BRPI1104239A2 - tranceptor device for communication between multipoint terrestrial wireless access system and non-geostationary satellite system - Google Patents

Abstract

Transceiver device for communication between point-to-multipoint terrestrial wireless access system and non-geostationary satellite system (100) comprising a point-to-multipoint terrestrial system antenna (110), an ERB receiving and transmitting module (120), a converter (130) and one or two antennas for NGEO system (140). Said device (100) is capable of generating a coverage area (210) for the point-multipoint terrestrial system, generating a spatial coverage area (240) in the NGEO satellite belt passing belt, and providing reception functionality, transmission, amplification and conversion of signals such that there is integration and communication between the terrestrial system and the NGEO satellite system.

Description

Patent Descriptive Report Transceiver device for communication between point-to-multipoint terrestrial wireless access system and non-geostationary satellite system.

Application field:

The present invention relates to a novel transceiver device capable of establishing communication between terrestrial wireless access systems (e.g. WiMAX) and non-geostationary satellite systems.

Description of the prior art:

Terrestrial point-to-multipoint wireless access systems for broadband data, voice and video applications employ base stations (ERBs) that mostly use omnidirectional or sectorial antennas, thus allowing end users to access (mobile or fixed) terminals under its coverage area. Such ERBs are typically integrated into telephony or data networks (e.g., the Internet) through other communication technologies which may be satellite links, optical links, point-to-point radio links, and others capable of carrying traffic. total communication from the user pool covered by the local ERB to a core network central station close to the telecommunications networks mentioned above.

In case this long-distance link is effected by a satellite link, integration is typically through a remote terrestrial station of the satellite network installed next to the terrestrial ERB, and the aggregate traffic of the ERB users is treated as a backhaut to the satellite system's central station (or HUB).

In the particular case of a system employing non-geostationary satellites (NGEO), the remote earth station shall contain mechanisms for maintaining the link via the nearest ERB satellite using directional antennas equipped with automatic satellite tracking systems along its arc. of movement in space. NGEO satellites are usually located in much lower orbits than geostationary satellites (GEO), and thus have a much shorter propagation delay, which positively influences the performance of many telecommunications applications.

In addition, due to the earth's natural obstruction of the NGEO satellite from a certain position during its passage through the ERB's visibility arc, it is necessary to employ a second directional antenna also equipped with a tracking system to communicate with the next NGEO satellite that will appear on the opposite horizon before the first one disappears or completely obstructs. Such antennas are large reflector-type antennas that have complex electromechanical automatic tracking systems that move each one from horizon to horizon of the satellite's arc, in opposite directions. Thus, the satellite link serving the ERB is secured at all times without being interrupted by the absence of antenna pointing.

However, such a solution - with two reflector antennas equipped with a tracking mechanism - makes the ERB satellite backlink more expensive, especially when the number of users served does not generate enough revenue for the network operator to adequately remunerate the investment costs in this power link (backhau!). In a way, the high cost creates drawbacks for the adoption of satellite systems, and more particularly NGEO satellites. Therefore, more flexible and less costly solutions are desirable for backhauI of remote wireless access systems, especially when using NGEO satellites.

Patent document MX04007734 (Wireless communications system and method using satellite-linked remote terminal interface subsystem) proposes the coupling of a satellite communications gateway station to a terrestrial communication network, allowing terrestrial network users to communicate through the interface. with this gateway station to the ground network ERB control station. In particular, the solution applies specifically to the Public Switched Telephone Network (PSTN). Figure 1 of this document MX04007734 presents this interface (242) as the element that interconnects the terrestrial base radio and the satellite earth station. This interface is called terrestrial terminal interface subsystem and contains two antennas, one for the terrestrial system and one for the satellite system, both co-located on the same terrestrial base station.

US5594780 (Satellite communication system that is coupled to a terrestrial communication network and method) also describes a system employing terrestrial gateway that allows a wireless telephone system to operate in cooperation with links from one or more satellites. In this case, gateways perform various functions, including call decoding and processing, handoff calls to other satellites, updating user databases in coordination with the network control center. The incorporation of these multiple functions into the gateway station makes it the same complex and consequently expensive, especially for a low density local system scenario of local users.

US5448623 (SateHite teiecommunications system using network coordinating gateways operative with a terrestrial communication system) describes a wireless telephone system capable of roaming the user via a satellite communication system with at least one ground gateway station. This gateway makes the final decision to cooperate with the network database to handoff between satellites in a constellation and without the need for satellite-based control. The incorporation of these handoff functionality between terrestrial user, satellite and roaming makes the gateway solution complex and expensive, especially considering low user density scenarios and remote areas where user access to the network can only be done through the gateway. the handoff decision between satellites can be made exclusively by the NGEO satellite constellation control system, depending on the location of the service area of the terrestrial wireless system in question.

