Systems (100) and methods (400) for providing Digital Selective Calling (DSC) based services. The methods involve: using Space-Born Maritime (SBM) receivers of satellites (104) deployed in space as a satellite constellation to collect and process DSC emergency messages transmitted from DSC transmitters of terrestrial radios; using the satellites to position validate the DSC emergency messages; determining first positions of the DSC transmitters in transit based on geolocation data and time location data respectively assigned by the satellites to the DSC emergency messages; and validating the first positions to more precise second positions based on results of cross-correlations of the geolocation data and time location data with Automatic Identification Systems (AIS) data obtained for the DSC transmitters.

This application provides a method for calibrating satellite short message communication charging. In the method, an electronic device sends a target satellite short message to a satellite, performs a pre-fee-deduction operation for a satellite short message service, and updates a first parameter to a first value, where the first parameter is a remaining quota that is of the satellite short message service and that is stored in the electronic device. When the electronic device is connected to a communication network, the electronic device sends the first value to a server. The electronic device receives a first calibration result sent by the server, where the first calibration result indicates whether the first value is consistent with a second value, and the second value is a value of a remaining quota that is stored in the server. The electronic device calibrates the first parameter based on the first calibration result.

Methods, systems, and devices are described for providing selectable service offerings to mobile users via mobile terminals over a satellite communication system. In embodiments, a database of access profiles for accessing a network via the wireless communication system may be maintained, wherein each access profile corresponds to a service offering of a plurality of service offerings selectable via the plurality of devices and is associated with a set of network destinations within the network. In embodiments, a request is received from a device of the plurality of devices for a particular service offering of the plurality of service offerings. An access profile may be identified from the database that is associated with the particular service offering. Communications may be permitted between the device and the respective set of network destinations associated with the identified access profile.

Methods, systems, and devices are described for providing selectable service offerings to mobile users via mobile terminals over a satellite communication system. In embodiments, a database of access profiles for accessing a network via the wireless communication system may be maintained, wherein each access profile corresponds to a service offering of a plurality of service offerings selectable via the plurality of devices and is associated with a set of network destinations within the network. In embodiments, a request is received from a device of the plurality of devices for a particular service offering of the plurality of service offerings. An access profile may be identified from the database that is associated with the particular service offering. Communications may be permitted between the device and the respective set of network destinations associated with the identified access profile.

The present disclosure addresses unresolved problems of task scheduling by adding redundancy in a collection task schedule generated by a ground control station. Embodiments of the present disclosure provide a randomization based redundant collection task scheduling for mitigating occlusions in sensing by small satellite constellations. The randomization based redundant collection task scheduling algorithm receives as input a set of region of observations tessellated into sub-regions, and then collection opportunities for each sub-region is computed based on satellite tracks data. Further, a sub-set of collection opportunities is determined from all the possible collection tasks for each sub-region to further generate the collection task schedule for each of the region of observation. Number of collections opportunities is controlled by a decay function which holds number of redundant collections to a bound, thereby increasing chance of good collection without investing too much resource in redundancy to mitigate occlusions.