BACKGROUND

Being the first global telecom success, GSM has the biggest footprint on earth, its commercial success not only because it has the longest history in operation, but also the cheapest handset that meets the voice call demands as well as its well-known SMS. Its major update GPRS, and EGPRS, also started mobile internet, which pave the way for 3G 4G and 5G.

The telecom market had been moved further to 5G, but GSM is still there in most part of the world. There are still over 1 billion people globally had never owned a mobile phone, and GSM service for them is still a great improvement for their life and work. GSM is still needed in many least developed countries (listed as LDCs by UN). To them get connected enables many great opportunities. It would jump start new economic growth and make many to have better and happier lives.

However, GSM terrestrial network establishment in LDC would not be so easy, as it needs to start with telecom fixed line network infrastructure. Some places have no electricity, and only started to have solar power. There is no fixed line communication system at all for most people, and electricity coverage is not 100%. Many places also have issues maintaining the safety of the cables, equipment and the assets doted sparsely.

Standard GSM User Equipment (UE), such as a GSM handset or GSM phone, communicates with a GSM base station (BTS) having ground-based cell towers that are within close range, typically up to 35 km and for extended TA feature 120 km. It does not communicate with a satellite, because of, for example, issues of the latency caused by the distance between base station-satellite-UE and the Doppler effect cause by the satellite at the speed of 7 km/sec to 8 km/sec, where intolerable latency and the Doppler effect with dynamic change as satellite flies over the UE being served by the satellite and on the earth, including the flying aircraft.

What is needed is a satcom GSM system directly talking to the GSM handsets which may be charged by solar power without relying on power grid and ground level telecom infrastructure over the country. To make it work, the BTS SW modification together with the latency normalization and Doppler compensation will be the necessary, which are disclosed in this filing.

SUMMARY

In the present disclosure application, the innovative modifications to base transceiver station (BTS), the GSM base station, housed in gateway sites, and a new sat RAN satellite beam handover mechanism allow a constellation of satellites with large enough phase array directly talk to the GSM handsets which may be charged by solar power without relying on mains electricity and ground level telecom infrastructure over the country or region. BTS/Core network (CN) satcom GSM of the present disclosure can directly talk to commercial unmodified GSM UEs for voice and data call.

