MXPA97009616A - Gran alti sub-orbital communication system - Google Patents

Abstract

The present invention relates to a wireless telecommunications system comprising a plurality of telecommunication nodes including receivers and transmitters that are located in a sub-orbital plane. Telecommunications signals are broadband digital radio signals that are modulated by time-spread multiple spread spectrum technology. The receivers include a plurality of antennas that are operable to receive signals of relatively weak telecommunications and that use spatial processing to identify their source, so that the maximum use of the spectrum is made available for use by the telecommunication signals without interference.

Description

SUB-ORBITAL COMMUNICATION SYSTEM OF GREAT ALTITUDE This patent application is a partial continuation of patent application Serial No. 08 / 100,037, filed July 30, 1993, entitled; SUB-ORBIT COMMUNICATION SYSTEM OF GREAT ALTITUDE. FIELD OF THE INVENTION This application relates to a communications system that is operational at the sub-orbital level and provides increased efficiency and increased utilization of available telecommunications channels. BACKGROUND OF THE INVENTION The increase in cellular telecommunications has posed enormous tensions on the telecommunications capacity that has been generated. Consequently, users of current analog cellular telecommunications systems find that they may have to wait for a telecommunications channel to become available before they can make or receive a call. In addition, a call in progress may find interference in the form of noise or really over-listening to another conversation. Sometimes, a call can be cut while it is in progress if one of the parties moves to a cell that does not have a telecommunications channel available.

