Survey of Important Issues in UAV Communication Networks (1603.08462v1)

Abstract: Unmanned Aerial Vehicles (UAVs) have enormous potential in the public and civil domains. These are particularly useful in applications where human lives would otherwise be endangered. Multi-UAV systems can collaboratively complete missions more efficiently and economically as compared to single UAV systems. However, there are many issues to be resolved before effective use of UAVs can be made to provide stable and reliable context-specific networks. Much of the work carried out in the areas of Mobile Ad Hoc Networks (MANETs), and Vehicular Ad Hoc Networks (VANETs) does not address the unique characteristics of the UAV networks. UAV networks may vary from slow dynamic to dynamic; have intermittent links and fluid topology. While it is believed that ad hoc mesh network would be most suitable for UAV networks yet the architecture of multi-UAV networks has been an understudied area. Software Defined Networking (SDN) could facilitate flexible deployment and management of new services and help reduce cost, increase security and availability in networks. Routing demands of UAV networks go beyond the needs of MANETS and VANETS. Protocols are required that would adapt to high mobility, dynamic topology, intermittent links, power constraints and changing link quality. UAVs may fail and the network may get partitioned making delay and disruption tolerance an important design consideration. Limited life of the node and dynamicity of the network leads to the requirement of seamless handovers where researchers are looking at the work done in the areas of MANETs and VANETs, but the jury is still out. As energy supply on UAVs is limited, protocols in various layers should contribute towards greening of the network. This article surveys the work done towards all of these outstanding issues, relating to this new class of networks, so as to spur further research in these areas.

Survey of Important Issues in UAV Communication Networks

The paper "Survey of Important Issues in UAV Communication Networks" by Lav Gupta, Raj Jain, and Gabor Vaszkun, published in IEEE Communications Surveys and Tutorials, provides a comprehensive overview of the unique challenges and considerations specific to Unmanned Aerial Vehicle (UAV) networks. The discussion facilitates a deeper understanding of the technological requirements and constraints associated with the deployment of UAVs in various domains, including civil, public, and military applications.

Overview of UAV Networks

Unmanned Aerial Vehicles (UAVs) hold significant promise for various applications, including those that pose risks to human life, such as disaster recovery, environmental monitoring, and military operations. Multi-UAV systems, characterized by their dynamic topology and potential for intermittent connectivity, offer advantages in operational efficiency and cost-effectiveness compared to single UAV deployments. However, the unique network characteristics of UAVs present distinct challenges that must be addressed to harness their full potential.

The paper highlights that while Mobile Ad Hoc Networks (MANETs) and Vehicular Ad Hoc Networks (VANETs) provide a foundational understanding, their methodologies fall short of addressing all UAV-specific issues. UAV networks, often characterized by fluid topologies and varying degrees of node mobility, require dedicated approaches to ensure stable and reliable communication.

Key Aspects and Challenges

The paper identifies several critical areas that demand attention for the effective deployment of UAV networks:

1. Network Architecture: Ad hoc mesh networks are posited as a potentially suited architecture for UAV communication. However, the fluidity of UAV networks necessitates constant reorganization and adaptation, presenting a significant design challenge.
2. Routing Protocols: Traditional routing protocols such as OLSR and AODV, while familiar, struggle with the high mobility and dynamic topologies of UAV networks. The paper explores alternatives like Enhanced PRoPHET (for delay tolerance) and opportunistic-type protocols that leverage UAVs' unique abilities to hover and move.
3. Software Defined Networking (SDN): SDN is advocated as a solution for flexible deployment and management of UAV networks. The centralized control in SDN helps to dynamically manage network resources, improving security and reducing costs. OpenFlow is discussed as a viable protocol for SDN implementation in UAV networks.
4. Energy Efficiency: Given the limited energy supplies on UAVs, energy-efficient design is crucial. Protocols across various layers must contribute to ‘greening’ the network, balancing performance requirements with energy conservation. Strategies such as power control, energy-efficient routing, and the utilization of duty cycles are highlighted.
5. Seamless Handover: The need for continuous service while UAVs join or leave the network makes seamless handover essential. Approaches from MANETs and VANETs, such as Media Independent Handover (MIH), and adaptations in UAV specific contexts are discussed.
6. Disruption Tolerant Networking (DTN): For environments where UAV networks experience frequent disconnections, DTN principles like store-carry-forward are imperative. They allow the networks to maintain communication during disruption periods by leveraging intermediary UAVs as temporary data holders.

Implications and Future Developments

The implications for improving UAV networks are multifaceted. Practically, advancements in UAV networking can enhance disaster response capabilities, provide robust environmental monitoring, and improve the efficiency of military operations. The need for energy-efficient designs aligns with the broader goal of sustainability, crucial for long-term UAV operation.

From a theoretical perspective, the paper of UAV networks pushes the boundaries of current wireless network protocols and requires novel approaches to routing, energy management, and network resilience. The interdisciplinary nature of the task – combining elements of network theory, control systems, and aeronautics – presents intriguing opportunities for future research.

Conclusion

This survey elucidates the distinct challenges posed by UAV networks and underscores the requirement for targeted research to develop suitable protocols and architectures. The research steps outlined provide a roadmap for addressing these challenges. By fostering advancements in network architecture, routing strategies, and energy management, the capabilities and effectiveness of UAVs in diverse applications can be significantly enhanced.