Chapter 1: Wireless sensor network
Wireless sensor networks, also known as WSNs, are networks that consist of sensors that are both geographically scattered and dedicated. These sensors monitor and record the environmental conditions and then transmit the data that they have gathered to a centralized point. WSNs have the capability to monitor aspects of the environment, including temperature, sound, levels of pollution, humidity, and wind. These networks are used in a variety of commercial and industrial applications, such as the monitoring and control of industrial processes and the health monitoring of machines.
A wireless sensor network (WSN) is composed of "nodes," which may range in number from a few to hundreds or thousands. Each node in the network is linked to other sensors. Each of these nodes typically consists of several components, including a radio transceiver with an internal antenna or a connection to an external antenna, a microcontroller, an electronic circuit for interfacing with the sensors, and an energy source, which is typically a battery or some form of energy harvesting that is embedded within the node. A sensor node might be as large as a shoebox or as small as a particle of dust (at least in theory), but microscopic dimensions have not yet been attained in practice. Similarly, the cost of a sensor node might range anywhere from a few dollars to hundreds of dollars, depending on the level of complexity of the node. The availability of resources like energy, memory, processing speed, and communications bandwidth might be limited due to size and cost limits. A WSN's topology may range from a simple star network to a complex multi-hop wireless mesh network. Both of these topologies are examples of WSNs. Both routing and flooding are viable options for propagation.
WSNs are often used for the purpose of area monitoring. In the process of area monitoring, a WSN is stationed throughout an area that is being observed for a certain phenomena. An example of geofencing in civilian life is the enclosing of gas or oil pipelines, whereas an example of its usage in the military would be the installation of sensors to detect the presence of hostile forces.
Implanted, wearable, and environment-embedded sensor networks are the three primary categories of sensor networks used in medical applications. The term "implantable medical devices" refers to those that are designed to be placed inside of a living patient. Wearable technology is any kind of electronic equipment that is intended to be worn on or carried by the user of the device. Sensors that are already present in the environment are used by environment-embedded systems. Measurement of the body's position, localization of individuals, and comprehensive monitoring of sick patients at home and in hospitals are all potential uses of this technology. The data collected by a network of depth cameras, a sensing floor, or other devices that are functionally equivalent are used as input by devices that are implanted into the environment. These devices monitor the physiological status of a person in order to provide a continuous health diagnostic. Information about a person's health, physical fitness, and amount of energy expended may be gathered via body-area networks.
Beginning with the Great Duck Island Deployment, wireless sensor networks have been used to monitor a wide variety of animals and ecosystems. These species and habitats include marmots, cane toads in Australia, and zebras in Kenya.
There are several applications in the field of monitoring environmental parameters; some examples of these applications are shown below. They are all faced with the additional difficulties of severe surroundings and limited power supplies.
Experiments have demonstrated that an individual's exposure to air pollution in urban areas may vary greatly from one person to the next.
It is possible to identify the beginning of a fire in a forest by installing a network of Sensor Nodes across the area. The nodes have the capability of being fitted with sensors for measuring temperature, humidity, and the gases that are created by fires in the trees or plants. Early detection is essential for effective response by the fire department; with the use of wireless sensor networks, the fire department will be able to determine when a fire was started and how it is spreading.
A wireless sensor network is used by a landslide detection system in order to detect the minor movements of soil and changes in different parameters that may occur before to or during a landslide. These movements and changes may occur at any time. It is likely that by analyzing the data collected, it may be possible to predict the onset of landslides far in advance of when they would really take place.
The monitoring of water quality includes conducting analyses of the physical characteristics of the water found in subsurface water reserves, dams, rivers, lakes, and oceans. The use of a large number of wirelessly distributed sensors makes it possible to generate a map of the water's condition that is more accurate. It also paves the way for the permanent installation of monitoring stations in areas that are difficult to access, eliminating the need for manual data retrieval.
Wireless sensor networks have the potential to be an efficient tool for mitigating the destructive effects of natural catastrophes such as floods. Rivers, which need real-time monitoring of fluctuating water levels, have been outfitted with wireless nodes, which have been successfully implemented.
For the purpose of machinery condition-based maintenance (also known as CBM), wireless sensor networks have been created because they allow additional functionality and provide considerable cost reductions.
With a wired system, it may be difficult or even impossible to reach some areas, such as whirling equipment and untethered vehicles. However, wireless sensors do not have this limitation.
The gathering of data for the monitoring of environmental information may also be accomplished via the deployment of wireless sensor networks. Keeping an eye on things like a refrigerator's temperature or the amount of water in an overflow tank at a nuclear power plant might be considered examples of this. After then, one may utilize the statistical data to demonstrate how well the systems have been operating. The ability of WSNs to provide "live" data feeds is one of the many ways in which they excel above traditional loggers.
Monitoring the quality and level of water includes many activities such as checking the quality of underground or surface water and ensuring a country's water infrastructure for the benefit of both human and animal.
It is possible to put it to use to prevent the wasting of water.
Using correctly interfaced sensors and wireless sensor networks, it is possible to monitor the state of civil infrastructure and associated geophysical processes in close to real-time, as well as over extended periods of time via data recording.
Wireless sensor networks are used in the vineyard as well as the winery's cellar in order to monitor the production of wine.
The Wide Area Tracking System, sometimes known as WATS, is a prototype network that was designed to detect ground-based nuclear devices. At the Los Alamos National Laboratory's (LLNL) Nonproliferation, Arms Control, and International Security (NAI) Directorate, one of the primary focuses of ongoing research is the creation of more effective sensors.
During a hearing on nuclear terrorism and countermeasures that took place on October 1, 1997 before the Military Research and Development Subcommittee of the United States House of Representatives, a presentation on WATS was given.
There have been studies that suggest that the use of sensors for incident monitoring makes a significant improvement in the manner that fire departments and police departments react to unforeseen events.
The most distinguishing features of a WSN are as follows:
Limits on the amount of power that may be used by nodes that rely on batteries or energy harvesting. Among the providers are such names as ReVibe Energy.
Capability to deal with the failure of individual nodes (resilience)
There is some movement in the nodes (for highly mobile nodes see MWSNs)
Heterogeneity of nodes
Homogeneity of nodes
Capability of scaling up to a very big deployment
Capacity to withhold severe circumstances imposed by the environment
Ease of use
Optimization of the cross-layers In addition to this, there are three primary issues with the conventional layered method:
The traditional tiered technique does not allow for the sharing of information across the various levels, which results in each layer lacking all of the necessary knowledge. The conventional layered strategy is unable to provide any assurance that the whole network will be optimized.
The conventional layered strategy is incapable of responding to changing external conditions due to its structure.
The standard tiered strategy that is used for wired networks is not suitable to wireless networks because of interference from the many users, access conflicts, fading, and changes in the surrounding environment in wireless sensor networks.
Therefore, the cross-layer may be used to provide the ideal modulation in order to increase the transmission performance in areas like as data rate, energy efficiency, quality of service (QoS), and many other areas. secondary ASICs, and perhaps secondary communication interfaces (e.g. RS-232 or USB).
The base stations may be one or more of the WSN's components and have much higher computing, energy, and communication resources than the other components. They...
