L-band Digital Aeronautical Communications System (LDACS) is the selected Air-to-Ground (A2G) technology for future aeronautical communications and a proposed candidate for Air-to-Air (A2A) links. Geographic greedy routing in sparse LDACS A2A networks, typical during gradual system deployment, frequently encounters local minima, necessitating backup mechanisms that are inefficient. Previous research has primarily focused on refining backup mechanisms, neglecting the root cause of geographic greedy routing failures. This paper investigates why geographic greedy routing performance deteriorates in sparse network scenarios, where failures occur more frequently than in dense deployments. We introduce a novel metric to quantify the quality of hop-by-hop forwarding decisions in geographic greedy routing. Furthermore, we develop a second-order absorbing Markov chain model to predict the success ratio and hop stretch factor. The model is validated through Monte-Carlo simulations over the French airspace with varying LDACS equipage fractions, achieving an average difference from simulation results of less than 3.4% for the success ratio and 1.5% for the hop stretch factor. The proposed model demonstrates high accuracy and can be generalized to evaluate other geographic routing protocols. Consequently, the outcomes provide valuable insights toward designing optimized geographic greedy routing protocols.

Replacing traditional wired connections with wireless systems on the aircraft can significantly reduce weight and fuel consumption. Furthermore, complementing existing wired systems with wireless sensors adds redundancy and fault tolerance. Although many applications are already envisioned under the umbrella of Wireless Avionics Intra-Communications (WAIC), finding a suitable communication technology remains challenging due to diverse Quality of Service (QoS) requirements. In this work we discuss challenges associated with the deployment of an in-cabin wireless sensor network (WSN) using different radio bands and propose a solution based on the IPv6 over the TSCH mode of IEEE 802.15.4 (6TiSCH) protocol stack. By extending the latter with cross-layer as well as layer-specific improvements, different challenges in terms of bounded end-to-end delay and high packet delivery ratio are addressed. The solution is validated in simulations using OMNeT++, showing the feasibility of meeting stringent QoS requirements for in-cabin WSNs.

The emergence of the L-band Digital Aeronautical Communications System (LDACS) presents a significant opportunity for enabling Air-to-Air (A2A) communication to accommodate the growing number of aircraft. However, it requires overcoming significant Medium Access Control (MAC) delays and enhancing connectivity in sparse networks. Geographic greedy routing, commonly used in Aeronautical Ad-hoc networks, utilizes position information to eliminate the need for topology discovery. Yet, its efficacy declines as network density decreases. With the gradual introduction of aircraft equipped with LDACS, it becomes crucial to improve greedy forwarding performance. This research investigates Greedy-k, a greedy forwarding variant using k-hop neighborhood information, to boost sparse network performance. We introduce a method to minimize beacon size by transmitting a subset of k-hop neighborhood data that fits within an LDACS time slot. We derived the subset size analytically and evaluated the performance through simulations benchmarked against the conventional Greedy-1. Our results indicate that the proposed approach achieves up to 13% higher Packet Delivery Ratio (PDR) than Greedy-1, while capturing additionally 70.1% and 34.6% of 2ndand 3rdorder neighbors, respectively.

The use of Unmanned Aerial Vehicles (UAVs) has been proposed for numerous applications from recreational photography to commercial deliveries and infrastructure monitoring. But their effective deployment depends on the establishment of an Unmanned Aerial Traffic Management (UTM) which in turn requires reliable communication protocols to ensure safe and efficient operations. Recently, Rate Decay Flooding (RDF) was proposed as a novel protocol to enable position sharing among UAVs, realizing one of the major UTM applications. Another application is the provisioning of a redundant control connection which allows for point-to-point communication between a UAV and its operator in case their proprietary primary connection breaks. Every protocol used for this must harmonize well with RDF so that both applications can be realized at the same time. In this work we propose Spotlight Flooding (SLF) and its enhanced version SLF+, which build on top of RDF to realize a fast and reliable point-to-point connection between any two nodes in the network. These protocols are evaluated in an open-source simulator considering two scenarios. First, we consider a single UAV in distress using SLF/SLF + to explore the performance of our novel protocols for networks of up to 525 UAVs. The results show, that even for large networks, SLF+ achieves a Packet Delivery Ratio (PDR) above 90 % at an end-to-end delay of less than 60 ms. Additionally, we evaluate a scenario of 300 UAVs with an increasing share of UAVs using SLF/SLF+. Again, even if half of the UAVs in the scenario use SLF/SLF+ a PDR above 90 % is achieved at a delay of 142 ms.

