SI8912082A - Satellite cellular telephone and data communication system - Google Patents

Abstract

A system that provides global cellular / bundle is described mobile communication. This system allows communication with the help of the hand held and moving cell phone. System enables two-way communication anywhere on earth or above the earth for up to several hundred kilometers above the ground. The system uses many satellites moving around earths in orbits low set above the earth. Direct connections from satellites to users and via switched public telephone networks with other users. They are satellites interconnected via links in a ring the structure surrounding the earth. Commutation is performed with pages of each satellite. Additionally each of the satellites hand over the call as it moves beyond the scope of the individual user.

Description

MOTOROLA, INC.

Satellite pulp phone and data communication system

The present invention relates to global mobile communications, and more specifically to satellite cellulas, telephone and data communication system.

Today's geostationary satellite communication systems enable point-to-point communication. This means that the satellite acts as a relay station or curved tube. The satellite only receives information from one point on earth and transmits it to another fixed point on earth.

One such satellite communications system is disclosed in U.S. Patent No. 4,720,873. This system displays point-to-point communication via satellite for network programming and advertising purposes.

Some basic multiplexing functions may be provided within the satellite communications system satellites. One such system is disclosed in U.S. Patent No. 4,480,328. This patent refers to a satellite communications system in which the satellite is a time division multiplexed (TDMA) relay station.

The systems mentioned above and other systems talk about using one satellite to communicate from one point to another. These satellite systems do not show selectivity or data switching among a multitude of users.

Accordingly, the invention has the task of providing a global satellite multicell cellular communication system in low orbit above the earth, which directly connects to many cellular telephones and users equipped for data transmission and also connects these users to a switched public telephone network (PSTN).

In order to achieve the object of the present invention, a new satellite cellulose telephone and data communication system is shown.

In more detail, the invention provides a satellite communications system for establishing communications between a plurality of users, and includes satellite switches placed in low-orbit orbit and connecting devices for connecting said users to said satellite commutations, wherein a communication link is established between a selected of said users via the aforementioned satellite switches.

In a preferred embodiment, a wireless communication link connects users to satellite switches. The satellite switches then establish a communication link between the selected users. Each current user's position is determined and updated periodically. The satellites then associate these positions with the corresponding underlying database for storage. When a mobile user makes a call, the call is processed in the satellite closest to him. When a mobile user is calling, the satellite switches address the call via the respective satellites to the current location of the called user. As described above, other information about the user itself can be stored at the same locations of the database.

Other features and advantages of the invention will be described in the following description of a preferred embodiment of the invention with the accompanying drawings, wherein:

FIG. 1 is a schematic diagram describing the configuration of a satellite switching system of the present invention;

FIG. 2 is a block diagram describing the interconnection of a satellite switch with associated mobile users and the interconnection with a public switch telephone network;

FIG. 3 projection of the areas supplied by the flight of cellulamous satellite switches around the earth;

FIG. 4 block diagram of database deployment for satellite cellular communication system.

Figure 1 shows the configuration for the satellite cellular communication system. Many satellites in orbit low above the earth are shown in this configuration. A certain number of satellites are positioned in each orbital plane. Multiple orbital planes - 3 to 8 - are shown and are actually inclined and provide commutator coverage of the entire earth.

This satellite cellulam structure is in some ways analogous to the current cellular cellular telephone system. In this system, cell positions are fixed and users are flexible. As the user moves from one cell position to another, his / her phone call is processed from one cellular switch to another.

In the present invention, the users are relatively fixed at any given time, while the satellites, which are cells, are in constant motion. Communication with the hand-held telephone or mobile cellular telephone with the satellite switches shown in Figure 1 shall be established directly between the hand-held and attached cell-phone with the nearest satellite switch. Each satellite is moving around the earth. When a satellite that has just acted as a switch for an individual user leaves the cell of that switch, the user's prompt is transferred to the corresponding adjacent cell. Adjacent cells may be cells in one satellite or cells of other satellites positioned either in a special orbital plane or in an adjacent orbital plane. Users can travel, but the distance traveled is relatively small compared to the traveled routes of satellite switches.

Similar to the cellular cellular telephone system, the satellite cellular communication system provides spectral efficiency. This means that several different satellite switches can be used simultaneously by the same frequency.

Spectral efficiency is ensured by the spatial diversity between satellite switches and users.

Users can be positioned anywhere on the surface of the earth, on water or in air at a height smaller than the low satellite orbit. For example, a person on the surface of the earth may call a person on another part of the earth, a person on a craft or a person on an aircraft.

