مقاله انگلیسی رایگان در مورد مسیریابی خطوط پایدار در WSN برای برنامه های IoT – الزویر 2018

Introduction

The field of microelectronics has been advanced in the recent decades and led to the development of research on wireless networks of low cost, low rate, and low power network devices such as tiny nodes and sensors, etc. Wireless Personal Area Network (WPAN) [1] has a broad range of applications like wireless sensor networks (WSN), underwater acoustic networks, body area networks, industrial wireless networks, radio frequency identification (RFID) systems, machineto-machine (M2M) communication systems and much more. These sensing, actuating, identification and other various processing devices are combined to form a network that achieves some shared objectives. They interact with the physical world pervasively with the aid of enhanced communication protocols and distributed intelligence, which constitute a novel paradigm called Internet of Things (IoT) [2,3]. ‘‘Anytime, anywhere, any media’’ was the vision for a long time in the past decades that pushed the communication technology into many advancements. Wireless technologies hold a pivotal role in this context. Today the ratio between the humans and radios achieving a value near 1 to 1. But shortly this proportion will increase by orders of magnitude which enables to integrate the radio devices in almost all objects. Then the word ‘‘anything’’ also added to the above vision which is nothing but the concept of IoT. However, these low-power low-rate radio devices are expected to operate autonomously for an extended period with small batteries of limited energy source. Since the unattended nature, replacement of those tiny batteries is impractical; hence the lifetimes of these multi-hop relaying networks directly depend on the residual energy level of its nodes. The actualization of the concept of IoT is possible through the integration of several different network infrastructures. RFID systems are used for the identification of the real-world object into digital format, and sensor networks are used for tracking the status of these objects. Performing any mechanical operations in the physical world is achieved through sensor–actuator networks. And M2M communications are used for automated data transmission and measurement between mechanical or electronic devices. All these different constituents together compose the backbone network infrastructure for IoT. At the same time, these application networks like sensor network have many similarities with other types of distributed systems; it has a lot of unique challenges and constraints such as self-management, energy limitation, congested packet transmissions, ad hoc deployment, unattended operation, high interference from peer relays, security restrictions, etc. This unique infrastructure nature of WSN demands a protocol designed that should fit for its specialties. If any node dies because of energy depletion, it may effectuate some remarkable changes in the topology that are significant enough to degrade the whole network. It may necessitate the reorganization of entire system. In IoT applications, it is a quite usual topology scenario that many senders are communicating to a destination node at the same time. Sensor nodes placed at different geographical area sending their collected information to the base station, communication between the RFID tags and the reader, data transmission between the actuators and the controller, communication between the nodes in the application network and gateway node to the backbone, etc. are some of the examples.