A 3D Mesh NoC Architecture with Supplementary 2D Links and Progressive Shortest-Path Routing

Abstract

In this paper, we study a mesh-based 3D network topology that is enhanced with a small number of additional 2D links. The 3D network is formed by vertically stacking and scaling identical 2D mesh planes along the Z-axis. Within each 2D plane, four supplementary links are added to connect the corner nodes to nodes located in the central region of the mesh. These supplementary links are activated only when the 2D routing distance exceeds N in an N × N × N 3D mesh N >= 4.  Under this condition, the added links consistently provide a shorter path, requiring fewer than N hops within the 2D plane, thereby reducing the overall hop count. The proposed network is evaluated using a progressive shortest-path routing algorithm. This algorithm computes the minimum 2D distance from the source node to candidate nodes equipped with supplementary links, as well as the distance from those nodes to the destination. The node that minimizes the combined 2D distance is selected, and the packet is routed through it. If the source and destination nodes are located in the same 2D plane, the packet is routed entirely within that plane. Otherwise, once the packet reaches the selected node, it is forwarded along the Z-axis, either upward or downward, to the destination plane, where it is finally routed to the target node. The results show the robustness of the proposed network using the link utilisation graph.