Medium-earth-altitude satellite-based cellular telecommunications
US5439190A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1993 |
| Grant date | Aug 8, 1995 |
| Priority date | — |
| Expiry date | Oct 12, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/195
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A satellite-based cellular telecommunications system employing a constellation of telecommunications satellites in medium earth orbit to provide multibeam radio frequency (rf) communications links for worldwide cellular telephone service with a minimum number of satellites. The telecommunications satellites are placed in a plurality of inclined orbits about the earth at an altitude of between approximately 5600 and 10,000 nautical miles. The characteristics of the orbits, such as the number of orbits, the inclination of each orbit, the number of satellites in each orbit and the altitude of the satellites, are tailored to maximize the coverage area of the satellites and their related line-of-sight elevation angles, while minimizing propagation time delays, the number of beam-to-beam and satellite-to-satellites handovers, and the total number of satellites. The present invention also includes several additional features which essentially eliminate beam-to-beam and satellite-to-satellite handovers, thus dramatically reducing the likelihood of dropouts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.