MXPA99004975A - Terrestrial communication system - Google Patents

Abstract

A terrestrial communication system, facilitating audio, video, data and any other type of communication within a local geographical area, and with an extremely large number of communication channels being made available simultaneously at a very low cost. It comprises at least one local terrestrial satellite (LTS), preferably located in a mast or any other supporting structure, each (LTS) having high frequency communication equipment substantially corresponding to a conventional geostationary satellite for digital transmission of video, audio or data, arranged to transmit in the L Band (1-2 GHz), the S Band (2-4 GHz) or a higher frequency band with a relatively low power output and having a preferably omnidirectional antenna installation for transmission in a substantially horizontal plane. The signals can be digitalized according to MPEG-2 or according to any known or future signal algorithm.

Description

TERRESTRIAL COMMUNICATION SYSTEM TECHNICAL FIELD The present invention relates to a terrestrial communication system that facilitates the communication of audio, video, data and any other type of communication within a local geographic area, and with an extremely large number of communication channels that are available from Simultaneously, at a very low cost.

BACKGROUND TECHNIQUE Audio, video and data communication are rapidly growing areas of interest, and terrestrial communication circuits, radio communication channels and satellite communication systems are used extensively. Dedicated cable systems are also being used to cover geographic areas with a large number of T.V. channels, and these cable systems can also be used for data transmission purposes. Digital transmission techniques have been developed and, as a result, T.V. consumer transmissions. are not available from satellite transponders and, due to the digital techniques used, the number of programs transmitted by each transponder is no longer a single P1331 / 99MX program, since several programs can be transmitted simultaneously, for each transponder. However, with respect to terrestrial transmission techniques, an adequate system has not yet been developed, but a dedicated system is expected to be available within a few years. This will require the development of suitable encoders and decoders developed specifically by digital ground transmission techniques and frequency bands currently used for terrestrial transmission purposes of T.V. Considerable efforts and large amounts of money have been invested in the development of appropriate techniques, but until now, these efforts have not been successful.

EXPOSITION OF THE INVENTION The present invention is based on the discovery that presents satellite transmission techniques that can also be used for terrestrial transmissions. As a result, a user who has equipment for the reception of digital satellite signals can also use the same equipment for the reception of transmissions by ground. This is achieved by having communication equipment of the type used in satellites such as Local Terrestrial Satellites (LTS - Local Terrestrial Satellites) in a P1331 / 99MX mast or other suitable foundation. The transmission from an LTS is based on one of the conventional standards for digital transmission used today by geostationary satellites in conventional orbit, for example, MPEG-2 or MPEG-1 or by any other suitable standard for audio transmission purposes, video or data. A currently preferred standard is frequency-modulated MPEG-2 (also compatible with MPEG-1), but other known or future standards can be used, also techniques of amplitude-modulated (AM) transmission can be used as an alternative to frequency transmission techniques modulated Each LTS is transmitting using relatively low output power and with an antenna array that preferably has little or no directional effect. As a result, an adequate number of LTS can be cloned to cover a local geographic area, giving residents access to individual communication channels for data, video (TV) and audio communication. The advantages of this system will be fully analyzed later. The terrestrial communication system, in accordance with the present invention, comprises at least one local terrestrial satellite (LTS), preferably located in a mast or in any other support structure, each LTS has corresponding high frequency communication equipment.

P1331 / 99MX practically to a conventional geostationary satellite for digital video, audio or data transmission, arranged to transmit in the L-band (1-2 GHz), in the S-band (2-4 GHz) or in a more frequent frequency band high with a relatively low output power and with an antenna installation preferably omnidirectional for transmission in a practically horizontal plane.

