Co-Operation in Wireless Sensor Networks for Smart Cities

Introduction

A smart city is a technologically advanced urban area that uses sensors to measure and monitor various data to improve quality of life for its citizens and streamline urban services. Large cities across the world have initiated projects to make their areas more citizen friendly in terms of transportation & utility services, waste management, energy consumption, and hospital services. There have been studies on the level of intelligence that is to be embodied in urban areas to qualify as a smart city (Halegoua, 2020). From a technological standpoint, the relevant aspect is to create a technological architecture that can scale to various levels of intelligence. Internet of Things (IoT) is the prime enabler of Smart cities that enables to acquire various kinds of data and perform an action. Urban areas around the world have created IoT deployment strategies based on the services it wants to offer to citizens and problems it intends to resolve (Alablani & Alenazi, 2020). Internet of Things (IoT) is a group of inter-related or interconnected computing devices performing a mechanical, electric, or biological function. An IoT network can also be referred to as a Wireless Sensor Network (WSN). WSN can be broadly defined as embedded devices that communicate wireless in an ad-hoc or infrastructure less network (Forster, 2016). In WSN the connectivity with the public network is via a gateway node. Therefore, IoT devices can be termed as devices with direct or in direct connectivity with the public network. Many recent literatures have proposed the integration of WSNs and IoT for large scale deployments (Rani, et.al, 2020). In this article we consider WSN as a subset of IoT where all devices are connected to the public network via single hop or multi-hop.

IoT systems represent the integration of four distinct components, namely:

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  Sensors/devices,

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  Connectivity,

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  Data processing,

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  User interface.

Sensor devices perform the function of measurement or monitoring an event. Connectivity component is responsible for sharing or passing the information to a centralized location or a peer device. In the case of industrial applications, the temperature or pressure data is transmitted to a centralized processing centre that consolidates data from different locations. There are cases of distributed connectivity where there are localized master nodes to reduce the data transmission load in the system. Connectivity is realized through a wireless radio interface that can send data over the air to a peer receiving device. There are several wireless protocols for sensor devices. The distinguishing aspects of these wireless protocols are the physical layer media and media communication layer mechanism. The media layer protocols are responsible for managing the spectrum resources and conserving the energy dissipated in the device for communication. In turn this implies that the media layer is for conserving the power or energy of the wireless device. A simple analogy is a human speaker adjusting his volume to reach out to the audience he is speaking to in a room. If all the audience are in proximity, then the speaker can speak at relatively lower volumes compared to the scenario where the audience are spread out in distance or when there are unwanted sound sources. Here the human speaker has the intelligence and information to make these decisions. The media access layer has a similar role and objective of conserving the power of the transmitting device and allocating the available resources to serve the maximal number of users.