Daniel Medina

Feasibility of an Aeronautical Mobile Ad Hoc Network Over the North Atlantic Corridor

In the near future, broadband air-ground (A/G) communications will be used by civil aviation aircraft flying over crowded continental areas such as Europe and North America to access a variety of services, ranging from safety- of-life to infotainment applications. This paper investigates the feasibility of extending this coverage via air-air (A/A) multihop communications over oceanic, remote and polar regions, where no such infrastructure is available, so that aircraft flying over these areas can access the ground services without having to use an expensive high-delay satellite link. We focus on a particularly attractive scenario, the North Atlantic Corridor, and use realistic flight data to extract statistics about the dynamic topology of the airborne ad hoc network, such as connectivity and link stability. In addition, we assess the performance of greedy forwarding in the aeronautical environment and show that, under moderate connectivity, this technique delivers almost all packets to their destinations with a minimum hop count.

A geographic routing strategy for north Atlantic in-flight internet access via airborne mesh networking

The Airborne Internet is a vision of a large-scale multihop wireless mesh network consisting of commercial passenger aircraft connected via long-range highly directional air-to-air radio links. We propose a geographic load sharing strategy to fully exploit the total air-to-ground capacity available at any given time. When forwarding packets for a given destination, a node considers not one but a set of next-hop candidates and spreads traffic among them based on queue dynamics. In addition, load balancing is performed among Internet Gateways by using a congestion-aware handover strategy. Our simulations using realistic North Atlantic air traffic demonstrate the ability of such a load sharing mechanism to approach the maximum theoretical throughput in the network.

Topology characterization of high density airspace aeronautical ad hoc networks

Aeronautical ad hoc networks represent a special type of ad hoc wireless networks, given their significantly larger scale and the distinct characteristics of their mobile nodes. Aircraft populate the international airspace very heterogeneously. Some regions experience highly dense air traffic, with aircraft headings being largely uncorrelated. Other regions remain only very sparsely populated, with aircraft typically flying parallel to each other. Moreover, the number of airborne aircraft in a given region changes significantly throughout the day. In this paper, we focus on the densely populated European airspace, and investigate the topological behavior of multihop ad hoc wireless networks formed by air-air links of varying communications range. We derive analytical expressions for various topological aspects, such as the lifetime of inter-aircraft links, and the projected hop length using greedy forwarding. These results are in good agreement with the behavior observed in our simulations of the European air traffic scenario. In addition, we assess the performance of greedy forwarding in the aero-nautical environment and show that, under moderate connectivity, this technique delivers almost all packets to their destinations with a minimum hop count.

A Crosslayer Geographic Routing Algorithm for the Airborne Internet

The Airborne Internet is envisioned to be a large scale multihop wireless mesh network of commercial passenger aircraft connected via long range highly directional air-to-air radio links. We propose a localized geographic load sharing technique to mitigate congestion in this network, taking into account the underlying link scheduling constraints with directional antennas. When forwarding packets for a given destination, a node considers not one but a set of next hop candidates, and spreads traffic among them based on queue dynamics. Our simulations show that introducing this flexibility in the routing function can greatly increase a nodes ability to satisfy its bandwidth demands during link scheduling, yielding significant performance improvements in terms of network throughput and average packet delay.

Optimization of routing and gateway allocation in aeronautical ad hoc networks using genetic algorithms

In this paper, we present a Genetic Algorithm approach to solving the joint Internet gateway allocation, routing and scheduling problem in wireless ad hoc networks with the goal of minimizing the average packet delay in the network. We analyze the performance of the proposed Genetic Algorithm by means of simulations and compare the solution that it provides to a hop count based routing and gateway selection solution. We also investigate the benefits that can be achieved by optimizing only the allocation of Internet gateways or the routing. It is shown that the Genetic Algorithm provides significantly better performance in terms of delay and packet delivery ratio.

Routing in the Airborne Internet

The Airborne Internet is envisioned to be a large scale multihop wireless mesh network of civil aviation aircraft connected via long range highly directional air-to-air radio links. We propose a novel geographic load share routing metric to mitigate congestion in this network, taking into account the underlying link scheduling constraints with directional antennas. When forwarding packets for a given destination, a node considers not one but a set of next hop candidates, and spreads traffic among them based on queue dynamics. Our simulations show that introducing this flexibility in the routing function can greatly increase a nodes ability to satisfy its bandwidth demands during link scheduling, yielding significant performance improvements in terms of network throughput and average packet delay. The ability to exploit this flexibility depends on the spatial reuse of the underlying network. For the simulated scenario, an increase in network throughput of 200% on average is shown, compared to a state-of-the-art geographic routing algorithm.

