Instituto Tecnológico de Informática (ITI), 46022 Valencia, Spain.
Departamento de Comunicaciones (DCOM), Universitat Politècnica de València (UPV), 46022 Valencia, Spain.
Sensors (Basel). 2021 Feb 4;21(4):1075. doi: 10.3390/s21041075.
IWSNs (Industrial Wireless Sensor Networks) have become the next step in the evolution of WSN (Wireless Sensor Networks) due to the nature and demands of modern industry. With this type of network, flexible and scalable architectures can be created that simultaneously support traffic sources with different characteristics. Due to the great diversity of application scenarios, there is a need to implement additional capabilities that can guarantee an adequate level of reliability and that can adapt to the dynamic behavior of the applications in use. The use of SDNs (Software Defined Networks) extends the possibilities of control over the network and enables its deployment at an industrial level. The signaling traffic exchanged between nodes and controller is heavy and must occupy the same channel as the data traffic. This difficulty can be overcome with the segmentation of the traffic into flows, and correct scheduling at the MAC (Medium Access Control) level, known as slices. This article proposes the integration in the SDN controller of a traffic manager, a routing process in charge of assigning different routes according to the different flows, as well as the introduction of the Time Slotted Channel Hopping (TSCH) Scheduler. In addition, the TSCH (Time Slotted Channel Hopping) is incorporated in the SDN-WISE framework (Software Defined Networking solution for Wireless Sensor Networks), and this protocol has been modified to send the TSCH schedule. These elements are jointly responsible for scheduling and segmenting the traffic that will be sent to the nodes through a single packet from the controller and its performance has been evaluated through simulation and a testbed. The results obtained show how flexibility, adaptability, and determinism increase thanks to the joint use of the routing process and the TSCH Scheduler, which makes it possible to create a slicing by flows, which have different quality of service requirements. This in turn helps guarantee their QoS characteristics, increase the PDR (Packet Delivery Ratio) for the flow with the highest priority, maintain the DMR (Deadline Miss Ratio), and increase the network lifetime.
工业无线传感器网络（IWSNs）由于现代工业的性质和需求，成为了无线传感器网络（WSNs）的下一步发展。通过这种类型的网络，可以创建灵活和可扩展的架构，同时支持具有不同特征的流量源。由于应用场景的多样性，需要实现额外的功能，以保证足够的可靠性，并适应正在使用的应用程序的动态行为。SDN（软件定义网络）的使用扩展了对网络的控制能力，并使其能够在工业层面部署。节点和控制器之间交换的信令流量很大，必须占用与数据流量相同的信道。通过将流量分段为流，并在 MAC（介质访问控制）级别进行正确调度，称为切片，可以克服这一困难。本文提出在 SDN 控制器中集成流量管理器，该管理器负责根据不同的流分配不同的路由，以及引入时间分片信道跳频（TSCH）调度程序。此外，TSCH（时间分片信道跳频）被纳入 SDN-WISE 框架（用于无线传感器网络的软件定义网络解决方案）中，并且修改了该协议以发送 TSCH 计划。这些元素共同负责通过控制器的单个数据包向节点发送流量的调度和分段，并且已经通过仿真和测试床评估了其性能。所获得的结果表明，由于路由过程和 TSCH 调度程序的联合使用，灵活性、适应性和确定性如何提高，这使得可以通过流创建切片，这些切片具有不同的服务质量要求。这反过来又有助于保证它们的服务质量特征，提高具有最高优先级的流的 PDR（分组投递率），保持 DMR（截止日期错过率），并延长网络寿命。