Going wireless is one of the key industrial trends, which assists the emergence of new manufacturing and maintenance processes by reducing the complexity and cost of physical equipment. However, the adoption of Wireless Sensor Networks (WSNs) in production environments is limited due to the strict Quality of Service (QoS) requirements of industrial applications. In particular, Wireless Avionics Intra-Communication (WAIC) systems operating in 4.3 GHz band are designed for intra-aircraft use cases with considerable restrictions on the transmission power of sensors, which results in multi-hop topologies, complicating a guaranteed QoS. The Internet Engineering Task Force (IETF) has developed the protocol stack IPv6 over the Time Slotted Channel Hopping (TSCH) mode of IEEE 802.15.4 (6TiSCH) based on the IEEE 802.15.4 Standard for Low-Rate Wireless Networks, which combines the TSCH reliability with ubiquitous IPv6 connectivity and with the robust Routing Protocol for Low-Power and Lossy Networks (RPL). The Scheduling Function (SF) is a core IPv6 over the TSCH mode of IEEE 802.15.4 (6TiSCH) component, but the specification of the SF is an open research topic: numerous scientific articles investigated how QoS for a wide range of applications can be met by developing specialized SFs. However, no full-scale information exchange between the layers of the 6TiSCH stack was considered to optimize the SFs and to improve the network performance. In this work, we propose a novel solution named 6TiSCH-CLX to satisfy demanding QoS requirements using cross-layer communication. It is an extension of the 6TiSCH framework at the network and Medium Access Control (MAC) layers, addressing latency and reliability challenges agnostic of the physical layer. 6TiSCH-CLX is evaluated both analytically and in simulations for several safety-critical avionic intra-communication use cases in WAIC. Preliminary results indicate considerable improvements to latency, while maintaining almost 100% Packet Delivery Ratio (PDR) without retransmissions and they highlight the capability of the cross-layer approach compared to existing solutions.

This paper analyses how data dissemination occurs in mobile Opportunistic Networks by evaluating the impact of different parameters such as density of neighbors, communication range, and speed. There exist several analytical models to evaluate the data dissemination time in OppNets. These models were developed based on a very strong assumption of uniform distribution of infected nodes. We prove that this assumption does not work for the whole spectrum of mobile OppNets. This paper shows our simulation results validated with our analytical model and discusses the impact of different parameters on data dissemination.

This paper focuses on modeling the charateristics of opportunistic networks (OppNets). The motivation of this work is to develop a model which is closer to the reality to represent the data dissemination in OppNets. This paper shows our preliminary results validating our model in OppNets scenarios which give an opportunity to exchange data among a group of people.

Content Centric Networking (CCN) is a new paradigm in networking and a future Internet architecture. Performance evaluations show that conventional CCN forwarding strategies which use replication of Interests (standard) or the shortest path (best-face) do not perform well under high bandwidth requirements and loaded networks. We have designed and evaluated the performance of an On-demand Multi-Path Interest Forwarding (OMP-IF) strategy which identifies a set of paths based on the disjointness of paths to content locations. Then, the discovered paths are used simultaneously to distribute (split) Interests based on the characteristics of the paths. We have evaluated OMP-IF strategy using a simulator with a large scale network scenario and a realistic traffic generation model. The results show improved performance in CCN networks considering download time, load balancing, content hit ratios, and others.

An ad-hoc network is a network whose particular characteristics include absence of any kind of infrastructure, dynamic topology and limited resources. Up to day, several routing protocols have been proposed to face such a hostile environment. These solutions usually provide to the sources of data flows with single valid paths towards their destinations. However, it has been proven that maintaining multiple paths can be favorable to the network, either using the paths at the same time (for load balancing) or using an alternative path, when the primary one fails. It is also a way to meet the Quality of Service requirements demanded by some particular applications. In this paper, we propose a novel routing mechanism based on Dynamic MANET On-demand (DYMO) routing protocol, in order to enable the establishment of more than one node disjoint routes towards the same destination. Simulation results show that there is a significant gain in end-to-end delay for data packets and a reduction in the number of the transmitted routing packets.