IEEE 802.15.4e: a Survey

Several studies have highlighted that the IEEE 802.15.4 standard presents a number of limitations such as low reliability, unbounded packet delays and no protection against interference/fading, that prevent its adoption in applications with stringent requirements in terms of reliability and latency. Recently, the IEEE has released the 802.15.4e amendment that introduces a number of enhancements/modifications to the MAC layer of the original standard in order to overcome such limitations. In this paper we provide a clear and structured overview of all the new 802.15.4e mechanisms. After a general introduction to the 802.15.4e standard, we describe the details of the main 802.15.4e MAC behavior modes, namely Time Slotted Channel Hopping (TSCH), Deterministic and Synchronous Multi-channel Extension (DSME), and Low Latency Deterministic Network (LLDN). For each of them, we provide a detailed description and highlight the main features and possible application domains. Also, we survey the current literature and summarize open research issues

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

Master's thesis Information- and communication technology IKT590 - University of Agder 2017Internet 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 scenario

On the Support of Massive Machine-to-Machine Traffic in Heterogeneous Networks and Fifth-Generation Cellular Networks

The widespread availability of many emerging services enabled by the Internet of Things (IoT) paradigm passes through the capability to provide long-range connectivity to a massive number of things, overcoming the well-known issues of ad-hoc, short-range networks. This scenario entails a lot of challenges, ranging from the concerns about the radio access network efficiency to the threats about the security of IoT networks. In this thesis, we will focus on wireless communication standards for long-range IoT as well as on fundamental research outcomes about IoT networks. After investigating how Machine-Type Communication (MTC) is supported nowadays, we will provide innovative solutions that i) satisfy the requirements in terms of scalability and latency, ii) employ a combination of licensed and license-free frequency bands, and iii) assure energy-efficiency and security

Markov Decision Processes with Applications in Wireless Sensor Networks: A Survey

Wireless sensor networks (WSNs) consist of autonomous and resource-limited devices. The devices cooperate to monitor one or more physical phenomena within an area of interest. WSNs operate as stochastic systems because of randomness in the monitored environments. For long service time and low maintenance cost, WSNs require adaptive and robust methods to address data exchange, topology formulation, resource and power optimization, sensing coverage and object detection, and security challenges. In these problems, sensor nodes are to make optimized decisions from a set of accessible strategies to achieve design goals. This survey reviews numerous applications of the Markov decision process (MDP) framework, a powerful decision-making tool to develop adaptive algorithms and protocols for WSNs. Furthermore, various solution methods are discussed and compared to serve as a guide for using MDPs in WSNs

Channel Access in Wireless Networks: Protocol Design of Energy-Aware Schemes for the IoT and Analysis of Existing Technologies

The design of channel access policies has been an object of study since the deployment of the first wireless networks, as the Medium Access Control (MAC) layer is responsible for coordinating transmissions to a shared channel and plays a key role in the network performance. While the original target was the system throughput, over the years the focus switched to communication latency, Quality of Service (QoS) guarantees, energy consumption, spectrum efficiency, and any combination of such goals. The basic mechanisms to use a shared channel, such as ALOHA, TDMA- and FDMA-based policies, have been introduced decades ago. Nonetheless, the continuous evolution of wireless networks and the emergence of new communication paradigms demand the development of new strategies to adapt and optimize the standard approaches so as to satisfy the requirements of applications and devices. This thesis proposes several channel access schemes for novel wireless technologies, in particular Internet of Things (IoT) networks, the Long-Term Evolution (LTE) cellular standard, and mmWave communication with the IEEE802.11ad standard. The first part of the thesis concerns energy-aware channel access policies for IoT networks, which typically include several battery-powered sensors. In scenarios with energy restrictions, traditional protocols that do not consider the energy consumption may lead to the premature death of the network and unreliable performance expectations. The proposed schemes show the importance of accurately characterizing all the sources of energy consumption (and inflow, in the case of energy harvesting), which need to be included in the protocol design. In particular, the schemes presented in this thesis exploit data processing and compression techniques to trade off QoS for lifetime. We investigate contention-free and contention-based chanel access policies for different scenarios and application requirements. While the energy-aware schemes proposed for IoT networks are based on a clean-slate approach that is agnostic of the communication technology used, the second part of the thesis is focused on the LTE and IEEE802.11ad standards. As regards LTE, the study proposed in this thesis shows how to use machine-learning techniques to infer the collision multiplicity in the channel access phase, information that can be used to understand when the network is congested and improve the contention resolution mechanism. This is especially useful for massive access scenarios; in the last years, in fact, the research community has been investigating on the use of LTE for Machine-Type Communication (MTC). As regards the standard IEEE802.11ad, instead, it provides a hybrid MAC layer with contention-based and contention-free scheduled allocations, and a dynamic channel time allocation mechanism built on top of such schedule. Although this hybrid scheme is expected to meet heterogeneous requirements, it is still not clear how to develop a schedule based on the various traffic flows and their demands. A mathematical model is necessary to understand the performance and limits of the possible types of allocations and guide the scheduling process. In this thesis, we propose a model for the contention-based access periods which is aware of the interleaving of the available channel time with contention-free allocations

Actas da 10ª Conferência sobre Redes de Computadores

Universidade do MinhoCCTCCentro AlgoritmiCisco SystemsIEEE Portugal Sectio