# IoT Blockchain Data Vercity with Data Loss Tolerance
## 2 Materials and Methods
### Literature Review  
In this section, our research starts with reviews of IoT related work in productivity improvement and with identifying the advantage of the IoT, as well as its challenges, specifically in terms of data veracity and data loss problems (Table 2), followed by technology reviews for remediation and solutions (Table 3). Considerable IoT system adoption has occurred in recent years, and data are captured on a continuous and real-time basis in [1; 7; 8; 9], IoT systems are deployed and it was shown that IoT could help with productivity improvement with consistent monitoring and control, and provided the insights for more accurate, appropriate actions and controls. Findings by [PERSON] et al. [7] showed that IoT systems could help the farm owner to scientifically fertilize and irrigate the farm to improve operations. The system was divided into perception, network/transport, information service, and application layers. It reduces the coupling between various services and improves the reliability of the farm IoT system. [PERSON] et al. [8] introduced two simple IoT tools, the Chameleon soil moisture sensor and Fullstop wetting front detector. These IoT sensors record substantial changes in the irrigation management at one scheme in response to the patterns, leading to much higher yields. The data were captured on a continuous real-time basis for monitoring with the right resources that improved the conventional irrigation systems. [PERSON] et al. [9] designed a sensor system to map soil nutrient contents of nitrate (N), phosphate (P) and potassium (K). [PERSON]'s system was designed to study the spatial and temporal behavior of NPK. The continuous monitoring of NPK along with the humidity and pH of soil lead to automation in agricultural to improve crop yield. Fiber optic sensing techniques are recommended in agricultural systems for their inherent advantages, such as their light weight and immunity to EMI and RFI. [PERSON] proved that advanced IoT optical sensors can be deployed for agricultural applications in providing insights to the operations. In [10; 11], the IoT system is complemented with intelligent small computing resources in more flexible deployments in the edge layer. [PERSON] et al. [10] introduced digital IoT and small computing resources to monitor cultivation by predicting and preventing the harmful diseases affecting the farm. [PERSON] et al. [11] proposed a water monitoring system with small computing resources. Use of small computing resources such as Arduino, Raspberry Pi and NodeMCU devices are options provided as cost effective IoT deployment equipment. [PERSON]'s team demonstrated that small computing resources add practical potential advantages to agricultural applications. In [12], [PERSON] et al. explored blockchain technology in creating a business case for an intelligent transport system (ITS). ITS achieved IoT data reliability and security with distributed storage and single-point-of-failure avoidance. Despite the exponential growth of IoT in various applications, as mentioned above, the IoT applications are mostly based on a consistent coupled network architecture. Edge or fog computing and blockchain are intensively studied as the potential solutions to alleviate the data loss problem. This research is therefore followed by the exploration of edge computing with the aims to have the computing, communication, and data storage in the edge layer. Moving data storage service closer to the edge sensor layer can be a workable model to improve data veracity. It creates a decoupling from a must-present consistent connected network. In addition, data distribution and redundancy in multiple nodes failure but leaving data veracity intact. Some IoT edge computing and blockchain related works highly in favour of this research interest are presented in Table 3.  
[PERSON] [13] introduced the convergence of IoT, fog and blockchain technological innovations in an effective communication framework.