MUST: a quasi-round robin access scheme for CAN networks
Gianluca Cena, Adriano Valenzano · 2002
Because of their low implementation costs, optimum responsiveness and widespread availability, controller area networks (CANs) are being more and more used today for supporting communications in real-time systems. However, under heavy traffic conditions, the access protocol of a CAN may exhibit a quite unfair behaviour, in particular when the control applications require that the same quality of service be ensured to a number of different objects. In this paper, a new technique is proposed, called MUST (medium utilisation state tracking), which is based on CANs and introduces few changes to the original protocol. Such a solution is able to ensure a very fair behaviour $which resembles the one obtained in token-based networks - while maintaining, at the same time, the reduced access delays typical of CANs when operating in low traffic conditions.