A channel control technique for a hyper multi-point data gathering satellite communication system

We propose an efficient channel control scheme for gathering data from many observation points scattered over an ultra-wide area using a satellite communication system. There are a huge number of observation points, and the data packets to be transmitted are relatively short. To implement the system economically, the proposed scheme is expected to manage tons of channels correctly without large control signal overhead even if there are bit errors on the satellite link. Most of the observation points acquire pre-scheduled (PS) data such as rainfall and temperature measurement, while a few of them acquire event-driven (EV) data such as landslides and earthquake tremors. A pre-assigned channel access scheme will be adequate for the PS-type data. However, it is difficult to assign a channel for EV data before an event because the events to be transmitted are not predictable. Therefore, we propose a channel access scheme that is built on a pre-assigned scheme but also has an immediate and reliable scheme alternation process to accommodate EV data gathering. Performance evaluations showed that the proposed scheme greatly increases accommodation capacity and throughput compared with the conventional schemes in various observation point situations and link error conditions.