Survey of Communication Protocols for Internet-of-Things and Related Challenges of Fog and Cloud Computing Integration (1804.01747v2)

Abstract: The fast increment in the number of IoT (Internet of Things) devices is accelerating the research on new solutions to make cloud services scalable. In this context, the novel concept of fog computing as well as the combined fog-to-cloud computing paradigm is becoming essential to decentralize the cloud, while bringing the services closer to the end-system. This paper surveys on the application layer communication protocols to fulfil the IoT communication requirements, and their potential for implementation in fog- and cloud-based IoT systems. To this end, the paper first presents a comparative analysis of the main characteristics of IoT communication protocols, including request-reply and publish-subscribe protocols. After that, the paper surveys the protocols that are widely adopted and implemented in each segment of the system (IoT, fog, cloud), and thus opens up the discussion on their interoperability and wider system integration. Finally, the paper reviews the main performance issues, including latency, energy consumption and network throughput. The survey is expected to be useful to system architects and protocol designers when choosing the communication protocols in an integrated IoT-to-fog-to-cloud system architecture.

• The paper surveys key application layer communication protocols used in IoT and analyzes the challenges of integrating them into fog-to-cloud architectures.
• It compares protocols like MQTT and CoAP based on performance (latency, bandwidth, energy, security) and highlights the challenge of a unifying standard.
• It discusses single and multiple protocol strategies across IoT, fog, and cloud layers, highlighting the need for future optimization and standardization.

A Survey of Communication Protocols for Internet of Things and Related Challenges of Fog and Cloud Computing Integration

The paper "A Survey of Communication Protocols for Internet of Things and Related Challenges of Fog and Cloud Computing Integration" provides an extensive review of application layer communication protocols used in the rapidly expanding Internet of Things (IoT) landscape, particularly in the context of fog-to-cloud (F2C) computing integration. The authors, Jasenka Dizdarevic, Francisco Carpio, Admela Jukan, and Xavi Masip-Bruin, aim to guide system architects and protocol designers through the intricacies of selecting suitable protocols for IoT-F2C system architectures.

Key Focus

The paper centers on application layer protocols such as MQTT, CoAP, HTTP, AMQP, XMPP, and DDS, examining their features, performance, and potential for implementation in systems that span IoT, fog, and cloud environments. A notable challenge highlighted in integrating these systems is the lack of a unifying standard in communication protocols, resulting in fragmented solutions and the need for general architecture considerations like device capabilities, data processing requirements, and security measures.

Comparative Performance Analysis

The paper discusses each protocol's interaction models, transport layers, quality of service (QoS) offerings, and security mechanisms. It emphasizes the significance of characteristics like latency, bandwidth utilization, energy consumption, and security in protocol selection:

• Latency and Bandwidth: Protocols such as CoAP and MQTT generally offer lower latency and bandwidth consumption due to their lightweight headers and interaction models. CoAP's use of UDP reduces overhead compared to TCP-based protocols, though it can suffer from reliability issues.
• Energy Efficiency: CoAP has been noted for its energy efficiency, which is crucial for resource-constrained IoT devices. In contrast, HTTP generally exhibits higher energy consumption due to its expansive headers and reliance on TCP.
• Security: While TLS and DTLS are standard for secure communication, their implementation can add overhead, thus affecting protocols' performance in IoT-F2C systems. The paper suggests that efforts to optimize these security layers for lightweight environments remain a critical avenue for future research.

Implementation Insights

The survey outlines scenarios where single and multiple protocols might be employed across IoT, fog, and cloud layers:

• Single Protocol Solutions: MQTT and HTTP are the most mature and widely adopted protocols, providing stability and ease of implementation for various IoT-F2C applications. However, they may not be sufficient to cover all architectures due to specific limitations in security or performance under particular conditions.
• Multiple Protocol Solutions: Combining protocols, such as using MQTT for IoT-fog interactions and AMQP between fog and cloud, allows leveraging each protocol's strengths. Ensuring seamless interoperability among protocols remains an open challenge, demanding solutions that permit efficient translation and integration.

Developer Adoption and Future Direction

The paper also discusses the preferences of IoT developers, noting a strong inclination towards MQTT and HTTP due to their maturity and extensive support frameworks. As new protocols like HTTP/2.0 evolve, it is anticipated that further studies will explore their potential in IoT-F2C architectures, potentially shaping future standards and practices.

Conclusion

This comprehensive review underscores the complexity within IoT-F2C systems, emphasizing the necessity for strategic protocol selection tailored to specific segment requirements. While certain protocols currently offer viable solutions, the ongoing development in protocol optimization, standardization, and interoperability will be pivotal to successfully unifying IoT, fog, and cloud domains. The paper provides a foundational reference point for researchers and developers striving for efficient, collaborative, and secure IoT-F2C ecosystems.