Relative clock synchronization in Delay Tolerant Network

在延迟容忍网络中，节点间的全局时钟同步是一个具有挑战性的问题，因为由于节点之间缺乏稳定的连接，参考时钟信息不能在节点上及时传播。我们提出了基于平均的分布式全局时钟同步算法，其中两个移动节点在相遇时交换它们的本地时钟时间，并将它们自己的时钟调整到它们的平均值。进一步进行了连续时间分析，揭示了节点时钟精度和节点间相遇速率对稳态收敛速度和稳态时钟同步精度的影响。

In delay tolerant networks, global clock synchronization among nodes is a challenging problem because reference clock information cannot be disseminated promptly over nodes due to the lack of stable connections among nodes. We proposed averaging-based algorithms for distributed global clock synchronization, where two mobile nodes exchange their local clock times when they meet and adjust their own clocks to the average of them. We further conducted the continuous-time analysis and revealed how the clock accuracy of nodes and meeting rates among them affect the rate of convergence to the steady state and the accuracy of clock synchronization in steady state.