Terrestrial and satellite hybrid network for new services

Abstract

The role of satellite communications in networks that provide new services, such as frame relay and multimedia, is investigated. Both passive and active (onboard switching, processing) satellite systems are considered. Novel techniques are developed for each system to demonstrate, via detailed analysis, how the communications bandwidth agility of multipoint/broadcast satellite channels, and the switchability of spot beams, makes it feasible to provide these new services via satellite in a resource-efficient manner. The current worldwide revolution in the telecommunications environment has led to significant changes in the generation and transmission of information. The coupling of local and global communications networks can make information, databases, and processing power available virtually everywhere. The essential infrastructure for this connectivity depends on the integrated services digital network (ISDN). Well-specified standards will initiate a worldwide movement toward the implementation of ISDN, and the 1990s are likely to be the decisive era for establishing the foundation for this new communications architecture. ISDN standards for interfaces, signaling procedures, service definitions, and other operational and architectural features will provide a common framework for developing satellite network configurations that can offer a range of new and enhanced services. The key elements of such communications systems will be the communications bandwidth agility of multipointlbroadcast satellite channels, global coverage, and the deployment of very small aperture terminals and mobile satellite terminals (VSATs and MSATs). These factors will play a crucial role in the cost-effective realization of ISDN; intelligent network deployment; the future public land mobile telecommunications system (FTLMTS); and ultimately, the universal personal telecommunications (UPT) service. There is a distinct paradigm shift in the way these telecommunications networks are evolving. The next generation, which will incorporate frame relay, broadband ISDN