# Bushfire Disaster Monitoring System Using Low Power Wide Area Networks (LPWAN)
## 3 Design and Implementation
### Location ID  
There are various formats for location such as GPS coordinates which can be used as an LID, such as in the example below:  
* degrees minutes seconds: 40\({}^{\circ}\)26\({}^{\prime}\)46\({}^{\prime}\) N 79\({}^{\circ}\)58\({}^{\prime}\)56\({}^{\prime}\) W.
* degrees decimal minutes: 40\({}^{\circ}\)26.76\({}^{\prime}\) N 79\({}^{\circ}\)58.93\({}^{\prime}\) W.
* decimal degrees: 40.446\({}^{\circ}\) N 79.982\({}^{\circ}\) W.  
There are benefits of using real-time GPS information in PAN, such as obtaining accurate LIDs in the lack of cell/Wi-Fi signalling areas, however, there are associated disadvantages such as an increased battery power consumption as well as security issues to consider. As deployed sensors will not change their location in most cases, it is not required to contact satellites to constantly update the LID in situations where the sensors' computational capacity is limited. If the capacity allows, the sensor can communicate with satellites to maintain an accurate location information on a regular basis, e.g., monthly or annually, and the connection to GPS may otherwise be limited to conserve battery power. Otherwise, the LID can be pre-programmed when deployed. In the example above, when the GPS coordinate is used for the LID (but not necessarily to connect to satellites), the format should  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Requirements**} & \multicolumn{3}{c}{**Licensed Spectrum**} & \multicolumn{3}{c}{**Unlicensed Spectrum**} \\ \cline{2-6}  & **LTE-M** & **NB-IoT** & **SigFox** & **LoRa** & **RPMA** \\ \hline
**Coverage** & 160 dB & 164 dB & 149 dB & 157 dB & 177 dB \\ \hline
**Bandwidth** & 1 MHz & 180 KHz & 100 Hz & 125 KHz & 1 MHz \\ \hline
**Battery Life** & 10+ years & 10+ years & 10+ years & 10+ years & 10+ years \\ \hline
**Throughput** & 1 Mbps & 250 Kbps & 100 bps & 290 bps–50 Kbps & 624 Kbps \\ \hline
**2 Way Data TX** & Yes & Yes & No & Depends & Yes \\ \hline
**Security** & \begin{tabular}{c} 3 GPP \\ (128–256 bit) \\ \end{tabular} & \begin{tabular}{c} 3 GPP \\ (128–256 bit) \\ \end{tabular} & \
\begin{tabular}{c} 16 bit \\ \end{tabular} &
\begin{tabular}{c} 32 bit \\ \end{tabular} & AES 128 bit \\ \hline
**Scalability** & High & High & Low & Medium & High \\ \hline
**Mobility** & Connected \& \
\begin{tabular}{c} Idle mode \\ \end{tabular} &
\begin{tabular}{c} Idle mode \\ \end{tabular} & No & Yes & Yes \\ \hline
**LBS Support** & Requires GPS & Requires GPS & No & Yes & Requires GPS \\ \hline \hline \end{tabular}
\end{table}
Table 1: Licensed and unlicensed spectrum technology option (adapted from [28]). Long-term evolution for machines (LTE-M); (NB-IoT); Random Phase Multiple Access (RPMA); long-range (LoRa); Location-based service (LBS); Global Positioning System (GPS).  
be defined on how to conform the content to the carrier network. For example, when International Telecommunication Union Telecommunication Standardization Sector (ITU-T) E.164 is used, the format can be as shown in Table 2 to accommodate the LID, for example, XY4044679982 (12 digits), where XY can be an identification of the network, whilst each country has its own national numbering plan, and therefore the XY format should follow the scheme. The number structure for global service by the E.164 also suggests three digits for the country code and 12 digits for the global subscriber number [29]. Alternatively, the LID can also be a proprietary format as long as it can traverse the networks without being rejected. In this way, the number of 12 digits can be further granulised as it does not have to include the degree portion of the GPS coordinate, which saves four digits for other information, for example, sensor measurements.