is crucial for hard real-time systems. We propose an algorithm, named as Token with Timer (TwT) algorithm, to guarantee periodic communication service on a timed token protocol network. In this algorithm, we allocate bandwidth to each node so that the summation of each bandwidth allocation is the Target Token Rotation Time (TTRT). The working of the proposed algorithm will be presented. The performance evaluation of TwT algorithm will be presented. This algorithm can always guarantee transmission of messages before their deadlines when network utilization is less than 50%. Finally, this talk will be concluded with some remarks on future works and related area for application.