Cluster-Based Network Time Synchronization for Resilience with Energy Efficiency

Abstract

Time synchronization of devices in Internet-of-Things (IoT) networks is one of the challenging problems and a pre-requisite for the design of low-latency applications. Although many existing solutions have tried to address this problem, almost all solutions assume all the devices (nodes) in the network are faultless. Furthermore, these solutions exchange a large number of messages to achieve synchronization, leading to significant communication and energy overhead. To address these shortcomings, we propose C-sync, a clustering-based decentralized time synchronization protocol that provides resilience against several types of faults with energy-efficient communication. Csync achieves scalability by introducing multiple reference nodes in the network that restrict the maximum number of hops any node can have to its time source. The protocol is designed with a modular structure on the Contiki platform to allow application transitions. We evaluate C-sync on a real testbed that comprises over 40 Tmote Sky hardware nodes distributed across different levels in a building and show through experiments the fault resilience, energy efficiency, and scalability of the protocol. Csync detects and isolates faults to a cluster and recovers quickly. The evaluation makes a qualitative comparison with state-ofthe-art protocols and a quantitative comparison with a class of decentralized protocols (derived from GTSP) that provide synchronization with no/limited fault-tolerance. Results also show a reduction of 56.12% and 75.75% in power consumption in the worst-case and best-case scenarios, respectively, compared to GTSP, while achieving similar accuracy.

Cluster-based Improvised Time Synchronization Algorithm for Multihop IoT Networks

“…This issue increases the overall message complexity of the network, impeding efficient data transmission and potentially leading to network congestion and reduced performance. The proposed C-sync [31], a clustering-based energy efficient decentralized time synchronization protocol, aims to achieve scalability by incorporating multiple reference nodes. However, the protocol's involvement of multiple reference nodes introduces message overhead, thereby increasing the time required to synchronize the entire network.…”

PCDE-Sync: A Time Synchronization Mechanism Based on Partial Clustering and the Doppler Effect for Underwater Acoustic Networks

“…Shivaraman et al [ 30 ] proposed C-Sync, a clustering-based time synchronization protocol that provides resilience against faults with energy-efficient communication. Experiment results show that C-Sync detects and isolates faults to a cluster and recovers quickly.…”

MPC-based time synchronization method for V2V (vehicle-to-vehicle) communication

“…Son and Chang (2020) proposed a clock synchronization method based on the precision time protocol (PTP) to estimate the information of the faulty node by collecting and analyzing the clock information of other nodes, but this method does not take into consideration the factor of packet loss, thus leading to inaccurate estimates. Shivaaraman, Schuster, Ramanathan, Easwaran, and Steinhorst (2021) proposed a cluster-based time synchronization protocol, but this method cannot reduce the synchronization error caused by packet loss. Jia, Wang, and Zheng (2020) proposed a clock synchronization protocol based on clustering algorithms, but this method did not take into consideration the impact of packet loss on the synchronization process.…”