## 4 IoT Deployment Opportunities in Developing Countries
### Leveraging Cellular Networks for IoT Deployments in Nigeria
#### 4.1.3 Security and IoT Issues  
Based on the security requirements of other wireless technologies for IoT, security and privacy issues are challenging and are considered in this paper for three IoT reference architectures: the perception; network; and application layers.  
Application Layer--The application layer comprises the service management and business services demanded by IoT users through known protocols. Constrained application protocol (CoAP), transmission control protocol (TCP), user datagram protocol (UDP), and message queue telemetry transport (MQTT) are good examples of efficient IoT protocols for relaying services to users. In our test networks, we used the TCP protocol due to its high reliability in terms of data transmission. The security issues of the application layer include privacy protection, and other problems of intellectual property protection. The end users of IoT applications in some use cases may require anonymity to protect user identity. In this scenario, advanced encryption techniques and digital signatures will intelligently provide the necessary security.  
Network Layer--As an intermediary function, the network layer allows data collected by the perception layer to be reliably transmitted to the application layer for processing and visualisation based on application requirements. Different Internet-based access network technologies applicable to IoT have been presented in Table 2 for device-to-device communication. However, it is also a channel through which security risks are introduced to the network. Malicious network signal interference could result in network nodes being compromised through denial of service (DoS), distributed denial of service (DDoS), or other network-related attacks such as IP and bandwidth spoofing. Transport layer security (TLS) and Internet protocol security (IPSec) have been demonstrated as an end-to-end security enablers for IoT deployment in constrained environments. In addition, the integrity and confidentiality of data in the NB-IoT network can be secured by cryptographic-based intrusion detection and prevention algorithms.  
Perception Layer--This is the IoT data generation layer which is aided by measurements by sensors and actuators located at the bottom of IoT architecture. The IoT devices  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Network Items** & **SigFox [48]** & **LoRaWAN [45]** & **NB-Fi [49]** & **NB-IoT [26]** & **LTE-M [50]** \\ \hline Bandwidth & 100 Hz & 250 kHz \& 125 kHz & 50 Hz-25.6 kHz & 200 kHz & 200 kHz \\ Modulation & BPSK & CSS & DBPSK & QPSK & QPSK \\ Standardisation & SigFox/ ETSI & LoRA Alliance & WAVIor & 3 GPP & 3 GPP \\ Max. Data Rate & 100 bps & 50 kbps & 25 kbps & 200 kbps & 200 kbps \\ Bidirectional & HD & HD & FD \& HD & HD \\ Architecture & SoS & SoS & SoS & SoS & SoS \\ Frequency & ISM-bands & ISM-bands & ISM-bands & LTE-bands & LTE-bands \\ Payload & UL-12 B \& DL-7 B & 243 B & 240 B & 1600 B & 256 B \\ Security & AES-128 & AES-128 & AES-256 & LTE Enc & LTE Enc \\ Interference & High & High & High & Low & low \\ Urban Range & 10 km & 5 km & 10 km & 1 km & 1 km \\ Rural Range & 40 km & 20 km & 40 km & 4 km & 4 km \\ \hline \hline \end{tabular} Note: B—bytes; SoS—star-of-stars; UL—uplink; DL—downlink; Enc—encryption.  
\end{table}
Table 2: Comparison of unlicensed and cellular IoT technologies [44; 45; 46; 47].  
can support edge processing and mostly wireless sensing enabled for remote access and tracking capabilities through gateways. The security of the data-generating edge devices is a sensitive part of IoT networks as they are prone to jamming, scrambling, spoofing, and other physical layer attacks [51]. The quality of data generated by the IoT depends on edge computing. IoT devices deployed in attack-prone areas need to be tamper-proof, with each device to be authenticated, verified, and the transmitted data encrypted.