Adaptive Real-Time Communication for Wireless Cyber-Physical Systems
Adaptive Real-Time Communication for Wireless Cyber-Physical Systems
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DOI：
10.1145/3012005
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发表时间：
2017-02
影响因子：
2.3
通讯作者：
Marco Zimmerling;L. Mottola;Pratyush Kumar;F. Ferrari;L. Thiele
中科院分区：
文献类型：
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作者：
Marco Zimmerling;L. Mottola;Pratyush Kumar;F. Ferrari;L. Thiele
低功耗无线技术有望在信息物理系统中带来更大的灵活性和更低的成本。为了获得这些益处，通信协议必须在资源受限的设备上在实时期限内可靠地传递数据包，同时适应应用需求（例如，流量需求）和网络状态（例如，链路质量）的变化。现有的协议无法同时解决所有这些挑战，因为它们的操作要么是局部的，要么是网络状态的函数，而网络状态会随时间不可预测地变化。相比之下，本文声称一种不使用网络状态信息作为输入的全局方法可以克服这些限制。Blink协议通过在多跳低功耗无线网络中对接收数据包的端到端期限提供严格保证，同时无缝处理应用需求和网络状态的变化，证明了这一说法。我们在非实时低功耗无线总线（LWB）的基础上构建Blink，并基于最早截止时间优先策略设计新的调度算法。使用专用的优先级队列数据结构，我们展示了我们的算法在资源受限设备上的可行实现。实验表明，Blink（i）满足接收数据包的所有期限，（ii）在一个94节点的测试平台上传递99.97%的数据包，（iii）在底层LWB的限制范围内将通信能耗降至最低，（iv）支持跨越四跳和九个源的100毫秒端到端期限，以及（v）在流行的微控制器上比传统的调度器实现快达4.1倍。
Low-power wireless technology promises greater flexibility and lower costs in cyber-physical systems. To reap these benefits, communication protocols must deliver packets reliably within real-time deadlines across resource-constrained devices, while adapting to changes in application requirements (e.g., traffic demands) and network state (e.g., link qualities). Existing protocols do not solve all these challenges simultaneously, because their operation is either localized or a function of network state, which changes unpredictably over time. By contrast, this article claims a global approach that does not use network state information as input can overcome these limitations. The Blink protocol proves this claim by providing hard guarantees on end-to-end deadlines of received packets in multi-hop low-power wireless networks, while seamlessly handling changes in application requirements and network state. We build Blink on the non-real-time Low-Power Wireless Bus (LWB) and design new scheduling algorithms based on the earliest-deadline-first policy. Using a dedicated priority queue data structure, we demonstrate a viable implementation of our algorithms on resource-constrained devices. Experiments show that Blink (i) meets all deadlines of received packets, (ii) delivers 99.97% of packets on a 94-node testbed, (iii) minimizes communication energy consumption within the limits of the underlying LWB, (iv) supports end-to-end deadlines of 100ms across four hops and nine sources, and (v) runs up to 4.1 × faster than a conventional scheduler implementation on popular microcontrollers.