Satellite transmission, reception and on-board processing signaling and switching

Abstract

This chapter explains the technology that makes onboard processing function as well as explores the new and important applications that communication payloads, based on onboard processing techniques, can effectively support. Further it assesses the pros and cons associated with employing this technology in terms of performance, complexity, reliability, and cost. Satellite systems providing fixed and mobile services are evolving from bent-pipe payloads to more and more enhanced satellites with more and more capabilities and "intelligence." Thus one has seen the evolution of satellite capabilities to be able to achieve more and more functionally in space. We started with so-called non-intelligent or bent-pipe satellites and then moved quickly to more flexible multi-points-type satellite services. Next there was the transition to more enhanced satellites with onboard switching, and then most recently there have been design innovations to bring true "intelligence to space." This has been seen in the move toward highly capable satellites with increasingly "intelligent forms" of onboard processing (OBP). This evolution involves moving from more efficient beam switching to actual processing of signals to enhance signal and remove attenuation affecting the uplink and thus partially overcome rain attenuation. The addition of so-called intelligent functions to the satellite that were once found only in terrestrial signaling and switching systems allows satellites to become more efficient and versatile. In particular this transition will allow the design and deployment of: • Multi-beam RF-IF switched transponder satellites (i.e., the ability to provide effective "beam switching" among satellite beams) This allows satellites to provide Physical Transport Layer Network Services that were once restricted to advanced terrestrial networks. • And eventually there will be an evolution to advanced packet switched ("Data Switched" Asynchronous Transmit Mode (ATM or ATM like services). This will allow onboard processed multi-beam satellite systems that provide specific and an increased array of network-level services.