Communication ranges for radio links to elevated node

There is a need to replace the radio links in the mobile core net. The purpose of this report is to investigate whether it is possible or not, radio-technology-wise, to use an elevated node to enable tactical communication over an area. Coverage is desired over the area occupied by a battalion or brigade. This is an area with a depth of about 70- 100 km. In this area, communication coverage is desired without being dependent on any fixed communication infrastructure. In this report, we evaluate four different system concepts, A-D. In concepts A-C an aerostat at 300 m heigth is tethered at the rear edge of the area to be covered. In system concept A the aerostat communicates directly with a low mast. In concept B a mobile ground node is added and in concept C additional masts are added. Concept D is a reference case based on today's structure. In the report, we calculate the communication ranges that the concepts would provide, for different terrain types, data rates and frequencies. The analyzed frequencies are 300 MHz, 1350 MHz and 4400 MHz. The range calculations show that concept A does not reach the desired range in the analyzed scenario. Concept B might give a communication range close to the desired if the two lower frequencies are used. Concept C gives sufficient communication range at the cost of additional masts. The number of needed nodes is similar in concept C and reference case D, but C gives a more mobile solution due to the lower masts.