In Wireless Networked Control Systems (WNCSs), the feedback control loops are closed over a wireless communication network. The proliferation of WNCSs requires efficient network resource management mechanisms since the control performance is significantly affected by the impairments caused by network limitations. In conventional communication networks, the amount of transmitted data is one of the key performance indicators. In contrast, in WNCSs, the efficiency of the network is measured by its ability to facilitate control applications, and the data transmission rate should be limited to avoid network congestion. In this work, we consider an experimental setup where multiple control loops share a wireless communication network. Our testbed comprises up to five control loops that include Zolertia Re-Mote devices implementing IEEE 802.15.4 standard. We propose a novel relevance- and network-aware transport layer (TL) scheme for WNCSs. The proposed scheme admits the most important measurements for the control process into the network while taking current network conditions into account. Moreover, we propose a mechanism for the scheme parameters adaptation in dynamic scenarios with unknown network statistics. Unlike the conventional TL mechanisms failing to provide adequate control performance due to either congestion in the network or inefficient utilization of available resources, our method prevents network congestion while keeping the control performance high. We argue that relevance- and network-awareness are critical components of network protocol design to avoid control performance degradation in practice.

翻译：在无线网络控制系统（WNCSs）中，反馈控制回路通过无线通信网络闭合。随着WNCSs的普及，需要高效的网络资源管理机制，因为控制性能会受到网络限制所导致的损伤的显著影响。在传统通信网络中，传输数据量是关键性能指标之一。相比之下，在WNCSs中，网络的效率以其支持控制应用的能力来衡量，数据传输速率应受到限制以避免网络拥塞。在本工作中，我们考虑一个实验设置，其中多个控制回路共享一个无线通信网络。我们的测试平台包含最多五个控制回路，这些回路使用实现IEEE 802.15.4标准的Zolertia Re-Mote设备。我们提出了一种面向WNCSs的新型相关性与网络感知传输层（TL）方案。该方案在考虑当前网络条件的同时，允许控制过程中最重要的测量数据进入网络。此外，我们提出了一种机制，用于在具有未知网络统计特性的动态场景中自适应调整方案参数。与由于网络拥塞或可用资源利用效率低下而无法提供足够控制性能的传统TL机制不同，我们的方法在保持高控制性能的同时防止网络拥塞。我们认为，相关性与网络感知是网络协议设计的关键组成部分，以避免实践中控制性能的下降。