Hand held mobile or attached radio telephones can be used in this system. Today's technology requires less than 10 W.

In this system, each satellite shown is a commutator. Existing satellite communications systems operate primarily as relay stations or a curved tube. That is, they provide communication from a fixed point to a fixed point. In the present invention, the switching function is provided in each of the orbiting satellites.

As previously mentioned, in a preferred embodiment of the invention, each of the orbital planes is substantially inclined. Orbital satellite planes with lower inclination may also operate. A smaller slope, however, requires more satellite switches and / or greater orbital heights to achieve full coverage of the Earth's surface than is the case with highly inclined satellite orbits.

In a preferred embodiment, in a highly inclined orbital configuration, it is found that a satisfactory overlap of the Earth's surface with forty-eight low-orbiting satellites can be achieved. These satellites can be arranged in six highly inclined orbital planes, each with eight satellites in one plane. Other configurations may also be used. Other layouts with low orbital inclinations would require essentially more satellites to obtain the same ground coverage as with a highly inclined configuration.

Each satellite includes a satellite switch, corresponding antenna 11 - e.g. screw antennas for uplink / downlinks and lenses for crosslinks - and unfolded arrangement of solar cells 12 together with rechargeable batteries (not shown) connected to solar cells to provide power to the commutator. Satellite carriers and vehicles are also low-cost satellites themselves, such as those commercially available. The satellites are launched into orbit with the help of rocket launchers. When in orbit, the arrangement of the solar cells opens, thereby activating the commutator. The satellites are then individually integrated via conventional telemetry, tracking and control (TT&C) channels to form a network.

As shown in Figure 1, user A moves with the phone in his hand. Its channel request is received by dedicated satellite 1 as shown in Figure 1. The user is assigned a channel frequency and the requested number to be dialed is sent through the system. Each satellite is a distributed local processor and provides call switching. Satellite 1 commutes the call to the corresponding cell contained either within its own cellulite complement or in the corresponding complement of the satellite cell. Each satellite commutator determines the route until the call is received by satellite 2. Satellite 2 then sends this call to individual user B of the hand-held telephone, as shown in Figure 1.

Although two users are shown with a hand-held telephone, users may be on the water, in a moving vehicle, aircraft or part of a PSTN where the connection is through a hub. Each satellite is a local processor. This system determines to which relevant satellite or cell the call is switched. Each satellite determines the best path from itself to the next appropriate satellite. These definitions may be based on the part of the official telephone number of the called user.

Each satellite can project four or more fields to the earth and comprise four or more relevant cells for commutation. These cover fields are achieved with antennas - typically screwed in with constant beam widths that correspond to the number of fields. The covering cells are then distinguished using the existing cellulame technique. These areas or fields are shown in Figure 3 for one single plane of satellite rotation around the earth. This image shows highly inclined orbital satellite cellulam switches. Each satellite determines the optimal route from itself to the next satellite, after which it will make a specific call or data transfer. These satellite commutations operate on data packets and can therefore transmit voice or data digitally. Downlink and uplink data / digital voice is received on an FDM basis demodulated and then packaged for satellite-to-satellite communication

Figure 2 shows the interconnection of part of the satellites in one plane. The connection from the satellite to the corresponding mobile satellite user and to the switched public network is additionally shown. Three satellites are shown, satellite 40, satellite 50 and satellite 60. Satellite 40 is connected to satellite 50 by a connection. Satellite 50 is connected to satellite 60 with i + 1 connection. Satellite 60 is connected to the next next plane satellite - not shown - via i + 2 connection. Satellite 40 is connected to the following previous satellite - not shown - by using the i-1 connection. Each satellite plane forms a ring of connected satellites around the earth.

As mentioned previously, the drawing in Figure 2 shows the satellite plane. Additionally, each satellite is connected to one or more satellites in other orbital planes.

This means that each satellite is connected to the preceding and following satellites in its orbital plane and to one or more satellites in other orbital planes.

Inter-satellite connections i-1, i, and so on can be made by transmitting data using a microwave beam ah laser beam. Current technologies provide such data transmission.

For example, the connection between satellites and their moving users is achieved by the bundles j-1, j and j + 1. These bundles correspond to the boxes shown in Figure 3 and the commutator cells mentioned above. These bundles are made with the help of satellite antennas up / down which provide communication with users via the user in all directions of the radiating antenna. The limit on the number of users that individual satellites can simultaneously process depends on the bandwidth allocated and the available satellite power. This number can characterize 50,000 users per satellite.