BRIEF DESCRIPTION OF THE DRAWINGS A number of non-limiting examples of the embodiments in accordance with the present invention will be described with reference to the accompanying drawings, wherein: Figure 1 is a top view showing in diagram a system basic in accordance with the invention, which includes only one local terrestrial satellite (LTS) and two users of the system. Figure 2 is a side view, shown in diagram, of a mast arranged to support two LTS at different heights. Figure 3 is a side view diagrammatically showing a system according to the present invention, which illustrates in theory how a large number of LTS can be placed in a circular array. Figure 4 is a top view of four LTS is a square arrangement, indicating the area in P1331 / 99MX where users can communicate with any one of these four LTS. Figure 5 is a side view of a number of masts, each supporting an LTS, intended to illustrate how the masts or any other support structure can be placed closer together; and Figure 6 is a diagrammatic view from above, illustrating how an LTS number can be attached for internal communication.

WAYS TO CARRY OUT THE INVENTION As mentioned above, the present invention is based on the discovery that current communication techniques used for digital satellite communication purposes can also be used for terrestrial communication purposes. This fact has not been done previously and, consequently, all research efforts have been directed to the development of alternative techniques that facilitate digital transmission within the T.V. conventional. In accordance with the present invention, communication equipment of the type currently used in modern Earth orbit communication satellites is arranged in a mast or in any other suitable structure, thus forming a local satellite Terrestrial P1331 / 99MX (LTS). The transponders are connected to an omnidirectional antenna system, and the parts using the system preferably use parabolic antennas that can be directed towards the omnidirectional antenna system. A simple system of the above type is shown diagrammatically from above in Figure 1, from Figure 1, showing an LTS with practically circular and geographically restricted coverage, the edge of which is designated as 1, and a number of dish antennas 2, 21, each connected to equipment 3, 3 'of the type used to receive and decode digital signals of the same type as those transmitted from conventional satellites. The output power from this type of equipment 3, 3 'is advantageously fed to a computer and a video signal can be observed on the monitor, television screen or any other medium, with the audio signal converted into audio from a speaker system. With respect to the data communication, it can be multidirectional, that is, a computer with relevant equipment for the reception / transmission of signals can receive and transmit signals from a computer to the LTS, and thus communicate with other connected computers to the LTS or other communication systems that communicate with the LTS.

