## 2 What Is IoNT?
### Applications of IoNT  
Based on the advent of technology, researchers have identified several potential uses of the IoNT spread across various fields that will have a significant future impact. At the moment that we are writing this, the IoNT has almost extended to almost all the domains that the IoT is served in. A brief overview of the applications of the IoNT, in each of the domains we identified, is provided as follows:  
* Smart cities  
Implementing a smart city allows interaction and communication with home appliances and the monitoring of various aspects pertaining to the city environment through deployed smart sensors, surveillance cameras, actuators, vehicles, and various other digital devices possessed by the citizens of the city, facilitating better management of the city. As of now, smart cities have already been established with the assistance of the IoT, wherein nanosensors are used to track and identify the location of litter found in high-absorption air regions and activate nanosensors to clear that area [1; 17]. The IoNT has the ability to gather real-time data that may then be used to enhance public utilities, services, infrastructure, and much more in the context of a smart city. On the other hand, with the aid of IoNT solutions, the relevant parties in the city can gather real-time data to enhance the living standards of citizens living in the city [4; 11];  
* Oil and Gas  
The IoNT offers convenient solutions to locate underground oil with high accuracy owing to the inherent characteristics of nanosensors [4; 14]. The conventional technique for finding oil locations is less effective than this because it depends on a strong magnetic field and a receiver inside a particular system to send nanocomposites to the desired location. The ability of nanosensors to pass through rock holes effectively helps to find oil bound to the rocks. However, some seismic and cross-well imaging tools have a more significant impact within this domain, though their firmness level needs improvement [4]. On the other hand, nanosensors are able to collaborate and connect via molecular communication, wherein the collected data can be transmitted in real time by using the neighboring gateway. As a result, it is optional to use an exact magnetic source and receiver to plot the position of the oil [1; 17];  
* Agriculture  
As of now, subject to various reasons such as volatile climate changes, the recent COVID-19 global pandemic, and pests and diseases, the world's agricultural food production is challenged, even though many attempts have been made to overcome such challenges to provide food for the growing world population. This has already emphasized the need for smart farming/precision farming solutions, wherein the IoT acts as the main enabling technology of such solutions. In this regard, there are several ways that the IoNT is currently coupling with smart agriculture, for example, nanosensors are being used to monitor soil conditions, water usage, and crop growth, and to optimize resource management and reduce waste [1; 2; 3; 4]  
In general, nanosensors allow facilities to monitor crop health, soil quality, and moisture levels in real time. Further, with the aid of the IoNT, farmers are now able to collect extensive data to enable them to optimize their processes and, as a result, increase their yields [7]. Additionally, in terms of livestock management, nanosensors are used to track the location of farm animals such as cattle, control the feed given to farm animals, and keep a close eye on their health. Further, in terms of animal health, nanoscale biosensors are injected inside animals to monitor underlying conditions and these injected sensors offer unprecedented access to information about farm animals' nutritional and medical needs [7; 8; 9; 10]. * Healthcare  
Healthcare is a domain wherein IoNT solutions are highly used as of now, compared to all other domains, as we have noted through the reviewed state of the art. A Body Sensor Network (B.S.N.) is one such example. A B.S.N.