A MAC Protocol with Time Reversal for Wireless Networks within Computing Packages

TL;DR

This paper introduces a Time Reversal-based MAC protocol for Wireless Network-on-Chip, enhancing bandwidth and reducing latency in many-core processors by mitigating interference through focused energy transmission.

Contribution

It proposes a novel TR-MAC protocol that manages parallel transmissions using time reversal and focused energy detection, improving wireless communication efficiency within chip packages.

Findings

TR-MAC improves latency and throughput in WNoC.

The protocol effectively manages multiple parallel transmissions.

It meets the physical layer requirements for on-chip wireless networks.

Abstract

Wireless Network-on-Chip (WNoC) is a promising concept which provides a solution to overcome the scalability issues in prevailing networks-in-package for many-core processors. However, the electromagnetic propagation inside the chip package leads to energy reverberation, resulting in Inter-Symbol Interference (ISI) with high delay spreads. Time Reversal (TR) is a technique that benefits the unique time-invariant channel with rich multipath effects to focus the energy to the desired transceiver. TR mitigates both ISI and co-channel interference, hence providing parallel communications in both space and time. Thus, TR is a versatile candidate to improve the aggregate bandwidth of wireless on-chip networks provided that a Medium Access Control (MAC) is used to efficiently share the wireless medium. In this paper, we explore a simple yet resilient TR-based MAC protocol (TR-MAC) design for WNoC. We propose to manage multiple parallel transmissions with simultaneous spatial channels in the same time slot with TR precoding and focused energy detection at the transceiver. Our results show that TR-MAC can be employed in massive computing architectures with improved latency and throughput while matching with the stringent requirements of the physical layer.