P1331 / 99MX The system analyzed in the above is a basic system, that is, only one LTS is exposed. However, the number of LTS within a local geographic area can be increased as desired, thereby increasing the number of communication channels practically indefinitely. This can be achieved by arranging more than one LTS on a mast or other supporting structure, separated by an appropriate vertical distance. This is shown diagrammatically in Figure 2. In addition, these masts or support structures can also be arranged horizontally spaced from each other (as illustrated in diagram in Figure 3), and unless a user has a suitable directional antenna installation, for example, a satellite dish or a multiple beam directional antenna, the antennas connected to the LTS transponders used only need to be spaced a few degrees apart in relation to the location of the antenna. a user, to reduce the interference from LTS located adjacent to an acceptable level (with interference from an adjacent LTS not selected, practically reduced to nothing). The communication between used LTS transponders and users involves low power output, normally an output power of 2 to 5 Wats is sufficient, even when the power of P1331 / 99MX increased output can also be used. High-frequency band transmission is also used, starting preferably in the 2 to 4 GHz S-band range, but oscillating up to 400 GHz. However, the transmission can also take place outside these limits, that is, within the L band (1-2 GHz). The low output power in combination with the high frequency transmission makes it impossible to limit the transmission to a restricted predetermined local geographic area. By increasing / decreasing the transmitted output power, the area covered by an LTS can be modified as desired. Modifications to the antenna system may also be used, in particular if interference is to occur between two or more LTS having different locations, whereby the output power in the undesired direction (s) may be reduced, as an alternative to the reduction in output power. There are no problems with interference between geostationary satellites orbiting the earth and an LTS in the system according to the invention, since the LTS are placed below the arc on the horizon defined by these satellites. Consequently, the signals transmitted from these geostationary satellites can be received without interference from signals transmitted by LTS on the same frequency, since the satellite dish P1331 / 99MX that receives has an increased angle to the horizontal plane when it is arranged to receive the signal from a satellite that orbits the earth, as compared to an antenna destined to receive signals coming from an LTS. The system according to the present invention makes this possible within a local geographic area, to obtain a considerable number of communication channels. It is known that the difference in the location of geostationary satellites needs to be only in the region of 2o to 3o to avoid interference between channels transmitted with the same frequency. Even if this angular difference is increased to 6o for a system in accordance with the present invention, this would result in 60 (360 ° / 6) LTS locations when located in a circular array as shown in Figure 3. Each mast or any another structure that supports local terrestrial satellites must be arranged to support three individual LTS (in a high, very high, and extremely high location), the number of LTS covering a restricted predetermined geographic area would be increased to 180 (3 x 60), while an arrangement with two LTS increases the number to 120 (Figure 2). Each LTS alone can transmit approximately 5,000 T.V. of acceptable quality and, as a result, the system in accordance with the present invention can P1331 / 99MX transmit simultaneously, 900,000 (180 x 5,000) different T.V. within a local district, without interference problems. This number, in fact, can be increased further, since the LTS can also be arranged alternating high-low in relation to the ground plane (as discussed in Figure 5), so that each location point can be even closer than shown in Figure 3. The circular configuration of Figure 3 can be replaced by any other configuration and, an additional example is shown in Figure 4. In relation to the equipment currently used for receiving signals from an LTS, they can parabolic dishes and satellite receivers with digital decoders should be used, provided that the frequencies of channels transmitted from the LTS fall within the same frequency range as that used by current geostationary satellites. Consequently, users will not require expensive additional equipment for the reception of T.V. or T.V. text, the only modification required would be to direct the parabolic dish antenna towards the LTS. In relation to the programs transmitted via the system in accordance with the present invention, it is obviously possible to fix an LTS that is used for transmission of T.V., connected to parabolic troughs and receiving equipment for programs transmitted from P1331 / 99MX orbiting geostationary satellites, and retransmit these programs via the LTS. As a result, a user would gain access to all these channels without the normally required large-diameter disk antenna and the control system that facilitates the rotation thereof, in order to locate and receive signals from various geostationary satellites that have different positions in relation to each other. reciprocal. Users may require channel payment programs of the system and receive a charge for the time of use. Another interesting feature with the system according to the present invention is the possibility of "video on demand". The use of digital transmission and "smart card" techniques has now made it possible to offer users of existing geostationary satellite systems the possibility of viewing certain on-demand programs, for example, motion pictures. However, current systems include the transmission of movies at predetermined times, and a user can telephone the operator, requesting one of the movies that pass at a certain start time. A specific signal is sent to the user, by means of which the decoder (or a smart card) is activated to decode the required film from the start time until the end of it. The cost to see P1331 / 99MX this particular movie is billed to the user. However, this can not be considered as video on actual order, since the user is limited to making a selection among a restricted number of movies and the user must also accept the predetermined start times. Due to the large number of channels available in a system according to the present invention, the video on demand that really fulfills any requirement of a user can be offered. Any desired movie can be ordered, for example by phone, as well as at any start time. When ordering, the user receives information on the channel number that will be used, for example, 28F. The operator has access to a library of video films, for example of satellite communication, and can obtain, from anywhere in the world, the desired film, transferred in digitized form at a high speed and stored by the operator in a medium of suitable storage, for example, a storage device on the hard drive. This means that any movie available in the world can be viewed at any time desired by an individual user, and the costs involved may be related to a specific user. As mentioned above, the system according to the present invention can also P1331 / 99MX used for data communication purposes. A computer suitably equipped with transmission and / or reception equipment connected to an antenna system, may therefore be arranged to communicate with an LTS. For example, communication can be established via the Internet facilitating high-speed communication, and with speeds not available through telephone circuits. The link from the LTS can be obtained through a geostationary satellite that orbits the earth, a cable, an LTS link system (which will be discussed below), or by any other suitable method. This computer can also be used as a T.V. receiver, or be linked to a separate monitor used as a television screen. As mentioned in the above, the system according to the present invention can also be used with one or more of the included LTS that are part of a terrestrial link system. By including a type of antenna preferably directional in the antenna system, directed towards a second LTS, which also preferably has a similar type of antenna directed towards the first LTS, a link can be established between them. The second LTS can be arranged in a manner similar to the first LTS to communicate with a third LTS, which in turn is equipped to communicate with a fourth LTS, and so on.

