Research And Implementation Of Key Technologies In Onboard ATM Switching Systems

As an important developing direction of communication infrastructures, broadband multimedia satellite communication network aims at integrating spacial and terrestrial broadband communications to form a joint space communication network. One of the common features of the new broadband multimedia satellite communication systems is the adoption of onboard processing and switching technologies: shifting communication and routing from ground to satellites. In this way, the capacity of satellite system is largely broadened, and multiple needs from users are satisfied. In this paper, we focus on the research and implementation of the key technologies of new broadband multimedia satellite systems - onboard switching. On the basis of a thorough analysis of the current status and future trend of broadband multimedia satellite systems as well as switching technologies home and abroad, we carry out research, design and implementation of switching technologies suitable for onboard environment. The main contribution of this paper includes:1. Research, analysis and design of switching technologies suitable for onboard implementation: taking the particularities of onboard environment into consideration, we choose ATM switching from ATM, IP and MPLS switching for its maturity, reliability and future potential.2. Research the format of cell and design onboard switching cells: taking the particularities of satellite channels (such as a high bit error rate), and the requirement of broadcast and multicast into consideration, error-corrected coding design and format adjustment are made on the original ATM cells.3. Research, analysis and design of onboard ATM switching unit: taking the non-blocking, multicast and broadcast requirements into consideration, Crossbar is chosen from the three implementations of Crossbar, shared memory and shared bus, which has also brought the advantage of easy-of-controlling. And design a special switch unit which is suitable for the space use. Besides, research, analysis and design of onboard ATM switching fabrics: with the analysis of typical multi-path ATM switching fabrics, and considering the existence of inner blocking and HOL and the limitations from non-blocking input, Clos network is chosen for its strong scalability, low blocking rate and cost-effectiveness.4. Research, analysis and design of onboard ATM switching network routing methods: with the analysis and comparison of typical routing algorithms for Clos networks, CRRD is chosen for its high throughput and easy-of-implementation.5. Finally, a complete solution for onboard ATM switching system is given, which is described from 3 aspects: general introduction, switching module and reliability implementation.