In-flight Connectivity Research Articles

AI-enabled cluster head selection through modified density based clustering in Aeronautical Ad Hoc Networks

Offering in-flight connectivity has emerged as an essential demand for everyday flights. Such aircraft’s high speed and dynamic characteristics make this task challenging, particularly in distant areas with no ground-to-air link. Aeronautical Ad Hoc Network (AANET), a network of commercial airplanes with air-to-air connectivity, is a viable solution to this problem. However, the instability of air-to-air links results in poor performance of such ad hoc networks. A cluster-based topology formation is an initial step to boost the performance and connectivity in such a network. Selecting a well-connected cluster head is the next stage in enhancing connection and stability. This study presents a new cluster head selection technique for AANETs that calculates the neighbor nodes within a given distance of each node and selects the node with the most connections as the new cluster head. A gateway node is chosen to facilitate connections with other clusters. According to simulations, the proposed method increases packet delivery ratio by 3%, end-to-end delay by 9%, and throughput by up to 10%. In addition, the proposed method reduces cluster head replacements by 17% and increases cluster head longevity by 8%.

A Proof of Concept on Digital Twin-Controlled WiFi Core Network Selection for In-Flight Connectivity

The in-flight connectivity (IFC) turns to a crucial need from luxury with technological advances. The WiFi-enabled IFC (W-IFC) meets most of this need by deploying access points within the aircraft. These access points can allow Internet connectivity through various core network links air-to-ground (A2G), air-to-satellite (A2S), and air-to-air (A2A) at different times during the flight. More specifically, the core network of W-IFC should be selected from these links according to their availabilities throughout the aircraft's flight. However, the ultra-dynamic characteristic of aeronautical networks caused by aircraft's high speed reduces W-IFC's core network selection efficiency. The problems on the core network selection of W-IFC increase the core network selection delay with higher packet losses. Additionally, the core network selection of W-IFC becomes more complex when user traffic heterogeneity is added to this connection availability. These complexities necessitate the continuous monitoring of the aircraft environment while dealing with multiple data entries. At that point, the digital twin (DT) technology enables us a continuous monitoring and management opportunity in a virtual manner for the ultra-dynamic aeronautical environment. By considering this, in this article, we aim to introduce a proof-of-concept (PoC) about the utilization of digital twin technology in WiFi core network selection for IFC. Our proposed DT module executes the hybrid combination by utilizing the connectivity and traffic-based core network selection models simultaneously. Here, the connectivity-based core network selection focuses on determining aircraft's possible core network links, while the traffic-based selection considers heterogeneous traffic flows of passengers. Results reveal that the proposed DT-controlled model reduces the WiFi core network selection delay 36 percent with 25 percent packet delivery improvement. Also, we prove the feasibility of the PoC W-IFC model through twinning rate with near-real-time measurements. And we show the decision performance of DT with false positive and false negative rates.

Enabling In-Flight Connectivity with the new Generation of Electronically Steered Antennas

In-flight communication (IFC) services offered to passengers and crew are of great importance to the air transport sector. The improvement of the satellite capacity with High Throughput Satellites (HTS) in GEO and the advent of MEO and LEO constellations will support the forecast growth of the IFC market. Antenna equipment for satellite communications will need to address multiple scenarios from G2G (Gate-to-Gate) to multi-operation under GEO-MEO-LEO systems. Under these conditions, antennas with the ability to track multiple satellites and having superior performance and reliability will play a key role. Electronically steered antennas (ESA) have emerged as a viable solution in response to these demands. The EU-funded LESAF project proposes an ESA solution of reduced size and greater efficiency for the next generation of in-flight connectivity services. This will be managed through the requirements definition, system analysis, technology assessment, prototyping and validation of ESAs. The project has successfully passed the first milestone corresponding to requirements consolidation, baseline architecture definition and candidate technology trade-offs. Multi-beam Electronically Steered Antennas, separated apertures for both transmission and reception, a flexible modular approach coupled with planar multilayer integration and an advanced beamformer design are the basis for the proposed concept. The following project phase will be focused on the design and validation of an antenna demonstrator aimed at proving the superior added value of ESAs technological solution for the aviation industry needs.

Aeronautical Networks for In-Flight Connectivity: A Tutorial of the State-of-the-Art and Survey of Research Challenges

The aeronautical networks attract the attention of both industry and academia since Internet access during flights turns to the crucial demand from luxury with the evolving technology. This In-Flight Connectivity (IFC) necessity is currently dominated by the satellite connectivity and Air-to-Ground (A2G) network solutions. However, the high installation/equipment cost and latency of the satellite connectivity reduce its efficiency. The A2G networks are utilized through the 4G/5G ground stations deployed on terrestrial areas to solve these satellites’ problems. This terrestrial deployment reduces the coverage area of A2G networks, especially for remote flights over the ocean. The Aeronautical Ad-hoc Networks (AANETs) are designed to provide IFC while solving the primary defects of dominating solutions. The AANET is an entirely novel solution under the vehicular networks since it consists of aircraft with ultra-dynamic and unstructured characteristics. These characteristics separate it from the less dynamic Flying Ad-Hoc Networks (FANETs). Therefore, the environmental and mobility effects cause specific challenges for AANETs. This article presents a holistic review of these open AANET challenges by investigating them in data link, network, and transport layers. Before giving the details of these challenges, this article explores the state-of-the-art literature about satellite and A2G networks for IFC. We then give our specific interest to the AANET by investigating its particular characteristics and open research challenges. The main starting point of this study is that there is a lack of compact research on this exciting topic, although IFC is an inevitable need for the aeronautical industry. Also, the AANET could be underlined by giving all state-of-the-art about the dominating IFC solutions. Therefore, this is the first work exploring the state-of-the-art for all the existing aeronautical networking technologies under a single comprehensive survey by deeply analyzing specific characteristics and open research challenges of AANETs. Additionally, the AANET is a novel topic and should be separately investigated from the FANETs as given in current literature.

