Presenter

Mr Thanh-Long Nguyen - ETRO, VUB [Email]

Abstract

Internet of Things (IoT) allows physical environments to be connected to the Internet by means of billions or even, in the near future, trillions of IoT devices such as wireless sensors and actuators. This leads to exciting possibilities for a variety of application domains, such as smart metering, smart cities, smart buildings, smart mobility, smart health, and industrial automation. For realising IoT, Wireless Sensor and Actuator Networks (WSANs), a subset of Low-power and Lossy Networks (LLNs) are important building blocks. Our research addresses the question of how to support efficient and reliable IoT-data communication in a context involving many types of devices, technologies, and services, integrated and operating under constrained conditions.
We investigate the benefits of using open standard protocols for LLNs. The investigation of the state-of-the-art protocols for constrained IoT devices is done by conducting performance evaluation using simulation studies and testbed experiments, and while doing so, giving guidelines for designers and developers to improve network performance. We focus on the Routing Protocol for LLNs (RPL), an Internet Protocol version 6 (IPv6) compatible Internet Engineering Task Force (IETF) standard. We highlight the design strengths of RPL and propose the design and implementation of three energy balancing routing metrics. Simulations show that our methods achieve better energy balance while keeping good energy efficiency and packet delivery ratio (PDR). We analyse the capabilities of RPL for Quality of Service (QoS) provisioning by enabling multi-instance (based on traffic classes) QoS routing. We also propose a QoS-aware cross-layer mechanism based on multi-instance RPL and carrier sense multiple access (CSMA) to enhance priority traffic in LLNs. The main purpose of the design is to increase the PDR as well as to reduce packet delivery latency (PDL) of high priority data. Our simulation results show the advantages of the design in terms of highly improved PDR and lower PDL in both hop-to-hop and end-to-end cases.
To enable interoperability in the very fragmented IoT market, different integration platforms are emerging. oneM2M is one of such platforms that enables interoperability in two ways: by standardizing the Hypertext Transfer Protocol (HTTP), Constrained Application Protocol (CoAP) and Message Queueing Telemetry Transport (MQTT) message format as transport vehicle for oneM2M primitives, or by including custom-developed Interworking Proxy Entities (IPEs). We proposed an architecture that enables horizontal integration of long-range low-power LoRa motes that run CoAP or MQTT on a full Transmission Control Protocol (TCP)/Internet Protocol version 6 (IPv6) stack in a oneM2M framework. OneM2M’s standardized bindings are used for interoperating these disparate application layer protocols as they allow to reduce the development time of an IoT application integrated in the Internet. However, they also cause extra overhead in terms of payload size. Our testbed results show that although oneM2M is a good interoperability enabler, a trade-off exists between ease of development/deployment and the amount of useful data that can be sent over LLNs. To integrate Datagram Transport Layer Security (DTLS) based solutions running on constrained devices in a oneM2M framework, we develop an IPE including a DTLS server in OM2M, which is an open source implementation of oneM2M. By doing so, we enable security in this horizontal IoT framework aiming at interoperability. To show the validity of our work, we set up a second testbed to evaluate the performance of the constrained devices in terms of processing and communication time, and energy consumption.

Short CV

Nguyen Thanh Long received the Engineer Diploma (5-year study) in IT from the Military Technical Academy, Vietnam, in 2000 and IT Master from the La Trobe University, Australia in 2007.