• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:

    公开号:NL1007685A1
    申请号:NL1007685
    申请日:1997-12-03
    公开日:1998-06-08
    发明作者:Keith Andrew Olds
    申请人:Motorola Inc；
    IPC主号:
    专利说明:

    HYBRID CONSTELLATION SATELLITE COMMUNICATION SYSTEMS AND METHODS WITH EFFICIENT SIGNALING AND CONTROL
    FIELD OF THE INVENTION
    The present invention relates to communication systems and, more particularly, to systems and methods for sending and receiving signals between satellites in communication systems.
    BACKGROUND OF THE INVENTION
    There are significant advantages to combining a constellation of low Earth orbit (LEO) satellites (LEO = Low Earth Orbit) and a constellation of geosynchronous (GEO) satellites to provide a global communication system. Many prior art systems have been proposed using a single constellation and some have been proposed using two or more constellations.
    In satellite communication systems, there are generally two classes of signaling data used to support and control the subscriber services provided by the system. In-band signaling is fed into the control channel and is closely linked to the service channel. In general, associated control channels share the same physical operating resources as the service channels, so that it is usually very low data rate channels to avoid overloading the service channel operating resources and deteriorating the ability of the system to generate revenue. Out-of-band signaling is sent using physical assets other than those used by the service channels. These signaling channels may or may not carry signaling data associated with an active service session.
    Prior art hybrid systems have limitations because these prior art systems have not made full use of the strengths and weaknesses of each constellation type. The GEO satellites in the systems are limited due to their fixed position. GEO satellites provide better equatorial coverage but, in connection with this, have more delay. Individual LEO satellites have limited coverage due to their relatively low height. LEO constellations provide better non-equatorial coverage and less delay.
    What is needed is a method and apparatus that overcome these limitations and that allow more efficient and cheaper satellite communication systems to be constructed.
    BRIEF DESCRIPTION OF THE DRAWINGS
    Figure 1 shows a block diagram of a hybrid constellation satellite communication system according to a preferred embodiment of the present invention;
    Figure 2 shows a block diagram of a subscriber device according to a preferred embodiment of the present invention;
    Figure 3 shows a block diagram of a system control center according to a preferred embodiment of the present invention;
    Figure 4 shows a flow chart of a method of operating a hybrid constellation satellite communication system according to a preferred embodiment of the present invention;
    Figure 5 shows a flow chart of a method of operating a system control center in a hybrid constellation satellite communication system, in accordance with a preferred embodiment of the present invention;
    Figure 6 shows a flow chart of a method of operating subscriber equipment in a hybrid constellation satellite communication system according to a preferred embodiment of the present invention;
    Figure 7 shows a block diagram of a GEO satellite in accordance with a preferred embodiment of the present invention;
    Figure 8 shows a flow chart of a method of operating a first satellite in a hybrid constellation satellite communication system according to a preferred embodiment of the present invention;
    Figure 9 shows a block diagram of an LEO satellite in accordance with a preferred embodiment of the present invention; and
    Figure 10 shows a flow chart of a method of operating a second satellite in a hybrid constellation satellite communication system according to a preferred embodiment of the present invention.
    DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
    The methods and systems of the present invention overcome these limitations and make it possible to construct more efficient and cheaper satellite communication systems. The method and apparatus of the present invention utilize the strengths of each constellation type and avoid many of the weaknesses of each individual constellation type. However, a hybrid constellation of this type requires coordination of service and constellation control to realize these benefits.
    The method and apparatus of the present invention provide a hybrid satellite system that includes an efficient control and signaling subsystem that efficiently manages the services provided by the system. In a preferred embodiment of the present invention, the hybrid satellite system includes a GEO constellation and an LEO constellation. For example, delay-sensitive services are routed over the LEO constellation, which has little propagation delay, and non-delay-sensitive services and signaling are routed over the GEO satellites for their stability and generally large capacity.