Later, the same inventors of US5448623 proposed another solution, described in patent document W09842143 (Satellite communications system having distributed user assignment and resource assignment with terrestrial gateways), which consists of the GLOBALSTAR low-orbit NGEO satellite system, which It operates to this day with its multitude of ground gate stations spread across the planet. In the case of GLOBALSTAR gateways, their role is to pass the traffic captured by the satellites in the links with the wireiess terminals to the public or private terrestrial network already established in the country, allowing the system users to communicate with each other. other telephones of the national terrestrial network. Also in the case of the GLOBALSTAR system, the mobile terminals used are terminals specially developed to allow direct user communication with the constellation satellites and are therefore more complex and expensive than typical terminals of terrestrial communication systems.

As can be seen, despite the state-of-the-art solutions proposed, there are still challenges and drawbacks to be overcome for integrating a point-to-multipoint terrestrial access network with a telecommunications network employing NGEO satellites. In fact, current state-of-the-art solutions enable this integration through the use of technically complex and financially expensive gateways, with many associated functionalities for network integration to take place as expected. Or, the solutions do not allow the use of conventional mobile terminals, requiring the use of technically more complex mobile terminals specifically designed to communicate with the gateway and the point-to-multipoint terrestrial network side.

Objectives of the Invention: In view of the foregoing, it is an object of the present invention to provide a more flexible and less costly alternative for integrating a point-to-multipoint terrestrial access network for broadband data, voice and video applications served by user terminals. typical terrestrial networks, to telephony and data telecommunications networks (eg, the Internet) employing non-geostationary satellites (NGEO) operated in equatorial orbit.

It is also an object of the present invention to propose a much simpler gateway device than existing and known gateway stations (cited) in the prior art.

Simplified Description of the Invention:

The proposed objectives are achieved through the transceiver device for communication between point-to-multipoint terrestrial wireless access system and non-geostationary satellite system,

which comprises:

- a point-to-multipoint ground system antenna (110) whose

Transmission and reception of radio frequencies occur in the frequency bands intended for the point-to-multipoint terrestrial system in question, in order to form a coverage area (210) of terrestrial users, allowing their access to the network;

- an ERB receiving and transmitting module (120) which performs the

amplification of the reception and transmission of radio frequencies, and performs the respective interconnections necessary for the operation of the terrestrial system users, both by the level of sensitivity required by the ERB for the proper reception of the signals emitted from the covered user terminals, and by the

transmission power level required for ERB emission towards those same ground terminals;

- a converter (130) which converts the frequencies and duplexing modes required to match signals from terrestrial users to the frequency ranges and duplexing modes.

intended for the NGEO satellite communication system, and vice versa; - one or two antennas for the NGEO system (140), one of which is the main antennas (140) providing communication with a constellation NGEO satellite located in the passing belt (240) of the satellites according to visibility and ERB geographical position of the corresponding multipoint ground system, and the other optional antenna (140) monitors what will be the next active satellite to enter the passing belt (240).

Description of the Figures:

The invention will be better understood from the detailed description of the related figures, of which:

Figure 1 schematically represents a block diagram of the elements that make up the device of the present invention.

Figure 2 illustrates the operation of the proposed device operating between a point-to-multipoint terrestrial wireless access system and a non-geostationary satellite system.

Detailed Description of the Invention:

According to Figure 1, in one possible embodiment, the transceiver device for communication between point-to-multipoint terrestrial wireless access system and non-geostationary satellite system (100) comprises a point-to-multipoint terrestrial system antenna (110), a ERB receiving and transmitting module (120), a converter (130) and one or two NGEO array arrays (140).

The point-to-multipoint terrestrial system antenna (110) is an omnidirectional or sector antenna that forms the coverage area of terrestrial users, allowing them to access the network. Its transmission and reception of radio frequencies occur in the frequency bands intended for the point-to-multipoint terrestrial system in question, generally distinct from the bands intended for the satellite communications system. In the case of Brazil, the 3400 to 3600 MHz band is primarily allocated to fixed and mobile services (both terrestrial) and was regulated by Anatel Resolution 537/2010, allowing the non-exclusive use of WiMAX systems, for example. However, in this same band, the use of satellite communications is authorized only on a secondary basis (without the right to protection by the primary systems) and only for the Fixed Satellite Service. Similarly, in Brazil, the 2500 to 2520 MHz band is also primarily allocated to fixed and mobile services (both terrestrial) and was regulated by Anatel Resolution 544/2010, allowing the non-exclusive use of WiMAX and LTE systems, for example. However, in this same range, the use of satellite communications is not allowed, demonstrating yet another case where frequency conversion between terrestrial and satellite systems is required.

