Medium-earth-altitude satellite-based cellular telecommunications

A constellation of telecommunication satellites which provides 24-hour cellular telephone communication coverage over a predetermined latitude range around the world for a cellular transceiver having an omni-directional antenna operating at a power level as low as 1/2 watt, comprising:

• a plurality of telecommunication satellites, each of said satellites having a plurality of multibeam antennas for enabling simultaneous bi-directional communication links with a plurality of cellular-based telecommunication devices;
• each of said satellites residing in one of a plurality of predetermined orbits, with the number of said satellites in each of said orbits being different than the number of said orbits to provide 24-hour cellular telephone communication coverage over a predetermined latitude range around the world which is less than whole earth coverage;
• and
• each of said predetermined orbits being related to the other orbits such that each of said predetermined orbits has a predetermined inclination angle with respect to the equator, a predetermined altitude of between approximately 5600 nmi and 7500 nmi, a predetermined ascending node spacing between satellites in different orbital planes, and a predetermined relative phase angle between satellites in different orbital planes such that an arriving satellite comes into view above a predetermined minimum elevation angle before a departing satellite disappears from view.

A cellular telephone communication system having at least one planetary-based gateway station, a plurality of telecommunication satellites having a plurality of multibeam cellular communication antennas and at least one land-based mobile telecommunication device which is randomly located in a fixed cellular service region, said cellular telephone communication system being characterized by:

• each antenna providing a predetermined field of view which is less than the field of view for any of said satellites limiting a maximum swing of the boresight angle of said antenna to approximately .+-.4.degree. relative to NADIR for communication coverage with said land-based mobile telecommunication device to achieve 24-hour cellular telephone communication coverage over a predetermined latitude range around the world which is less than whole world coverage, and
• an orbital configuration of said satellites in which each of said satellites resides in one of a plurality of predetermined altitude orbits of between approximately 5600 nmi and 7500 nmi, each of said predetermined orbits being related to the other orbits such that each of said predetermined orbits has a predetermined inclination angle with respect to the equator, a predetermined ascending node spacing between satellites in different orbital planes and a predetermined relative phase angle between satellites in different orbital planes.

A cellular telephone communication system having at least one planetary-based gateway station, a plurality of telecommunication satellites having a plurality of multibeam cellular communication antennas and at least one land-based mobile telecommunication device which is randomly located in a fixed cellular service region, said cellular telephone communication system being characterized by:

• each antenna providing a predetermined field of view which is less than the field of view for any of said satellites, and
• an orbital configuration of said satellites in which each of said satellites resides in one of a plurality of predetermined altitude orbits of between approximately 5600 nmi and 7500 nmi, with the number of said satellites in each of said orbits being different than the number of said orbits, each of said predetermined orbits being related to the other orbits such that each of said predetermined orbits has a predetermined inclination angle with respect to the equator, a predetermined ascending node spacing between satellites in different orbital planes, and a predetermined relative phase angle between satellites in different orbital planes;
• the number of said satellites, the field of view of said satellites and said orbital configuration combining to provide 24-hour cellular telephone communication coverage over a predetermined latitude range around the world which is less than whole earth coverage.

A cellular telecommunications system, comprising:

• at least one mobile cellular telephone station having an omnidirectional antenna, said mobile cellular telephone station including means for transceiving radio frequency energy (RF);
• at least one additional mobile or fixed telephone station being spaced from said mobile cellular telephone station within a predetermined region of the earth, with the fixed telephone station being connected to a gateway station including an antenna for transceiving radio frequency energy (RF);
• a satellite constellation located in space over the earth and including apparatus for transceiving radio frequency energy (RF) for providing a radio frequency energy communication link with said mobile cellular telephone station and said additional mobile or gateway station, said satellite constellation comprising:
• a plurality of telecommunications satellites, said plurality of telecommunications satellites being spaced and moving in a plurality of orbits about the earth with the movement of said satellites being non-synchronous to the rotation of the earth, said plurality of orbits being circular;
• all of said plurality of telecommunications satellites being at an altitude between approximately 5600 nmi and 7500 nmi above the earth;
• and
• at least one of said telecommunications satellites being in the line of sight to both said mobile cellular telephone station and said additional mobile or gateway station at any instant of time, with said line of sight being at a minimum elevation angle of no less than 10.degree.;
• wherein a radio frequency energy (RF) propagation time between said mobile cellular telephone station or said additional mobile or gateway station to said telecommunications satellite is less than 60 msec;
• and
• wherein said telecommunications satellites have receiving antennas permitting reception at said altitude of signals emitted from said mobile cellular telephone station having an omni-directional antenna.

