Multiple spanning tree construction for deadlock-free adaptive routing in irregular networks

This paper proposes a new adaptive deadlock-free routing scheme to improve the performance of irregular networks by using multiple spanning trees. The traditional up*/down* routing algorithm used a single root, where the root can be a hotspot. The multiple layer spanning tree scheme used different virtual networks for different spanning trees. Bandwidths of the system may be not fully utilized. The proposed new deadlock-free adaptive routing scheme uses multiple spanning trees, where different packets are delivered along different trees. There may exist some potential cyclic channel dependencies based on the multiple-spanning-tree-based routing scheme in VCT-switched networks. A simple scheme is proposed to avoid potential cyclic channel dependencies by selecting the minimum number of constrained turns. Sufficient simulation results are presented to show the effectiveness of the proposed method.