# Smart Waste Collection System with Low Consumption LoRaWAN Nodes and Route Optimization
## 3 System Proposed
### WSN Energy Comparison and Selection  
Urban areas have a lot of communication networks where the sensor network proposed in this work could be implemented. These networks are based on different radio technologies as the ones previously seen. Table 2 presents a comparison of the available technologies along with their relevant features. Features such as range, consumption and availability are emphasized because they are essential factors for developing the device. In Table 2, MCL represents the minimum coupling loss, which means the minimum power through which communication between two devices is possible. The range of each technology as well as its availability on the area where the sensor network is intended to be deployed are especially important in semi-urban or rural areas. Some technologies such as Wi-Fi ah or cellular cannot be applied when requiring a greater range (Wi-Fi) or when there is no availability (it depends on the cellular operator). Power consumed by radio modules both in sleep mode and active mode to transfer or receive data from the network is another key factor when selecting the technology to be employed for the sensor network. Increasing the device's battery life is crucial. Considering these two factors, there are three options: Sigfox, LoRa and NB-IoT. On one hand, NB-IoT is currently dismissed due to its current availability and the high cost of its modules. On the other hand, Sigfox technology is only available on a subscription basis, which means an extra cost for the developed solution. Consequently, the technology selected for our system was LoRa. Once the technology was selected, we decided to use LoRaWAN, which uses LoRa as a physical layer. LoRaWAN networks have previously been employed in the literature in other domains, for example, in an experimental performance evaluation of LoRaWAN over a real environment \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Name**} & \multicolumn{2}{c}{**Minimum**} & \multirow{2}{*}{**Range (km)**} & \multirow{2}{*}{**Standby**} & \multicolumn{1}{c}{**Tx**} & \multirow{2}{*}{**Modulation**} & \multirow{2}{*}{**Availability**} \\  & **Coupling Loss (MCL) (dB)** & & & & & & \\ \hline Random Phase & & & & & & \\ Multiple Access & 160 & 100 & 0.5 uA & 85 mA & RPMA + DSSS & Spec. zones \\ (RFMA) & & & & & & \\ Weightless P & 128 & 2 & 0.7 uA & \textless{}0 mA & GMSK + QPSK & Worldwide \\ ZigBee & 102 & 0, 20 & 3 uA & 30 mA & BPSK & Worldwide \\ LoRa & 157 & 5-15 & 0.5 uA & \textless{}90 mA & LoRa & Worldwide \\ Sigfox & 149 & 3-10 & 0.5 uA & \textless{}70 mA & BPSK & Worldwide \\ Cellolars & 118 & 2-5 & 10 mA & 800 mA & BPSK & Worldwide \\ WiFi ah & 90 & \textless{}1 & \textasci{}100 mA & QPSK/256 QAM & N/A \\ NB-IoT & 118 & 2–5 & 5 uA & \textless{}100 mA & QPSK & Spec. zones \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Wireless Sensor Network comparison. in Bangkok by [PERSON] et al. [80] and in a long range wide area network-based smart pest monitoring system by [PERSON] et al. [81], among others [82]. Together with this decision, another important step to be considered was the selection of the LoRaWAN network server (and all the software involved). There were several options to deploy the LoRaWAN architecture which can be summarized in three options: (1) a free and open source option like LoraServer.io [83] which provides the software to implement the required features to be LoRaWAN compliant, specifically, the LoRa gateway bridge (packet forwarder), the LoRaWAN network server and the LoRaWAN application server. The maintenance and the hosting of the network server and some other application services are the responsibility of the user. (2) A free, open source and collaborative option like The Thing Network (TTN) [84] provides a self-hosted option, but also provides a free and collaborative platform as a service. That is, the platform is free, but every gateway using it can receive data from any node belonging to a TTN application.