A cellular telecommunications system, comprising:

• at least one mobile cellular telephone station, said mobile cellular telephone station having an omni-directional antenna and including means for transceiving radio frequency energy (RF);
• at least one additional mobile or fixed telephone station being spaced from said mobile cellular telephone station within a predetermined region of the earth, with the fixed telephone station being connected to a gateway station including an antenna for transceiving radio frequency energy (RF);
• a satellite constellation located in space over the earth and including apparatus for transceiving radio frequency energy (RF) for providing a radio frequency energy communication link with said mobile cellular telephone station and said additional mobile or gateway station, said satellite constellation comprising:
• a plurality of telecommunications satellites, said plurality of telecommunications satellites being spaced and moving in a plurality of orbits about the earth with the movement of said satellites being non-synchronous to the rotation of the earth, said plurality of orbits being circular;
• all of said plurality of telecommunications satellites being at an altitude between approximately 5600 nmi and 7500 nmi above the earth;
• at least one of said telecommunications satellites being in the line of sight to both said mobile cellular telephone station and said additional mobile or gateway station at any instant of time, with said line of sight being at a minimum elevation angle of no less than 10.degree.;
• wherein a radio frequency energy (RF) propagation time between said mobile cellular telephone station or said additional mobile or gateway station to said telecommunications satellite is less than 60 msec;
• wherein said telecommunications satellites have receiving antennas permitting reception at said altitude of signals emitted from said mobile cellular telephone station having an omni-directional antenna;
• and
• wherein the number of orbits and the number of telecommunications satellites per orbit and the spacing of said satellites is sufficient to insure that said mobile cellular telephone station is always within view of at least two satellites.

A cellular telecommunications system, comprising:

• at least one mobile cellular telephone station, said mobile cellular telephone station having an omni-directional antenna and including means for transceiving radio frequency energy (RF);
• at least one additional mobile or fixed telephone station being spaced from said mobile cellular telephone station within a predetermined region of the earth, with the fixed telephone station being connected to a gateway station including an antenna for transceiving radio frequency energy (RF);
• a satellite constellation located in space over the earth and including apparatus for transceiving radio frequency energy (RF) for providing a radio frequency energy communication link with said mobile cellular telephone station and said additional mobile or gateway station, said satellite constellation comprising:
• a plurality of telecommunications satellites, said plurality of telecommunications satellites being spaced and moving in a plurality of orbits about the earth with the movement of said satellites being non-synchronous to the rotation of the earth, said plurality of orbits being circular;
• all of said plurality of telecommunications satellites being at an altitude between approximately 5600 nmi and 7500 nmi above the earth;
• and
• at least one of said telecommunications satellites being in the line of sight to both said mobile cellular telephone station and said additional mobile or fixed telephone station at any instant of time, with said line of sight being at a minimum elevation angle of no less than 10.degree.;
• wherein a radio frequency energy (RF) propagation time between said mobile cellular telephone station or said additional mobile or gateway station to said telecommunications satellite is less than 60 msec;
• wherein said telecommunications satellites have receiving antennas permitting reception at said altitude of signals emitted from said mobile cellular telephone station having an omni-directional antenna;
• and
• wherein a predetermined relative phase separation between said telecommunications satellites in adjacent orbital planes ensures that, before a leaving telecommunications satellites disappears from view above said minimum elevation angle, at least one arriving telecommunications satellites comes into view above said minimum elevation angle.

A cellular telecommunications system, comprising:

• at least one mobile cellular telephone station, said mobile cellular telephone station having an omni-directional antenna and including means for transceiving radio frequency energy (RF);
• at least one additional mobile or fixed telephone station being spaced from said mobile cellular telephone station within a predetermined region of the earth, with the fixed telephone station being connected to a gateway station including an antenna for transceiving radio frequency energy (RF);
• a satellite constellation located in space over the earth and including apparatus for transceiving radio frequency energy (RF) for providing a radio frequency energy communication link with said mobile cellular telephone station and said additional mobile or gateway station, said satellite constellation comprising:
• a plurality of telecommunications satellites, said plurality of telecommunications satellites being spaced and moving in a plurality of orbits about the earth with the movement of said satellites being non-synchronous to the rotation of the earth, said plurality of orbits being circular and having an altitude of approximately 5600 nmi above the earth;
• and
• at least one of said telecommunications satellites being in the line of sight to both said mobile cellular telephone station and said additional mobile or fixed telephone station at any instant of time, with said line of sight being at a minimum elevation angle of no less than 10.degree.;
• wherein a radio frequency energy (RF) propagation time between said mobile cellular telephone station or said additional mobile or fixed telephone station to said telecommunications satellite being less than 60 msec;
• and
• wherein said telecommunications satellites have receiving antennas permitting reception at said altitude of signals emitted from said mobile cellular telephone station having an omni-directional antenna.