Satellite 40 is shown in conjunction with an outside line ah node 10 via beam j-1. Any sitelink, such as satellite 40, is suitable for transmitting and receiving data from a node such as node 10. This node connection may be made using packetized data similar to a sate-to-sate connection.

Node 10 includes devices that connect to the Public Switched Telephone Network 20 (PSTN). All users of the 30 switched public telephone network are connected to the switched public telephone network 20. Since the sateht 40 is connected to the PSTN 20 via node 10, the mobile user of the satellite cellular system, which is directly connected via the sash with the sash, can transmit voice data via satellite structures - satellite satellite via appropriate connection - via node 10, via switched public telephone network 20 to selected user 30 PSTN ah vice versa.

Each sateht provides multiple bundles for data transmission. These data transmission bundles project overlapping fields, as shown in Figure 3 (showing the 400 NM polar orbital 6x8 configuration) showing four fields. Each sateht projects four such fields. As shown in Figure 2, a sateht can use one or more of its bundles to provide a connection to a node. At least one bundle is required to establish a connection between each node and the weigher. Typically, sateht connects to only one node. One hub provides enough outside lines to connect many mobile users to a switched public telephone network 20.

Each satellite performs internal switching between its four bundles or cells. This is analogous to switching within a forwarding point on conventional telecommunications systems.

The arrangement of the up / down link between satellites and their moving users ah the nodes through the bundles can transmit and receive data in the range of, for example, about 2.1 GHz to 3.9 GHz. Today's availability of technology and bands make it the preferred data transfer volume. However, the object of such an invention is not limited to the transfer of data in the art.

As previously mentioned, data - digital voice data - is transmitted in packet format. As a consequence, high speed data transmission as well as voice data transmission through the satellite system can be created. Data rates that are available with the available bandwidths are at least 1200 baud. However, with increased bandwidth, a significantly higher data rate can be achieved in the system.

Figure 4 describes a satellite commutator 100 that is directly connected to a moving user 120 via a beam 102. Satellite 100 is connected to a database computer 110 by a beam 104. Satellite 100 is also connected to a computer database 130 by a beam 106. This connection is can be directly through bundle 106, as shown in Figure 4, but indirectly via other satellites to the computer 130 of the database.

The agile user can travel around the home area. The home area can be places like New York, Los Angeles and more. The database computer 110 comprises all information pertaining to each of its moving users. As long as the individual moving user is operating in the home area, all available information relating to that user is available on the home computer database.

For example, if a user from Los Angeles travels to New York and intends to use their satellite celluloma phone to communicate, the database computer in the user's new perimeter, New York City, is unaware of that user's existence. If the home computer, Los Angeles, has a computer computer 110 for the moving user, then the computer computer 110 includes all the information for that individual moving user. As a result, the moving user would not be allowed to send calls because it was not recognized by the database computer from its home environment.

In order to cope with this problem, every moving user is periodically asked by the system about his location, so that even when he travels, his call for service can be identified and his route determined. However, since the database for the individual user is stored on the computer of the home environment database via the satellite system, the satellite system first scans the home environment to determine if it is no longer there and to obtain the user's commutator information. Once the determination is made, the database computer for the new home environment can be adapted to include the itinerant user. As a result, the user is then allowed to send and receive calls in their area. Because the satellite system asks the computer of the home environment database to determine its location, the user can be found throughout the satellite system. So the system has the ability to find and communicate with traveling users.

To facilitate the monitoring of each moving user, each mobile phone provides a control signal that is periodically monitored so that the nearest satellite can locate it when a subscriber initiates a call and asks his / her home computer database through the satellite network to determine information about to his permanent client. A mobile phone can automatically mark a new location on the satellite network in order to update the database computers. This control signal enables incoming calls from the itinerant user to be verified via a satellite-to-satellite link that reaches the computer of the home environment database.

Each satellite in the satellite cellulite communication system is independently navigable. This means that it uses a global positioning satellite system (GPS) or time or ephemeris data from which to calculate information about its position. In addition, from the fixed position of a global positioned satellite system or other vehicle, each satellite can determine its position and change its path according to staying inside its own orbit for as long as it performs commutator services.

Each satellite can switch an inter-satellite call - within an individual switch unit or cell - or it can connect a call through microwave or laser links, connect i, i + 1, and so on - to another satellite in its plane or out of plane, i.e. in the adjacent plane. Each satellite can distinguish between an individual telephone number and determine whether that number is within its own calling area or the calling area of another satellite. If it is in the call area of another satellite, the call is cross-linked to the next corresponding satellite or cell, which now makes the same determination until it reaches the satellite that uses that telephone number. This satellite links down to the individual moving user who needs to be called. Thanks to such a structure, the satellite network provides the capability of distributed node switching. Each satellite is a local switch for a specific area, but the area is constantly changing. Calls are therefore emitted as long as the satellite moves outside the area of each telephone user.

