CMTS: Consensus-based Multi-hop Time Synchronization protocol in wireless sensor networks

Randomized and Efficient Time Synchronization in Dynamic Wireless Sensor Networks: A Gossip-Consensus-Based Approach

“…Distributed timing protocol based on the idea of the consensus algorithm was originally achieved with the Average TimeSynch (ATS) [11] protocol which fully compensates clock rate and offset. To accelerate convergence speed, the Maximum Time Synchronization (MTS) [12] protocol was developed by which the system trajectories of rate and offset are updated to achieve the maximum-value under a normal distribution delay model, and Saiah et al [14] proposed the Consensus-based Multi-hop Time Synchronization (CMTS) protocol under the Gaussian delay model. Panigrahi and Khilar [13] proposed a multiobjective evolutionary strategy-based topological optimization for the consensus timing protocol to deal with a trade-off between the minimizing of delays and the selection of sync initiating nodes, but the delays are assumed to be symmetric.…”

“…Recently, based on distributed consensus algorithms [9,10] of multiagent networks, consensus-based approaches for designing distributed timing protocols [11][12][13][14][15][16][17][18][19][20][21] have received a lot of attention in WSNs. These protocols utilize local information to achieve global synchronization and easily adopt to WSNs' distributed sensor property with computational lightness.…”

“…This problem will directly affect the implementation of the logical clock rate and offset compensation, and become more paramount as the change of connected relation of WSNs gets faster. On this issue, the existing consensus-based timing protocols can be classified into two categories: (1) deterministic synchronization, which relies on a fixed link, such as [11][12][13][14][15][16][17][18]; and (2) randomized synchronization, such as [19][20][21]. Brown et al [19] investigated the transient consensus behavior of the random pairwise consensus synchronization (RPCS) algorithm.…”

“…A major concern is the lower convergence speed which increases the message complexity and consumes the limited power of the sensor nodes. However, many protocols [11,[13][14][15][16][19][20][21] are proposed based on the average-value-based criterion, which need more iterations to achieve acceptable synchronization error.…”

“…3) The delay model is unrealistic. Several protocols suppose the uplink delay and the downlink delay among two nodes are symmetric [13,19] or obey a statistical delay model [12,14], such as normal distribution and Gaussian distribution. Worse still, the uncertainty regarding the delay is associated with the influence of the exterior environment.…”