Software Defined-High Altitude Platform Relays in Integrated Terrestrial-HAP-Satellite Networks

Space and air communication systems provide different service connectivities to aircraft in terms of coverage and required communication performance. This stems from their inherent network topology design and altitude operations, among others, which may lead to provisioning low quality-of-service (Qo$S$) in terms of data rate or latency, unless they are operating in a unifying (integrated) manner. This paper introduces the deployment of software-defined high-altitude platform (HAP) relays to support aircraft satellite communications. A critical challenge emerges is to leverage the routing capabilities of satellite and HAP relay nodes in an integrated terrestrial-HAP-satellite network to provide effective and reliable aircraft satellite communications. A software-defined networking (SDN) driven HAP information relay based probabilistic routing protocol (SHIP) is introduced to enable a software-defined HAP functioning as bi-directional relays. It supports different software-defined transmission communication control links, namely: terrestrial-HAP-satellite (THS) and terrestrial-to-satellite (T2S) transmission schemes for enhancing terrestrial networks performance and strengthen satellite communications. The simulation results show that SHIP achieves throughput gain in downlink and uplink in comparison to other baseline transmission control mechanisms.