Unmanned Aerial Vehicles (UAVs) have become increasingly important in assisting 5G and beyond 5G (B5G) mobile networks. Indeed, UAVs have all the potentials to both satisfy the ever-increasing mobile data demands of such mobile networks and provide ubiquitous connectivity to different kinds of wireless devices. However, the UAV assistance paradigm faces a set of crucial issues and challenges. For example, the network management of current UAV-assisted systems is time consuming, complicated, and carried out manually, thus causing a multitude of interoperability issues. To efficiently address all these issues, Software-Defined Network (SDN) and Network Function Virtualization (NFV) are two promising technologies to efficiently manage and improve the UAV assistance for the next generation of mobile networks. In the literature, no clear guidelines are describing the different use cases of SDN and NFV in the context of UAV assistance to terrestrial networks, including mobile networks. Motivated by this fact, in this survey, we guide the reader through a comprehensive discussion of the main characteristics of SDN and NFV technologies. Moreover, we provide a thorough analysis of the different classifications, use cases, and challenges related to UAV-assisted systems. We then discuss SDN/NFV-enabled UAV-assisted systems, along with several case studies and issues, such as the involvement of UAVs in cellular communications, monitoring, and routing, to name a few. We furthermore present a set of open research challenges, high-level insights, and future research directions related to UAV-assisted systems.

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Softwarization of UAV Networks: A Survey of Applications and Future Trends

Mobile ad hoc networks (MANETs) are wireless networks formed spontaneously. Communication in such networks typically involves multi-hop relays, and is subjected to dynamic topology changes and frequent link failures. This complex scenario demands robust routing protocol standards that ensure correct and timely delivery of messages. Recently, formal verification has been successful in detecting ambiguities in protocol standards. We consider the Ad hoc On Demand Distance Vector (AODV) protocol, a reactive protocol currently undergoing standardisation at the IETF (RFC3561). AODV performs route discovery whenever a route to the destination is needed, and retains routing information for a period of time specified by the standard. We apply the real-time model checker Uppaal to consider the effect of the protocol parameters on the timing behaviour of AODV, thus complementing the earlier untimed verification effort. Our study of the recent versions of the standard (RFC3561-bis-01) has highlighted a dependency of the lifetime of routes on network size, which can be alleviated by allowing the route timeouts to adapt to network growth.

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A timing analysis of AODV

Mobile Ad-hoc network (MANET) is a dynamic wireless network in which each mobile node acts as a router. MANETs do not have any fixed network topology. The connection is established between the mobile nodes whenever the nodes need to exchange data. The connection is terminated as soon as the exchanging of data is completed. Routing in such a dynamic environment is a critical task. All these complexities are handled by the routing protocols. Routing protocols are the key component for communication among mobile nodes. The performance of routing protocols directly affects the performance of network. Performance of routing protocols is measured in terms of various qualitative and quantitative metrics. For better performance of Ad-hoc networks it is necessary to optimize the routing protocols. The AODV routing protocol is the most prominent among the reactive routing protocols. This survey paper provides the comparative analysis of AODV, AODV-UU, AOMDV, DSR and DYMO protocols.

A survey of reactive routing protocols in MANET

Wireless multi-hop networks such as mobile ad-hoc (MANET) or wireless mesh networks (WMN) have attracted big research efforts during the last years as they have huge potential in several areas such as military communications, fast infrastructure replacement during emergency operations, extension of hotspots or as an alternative communication system Due to various reasons, such as characteristics of wireless links, multi-hop forwarding operation, and mobility of nodes, performance of traditional peer-to-peer applications is rather low in such networks In this book chapter, we provide a comprehensive and in-depth survey on recent research on various approaches to provide peer-to-peer services in wireless multi-hop networks The causes and problems for low performance of traditional approaches are discussed Various representative alternative approaches to couple interactions between the peer-to-peer overlay and the network layer are examined and compared Some open questions are discussed to stimulate further research in this area

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Peer-to-Peer Overlay in Mobile Ad-hoc Networks

Recently, voice over IP (VoIP) has become an important service for the future internet. However, for ubiquitous wireless VoIP services, greater coverage will be necessary as promised by the advent of e.g. 802.11 WLAN based wireless meshed networks. Unfortunately, the transmission of small (voice) packets imposes high overhead which leads to low capacity for VoIP over 802.11 based multihop meshed networks. In this work, we present a novel packet aggregation mechanism that significantly enhances capacity of VoIP in wireless meshed networks while still maintaining satisfactory voice quality. Extensive experiments using network simulation ns-2 confirm that our packet aggregation algorithm can lead to a significantly increase in the number of supported concurrent VoIP flows over a variety of different hop numbers while reducing the MAC layer contention.

Capacity Increase for Voice over IP Traffic through Packet Aggregation in Wireless Multihop Mesh Networks

In mobile ad-hoc networks, autonomous nodes with wireless communication equipment form a network without any pre-existing infrastructure. The functionality of these networks heavily depends on so c ...

Björn Wiberg

Papers

Porting AODV-UU Implementation to ns-2 and Enabling Trace-based Simulation