Network Traffic Regulator for Diagnostic Messages in Modular Product

Abstract: The aim of this thesis project is to explore a network traffic regulator using bandwidth management techniques that regulates data traffic with the objective to use the network bandwidth to its maximum capacity while ensuring that the network is not overloaded. The bandwidth in the existing network architecture is shared between two co-existing, distinct data flows for on-board communication and diagnostic communication in an in-vehicle network. The diagnostic communication must not interfere with the more critical on-board communication and it should comply with the remaining bandwidth. In the existing solution, fixed delays are imposed on the data traffic which result in a waste of network capacity. The approach presented in this thesis uses two regulation algorithms for different types of diagnostic services. One regulation algorithm is activated for diagnostic services that require data segmentation and multiple data frames to accommodate the transferred data. This algorithm makes use of the Flow Control parameter Separation Time specified in ISO 15765-1:2011 "Road vehicles -- Diagnostic communication over Controller Area Network (DoCAN)". The other algorithm regulates diagnostic services that generate bursts of single frames where data segmentation is not required and it does so using traffic shaping techniques. The results in this thesis show that the network traffic indeed can be regulated for different diagnostic services by using the two mentioned regulation algorithms. The results also show that data is not lost due to high network utilisation and that the bandwidth is used to its maximum capacity without having to impose fixed delays on the network system. The regulator is adaptive in the sense that it can be used for different vehicle configurations with compatible network systems to ensure quality of service and a robust network system.