The problem is further aggravated by the fact that there is only a limited number of frequencies allocated for cellular telecommunications. Thus, it is foreseeable that the problem will increase as the demand for cellular telecommunications expands. The industry has developed several improved analog and digital technologies that have been used successfully to increase the number of telecommunications channels within the limited number of available frequencies. The most important of these technologies are multiple access by time distribution (TDMA) and multiple access by code distribution (CDMA). TDMA is the technology that has the widest use. It allows to use an individual telecommunication channel to vary calls. Each call is assigned a particular discrete time interval in the cycle of telecommunication signals, thereby improving efficiency. CDMA uses a broad band of spectrum for telecommunications signals to achieve efficiency. Difference between calls by printing a distinctive "noise" propagation signal on each telecommunications signal to differentiate it from other telecommunications signals in the cell. The computer-assisted receiver decodes the assigned "noise" signal to identify the call and then disproves the telecommunications signal. "Frequency Hopping" is a form of CDMA that propagates a call over a series of frequencies. Use a code to identify the sequence of frequencies used. Additionally, work has been done with respect to the development of systems that can identify weak signals coming from a cell and segregate these signals from other signals coming from the same cell, so that when combined with a digital multiple access technique such as CDMA, the number of available telecommunications channels increases enormously. Attempts to increase the availability of telecommunications channels have also included attempts to reduce the size of the cells and to reduce the energy requirements necessary for communication with a base station: This follows from the fact that a weak signal has a capacity reduced to spread. Thus, since its intensity dissipates rapidly, the same frequency can be used in a neighboring non-continuous cell. However, to provide the required number of cells that would be necessary to support a high volume of telecommunications, there should be a huge number of base stations. Some experts estimate that at least 100,000 cells would be needed simply to cover important metropolitan areas in the United States. Each cell would require its own stationary antenna tower. further, a highly complex computer system would be required in order to process the commutations that would be necessary when cell phones move from one cell to another and to manage the reuse of the frequencies assigned to particular calls. It is not true that the problem can be solved with a land-based system at a reasonable cost and in a reasonable period. Thus, although the typical limitations associated with such systems as line of sight, obscuration due to signal reflection, attenuation and horizon limitations, are eliminated by reducing the size and increasing the number of cells, geographic, political, environmental and social factors they can prohibit the placement of antenna towers in certain places, making it impossible to get cells of an appropriate size in those places. A system of satellites where each of the satellites works as a node of base stations and contributes to the creation of a cellular network avoids these problems. However, relatively powerful transmitters are required in a system of this type because the satellites are typically in orbit at approximately 22,500 miles above the earth. In addition, unless they are geosynchronous, a means must be provided to switch signals from one satellite to another when they pass a given point on the ground. In addition, as with terrestrial nodes, a means of switching is needed when a requesting partner moves between cells. Additionally, satellite systems suffer enormous costs in relation to the launch, and the virtual impossibility of repair. Accordingly, taking into account the above, the present invention relates to a wireless telecommunications network system comprising a plurality of telecommunication nodes that are located in a sub-orbital plane. Each of the nodes comprises means for issuing and receiving broadband digital radio communications signals through a wireless telecommunications channel. The telecommunications signals are modulated by multiple access propagation spectrum technology by code distribution. The means for emitting and receiving wireless digital telecommunications signals include a plurality of antennas that are operable to receive relatively weak telecommunication signals from a source. Means are provided to decode the telecommunications signals received by each of said antennas so that the node can identify the source, and the antenna and decoding means are operative to increase the sensitivity of the node, so that it can detect and receive signals from relatively weak telecommunications, so that the maximum use of the spectrum is available for use by telecommunication signals without interference. DESCRIPTION OF THE DRAWINGS The invention can be further understood by reference to the accompanying drawing of a presently preferred embodiment thereof, and wherein: Figure 1 is a schematic drawing showing a telecommunications system constructed in accordance with a form of the presently preferred invention. Figure 2 is a schematic drawing showing an aspect of the detection and decoding means. DESCRIPTION OF A PREFERRED EMBODIMENT With reference now to Figure 1, a system , such as that described in patent application Serial No. 08 / 100,037, comprises a land-based portion 12 and an air-based portion 14. The air-based portion 14 can be positioned at an altitude between about 12 to 35 miles above the earth. The land-based portion 12 may comprise a conventional telephone network 16 with taps which are connected to ground stations 18, 120 and 140 having long-distance transmission and reception means, such as antennas 20, 118 and 138. The portion Land-based 12 can also comprise mobile phones of well-known types such as cell phones that can be carried by people 22 or in vehicles 24. Antennas 20, 188 and 138 are operative to transmit and receive telecommunication signals to and from a high-altitude relay station, sub-orbital 28, which is located at an altitude of approximately 12 to 35 miles above the earth. This altitude is selected because it is well above the atmospheric activity, so that the relay station will not be subject to the stresses that may be caused by the weather. Preferably, there are a plurality of relay stations 28; each comprises a balloon 32 which is held in flight and stationary on a particular location on the ground using a guide module 56 which is connected by a guide antenna 56 to antennas 36 for ground connection, as described in the application Patent Patent Serial No. 08 / 100,037, filed July 30, 1993. As is well known, each relay station 28 contains means for receiving a telecommunication signal by telephone from one of the ground stations 20, 120 and 140, of persons 22 and 122 or vehicles 24 and 124 and then transmitting it to another ground station 120 and 140, to person 122 or vehicle 124 either directly or through another relay station. The telecommunications channel thus established could be simplex, duplex or semi-duplex. Once the signal returns to the ground-based portion 12 of the system 10, the telecommunications call is completed in a conventional manner, such as by connecting the wired, land-based telephone system through switches 34, 134 and 144 appropriate. The switches can be of any type suitable for telecommunications signals including digital and analog. As is well known, each of the relay stations 28 defines a mode in the telecommunications system, where each node defines a "cell". Preferably, each of the nodes comprises means for emitting and receiving broadband digital radio communications signals through a wireless telecommunications channel. Preferably, the telecommunications channel has a frequency bandwidth that is greater than about 8 MHz. The telecommunication signals are preferably modulated by multiple access propagation spectrum technology by code distribution. To utilize the maximum available frequencies beyond what is currently available with CDMA, the cells should be relatively small and the signal strength required for telecommunications signals should be very low. This will improve the possibility of frequency reuse and reduce interference. However, the reduced signal strength makes it more difficult for base stations to track the movement of particular cell phones. A detection system is provided which comprises an appropriate series of decoder antennas 48 in each of the relay stations. The detection system is of a type similar to the spatial processing system described in FORBES ASAP; June 5, 1995, on pages 125-141. The system processes the signal received by each of the antennas in the series. The decoded signals identify the transmitter and its location in the cell. So that, although a very weak signal is received, which can be lost ordinarily, by the detection system, it can still be recognized and processed to complete a telecommunications channel. The advantages of the combination of CDMA propagation spectrum and the detection system comprising the series of antennas described above are improved when they are combined and placed in the sub-orbital plane, since all the disadvantages of terrestrial systems are avoided. of satellites, while maintaining their advantages, such as vertical propagation of signals, thus increasing the use of the telecommunications spectrum. In addition, the energy requirements can be reduced and the weight of the transmitters at the nodes can be correspondingly reduced. Also due to the modulation technique, the number of transmissions can be reduced. Thus, a large number of telecommunications channels can be established in a cell defined by a particular node without the interference problems resulting from cross calls, reflection, frequency reuse and the like. Additionally, the relatively high energy requirements that a system of this type would require if associated with a satellite-based telecommunications system are avoided. It is contemplated that the system that has been described will use multiple access propagation spectrum technology by time allocation; including direct sequence and / or frequency hopping techniques. Still further, although the frequency assignments for the telecommunications system have not been identified with particularity, it should be understood that they could be the same as those assigned for terrestrial telecommunications, or those assigned for satellite telecommunications. Similarly, it is within the scope of the invention that the frequencies are those that are used exclusively for the telecommunications system. Although the invention has been described with respect to certain forms and embodiments, it is clear that other forms will be apparent to those skilled in the art in light of the above description. Thus, the scope of the invention should not be limited by the description, but rather only by the framework of the appended claims.

