# Sensor-Based Solid Waste Handling Systems: A Survey
## 6 Comparison and Discussion
IoT-based solid waste man agement approaches are superior to previous approaches in terms of interoperability and the self-configuring capability of the monitoring nodes. Several IoT-based approaches are analyzed in this study and many of them are presenting promising design and experimental proofs for the feasibility of the proposed systems. The industry also showing favor toward IoT-based systems through their new releases of low-power microcontrollers integrated with radio devices and low power sensors. Consequently, it reduces the overall power consumption of the sensor nodes. A Wi-Fi and Zigbee-based solid waste management system enabled with IoT is discussed in [41; 45], respectively. Even though the aforementioned approaches are feasible for real-time deployment, they are not a perfect solution when considering wide-area deployment for smart cities. Short-range communication protocols require additional infrastructure to increase their coverage and ultimately results in additional cost and complexity in deployment. The adoption of LPWAN protocols such as LoRaWAN, Sigfox, and NBIoT shall be considered as a solution to overcome the aforementioned limitations. LPWAN protocols are capable of sending data to long-range (several km) distances while consuming low power. From the study performed on LPWAN communication technologies, LoRaWAN shall be considered as the best choice for IoT-enabled solid waste management systems since they are open source and easy for distributed node deployment. Moreover, the low data rate of LoRaWAN is sufficient for sending bin status periodically. LoRaWAN-based solid waste management architecture is presented in [51; 52; 53], but the end nodes are designed with evaluation boards; consequently, the performance metrics are not true to industry standards. Meanwhile, in [54; 55; 56; 57; 58], customized nodes are designed and performance metrics are evaluated with real-time deployment. An estimated cost comparison of some of the promising IoT-based approaches identified from the study is presented in Table 7. It can be inferred that the system developed with customized node designs is costlier than the others developed with evaluation boards or development boards. However, customized node designs would be superior in achieving low power consumption, an extended lifetime of batteries, and compactness. The discussion on the state art solutions for waste management will not be completed without mentioning commercially available solutions. Some of the major commercial solid waste management systems in the industry are highlighted here. Bigbelly [59] is one of the leading providers of commercial smart garbage and recycling systems, with installations in cities, campuses, and workplaces in more than 50 countries worldwide. BIN-E [60] is an IoT-enabled trash bin that automatically sorts and compresses recyclables. To make waste management convenient and effective, it combines unique AI-based object recognition, fill level control, and data processing. EcoBins [61] is a smart city service that uses IoT technology to improve municipal waste collection operations. Sensor data are sent to the main server through a local GSM network for cloud-based analytics. Nordsense [62] provides another commercial approach for smart waste management to make cities clean, green, and smart. It offers a complete end-to-end solution based on IoT technology and an in-house developed navigation application. However, on the basis of the study performed on the state-of-art approaches and by considering commercially available solutions towards