面向现场级工业无线网络混合流量分级调度的时隙分配策略

工业无线传感网络在关键位置监测和控制系统中发挥着越来越重要的作用. 然而复杂工业现场混合关键流量共存, 无法满足关键数据传输低时延和高可靠性要求, 突发流量会导致网络时延大幅抖动甚至网络拥塞, 给工业生产造成严重的后果. 针对上述情况, 本文提出了流量分区超帧架构, 考虑到设计复杂度和应用场景需求设计了R-MAC(时隙预留接入协议)和C-MAC(时隙争用接入协议). 上述两种协议以帧抢占的方式保障突发流量的实时接入, 采用了不同的重传机制提升周期性高优先级数据传输的可靠性. 最后本文对两种协议进行了评估, 与实时工业无线传感网络WirelessHART相比, 限定了突发流量的最差接入时延上界, 实现了多优先级流量服务差异化, 提升了高优先级流量的平均成功接入率.

A time slot allocation strategy for hierarchical scheduling of mixed traffic in industrial field wireless networks

Industrial wireless sensor networks are playing an increasingly important role in critical position monitoring and control systems. However, the coexistence of mixed critical traffic in complex industrial sites cannot meet the requirements of low delay and high reliability of critical data transmission. Burst traffic will lead to network delay jitter and even congestion, which will cause serious consequences to industrial production. In view of the above situation, Traffic partition superframe architecture is proposed in this paper. R-MAC (Slot reservation access protocol) and C-MAC (Slot contention access protocol) protocols are designed considering the design complexity and the requirements of application scenarios. The two protocols ensure the real-time access of burst traffic through frame preemption and adopt different retransmission mechanisms to improve the reliability of periodic high-priority data transmission. Finally, the two protocols are evaluated. Compared with the real-time industrial wireless sensor network WirelessHART, the worst access delay upper limit of burst traffic is defined, the multi-priority traffic service differentiation is realized, and the average successful access rate of high-priority traffic is improved.