Fuzzy-Token: An adaptive MAC protocol for wireless-enabled manycores

Abstract

Recent computer architecture trends herald the arrival of manycores with over one hundred cores on a single chip. In this context, traditional on-chip networks do not scale well in latency or energy consumption, leading to bottlenecks in the execution. The Wireless Network-on-Chip (WNoC) paradigm holds considerable promise for the implementation of on-chip networks that will enable such highly-parallel manycores. However, one of the main challenges in WNoCs is the design of mechanisms that provide fast and efficient access to the wireless channel, while adapting to the changing traffic patterns within and across applications. Existing approaches are either slow or complicated, and do not provide the required adaptivity. In this paper, we propose FUZZY TOKEN, a simple WNoC protocol that leverages the unique properties of the on-chip scenario to deliver efficient and low-latency access to the wireless channel irrespective of the application characteristics. We substantiate our claim via simulations with a synthetic traffic suite and with real application traces. FUZZY TOKEN consistently provides one of the lowest packet latencies among the evaluated WNoC MAC protocols. On average, the packet latency in FUZZY TOKEN is 4.4× and 2.6× lower than in a state-of-the art contention-based WNoC MAC protocol and in a token-passing protocol, respectively.