Low latency information transfer based on precision time synchronization via wireless interferometry

Abstract

The growing demand of high-bandwidth and low-latency information transfer in information and communication technologies such as data centres and in-vehicle networks has increased the importance of optical communication networks in recent years. However, complicated arbitration schemes can impose significant overheads in data transfer, which may inhibit the full exploitation of the potential of optical interconnects. Herein, we propose an arbitration protocol based on precision time synchronization via wireless two-way interferometry (Wi-Wi), and numerically validate its efficiency including the ability to impose a strict upper bound on the latency of data transfer.Compared with the conventional carrier sense multiple access/collision detection (CSMA/CD)-based approach, a significant improvement in the data transfer was observed especially in the cases with high traffic flow rate.Furthermore, we conducted a proof-of-principle experiment for Wi-Wi-based data transfer between two electrically connected nodes and confirmed that the skew was less than 300 ns and remained stable over time.Conversely, non-WiWi-based data transfer exhibited huge and unstable skew. These results indicate that precision time synchronization is a promising resource to significantly reduce the communication overheads and ensure low latency for future networks and real-time applications.

Delay-Bounded Wireless Network Based on Precise Time Synchronization Using Wireless Two-Way Interferometry

“…In our experiments, Wait time 2 indeed converged to a constant value as the traffic rate increases as shown in Fig. 4(e); thus, we can substitute Wait time 2 obtained from the simulation for 1/µ in (16). Then, the condition for instability in CSMA/CA is given by:…”

“…As introduced in Section I, CSMA/AP is a contentionbased approach. Here, the idea is that by using precise time synchronization among all terminals, the absolute collisionfree property is realized by periodic assignments of designated time duration shared among all terminals, called Arbitration Point (AP) [16]. Each terminal receives the timing of AP in chronological order while the time difference between successive APs is kept equal to a constant value.…”

“…Koyama et al proposed a new arbitration dedicated to optical ring network based on precise time synchronization via Wi-Wi where the maximum value of delay is strictly bounded. In the article [16], the notion of Arbitration Point is introduced as a periodic timing shared by all terminals, such that the proposed protocol provides an equal opportunity for all nodes connected to the optical ring.…”