A cellular telecommunications system, comprising:

• at least one mobile cellular telephone station, said mobile cellular telephone station having an omni-directional antenna and including means for transceiving radio frequency energy (RF);
• at least one additional mobile or fixed telephone station being spaced from said mobile cellular telephone station within a predetermined region of the earth, with the fixed telephone station being connected to a gateway station including an antenna for transceiving radio frequency energy (RF);
• a satellite constellation located in space over the earth and including apparatus for transceiving radio frequency energy (RF) for providing a radio frequency energy communication link with said mobile cellular telephone station and said additional mobile or fixed telephone station, said satellite constellation comprising:
• a plurality of telecommunications satellites, said plurality of telecommunications satellites being spaced and moving in a plurality of orbits about the earth with the movement of said satellites being non-synchronous to the rotation of the earth, said plurality of orbits being circular;
• all of said plurality of telecommunications satellites being at an altitude between approximately 5600 nmi and 7500 nmi above the earth;
• and
• at least one of said telecommunications satellites being in the line of sight to both said mobile cellular telephone station and said additional mobile or fixed telephone station at any instant of time, with said line of sight being at a minimum elevation angle of no less than 10.degree.;
• wherein a radio frequency energy (RF) propagation time between said mobile cellular telephone station or said additional mobile or fixed telephone station to said telecommunications satellite satellites is less than 60 msec;
• wherein said telecommunications satellites have receiving antennas permitting reception at said altitude of signals emitted from said mobile cellular telephone station having an omni-directional antenna;
• and
• wherein each of said telecommunications satellites includes an antenna capable of transceiving over multiple radio frequency energy beams.

A method of providing cellular telecommunications, comprising the steps of:

• establishing a satellite constellation having a plurality of telecommunications satellites spaced in a plurality of inclined orbits about the earth with the movement of said satellites being non-synchronous to the rotation of the earth, all of said plurality of telecommunications satellites being at an altitude between approximately 5600 nmi and 7500 nmi above the earth;
• providing a plurality of mobile or fixed cellular telephone stations for users on the earth;
• initiating a telephonic communications session with a mobile cellular telephone station, said mobile cellular telephone station including means for transceiving radio frequency energy (RF) and an additional mobile or fixed telephone station being spaced from said mobile cellular telephone station within a predetermined region of the earth, with the fixed telephone station being connected to a gateway station including an antenna for transceiving radio frequency energy (RF), by transmitting a radio frequency energy (RF) signal from said mobile cellular telephone station through an omni-directional antenna to be received by one satellite of said constellation of telecommunications satellites for providing an RF communication link between said mobile cellular telephone station and said additional mobile or fixed telephone station;
• wherein at least one of said telecommunications satellites is in the line of sight to both said mobile cellular telephone stations and said additional mobile or gateway station at any instant of time, with said line of sight being at a minime elevation angle of no less than 10.degree.;
• wherein the radio frequency energy (RF) propagation time between said mobile cellular telephone station or said additional mobile or gateway station to said telecommunications satellite is less than 60 msec;
• and wherein said telecommunications satellites have receiving sensitivity and antennas permitting reception at said altitude of signals emitted from a mobile cellular telephone station having an omni-directional antenna with an RF power level of one half watt;
• and
• retransmitting said RF signal through an antenna of said satellite to said additional mobile or gateway station to be received at said additional mobile or gateway station and establishing a communication link between said additional mobile or gateway station and said mobile cellular telephone station.

A medium-earth-orbit, satellite-based cellular telecommunications system comprising:

• a plurality of mobile cellular telephone stations including at least one transceiver with an omni-directional antenna;
• a constellation of telecommunications satellites providing a multibeam radio frequency (rf) communications link for said plurality of cellular telephone stations, the satellites being placed in a plurality of inclined orbits about the earth at an altitude of between approximately 5600 and 7500 nautical miles, wherein at least one satellite includes:
• a multibeam antenna having a boresight;
• and
• directing means for adjusting said antenna boresight to focus on a predetermined region of the earth as the satellite orbits said predetermined region.