# Resilient Green Cellular IoT for Landslide Monitoring Using Voice Channels
## 2 Related Work  
Since DoS attacks in IoT nodes is a well-analyzed topic, we first discuss a few comprehensive reviews that cover more than 225 contributions in this area. Then, we consider research articles that examine DoS attacks specific to resource-constrained devices. Finally, we provide a comparative analysis of these papers based on a number of important features in Table 2.  
[PERSON] et al. [10] review various state of art work in IoT security and highlight research trends in IoT security. They also present a unique taxonomy by comparing and analyzing nearly 100 research contributions in this field. However, none of these papers address green IoT with ultra-low resources while enhancing Industrial IoT security to minimize DoS attacks. [PERSON] et al. [15] provides an overview of the recent denial of service attacks in networked control systems. It provides an outlook based on game theory and uses optimization, and probabilistic techniques for modeling these attacks. Another work [16] studies distributed DoS attacks in IoT devices as well as in the cloud environment. They also discuss various multi-vector DDoS attacks. [PERSON] et al. [11] review the current research topics of cyber-security in each of the layers, such as sensing layer, networking layer, middleware layer, and application layer. Another comprehensive survey on various security threats on real IoT devices and vulnerabilities in IoT technologies is presented in Reference [17]. The authors do a comparison of IoT technologies with respect to security parameters, like integrity, anonymity, confidentiality, access control, authentication, etc. The work in Reference [18] gives an overview of various security considerations in real-world applications, such as landslide monitoring and warning system. The work in Reference [19] uses statistical learning methods to determine the device behavior and flag the deviations as anomaly packets in resource constraint devices. The methods are evaluated using Beagle Bone blackboards with 512 MB RAM and dual micro-controller architecture. However, for ultra-low resource hardware, such as 2 KB of RAM and 8 Mhz of a micro-controller, these methods are not applicable, and a simpler method to reduce DDoS attack is required. A method to defend large-scale DDoS attacks in resource-constrained devices is described in Reference [20], where a third party algorithm is introduced to handle the risk. The algorithm is implemented at the gateway router, and the gateway handles low rate attacks (Blacklist, Greylist) and filters them. However, in our case, the nodes are densely deployed and connected to open public Internet without any gateway or firewall. [PERSON] et al. [21] propose a method called security-by-design for the Industrial Internet of Things that runs in two different levels-modeling and simulation. However, the entire software architecture needs high processing speed and memory. The work in Reference [22] discusses possible attacks, such as DoS and DDoS, that can happen in resource-constrained devices. The designed algorithm is implemented at a 6 LoWPAN Border Router to filter out all the malicious junk packets at an early stage itself. The proposed method deals with two algorithms called Primary-check in which incoming packets with source IPs belonging to the blacklisted IPs are dropped, and, in Secondary-check, packets from all the non-blacklisted IPs (Grey listed IP) undergo a payload inspection for detecting DoS and DDoS attacks. The method is suitable wherever an access gateway \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Protocol** & **Type** & **Real-Time** & **Vulnerability Level** & **Power Consumption** \\ \hline MQTT & P/S & Y & High & High \\ AMQP & R/R,P/S & N & Low & Moderate \\ CoAP & R/R,P/S & N & Low & Moderate \\ XMPP & R/R,P/S & N & Low & Moderate \\ VRITHI & Dual Channel & Y & Low & Low \\ \hline \hline \end{tabular}
\end{table} 
Table 1: IoT protocols characteristics (P/S): Publish/Subscribe, (R/R): Request/Response. or firewall is placed as a proxy for the IoT devices.