Enhancing SDN WISE with Slicing Over TSCH

Abstract

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.

Scalability Enhancement on Software Defined Industrial Wireless Sensor Networks Over TSCH

“…2, This stack is composed of the following layers: Application, In-Network Packet Processing (INPP), Topology Discovery (TD), Forwarding (FWD), the MAC level and the physical layer, which is 802.15.4. The MAC layer was replaced by TSCH in [5], where SDN WISE TSCH is proposed, which extends the functionalities of SDN WISE, to guarantee industrial level requirements with a highly deterministic system. The controller has a stack of applications that allows centralized control of all processes in the nodes (MAC, Routing, QoS, Application).…”

“…This is intended to achieve a high degree of flexibility and scalability [4]. An example of the flexibility of SDN is described in [5], where QoS is guaranteed in a TSCH IWSN through optimized TSCH resource allocation and network load balancing, however, scalability is not addressed. In [23] the scalability of SDN in an IWSN under the CSMA protocol is studied, in this case the network reaches 289 nodes and has a lower energy consumption than using RPL, however due to the use of the CSMA protocol the PDR decreases as the number of nodes increases.…”

“…This enables the elimination of the bottleneck originated in the nodes close to the sink. In this way, the scalability and flexibility of these deterministic mesh networks is improved, while maintaining the QoS parameters observed in [5]. Table 1 contains a summary of related work and the most relevant aspects of each one.…”

“…This information is used by the SDN controller to build a global representation of the topology by combining information from multiple sources. In SDN WISE TSCH [5], this traffic is composed of periodic packets such as beacon and reports, and aperiodic packets which are the configuration packets (OpenPathTSCH). The beacon packets (B i in Fig.…”

“…Increasing the number of shared slots directly reduces the number of slots available for data. Therefore, the actual throughput available for data in the sink is calculated according to Equation (5).…”