Claims (38)

1. A wireless telecommunications network system comprising: a plurality of telecommunication nodes, said nodes being located in a sub-orbital plane approximately 12 to 35 miles above the earth, each of said nodes comprising means for emitting and receiving signals from radio telecommunications by time-sharing multiple access propagation spectrum technology, and further including said means for emitting and receiving said radio telecommunication signals a plurality of antennas that are operative to receive relatively weak telecommunication signals from a source, means for decoding the telecommunications signals received by each one of said antennas, so that each one can identify said source, and said antennas and said decoding means being operative to increase the sensitivity of said node, so that it can detect and receive signals of telecommunication relatively weak, so the maximum use of the spectrum is available for use by such telecommunications signals without interference.

2. A system as defined in claim 1, wherein said multiple code spread access propagation spectrum technology is direct sequence.

3. A system as defined in claim 1, wherein said multi-access code spread propagation spectrum technology is frequency hopping.

4. A system as defined in claim 1, wherein said wireless telecommunications channel has a frequency bandwidth that is greater than about eight MHz.

5. A system as defined in claim 1, wherein each of said nodes is stationary on its own point on the ground.

A system as defined in claim 1, wherein said means for emitting and receiving broadband digital radio telecommunications signals through a wireless telecommunications channel comprises: at least one transmitter and receiver, and said transmitter and receiver they carry a plurality of duplex telecommunications channels.

7. A system as defined in claim 6, wherein said transmitter is of low power and light weight.

8. A system as defined in claim 1, including: a land-based telecommunications network, and means for connecting said wireless telecommunications network system to said land-based telecommunications network.

9. A system as defined in claim 8, wherein said means for connecting said wireless telecommunications network system to said ground-based telecommunication network includes switches.

10. A system as defined in claim 9, wherein said switches are digital.

11. A system as defined in claim 9, wherein said switches are analog.

12. A system as defined in claim 1, wherein said knots are supported by balloons.

13. A system as defined in claim 1, wherein said wireless telecommunication frequencies are the same as those assigned for terrestrial telecommunications.

