## 2 Radio Communication Technologies
### The Main Characteristics of LPWAN Technologies
#### 2.2.6 Security and Privacy Support
NB-IoT authentication and credential provisioning are subject-based, meaning that first a specific identity is asserted to help the other side, such as the network, verify whether the credentials match that identity. The main assumption is based on the uniqueness of the identifier, which is permanently mapped to one subject. In another case, any authentication of that identity may be overthrown [24]. It should be noted that LPWAN IoT devices mostly comprise certain security parts for low-power embedded systems. Some large-scale analyses of low-power embedded devices in firmware show that most of the firmware is vulnerable. When it comes to security, IoT technology is yet to be explored due to its fast development pace, meaning that low-power systems (embedded systems) are vulnerable to being exploited for security attacks [24]. One experiment investigated security threats towards any LPWAN standard, considering 3 attack scenarios that tested their security level. Based on the results of the experiment, currently Sigfox should not be used for applications in critical use cases. For such deployments, better replay protection is needed at a higher layer, which is the downside of Sigfox's small payload size. On the other hand, LoRaWAN and NB-IoT provide considerable security guarantees but under proper enforcement conditions. In particular, LoRaWAN packets can be forged in some situations to receive garbage-loaded packets, causing a DoS attack. Therefore, LoRaWAN applications must be \"garbage-proof\" and disallow the sending of invalid packets. In the case of NB-IoT, the experiment shows that before deploying serious applications, the user should be sure that the network operator defines the best security practices [25]. Based on the features [27; 28] organized in Table 1, a respective visualization of the advantages of Sigfox, NB-IoT, and LoRaWAN is provided in Figure 3. \begin{table}
\begin{tabular}{c|c c c} \hline \hline  & **Sigfox** & **NB-IoT** & **LoRaWAN** \\ \hline
**Battery life*** & 10+ years & 10+ years & 15 years \\ \hline
**Bandwidth** & & & \\
**(Operational** & 0.1 kHz & 180 kHz/200 kHz & 125 kHz/250 kHz \\
**frequencies** & & & \\ \hline
**Range** & \textless{}17 km & \textless{}22 km & \textless{}14 km \\ \hline
**Scalability** & & & \\
**(end-devices per** & 50k/cell & 100k/base station & 50k/cell \\
**base station/cell** & & & \\ \hline
**Average data** & 100 bps & 200 kbps & \textless{}10 kbps \\
**rate/speed** & & & \\ \hline
**Uplink data rate** & 0.1–0.6 kbps & 0.3–62.5 kbps & 0.3–50 kbps \\ \hline
**Downlink data rate** & 0.6 kbps & \textless{}300 kbps & 0.3–50 kbps \\ \hline
**Maximum payload** & 12 bytes (UL), 8 bytes & 1600 bytes & 243 bytes \\
**length** & & & \\ \hline
**Security support** & \
\begin{tabular}{c} AES-128 (AES \\ Cryptographic \\ algorithms) \\ \end{tabular} & LTE security &
\begin{tabular}{c} AES-128 (AES \\ Cryptographic \\ algorithms) \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 1: A comparative view of the features of Sigfox, NB-IoT, and LoRaWAN. The latest statistical analysis (Table 2) on commercial mobile IoT networks showed the dominance of the NB-IoT communication technology around the globe, indicating its potential to grow more [29].