If the antenna 110 is of the sectoral type, it is a radiation diagram antenna for coverage on only a specific angular sector of the Earth's surface from the ERB where point-multipoint terrestrial system users are located. If the antenna 110 is of the omnidirectional type, it is an antenna with radiation diagram for all-round coverage (all directions) from the ERB where point-multipoint ground system users are located.

The ERB receive and transmit module (120) performs amplification of radio frequency reception and transmission. In addition, module 120 performs the respective interconnections necessary for the operation of terrestrial system users, both at the level of sensitivity required by the ERB for proper reception of signals emitted from the covered user terminals, and at the level of transmission power. required for the issuance of the ERB towards these same ground terminals.

The converter (130) converts the frequency division and doubling modes (TDD), the frequency division doubling (FDD) necessary to match signals from terrestrial users to the frequency ranges and duplexing modes intended. NGEO satellite communication system, and vice versa (adjusting signals from the NGEO satellite communication system to frequency bands and duplex modes intended for terrestrial users).

The transceiver device (100) has one or two NGEO array arrays (140). Array antennas make it easy to integrate with the other components of the transceiver device (100) and even allow NGEO satellite tracking only electronically, eliminating complex and expensive mechanical systems typically employed in reflective antennas (present in state-of-the-art solutions ).

Each of the two NGEO system antennas (140) is intended for

a particular function: (i) one of the antennas (140) provides communication with any and all constellation NGEO satellites located on the satellite passing belt in accordance with the visibility and geographical position of the ERB of the corresponding multipoint ground system; ii) the other antenna (140) monitors what will be the next active satellite, that is, the next constellation NGEO satellite that will enter the monitored passing belt. This second antenna 140 becomes optional if the electronic tracking system of the first antenna is implemented such that the beam switching time between the first satellite's disappearing position and the second satellite's appearance position is less than or equal to the active satellite status switching time between each other by the system operator or satellite constellation NGEO.

Said antennas (140) can be of two types: sectoral or variable beam directional. If sectorial, antenna 140 may be unique because it has a radiation diagram for coverage from the ERB in only one specific sector of the space where the system's NGEO satellites are located. If it is a variable beam directional type, antenna 140 has a directional radiation diagram and is capable of tracking in space a satellite in operation within the intended arc of passage for the system's NGEO satellites. In this case a second directional antenna may be required depending on the switching times between satellites mentioned above. The proposed device (100) differs from existing solutions in the state of the art, more particularly from the solution presented in MX04007734 (Wireless communications system and method using satellite-linked remote terminal interface subsystem) in that it integrates the two antennas intended for terrestrial systems. and satellite, as well as two other components responsible for the conversion, reception and transmission of signals in both communication systems. This integration is made possible especially by the great angular and spectral discrimination between the signals transmitted in each of the terrestrial and satellite systems (segments).

Additionally, the present device (100) stands out in relation to the solutions known also by the fact that it communicates with NGEO satellites in a single equatorial circular orbit, at which time only one of the constellation satellites is operational, ie it is the communication signal provider for a given ground system ERB. When a satellite approaches its angular limit of visibility on the horizon (west), in a short period of time that satellite passes the communication to the next active satellite, which appears in the same orbit on the opposite horizon (east).

Thus, the antennas (140) for communication with the active satellite and for monitoring the next active satellite have the primary function of enabling continuous communication with the operating satellite of the equatorial arc during its transit period, and its trajectory in space. is fully predictable based on the height and periodicity parameters of the respective satellite constellation.

Such predictability greatly simplifies the resources (hardware and software) required for the antennas (140) to ensure the pointing and minimum gain required to communicate with the operational satellite, unlike the constellation of NGEO satellites in multiple polar orbits. . In satellite constellations in polar orbits, multiple satellites can be seen at the same time from a given earth station, thus making it difficult to employ high gain directional antennas on these stations. And the process of deciding which satellite will be responsible for the communication link with the earth station at any moment becomes dependent on a complex algorithm controlled by the NGEO constellation management system. In the case of equatorial orbits, only one satellite is preferred and closest to the earth station at any given time, making it easier to track and employ high-gain directional antennas.

Figure 2 illustrates the operating principle of the proposed device 100 operating between a point-to-multipoint terrestrial wireless access system and a non-geostationary satellite system.

The point-to-multipoint ground system antenna (110) of device (100) produces a coverage area (210) of the point-to-multipoint ground system. Likewise, the NGEO system antenna (140) of the device (100) produces a spatial coverage area (240) relative to the passing belt of an operating satellite (250) of the NGEO satellite system.

