Table 1.

Summary of existing survey.

Main Ideas	Survey Scope	Cross-Layer Inspired?	Challenges	Reference
Focused on cross-layer optimization in IoT and multi-channel cross-layer MAC framework.	Low-power, wide-area networking protocol (LoRaWAN) in IoT, cyber security management protocol, 6G communication.	Yes	Protocol optimization, data rate, duty cycle, massive connectivity energy constraint.	[9]
Focused on cyber-physical systems and vulnerability modeling.	Cyber-physical systems, privacy-preserving, cybersecurity information sharing.	No	Data security, vulnerability modeling, sensitive information protection.	[10]
Social IoT Security (SIoT), hybrid risk identification methodology, four-step risk identification process.	SIoT security, risk identification in industry, risk management standards and frameworks.	Yes	Security, energy efficiency and comprehensive risk identification and redundancy of risks.	[11]
Focused on IoT security challenges and solutions, Flying Ad Hoc Networks (FANETs), and energy-aware routing scheme	IoT security challenges, routing algorithms in FANETs, Comparison of routing schemes	No	Security vulnerabilities, cryptographic protocols, dynamic topology and high mobility, efficient path selection	[12]
Focused on smart city security and privacy, solutions using blockchain and encryption, and blockchain for security.	Adaptive cybersecurity, IoT and cloud-based security issues, data privacy and security solutions, smart city data management.	No	Real-world network packet collection, machine learning, resource optimization vs. security, decentralized and distributed structure.	[13]
Focused on IoT security, case study on camera-based IoT, and privacy	IoT security, threat analysis for Smart Camera Systems (SCSs), IoT security and privacy.	No	IoT development, security solutions, complexity of IoT security, vulnerabilities in IoT applications.	[14]
Focused on Non-orthogonal Multiple Access (NOMA)-based IoT communication systems, 5G and energy-efficient optimization	IoT networks and communication, energy efficiency and optimization techniques.	Yes	Energy efficiency, complexity of optimization, and quality of service.	[6]
Energy-efficient routing for smart networks, energy-efficient routing, fuzzy clustering and optimization.	Smart energy-efficient routing, routing architectures, optimization techniques.	No	Energy-efficient routing, network performance, network stability, efficient routing.	[15]
Cognitive energy-efficient IoT, spectrum demand, communication protocols.	Cognitive Radio (CR) technology for IoT, cross-layer optimization, performance evaluation.	Yes	Spectrum optimization, energy efficiency, network adaptation.	[16]