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Diseases related to poor water and sanitation conditions have over 200 million cases reported annually, causing 5–10 million deaths world-wide. Water quality monitoring has thus become essential to the supply of clean and safe water. Conventional monitoring processes involve manual collection of samples from various points in the distribution network, followed by laboratory testing and analysis. This process has proved to be ineffective since it is laborious, time consuming and lacks real-time results to promote proactive response to water contamination. Wireless sensor networks (WSN) have since been considered a promising alternative to complement conventional monitoring processes. These networks are relatively affordable and allow measurements to be taken remotely, in real-time and with minimal human intervention. This work surveys the application of WSN in environmental monitoring, with particular emphasis on water quality. Various WSN based water quality monitoring methods suggested by other authors are studied and analyzed, taking into account their coverage, energy and security concerns. The work also compares and evaluates sensor node architectures proposed the various authors in terms of monitored parameters, microcontroller/microprocessor units (MCU) and wireless communication standards adopted, localization, data security implementation, power supply architectures, autonomy and potential application scenarios.

Wireless Sensor Networks (WSN) provide an affordable infrastructure that allows numerous control and data collection processes to be conducted with high spatial and temporal resolution. The recent arrival of Low Power Wide Area Networks (LPWAN) has given rise to WSN solutions with long range capabilities and a high level of autonomy. However, this has come at a cost of having low data rates and poses quite a huge challenge on implementation of high bandwidth applications such as Firmware Updates Over the Air (FUOTA). Firmware updates are essential throughout the lifetime of a product for several reasons including post deployment bug fixes, introduction of new security features and implementation of performance optimizations. This paper proposes a generic and hypothetical approach to designing an efficient FUOTA mechanism for WSN/LPWAN. The paper also presents a review of past literature on similar works and how best existing approaches have addressed the challenges of remote sensor node reprogramming.

Wireless Sensor Networks (WSNs) provide reliable and affordable infrastructure for various applications ranging from environmental monitoring, industrial automation, telemedicine, to military surveillance. These networks allow monitoring processes to be conducted remotely, in real-time and with minimal human intervention. Water quality monitoring is essential to the provision of clean and safe water. In Botswana, Water Utilities Corporation (WUC), has adopted a conventional like process that employs several independent hand held meters for sampling different water quality parameters manually. However, this process has proved to be ineffective since it is expensive, time consuming, requires considerable human resource capacity and lacks real-time results to promote proactive response to water contamination. In this work, an integrated WSN based solution that employs Libelium's Waspmote platform has been developed. The sensor node is based on ATMEL's ATmega 1281 8-bit low power microcontroller which can operate for more than a year without recharging its battery. Results have shown that the proposed system managed to sample associated water quality parameters in real time with the same accuracy as currently adopted methods. In addition, the system is autonomous, easy to install, highly scalable and has a relatively high sampling rate which improves the temporal resolution of the monitoring process.