Bi-Directional Benes With Large Port-Counts and Low Waveguide Crossings for Optical Network-on-Chip

Abstract

We propose a new variant of the Benes network using a merge-replace-fold approach. It is to realize a large port-count optical switch with low waveguide crossings. A bidirectional switch is built instead of a unidirectional switch. Compared to the classical Benes, it requires the same number of switches but far fewer intersections. The novel designs enable a 24-percentage reduction in waveguide intersections. Moreover, it has a worst-case insertion loss of 12.01 dB and a comparable crosstalk level of -13.67 dB between the neighbouring paths. Thus, it is suitable for use in high-speed optical networks-on-chip.INDEX TERMS Optical interconnections, Optical NoC, Silicon photonics, Optical resonators, Optical switches.

Making Path Selection Bright: A Routing Algorithm for On-Chip Benes Networks

“…A comparison is made between the same type of design with and without the proposed algorithm, and it runs at 50 Gbps. The transmission performance can be further enhanced over that reported in our previous work [3,4]. Traditional loop algorithms show a very high degree of symmetry of the paths, such that the worst-case straight line with the largest IL occurs exactly twice, i.e., between the input and output ports of 1 and 32.…”

“…As usual, the first step is to calculate the routing tables in the traditional manner [3,4]. To provide maximum BW, we previously demonstrated an auxiliary graph to establish connections between all input and output ports.…”

“…Driven by cloud computing and ever-increasing cloud content, data center (DC) networks are experiencing a surge in traffic, with an estimated 77% of total switched traffic by 2030 [1][2][3][4][5]. Like DCs, high-performance supercomputers (HPCs), such as Blue Gene/Q, PERCS/Power 775, and P7/IH, have widely used optical modules.…”

“…Recently, we demonstrated the first-ever bi-Benes architecture based on 32 × 32 reconfigurable nonblocking switches, which allowed us to suppress the power consumption to as low as 85 µW [3,4]. The Benes network has several favorable qualities.…”

“…One can reroute the existing links to accommodate the new requests. In this context, designing an intelligent routing table for Benes has been a hot topic in recent years in both academia and industry [3,4,[9][10][11][12][13].…”