P1331 / 99MX successively (Figure 6). The local district can thus be interconnected with each other and / or links can be established for communication of data, video or audio over long distance and / or for communication with appropriate centers that give access to communication networks by cable or satellite communication or to any other desired function. It is also within the scope of the present invention to use the LTS only for audio communication, i.e. a user can make contact with an LTS by means of a small transceiver to establish verbal contact with another user having similar communication equipment. . In addition, the LTS can also be connected to a public telephony network, whereby a user with equipment that is practically similar to a cell phone can initiate or receive telephone calls. The type of LTS used in the terrestrial communication system in accordance with the present invention has not been described in detail, but is composed of communication equipment known to a person skilled in the art and suitable for a communication satellite in Earth orbit. , commonly known as a geostationary satellite. The antenna system is commonly omnidirectional, but can, as mentioned above, also include antennas with certain P1331 / 99MX purposes that have a more or less directed lobe. The equipment for receiving signals from an LTS includes equipment of a similar preference to that used for the reception of signals from geostationary satellites using digital transmission techniques. An advantage of the present system is that the directional antenna of required plane can be manufactured in a way that is very small, in comparison with the plates used for receiving signals from geostationary satellites. A preferred signaling technique is MPEG-2, but as stated above, any other known or future digital transmission technique can be used, among which the first version of MPEG (MPEG-1) is included. Frequency modulation (FM) is a preferred modulation technique, but amplitude modulation (AM) can also be used. The examples of use provided in the above, of the system according to the present invention, are only intended to expose some of the possible applications with the system according to the present invention. However, the fields of use are not left in any way, limited to these examples, since the present invention opens up new and previously unknown possibilities due to the extremely large amount of communication channels available in P1331 / 99MX any given area and without problems with the interference of other channels or transmitters (due to the short range of the signals and the addressing capacity of the antennas used for reception purposes). The LTS included in the system can advantageously make use of existing masts and other tall structures and the low cost of an LTS makes it possible to implement the system in accordance with the present invention at very low costs. The reception of television programs requires only equipment that is currently available and widely available, such as that used to receive signals from geostationary satellites. The possibility of two-way communication from a computer to an LTS opens the field of communication for companies, local authorities and other entities, and an individual can communicate with local stores and other local businesses to, for example, place orders and make purchases. . All this is achieved by using low-cost equipment and well-proven techniques, resulting in an enormous availability of communication channels / frequencies within a local and restricted geographical area.

Industrial Application The system in accordance with this P1331 / 99 X invention solves the problem of terrestrial transmission of digital video, audio and data signals. The existing satellite that receives sets of T.V. it can receive, without modifications or additional equipment, several hundred channels, of television from one of the LTS included in the system. The T.V. systems Therefore, cable systems are obsolete due to the low number of programs that can be transferred via cable, and also due to the initial costs to establish a cable network. All problems with "shadows" (echoes) in conventional terrestrial TV systems are also avoided. Moreover, the system can be used for data communication purposes, by means of which the communication speed is increased at speeds equivalent to those of a local area network (LAN -local area network). For example, in a municipality, the local administration data system can be accessed from schools, rescue service and other local services without the need for a local, high-speed cable system. Local television can also be made available to all inhabitants at an extremely low cost. The local systems according to the present invention can also serve as repeaters of TV programs transmitted from P1331 / 99MX geostationary satellites or TV programs transmitted by land, and local systems can also be linked together in a network. The availability of this large number of channels / frequencies at such low cost opens previously unknown possibilities for using information technology (IT - information technology) with new and valuable purposes, for example, education, local purchases, video on demand, work (distance work from home), communication to the Internet at high speed and many other fields of use.

