| Satellite Communications plays a significant role in supporting next generation IP-based heterogeneous communication network infrastructure for broadband fixed and mobile services. Emerging media streaming, mobile broadcasting, content delivery and distribution, and broadband Internet access require Quality of Service (QoS) guarantees. The unique behavior of satellite links such as, dynamic channel characteristics, propagation delays, need of fading countermeasures, QoS requirements for multiple traffic classes, and bandwidth asymmetry, pose significant challenges in designing protocol architectures including, layers, link level, network and transport layers for supporting high speed multimedia applications. Traditionally, satellite network protocol design has been based on a layered approach in which each layer in the stack is designed and operated independently with interfaces between the layers. The system dynamics representing the interactions among the protocols at the different layers is complex due to the existence of the parameters at different layers. However, exploitation of cross-layer protocol optimization and engineering lead to efficient performance and provisioning of end-to-end QoS.
In this paper we propose cross-layer protocol design approaches for satellite communication network. We provide a brief overview of cross-layer protocol optimization research emphasizing the interactions among, PHY, data links, network, transport and application layer. The iterations between physical layer and bandwidth allocation considering fade countermeasures, and dynamic resource allocation and the effect on transport control protocol (TCP) throughput are illustrated through examples. We provide some simulation results for geostationary (GEO) satellite network TCP throughput for different modulations at the physical level. Our simulation results demonstrate that the interaction/adaptation of these different layers of TCP/IP protocol stack for a satellite network improve the higher-layer goodput and satisfy application QoS requirements. Future research directions and standardization will be addressed including impact analysis of lower layers on the applications performance.
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| Dr. Sastri Kota is a Senior Scientist in Harris Corporation. He has held technical and management positions at Loral, Lockheed Martin, SRI International, the MITRE Corp, and Xerox Corp contributed to military and commercial satellite communication systems and broadband network design and analysis. Dr. Kota received his Ph.D from the University of Oulu, Finland; Electrical Engineer’s Degree from Northeastern University, Boston, MA; MSEE from IIT; BSEE from BITS, India. He is the principal author of a book Broadband Satellite Communications for Internet Access, co-edited book Emerging Location Aware Broadband Wireless Ad Hoc Networks, and wrote book chapters on Satellite TCP/IP and Broadband Networks. He has published over 100 papers and served in various capacities in IEEE, AIAA, and ACM conferences. He is member of the editorial boards on the International Journal of Satellite Communications and Networking, and the Space Communications Journal. He is on the Industry Advisory Boards of national and International universities. He is the USA Chairman of ITU-R Working Party 4B. He is the recipient of the Golden Quill Award from Harris Corporation, publication awards from Lockheed Martin and ATM Forum Spotlight Award. He is a Senior Member of IEEE, Associate Fellow of AIAA, and Member of ACM.
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