A Reference Model for Monitoring IoT WSN-Based Applications

Juan Capella, José Campelo, Alberto Bonastre, Rafael Ors
2016 Sensors  
The Internet of Things (IoT) is, at this moment, one of the most promising technologies that has arisen for decades. Wireless Sensor Networks (WSNs) are one of the main pillars for many IoT applications, insofar as they require to obtain context-awareness information. The bibliography shows many difficulties in their real implementation that have prevented its massive deployment. Additionally, in IoT environments where data producers and data consumers are not directly related, compatibility
more » ... certification issues become fundamental. Both problems would profit from accurate knowledge of the internal behavior of WSNs that must be obtained by the utilization of appropriate tools. There are many ad-hoc proposals with no common structure or methodology, and intended to monitor a particular WSN. To overcome this problem, this paper proposes a structured three-layer reference model for WSN Monitoring Platforms (WSN-MP), which offers a standard environment for the design of new monitoring platforms to debug, verify and certify a WSN's behavior and performance, and applicable to every WSN. This model also allows the comparative analysis of the current proposals for monitoring the operation of WSNs. Following this methodology, it is possible to achieve a standardization of WSN-MP, promoting new research areas in order to solve the problems of each layer. Thus, WSNs correct behavior is fundamental for the correct operation, and maybe the future success, of IoT applications. However, although WNS designs show good performance and behavior when being evaluated in controlled environments, experience has shown that their deployment in real environments results in poorer performance and behavior [3] . It is therefore necessary to improve this behavior, and for that, to have more accurate information of the internal WSN operation [3] [4] [5]. This information may be obtained by the utilization of appropriate tools, the so called WSN Monitoring Platform (WSN-MP) being the most suitable. A WSN-MP is a distributed system which monitors the operation of a WSN, by means of a set of devices and/or modules which acquire information from different elements of the WSN (from the motes, wireless network, gateways, and even communication channel), and then collects, analyzes and presents it to the user to provide internal information about the WSN's operation. Many efforts have been carried out to debug the operation of WSNs, but as explained in the next section, those efforts have resulted in specific tools that only can be applied to specific WSNs, while cooperation between heterogeneous WSNs is a key issue in IoT applications. The use of WSN-MP may help in all the states of the life-cycle of a WSN. WSN researchers may use a WSN-MP to perform comparative analysis on new proposals. Designers may select the most suitable techniques for the requirements of any application. When deploying a WSN, the enhanced debugging capabilities added by the WSN-MP are unbeatable. The deployment is much easier when the correct functioning of the motes can be verified in-situ. During operation, malfunctions may be diagnosed without stopping the system, and the redesign of the system can use more detailed information about current functioning. In addition, these tools can become fundamental in the standardization and certification of applications based on the WSN. With these goals in mind, WSN-MPs are an increasingly important research line, a fact corroborated by the publication of a large number of papers on this area in the scientific literature. The study of these proposals has shown the great disparity of different WSN-MPs and the lack of methodology for their analysis and design, which leads to the fact that each proposal uses different ad-hoc solutions. Additionally, we conclude that there is a set of different issues that every WSN-MP must solve to be functional, and the different solutions of these problems could be combined in order to obtain the appropriate characteristics for the desired Monitoring Platform. From the authors' point of view, this situation is similar to those of computer networks, which began as a set of ad-hoc systems that did not follow any standard. The spectacular advances achieved in this field had been partially possible because of the adoption of a universally accepted architecture that promoted the use of standards. Following this approach, many researchers and standardization organisms have promoted the standardization of WSNs in the last years [6-10]. Now, we advocate for the standardization of WSN Monitoring Platforms (WSN-MPs). Considering the example of computer networks, the aim of this paper is to propose a new reference model for WSN-MPs, to establish a systematic methodology for the analysis, design, implementation and operation of monitoring platforms on sensor networks. This model allows the comparative analysis of WSN-MPs, and offers a common environment for the design and standardization of new platforms [5]. It is based on decomposing the monitoring process into different layers, identifying the responsibilities and establishing the services, protocols and interfaces needed to accomplish them. This approach offers several new interesting features, such as flexibility (adaptable to any type of system or application), simplicity (due to layer division), universality (foreseeing any system), and adaptability (able to follow the future evolution of WSNs and their WNS-MPs). This model could serve as first approach to achieve a standardization of WSN-MPs. If WSN-MPs' design and implementation were to follow a standard, a rigorous and systematic approach to the characteristics of WSN would be possible, as far as it can be granted that the WSN-MP used when analyzing that both WSNs have the same properties, and thus certify their operation. This point becomes critical for IoT applications as data producers and consumers are decoupled. On the other hand, the implementation of new WSN-MPs may be simplified, building new monitoring
doi:10.3390/s16111816 pmid:27809218 pmcid:PMC5134475 fatcat:dn3yayeppvcmpco5mrjrumse5i