Adaptive Dynamic Channel Allocation Scheme for Spotbeam Handover in LEO Satellite Networks

Among satellite systems, low earth orbit (LEO) satellite system will make an important role in new fiture communication services, because of its less propagation delay, less power consumption in the user terminal and the satellites, and efficient spectrum utilization using smaller coverage area for each satellite than geostationa y (GEO) counterpart. However, a number of mobility problems that did not exist in GEO satellite systems should be solved. One noticeable mobility problem is the spotbeam handover which occurs most frequently in LEO satellite systems. The frequent spotbeam handover requires a technique to decrease handover blocking probability. In this paper, an adaptive dynamic channel allocation (ADCA) scheme is introduced for LEO satellite networks. The ADCA scheme estimates the future number of handover events based on the user location database, and reserves corresponding number of channels in order to decrease the overall handover blocking probabilities. Performance evaluation shows that the handover blocking probabilities of ADCA technique substantially decrease in comparison with the other channel allocation schemes. Keywords-LEO Satellite Network, Channel Allocation, Blocking Probability 'This work is supported by DoD, National Security Agency under Grant #MDA904-97-C-1105-0003.