By Kenneth M. O’Hara and Gregory J. Skidmore, Remcom Inc., State College, Pa.
This whitepaper describes the modeling of a SATCOM link, specifically the use case of using a satellite overlay to extend service continuity to IoT devices in a poorly covered rural area.
The discussion focuses on how satellite coverage can be modeled using predictive simulation. Such models can simulate the SATCOM channel, capturing important effects such as terrain masking, shadowing due to foliage, and multipath fading, which are essential to a proper evaluation of the link budget. Further, ray tracing models can be used to identify cases where terrestrial coverage needs to be supplemented with a LEO satellite overlay to improve NB-IoT coverage in rural areas. These LEO satellites can provide coverage with relatively low latency, though this comes at the cost of complicating the communications channel, as large Doppler shifts must be compensated by the satellite and/or the UE.