A Proposal for Service Satellite Selection over LEO Satellite Networks Using Geographical Location Information

摘要

Since LEO (Low Earth Orbit) satellites move relative to Earth, handovers are required from time to time. Some LEO satellite networks have satellites orbiting in two different direction. One from north to south and one from south to north. Communication between satellites orbiting in different directions can take place only through the polar region. Therefore when terminals are connected to satellites orbiting in different directions propagation delay is longer than when they are connected to satellites orbiting in the same direction. Usually two satellites can be seen by a ground terminal, one satellite orbiting in each direction. Conventional service satellite selection method, select the satellite which has the highest angle of elevation to handover a terminal, which can result in two communicating terminal getting connected to satellites orbiting in different directions. In the case of handover between satellites orbiting in different directions the degradation of communication quality is higher due to the drastic change in delay. In this paper we propose a satellite selection method to connect communicating terminals to satellites orbiting in the same direction, using geographical location information of the communicating terminals, We show through simulation that the proposed method reduce the delay and jitter, number of hops required for communication as well as congestion in polar region links.