Relevance- and Aggregation-based Scheduling for Data Transmission in IEEE 802.15.4e IoT Networks

Abstract

Internet of thing (IoT) is regarded as a new communicating paradigm with Internet connectivity enabling embedded devices to interact with each other on a global scale. IoT has the potential to become the largest producer of information because of a massive number of connected devices with diverse applications ranging from environmental monitoring, home, and building automation. This ubiquitous connectivity requires reliability, efficiency, and sustainability of access to information. As an enabling technology, wireless sensor networks (WSNs) have opened new opportunity with recent technological developments in making miniaturized smart connected devices. With an increase in the activity of these smart devices, there are challenges in maintaining their limited energy, lifetime, and reliability required for IoT applications. The reason is that these devices are mostly battery powered. In this respect, an insight into the activities of sensing devices produced by different vendors with interoperability based on industrial standards is needed. As an enhancement of IEEE 802.15.4 MAC sublayer, the ratification of IEEE 802.15.4e standard makes a step towards IoT medium access control (MAC) for industrial applications. One of the significant enhancements in IEEE 802.15.4e is different MAC modes. However, IEEE 802.15.4e does not specify standardized scheduling policy for network building and data transmission maintenance. It is basically application specific. In general, activities performed at the MAC sublayer contribute to sensor energy consumption. Therefore, an efficient MAC scheme is needed to utilize network resources more efficiently, minimize energy consumption level and at the same time improve data transmission of the network. In this thesis work, we focus on proposing transmission schemes for improving energy consumption for data transmission in IoT networks and as well as increasing average packet delivery ratio (PDR). Our target is to improve time slotted channel hopping (TSCH) mode that enables deterministic access and robust network. The focus is on dedicated and shared slots in TSCH. More specifically, we propose two MAC schemes; relevance- and aggregation-based scheduling for data transmission in IEEE 802.15.4e IoT networks. With relevance-based scheduling, the coordinator node builds and maintains communication in the network based on a historical data value of member nodes. On the other hand, aggregation-based scheduling iii enables the coordinator node to build and maintain communication by integrating multiple data inside a single frame payload at the source node before transmission. Further, the proposed schemes are implemented using network simulator version 3 (ns-3). We use Ubuntu 16.04.2 as the operating system for our implementation and performance evaluation. Numerical results for a few performance metrics including PDR, collision probability, delay, and energy consumption are obtained through extensive simulations. The superiority of the proposed schemes is demonstrated by comparing the simulation results with that of IEEE 802.15.4e TSCH standard under varies network scenarios