A novel heterogeneous congestion criterion for mesh-based networks-on-chip

Abstract

In recent years, congestion in Networks-on-chip (NoC) has emerged as an important research topic due to the increasing number of processing cores. To solve the congestion, all the methods that have been proposed require a congestion criterion to detect whether a node is congested or not. All the congestion criteria that have been developed so far have similar behavior for all nodes in the network. In this paper, for the first time, a heterogeneous congestion criterion is proposed for a two-dimensional mesh network that is determined for each node based on its betweenness centrality. This criterion can be generalized to the other topology such as torus easily. This criterion is calculated before the network starts up and does not have any overhead in run time. Using this criterion will reduce the average latency of any congestion-aware method, such as congestion-aware routing algorithms. The evaluation section shows that the use of this criterion in three famous routing algorithms reduces the average latency up to 48% (21% on average for all algorithms and traffic patterns) in both real and synthetic traffics. In addition, the usage of this criterion reduces the power consumption in all simulation conditions because of reducing the average latency and lack of overhead. It is also shown at the end of the evaluation section that an increase in the network size will result in better performance of this criterion.