A system as defined in claim 1, wherein said means for emitting and receiving broadband digital radio telecommunications signals through a wireless telecommunications channel comprises: at least one transmitter and receiver and said transmitter and receiver carry a plurality of simplex telecommunications channels.

15. A system as defined in claim 14, wherein said transmitter is of low power and light weight.

16. A system as defined in claim 1, wherein said means for emitting and receiving broadband digital radio telecommunications signals through a wireless telecommunications channel comprises: at least one transmitter and receiver and said transmitter and receiver carry a plurality of semi-duplex telecommunications channels.

17. A system as defined in claim 16, where said transmitter is of low power and light weight.

18. A system as defined in claim 1, wherein said wireless telecommunication frequencies are the same as those assigned for orbital telecommunications.

19. A system as defined in claim 1, wherein said wireless telecommunication frequencies are used exclusively by said telecommunications system.

20. A method for establishing wireless telecommunications, comprising the steps of: providing a plurality of telecommunications knots, said knots defining a network, locating said knots in a sub-orbital plane approximately 12 to 35 miles above the ground, providing each of said means knots for emitting and receiving wireless digital radio telecommunications signals through a wireless telecommunications channel, providing each of said nodes with a plurality of antennas that are operative to receive relatively weak, digital radio communications signals from a source, modulating said telecommunication signals by multiple code spread propagation spectrum technology, decoding said telecommunications signals received by each of said antennas, so that said node can identify said source, and said antennas and said decoding media so n operations to increase the sensitivity of said nodes, so that they can detect and receive relatively weak telecommunication signals, so that the maximum use of the spectrum is available for use by said telecommunication signals without interference.

21. A method as defined in claim 20, wherein said multiple code spread access propagation spectrum technology is modified by direct sequence.

22. A method as defined in claim 20, wherein said multiple code spread access propagation spectrum technology is modified by frequency hopping.

23. A method as defined in claim 20, wherein said wireless telecommunications channel has a frequency bandwidth that is greater than about eight MHz.

24. A method as defined in claim 20, wherein each of said knots is stationary on its own point on the ground.

25. A method as defined in claim 20, wherein said step of sending and receiving broadband digital radio telecommunications signals through a wireless telecommunications channel comprises: the step of providing a plurality of transmitters and receivers, and each of said transmitters carries a plurality of duplex telecommunications channels.

26. A method as defined in claim 25, wherein said transmitters are of low power and light weight.

27. A method as defined in claim 20, which includes the steps of: providing a land-based telecommunications network, and connecting said wireless telecommunications network system to said land-based telecommunications network.

28. A method as defined in claim 27, including the step of: providing switches for connecting said wireless telecommunications network system to said land-based telecommunications network.

29. A method as defined in claim 28, wherein said switches are digital.

30. A method as defined in claim 28, wherein said switches are analog.

31. A method as defined in claim 20, including the step of supporting said knots by balloons.

32. A method as defined in claim 20, wherein said wireless telecommunication frequencies are the same as those assigned for terrestrial telecommunications.

33. A method as defined in claim 20, wherein said step of issuing and receiving broadband digital radio telecommunications signals through a wireless telecommunications channel comprises: the step of providing at least one transmitter and a receiver, and transmitter and receiver carry a plurality of simplex telecommunications channels.

34. A method as defined in claim 33, wherein said transmitters are of low power and light weight. 33.

A method as defined in claim 20, wherein said step of emitting and receiving broadband digital radio telecommunications signals through a wireless telecommunications channel comprises: the step of providing at least one transmitter and a receiver, and said transmitter and receiver carry a plurality of radio channels. semi-duplex telecommunications.

36. A method as defined in claim 35, wherein said transmitters are of low power and light weight.

37. A method as defined in claim 20, wherein said wireless telecommunication frequencies are the same as those assigned for orbital telecommunications.

38. A system as defined in claim 20, wherein said wireless telecommunication frequencies are used exclusively by said telecommunications system.