P1331 / 99MX

Claims (11)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property; 1. A terrestrial communication system that facilitates unidirectional or bidirectional communication for users within a restricted geographical area, with the use of frequencies within the microwave range and a relatively low output power, characterized in that the system comprises at least two terrestrial local satellites that have high frequency communication equipment and which corresponds to practically a conventional geostationary satellite that uses digital transmission techniques, the antenna system of each local terrestrial satellite is located separately from the rest of the local terrestrial satellites that serve the geographical area to be covered, the antenna systems are preferably omnidirectional and are arranged for transmission in a practically horizontal plane; system users have directional antenna facilities that can select the desired local terrestrial satellite by changing the directional antenna in the horizontal plane (rotating) or in the vertical plane (inclination plane), thus facilitating the frequencies used by a local satellite P1331 / 99 X terrestrial system are also used by any other local terrestrial satellite included in the system for similar or different communication purposes, thereby increasing the number of communication channels available within a given frequency segment to a practically unlimited number of channels, through the inclusion of an additional local terrestrial satellite - covering the intended geographical area.
2. 2. A terrestrial communication system according to claim 1, characterized in that the antenna systems of at least two local terrestrial satellites located adjacently are supported separately from each other at different heights in a mast or in any other supporting structure, sufficiently separated from one another to facilitate the transmission and / or reception of signals at any channel frequency with respect to users having directional antenna systems with a certain degree of tilt, without undue interference from other signals transmitted and / or received at the same frequency from antenna systems located at different heights, thus facilitating simultaneous multiple use of any frequency used by the system.
3. 3. A terrestrial communication system according to claim 1 or 2, characterized in that the P1331 / 99MX geographical location in horizontal plane of adjacent local terrestrial satellites, covering almost all or part of the same geographical area, are located sufficiently far apart to facilitate the transmission and / or reception of signals at a specific frequency with with respect to users who have directional antenna systems without undue interference from signals transmitted and / or received at the same frequency from local terrestrial satellites having a different geographical location, thus facilitating the simultaneous multiple use of any frequency used by the system .
4. A terrestrial communication system according to any of claims 1 to 3, characterized in that the local terrestrial satellites are arranged and connected to a system for communication with geostationary satellites, and are arranged to serve as repeaters of the signals received from the satellites geostationary or transmitted to geostationary satellites.
5. 5. A terrestrial communication system according to any of claims 1 to 4, characterized in that the local terrestrial satellites are arranged to be connected to a system for the distribution of video films, and because any video film available within the P1331 / 99MX system can be requested so that a user of the system can see it individually at any desired time.
6. 6. A terrestrial communication system according to any of claims 1 to 5, characterized in that at least one local terrestrial satellite is arranged with a cable connection to a data communication network, to a private or public telephone network or to any other network by existing cable.
7. 7. A terrestrial communication system according to any of claims 1 to 6, characterized in that at least two terrestrial local satellites are arranged to communicate with each other, preferably with directional antenna systems for this purpose.
8. 8. A terrestrial communication system according to any of claims 1 to 7, characterized in that the number of communication channels within a specific geographical area and with a determined number of communication frequencies is increased by an increase in the number of local satellites terrestrials that cover the specific geographical area, each local terrestrial satellite "reuses" the determined number of communication frequencies, that is, the number of available communication channels is equal to the determined number P1331 / 99MX of frequencies multiplied by the number of local terrestrial satellites.
9. 9. A terrestrial communication system according to any of claims 1 to 8, characterized in that the signals transmitted from and / or received by the terrestrial local satellites are digitized in accordance with MPEG-2 or in accordance with any known or future signal algorithm .
10. 10. A terrestrial communication system according to any of claims 1 to 9, characterized in that the system is preferably arranged to operate within the L-band (1-2 GHz) or within the S-band (2-4 GHz) or, in any case at frequencies below 25 GHz.
11. 11. A terrestrial communication system according to any of claims 1 to 10, characterized in that the geographical area covered by each local terrestrial satellite is increased or reduced as required, by adjusting the output power. P1331 / 99MX