Example signal traffic through device (100):

A signal (211) from a user terminal within the coverage area (210) of the point-multipoint ground system is picked up by the antenna (110) of the device (100). This signal (211) is received by the receiving and transmitting module of the ERB (120) and will have its radio frequency amplified (211 '). The converter (130) then converts the radio frequency assigned to the terrestrial system employed in that signal (211 ') to a frequency range assigned in a manner compatible with the NGEO satellite communication system, and also converts the duplex mode of that signal. (211 ') (e.g. TDD) to a more suitable duplex mode (e.g. FDD) to the NGEO satellite communication system. The result of this process is a signal converted (241) to the satellite system standard and which is transmitted from one of the antennas (140) of the device (100) to the operating satellite (250) that is present and active at the time belt. passage - spatial coverage area (240) - of the NGEO satellite system. Similarly, a signal (242) from an operational satellite (250) in the space coverage area (240) of the NGEO satellite system is picked up by one of the antennas (140) of the device (100). This signal (242) passes through converter (130), which converts the radio frequency assigned to this satellite signal (242) to a frequency range assigned to the point-to-multipoint terrestrial system, and also converts the duplex mode of this signal (242). (e.g. FDD) to a suitable duplex mode (e.g. TDD) to said point-multipoint ground system. The result of this process is a signal converted (212) to the terrestrial system standard, which is then routed to the ERB receiving and transmitting module (120), which amplifies its frequency (212 '). This signal 212 'is then transmitted by antenna 110 to a user terminal within the coverage area 210 of the point-multipoint ground system.

Although the invention has been described in connection with certain preferred embodiments, it should be understood that it is not intended to be limited to those particular embodiments. Rather, it is intended to cover all possible alternatives, modifications and equivalents within the spirit and scope of the invention.

Claims (6)

Transceiver device for communication between a point-to-multipoint terrestrial wireless access system and a non-geostationary satellite system (100) comprising: - a point-to-multipoint terrestrial system antenna (110) whose transmission and reception of radio frequencies occur at frequency bands intended for the point-to-multipoint terrestrial system concerned, with the aim of forming a coverage area (210) of terrestrial users, allowing their access to the network; - an ERB reception and transmission module (120) which performs the amplification of radio frequency reception and transmission, and performs the respective interconnections necessary for the operation of terrestrial system users, both at the level of sensitivity required by the ERB for proper reception of signals emitted from the covered users' terminals, as well as the level of transmitting power required for ERB emission towards these same land terminals; - a converter (130) which converts the frequencies and duplexing modes necessary to match signals from terrestrial users to the frequency bands and duplexing modes intended for the NGEO satellite communication system, and vice versa; - at least one NGEO system antenna (140) providing communication with a constellation NGEO satellite located in the satellite passing belt (240) according to the ERB visibility and geographical position of the corresponding point-multipoint ground system. 2. A transceiver device for communication between a point-to-multipoint terrestrial wireless access system and a non-geostationary satellite system (100) as claimed in claim 1, which optionally comprises a second antenna (140) which monitors the one that will be the next active satellite to enter the passing belt (240) if the switching time of the main antenna tracking system is not less than or equal to the traffic switching time between the two NGEO satellites operated on that same belt (240). 3. A transceiver device for communication between a point-to-multipoint terrestrial wireless access system and a non-geostationary satellite system (100) as claimed in claim 1 which in the sense of terrestrial-satellite transmission is characterized by said antenna (110) receiving a signal (211) from a user terminal within the terrestrial system coverage area (210), send that signal (211) to said ERB receive and transmit module (120) where it will be amplified (211 '), and the said converter (130) converts the radiofrequency and duplex mode assigned to the terrestrial system of that signal (2110 to a frequency range and duplex mode assigned compatible with the NGEO satellite communication system, generating a converted signal (241) to the satellite system standard and which is transmitted by one of the antennas (140) to the operational NGEO satellite (250). 4. A transceiver device for communication between point-to-multipoint terrestrial wireless access system and non-geostationary satellite system (100) as claimed in claim 1 which in the sense of satellite-terrestrial transmission is characterized by one of said antennas (140) receiving a signal (242) from an operating NGEO satellite (250), send that signal (242) to said converter (130), which converts the radiofrequency and duplex mode assigned to that satellite signal (242) to a frequency range and a duplex mode assigned to the point-multipoint terrestrial system, generating a signal converted (212) to the terrestrial system standard, which is subsequently routed to said ERB receiving and transmitting module (120), wherein that signal (212) it will have its amplified frequency (212 ') and will be transmitted by the antenna (110) to a user terminal within the coverage area (210) of the point-multipoint ground system. 5. Transceiver device for communication between point-to-multipoint terrestrial wireless access system and non-geostationary satellite system (100) according to claim 1, characterized in that said point-to-multipoint terrestrial system antenna (110) is of the sectoral type or omnidirectional type. 6. A transceiver device for communication between a point-to-multipoint terrestrial wireless access system and a non-geostationary satellite system (100) according to claim 1, characterized in that each of said NGEO system antennas (140) is of the sectoral type or of the omnidirectional type.