Editorial for Wiley's IJSCN Special Issue “Satellite networks integration with 5G”

Editorial for Wiley's IJSCN Special Issue “Satellite networks integration with 5G”

Twin-Component Near-Pareto Routing Optimization for AANETs in the North-Atlantic Region Relying on Real Flight Statistics

Integrated ground-air-space (IGAS) networks intrinsically amalgamate terrestrial and non-terrestrial communication techniques in support of universal connectivity across the globe. Multi-hop routing over the IGAS networks has the potential to provide long-distance highly directional connections in the sky. For meeting the latency and reliability requirements of in-flight connectivity, we formulate a multi-objective multi-hop routing problem in aeronautical ad hoc networks (AANETs) for concurrently optimizing multiple end-to-end performance metrics in terms of the total delay and the throughput. In contrast to single-objective optimization problems that may have a unique optimal solution, the problem formulated is a multi-objective combinatorial optimization problem (MOCOP), which generally has a set of trade-off solutions, called the Pareto optimal set. Due to the discrete structure of the MOCOP formulated, finding the Pareto optimal set becomes excessively complex for large-scale networks. Therefore, we employ a multi-objective evolutionary algorithm (MOEA), namely the classic NSGA-II for generating an approximation of the Pareto optimal set. Explicitly, with the intrinsic parallelism of MOEAs, the MOEA employed starts with a set of candidate solutions for creating and reproducing new solutions via genetic operators. Finally, we evaluate the MOCOP formulated for different networks generated both from simulated data as well as from real historical flight data. Our simulation results demonstrate that the utilized MOEA has the potential of finding the Pareto optimal solutions for small-scale networks, while also finding a set of high-performance nondominated solutions for large-scale networks.

Techno‐economic analysis of inflight connectivity using an integrated satellite‐5G network

SummaryThe demand for mobile broadband services is increasing exponentially alongside with user expectations regarding the reachability of these services and their prices. This paper presents an integrated satellite and fifth generation (5G) network for providing inflight connectivity and evaluates the economic viability of offering broadband connectivity to passengers on commercial airplanes by the development of a techno‐economic framework, which considers both capital and operational expenditures to compute the total cost of ownership (TCO) and an average cost per user and per Megabyte. Results show high operational costs mainly due to satellite bandwidth usage. Therefore, caching popular content on the network onboard is beneficial to reduce the traffic carried over the satellite link, thus lowering the operational costs as well. Furthermore, the framework is used to compare the identified business models for Inflight Entertainment and Connectivity offerings and their pricing strategies, alongside a benchmark against the current inflight connectivity pricing. Finally, a sensitivity analysis is elaborated in order to mitigate the uncertainty of inputs (e.g., rate of caching) used to feed the TCO model. Following concrete recommendations are the main result of this research: (1) Providing inflight broadband services with a 2–5 Mbps throughput per user is feasible if satellite communications is integrated into the 5G network. (2) Caching popular data reduces the operational costs and hence the average cost per user (from 25% to 32% depending on the caching rate adopted). (3) This framework allows to provide recommendations on the best suited business models and related pricing schemes.

Smart Diversity Through MIMO Satellite $Q/V$-Band Feeder Links

With sum throughputs exceeding 1 Tb/s, next-generation high throughput satellite will play a key role in 5G networks for applications including backhauling or broadband in-flight connectivity. Such satellites require the deployment of tens of $Q/V$ -band feeder links to support the data traffic in their uplink. Meanwhile, geographical restrictions and cost considerations significantly constrain the search for gateway deployment sites. Diversity strategies are, furthermore, necessary to cope with strong rain fades. In this paper, multiple-input-multiple-output (MIMO) feeder links are proposed to address these challenges. Using two active gateway antennas per feeder link, a MIMO-based solution enables to support twice the user link bandwidth per link compared to the state-of-the-art. On-ground and onboard processing strategies for such MIMO links are introduced, and the link outage probabilities are determined. An extension of smart diversity schemes to MIMO-based architectures is also presented to guarantee a sufficient robustness against rain fades. An analysis of the achieved uplink CINR demonstrates the superiority of the proposed concept and provides guidelines for an efficient design.

Simulation/Optimization Modeling for Robust Satellite Data Unit for Airborne Network

The objective of this paper is to present a Simulink model–based approach for simulation and optimization of a robust satellite data unit (SDU) able to deliver safety and nonsafety aeronautical mobile satellite services, including capabilities to operate in an airborne network. For this purpose, analysis and modeling of the main avionics system signals and data traffic to be treated in an SDU were performed. The main contribution here is the design of the SDU data traffic model, which integrates different simulation models in avionics systems, such as automatic dependent surveillance—broadcast, aircraft communications addressing and reporting system, and in-flight connectivity for future implementation and optimization, thus allowing the characterization of a device onboard in a modular framework. To conclude, this paper describes a modeling and analysis tool aimed at providing the aviation industry with the means to reduce the amount of equipment onboard (and thus the weight of aircraft to reduce fuel consumption) and fulfill passengers’ demand for connectivity. Finally, note that this modeling is a step further toward the development of a device that ensures greater operational safety and ease of repair and maintenance.