Survey of Important Issues in UAV Communication Networks

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