Aeronautical Data Networks

The wireless connectivity is becoming an integral part of our society. The advances in signal processing, rapid prototyping and an insatiable consumer demand for wireless connectivity is opening a new paradigm of data service, “Aeronautical Data Networks (ADN)”. Programs lead by National Aeronautics and Space Administration (NASA), Federal Aviation Administration (FAA) [NASA/CR-2008], EUROCONTROL and Networking the Sky for Civil Aeronautical Communications (NEWSKY) [Newsky] are all including the aeronautical platform as part of their network. The objective is to provide a low delay and cost effective data network for an aeronautical platform, as well as use it as a relay for ground and airborne nodes [Sakhaee], [Medina]. Most of current systems use a satellite for connecting to an aeronautical platform. Satellite resources are limited, expensive and offer limited data throughput as compared to a terrestrial networks. Moreover, frequency spectrum is a valuable estate and needs to be used efficiently. Hence, advance spectrum efficient techniques needs to be evaluated for this environment. The book chapter will explore the challenges of aeronautical environment to provide connectivity at all times. A detail analysis with mathematical equations will be presented to show the aeronautical channel impairments. The impact of Doppler on the channel that limits the use of a highly efficient modulation scheme, such as orthogonal frequency division multiplexing (OFDM), will be presented. Doppler has a major impact on OFDM based systems. In addition, Doppler spread in ADN depicts rather different characteristics compared to terrestrial networks, i.e., multiple Doppler shifts in the channel and profound delays. Results of parametric spectrum estimation methods for extracting the Doppler shifts will be presented. OFDM in combination with dense encoding, offers a robust communication and spectrum compression, however its usage is limited to terrestrial domain due to Doppler. OFDM sensitivity to frequency shifts results in intercarrier interference (ICI) and degrades spectral efficiency. High mobility platform, such as train and aircraft offer a challenging environment for OFDM. OFDM ICI and frequency shift caused by the high mobility of the platform is investigated and potential methods are proposed. ADN’s can provide a critical service for various situations, such as: public safety communications, denial of service (DoS), disaster situations, in-flight Internet, as well as mobile communication on the ground such as providing services for highways, trains etc. The network connectivity of ADN will be explored. Current and future prospects of ADN will be discussed in terms of cross interoperability with a terrestrial backbone. The result of