The Airborne Internet

Mobile communications and internet access are increasingly becoming an essential part of peoples lives in todays information society. The growing interest by commercial airlines in providing internet access and cellular connectivity in the passenger cabin has lead to the emergence in recent years of the first satellite-based inflight connectivity providers, including Connexion by Boeing (now defunct), OnAir, AeroMobile, and Panasonic Avionics Corporation. Given the long range of transcontinental air travel, a satellite communications link is the most natural and flexible way to keep the aircraft connected to the ground throughout the flight. Long-distance flights typically traverse oceanic and remote airspace, e.g., large bodies of water, deserts, polar regions, etc., where no communications infrastructure can be deployed on the ground. However, direct air-to-ground (A2G) cellular networks are being deployed (e.g., AirCell in the United States) to provide faster and cheaper access during continental flight. This Chapter presents the vision of the Airborne Internet, a new paradigm for inflight connectivity based on the concept of mesh networking (Akyildiz & Wang, 2005). Airborne mesh networks are self-organizing wireless networks formed by aircraft via direct air-to-air (A2A) radio communication links. Such networks have so far been considered mainly in the context of military aviation (DirecNet, 2007; Bibb Cain et al., 2003). The concept of the Airborne Internet was first proposed at NASA Langley Research Centers Small Aircraft Transportation System (SATS) Planning Conference in 1999. In one conference session, it was suggested that such a system would require a peer-to-peer communications network among the aircraft. The Airborne Internet Consortium (AIC) formed subsequently to promote and aid in the development of such a system. Consortium members include Aerosat, C3D Aero, and United Airlines. As shown in Fig. 1, aeronautical mesh networking is envisioned as a means to extend the coverage of A2G access networks offshore to oceanic or remote airspace. By enabling aircraft themselves to act as network routers, an airborne mesh network is formed in the sky, as illustrated in Fig. 2. At any given time, only a fraction of all aircraft are within direct A2G coverage, as they fly over the ground infrastructure deployed on shore. During oceanic flight, the aircraft can stay connected by using the airborne mesh network as a bridge to the ground infrastructure, thus bypassing the costly satellite link. From an airline’s perspective, avoiding the satellite link can result in significantly reduced communication costs. Another potential benefit is reduced latency compared to a geostationary satellite, enabling delay-sensitive applications such as voice and video conferencing. With a geostationary

Optimum Internet Gateway Selection in Ad Hoc Networks

Wireless ad hoc networks are connected to the fixed Internet by means of Internet gateways. Whenever a node within the ad hoc network wishes to communicate with a host in the Internet, it selects a default Internet gateway to relay its traffic from the ad hoc network to the Internet. In this paper, we formulate the problem of selecting the best Internet gateway as a mixed integer linear program minimizing the maximum node utilization in the wireless network. By simulations, we show that the performance that can be achieved by solving this optimization problem is significantly higher than what is achieved by standard gateway selection algorithms based on hop count or gateway load. In particular, these heuristic algorithms fail to adapt to the offered traffic and available capacity in the network.

FACTS: an OMNeT++ based simulator for aeronautical communications

In this paper, we present a concept for an aeronautical communications simulator based on the discrete event simulation platform OMNeT++. In the aeronautical environment, there is a mutual dependency between the movement of the aircraft and the data traffic that is generated, making an accurate modeling particularly difficult. In addition, such a simulator requires a modular architecture due to the heterogeneous link situation and variety of application scenarios that it will have to deal with.

North Atlantic Inflight Internet Connectivity via Airborne Mesh Networking

The Airborne Internet is a vision of a large scale multihop wireless mesh network consisting of commercial passenger aircraft connected via long range highly directional air-to-air radio links. We propose a geographic load sharing strategy to fully exploit the total air-to-ground capacity available at any given time. When forwarding packets for a given destination, a node considers not one but a set of next hop candidates, and spreads traffic among them based on queue dynamics. In addition, load balancing is performed among Internet Gateways by using a congestion-aware handover strategy. Our simulations using realistic North Atlantic air traffic reveal the potential of such a load sharing mechanism to approach the maximum theoretical throughput in the network.