A proactive backup scheme for reliable real-time transmission

Reliable transmission is a key issue for distributed real-time applications. The concept of Real-time Dependable Channel was introduced to provide availability to real-time transmission. Two aspects are important for the efficiency of a Real-time dependable channel: assuring the end-to-end delay bound and optimising the utilisation of network resources. A packet can miss its delay bound for two reasons: network congestion or network failure. The classic solution to this problem has been the use of Backup Channels which introduces the notion of availability at the expense of increasing the use of network resources. However, this over-provisioning of resources is potentially wasted, since the failure rate is very low.This paper introduces a new failure detection scheme for Real-time Transmission, which is called Proactive Backup Channel. This scheme is based on activating the backup channel before a network failure or congestion is produced. This way, the failure recovery time is reduced, and, as proven in the paper, the use of network resources is minimized.