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Conflict-Free Replicated Data Types (CRDTs) are data types that can be used in distributed systems when optimistic replication is tolerable. Replicas can be updated locally, without coordination, and consistency is obtained eventually by asynchronously propagating updates among replicas. Because CRDTs can tolerate asynchronous transmissions, they can serve as software elements in opportunistic networks (OppNets), where the dissemination of information is dependent on unplanned transient radio contacts between mobile nodes. In this paper we investigate the problem of implementing operation-based, state-based, and delta-state-based CRDTs in OppNets. A contact-driven synchronization algorithm is proposed for each kind of CRDT, and experiments based on realistic tracesets are conducted in order to compare how these algorithms can perform in an OppNet. Experimental results show that delta-state-based CRDTs globally outperforms operation-based and pure state-based CRDTs, especially when considering the number of messages required to ensure the synchronization of replicas. [ABSTRACT FROM AUTHOR]

In this paper, we address the problem of implementing distributed slice allocation algorithms for tactical networks deployed in regions lacking a communication infrastructure. We propose a multi-agent game implementation in which Application Slice Agents (ASAs) compete for shared computational and bandwidth resources in the network. We prove that the game can be implemented as a two stage potential game, with the first stage ensuring the selection of computational servers with load balancing, and the second stage improving connectivity and network throughput by promoting inter-slice cooperation. Our proposed analysis framework also incorporates a theoretical model to capture the impact of mitigation methods for timing channel leaks for the shared resources for different slices, and proposes a theoretical framework that allows for a security-delay tradeoff analysis. [ABSTRACT FROM AUTHOR]

An efficient and reliable route is the backbone of a Mobile Ad hoc Network (MANET). nodes can move around freely, due to the dynamic nature of MANETs, and there is no fixed topology. Thus, route selection becomes a very critical issue, as many factors affect the communication between mobile nodes. Limited battery life and moving nodes lead to frequent route changes, and increase in hops and delays cause rapid battery consumption. Mobility is a critical factor that affects the communication between nodes of a wireless ad hoc network. Conventional algorithms consider hop count as the only parameter during selection of a route from source to destination and other significant QoS parameters like battery, mobility, end-to-end delay are ignored. As a consequence, these approaches do not attain the desired packet delivery ratio levels needed for a highly dynamic network. This paper proposes a QoS aware AHP based Cognitive Route selection in MANETs (QACRM). It is an Analytic Hierarchy Process-Simple Additive Weighing (AHP-SAW) based cognitive approach for optimal route selection. In this work, routes are ranked based on hop count, battery, mobility, and end-to-end delay. The importance of QoS parameters is decided based on human expert judgement provided to the system. The route which is ranked highest is selected for transmission. This approach identifies reliable and optimal routes for communication between the nodes. Results attest that the proposed technique (QACRM) performs better when compared with AODV and other existing methods for packet delivery ratio, consumption of energy, size of network, and changing least number of routes in a dynamic environment. [ABSTRACT FROM AUTHOR]

Previous work has demonstrated the feasibility of Bluetooth Low Energy (BLE) as an alternative technology for data transfers in inter-vehicular communication (IVC) scenarios. Bluetooth 5.x core specifications enhance the trade-off between energy requirements, communication range and flexibility. In this paper, we aim to analyse the potential of Bluetooth 5 features for VANET applications, proposing a connectionless communication system. By means of field experiments, we evaluate long range and 2 × speed features, defining a set of communication scenarios. This allows us to test both Bluetooth 5.x range and application throughput. The evaluation includes experiments of V2I communications carried out under real highway traffic conditions. The experiments conducted demonstrate that communication ranges up to 300 m may be achieved depending on the communications scenario. The results also show how throughput degrades as the distance between devices increases. The results obtained are used to discuss future work, aimed at deeper analysing Bluetooth 5 features for VANET applications, completing the development of our prototype and evaluating VANET connectionless communications with the features included in the latest Bluetooth 5.2 specification. [ABSTRACT FROM AUTHOR]

A model that can describe the functioning of large-scale systems with a dynamical and adaptive network topology is developed. Dynamical graph theory is chosen as the mathematical tools on which the model is based. Therefore, the functioning of the ad hoc network is represented as a set of static graphs, each of which corresponds to a certain timestamp. Dynamic graphs allow one to track changes in the network and mark them as legitimate or illegitimate. The choice of key parameters of the developed model is based on the practical experience of researchers involved in the detection of different attacks in ad hoc networks, which makes the model a priori focused on subsequent security analysis. [ABSTRACT FROM AUTHOR]