# A Survey of GIS and IoT Integration: Applications and Architecture
### Motivation  
As it is discussed, the emergence of IoT into real life is getting noticeable [4; 7; 9; 18]. Although the rapid growth of technologies will result in addressing a wide variety of problems, it will cause challenges, too. Hence, an integrated version of IoT with other technologies not only would be a great step toward facing those challenges but also can solve the problems more optimally. GIS, with the vast number of functionalities, could be a part of those mentioned integrated versions [19]. Since geography can be considered as an indispensable part of many applications, many studies have been done to research a new layer of IoT [20] and that is the involvement of GIS into it [21]. In addition to playing the role in a new layer of IoT, each node in IoT needs a unique IP which means a unique geographical location. Therefore, the existence of GIS in IoT-based systems is unquestionable. With the capability of dealing with spatial and attribute data, GIS could also be easily scaled up for different applications and locations. Besides, traditional GIS and pure GIS systems suffer from a low level of coordination and automation due to the constrained computing resources and inability to accommodate marginalized groups [22; 23]. Therefore, the involvement of IoT in GIS systems can lead to an optimal system that no longer is error-prone, time-consuming as much as before [24]. In conclusion, GIS and IoT can be beneficial to both current IoT or GIS-based systems, and integration of these two technologies is a win-win situation. For the current state of this research field, few papers were found investigating the integration of IoT and GIS in terms of application and architecture at the same time [25]; furthermore, they had focused on specific areas and not explored the whole integration in different kinds of application. The lack of enough review studies for this kind of integration would be another testimony to the significance of this study.  
In this paper, GIS and IoT integration studies are reviewed. The purpose is to examine the different combinations of these technologies and see how GIS has been taken into account. The study is based on a two-step approach. In the first step, use cases of IoT and GIS combination are categorized into seven groups and in each category, a summary of related literature is provided. As one of the novelties of this paper, the capabilities and challenges of the systems using only one of these technologies are discussed and at the end, papers benefiting from the integrated versions of IoT and GIS are investigated to see the enhancement compared to the previous systems. Then, as the second novelty of this study, GIS and IoT architectures are defined and studies utilizing GIS in their proposed IoT-based system are summarized to analyze the role of GIS.  
The goals that this study aims to satisfy are:  
1. [label=()]
2. What are the capabilities offered by systems benefiting from just IoT or GIS in each application category?
3. What are the capabilities offered by using IoT and GIS simultaneously?
4. How GIS can be employed in IoT architecture?  
The rest of the paper is structured as follows. The methodology of the study is discussed in Section 2. GIS and IoT integrated use case studies are discussed in Section 3. In Section 4, in addition to introducing IoT and GIS architectures, the architectures of integrated IoT and GIS systems are discussed. The discussion of analyzing studies is addressed in Section 5. Section 6 concludes with a summary and directions for future research.