Different multiplexing procedures - such as FDMA, TDM, CDMA and others - can be used to extend the ability to transmit between different satellites with connections, as shown in Figure 2.

As the commutator units of the system move in orbit around the earth and are relatively prone to failure, this system makes it possible to maintain reliability through a process of encoding and decoding data commonly known in the art. Because the commutators are hundreds of miles above the ground, the system is also suitable for military communications applications.

Although the present preferred embodiment of the invention has been illustrated and described in detail in this form, it will be readily apparent to those skilled in the art that various modifications can be made without departing from the spirit of the invention or the scope of the appended claims.

Claims (21)

PATENT APPLICATIONS 1. Satellite cellulite communication system for establishing communication between a plurality of users, characterized in that it includes satellite commutator means located in orbit around the earth and linking means connecting said users to said satellite commutator means, establishes the connection between a selected of said users via said satellite switching means. System according to claim 1, characterized in that said satellite commutator means include a plurality of low-orbiting satellite commutators and other interconnecting means to enable multidirectional communication between the commutator of one satellite and the commutator of any adjacent satellite . System according to claim 2, characterized in that said other connecting means include microwave communication devices. System according to claim 2, characterized in that said other means of connection include laser communication devices. 5. System according to claim 2, 3 or 4, characterized in that said satellite switches include antenna means connected to said plurality of users for establishing communications between said users and satellite switches, and solar cells for providing power to said satellite switches , and the batteries associated with said solar cells for storing said energy. System according to any one of claims 1 to 5, characterized in that said satellite switching means comprise a plurality of cellular means connected to one another, wherein one of said cellular means transmits said established communication links between users to another of said cellular agents. A system according to any one of claims 1 to 6, characterized in that each of said users is connected to said cellular telephone connection means. System according to any one of the preceding claims, characterized in that it includes a database agent connected to said satellite switching means via said connecting means, and said database means and for transmitting switching information describe each of said crowds of users. System according to claim 8, characterized in that said database means include a computer database processing means and database linking means for connecting said computer database processing means to said satellite switching means for transmitting said switching information which refer to said users of said satellite switching means. A system according to claim 9, characterized in that said computer database processing means comprises a plurality of computer database processing units located in a corresponding plurality of geographical areas across the earth. System according to Claims 7 and 8, characterized in that said cellulose telephone has a control signal for connecting each of said users to said satellite switching means via said connecting means, said satellite switching means acting in response to said control signal each of said user cellulam phones to update said database with the current location of each user. System according to claim 1, characterized in that said satellite switching means include a plurality of cellular means connected to each other, wherein one of the cellular means transmits said established communication links between users of another of said cellular means. System according to claim 12, characterized in that each of said users is connected to said means for connecting via a cellular telephone. 14. Satellite-cellulite communication system for establishing communication between a plurality of users, characterized in that it includes satellite commutator means located in low-orbit orbit, interconnecting means that directly link certain of said users to said satellite commutator means, and a switched public telephone network which is connected to said satellite switching means via said connecting means, wherein the other of said users are connected to said switched public telephone network and said switched public telephone network operates by selectively connecting users of said switched public telephone telephone networks with users directly connected to said satellite switching means via said linking means. 15. The system of claim 14, further comprising means for connecting said means to said switched public telephone network, said connecting means providing node services between said satellite switching means and said switched public telephone network. System according to claims 14 or 15, characterized in that each of said designated users is connected to said cellular communication means. System according to claims 14, 15 or 16, characterized in that said satellite switches include a plurality of satellite switches arranged to encircle the earth in low orbit and another means of interconnection to allow multiple communications between one satellite commutators and commutators of any adjacent satellite. 18. The system of claim 17, wherein said second coupling means includes microwave communication devices. The system of claim 17, wherein said second coupling means includes laser communication devices. 20. A system according to claim 17, 18 or 19, characterized in that said satellite commutator units include antenna means connected to said plurality of users for communication between said users and satellite commutator units, and solar cells for providing power to said satellite commutators and rechargeable batteries which are connected to said solar cells for storing said energy. 21. The system of claim 14, wherein said satellite switching means comprise a plurality of cellular means connected to one another, wherein one of the cellular means transmits said established communication links between users to another of said cellular means.