Application of a Model of Space-Correlated Time-Series into a Simulation Platform of Adaptive Resource Management for Ka-Band OBP Satellite Systems

Abstract

Multibeam Ka-band satellites are an attractive solution to address the capacity issue in satellite communication so as to allow provision of broadband multimedia services to the end user at acceptable cost. Although Ka band is attractive from the point of view of the amount of frequency bandwidth that the satellite can potentially use, the major limitation is the effect of radio-wave propagation through the lowest layers of the atmosphere, and requires the implementation of Fade Mitigation Techniques (FMT). In the design of a capacity and then cost-efficiency satellite systems it is of paramount importance to define a traffic management procedure to optimize the use of the satellite resource while providing the users with the required Quality of Service (QoS). One of the main problematic of resource management and signalling regards the impacts of the variable system capacity introduced by the adaptative physical layer of FMTs. A simulation platform to model Ka-band OBP satellite systems involving FMT has been developed. This OPNET network-oriented simulation platform enables to optimise and simulate resource management techniques taking into account channel propagation information and FMT behaviour, and constitutes a novel approach of linking channel impairments to higher layers performance. The simulator integrates three types of channel information: PDF of propagation effects such as attenuation and scintillation, space correlated attenuation time-series, radar maps of rain intensity field allowing to model spatial variability of rain cells in a medium-scale geographical area (typ. 200 km*200 km). The simulator enables to derive performance results covering different levels: system level (average throughput, link availability), call level (blocking and dropping probabilities), packet level (mean bit rate, buffer occupancy, packet scheduling statistics), and frame/slot level (slot occupation rate).