    The method and apparatus of the present invention also have other advantages. One advantage is that there are no inter-satellite connections between the LEO and GEO satellites. Coordination between the two constellations is performed without a direct inter-satellite connection between them. A second advantage is that a staged betting strategy can be used that improves the financial performance of the system.
    In a preferred embodiment of the present invention, the initial acquisition and signaling always takes place via the higher delay path, which is typically a GEO constellation. In addition, the services between the two constellations are divided according to their delay sensitivity. For example, time delay sensitive services are provided by the LEO constellation, and non time delay sensitive services are provided by the GEO constellation. Also, the coordination and control of the two constellations is performed in the System Control Center (SCC). In alternative embodiments, the reason for choosing a specific constellation for the provision of services could be that the marginal performance may be better eliminated or that the performance across populated areas may be better linked.
    In a preferred embodiment of the present invention, the system control center (SCC = system control center) is divided into three parts: the network operating system (NCS = network control system), the GEO constellation operating system (GCS = GEO constellation control system) and the LEO constellation control system (LCS = LEO constellation control system). The GCS and the LCS perform traditional satellite management functions for the two satellite constellations. The NCS operates the network and provides the services. Most NCS functions are standard network management and service control functions.
    In a preferred embodiment of the present invention, the SCC provides a unique method of routing signaling and services through the network. As noted above, almost all alerts about the GEO constellation are sent, saving valuable LEO assets for revenue-generating services. The LEO assets are more valuable because they support delay-sensitive services, and therefore the channel assets must be available to support this service on request. The NCS part of the SCC also ensures that the correct services are routed to the LEO and GEO constellations.
    In a preferred embodiment of the present invention, a higher value is attached to the LEO assets. Because the higher value is placed on the LEO assets, the system control channels are supported by the GEO constellation. Not only does this use the less time-critical GEO assets, it also provides a more stable control channel environment. The control channels are used by the subscriber equipment (SE = subscriber equipment) to gain access to the network. The control channels are used by the system to alert an SE that it has pending service requests. The relative stability of the GEO satellites is a significant advantage over the LEO satellites. Because the location of the GEO satellites is fairly fixed, the SE can easily use directional antennas, can easily and accurately predict the propagation delay to the satellite, and does not suffer from large Doppler shifts in the satellite frequency. The SE should address all these issues by using the LEO system procurement satellites.
    Figure 1 shows a block diagram of a hybrid constellation satellite communication system according to a preferred embodiment of the present invention. For example, constellations can be distinguished by the number of satellites and / or the height at which the satellites are positioned. In a preferred embodiment of the present invention, the hybrid constellation satellite communication system 100 includes a constellation of GEO satellites 110, a constellation of LEO satellites 120, system control center (SCC) 140 and subscriber equipment (SE) 150. SCC 140 has three main subsystems: the NCS, LCS and GCS. In a preferred embodiment, the SCC 1 ^ 0 is shown as a single unit. Those skilled in the art will recognize that the operations performed by SCC 140 could be distributed to other units. The satellites in each constellation are interconnected through a network of intersatellite links (ISLs = inter-satellite links), but the two constellations are not interconnected by ISLs. The first type of satellites 110 are interconnected using ISL 115 and are shown in orbit 117 above the surface of Earth 130. The second type of satellites 120 are interconnected using ISL 125 and are shown in orbit 127
    Both constellations have connections to the SE 150 via two-way earth-to-space subscriber connections, and to SCC 140 via two-way earth-to-space control connections. Subscriber connections 1 ^ 5 provide service channels between SE 150 and satellites 120 in the LEO constellation. Subscriber connections 155 from SE 150 to satellites 110 in the GEO constellation provide service channels and control channels. Control links 135 provide service channels between SE's I5O and satellites 120 in the LEO constellation. Control links 105 from SEs 150 to satellites 110 in the GEO constellation provide service channels and control channels. The ISLs provide a network for carrying services and control data anywhere on Earth or in the constellations.
    The hybrid constellation satellite communication system 100 may include special classes of SEs, but these special classes of SEs are not required for the present invention. For example, a special class of SE could be a port that allows interconnection to a public switched telecommunications network (PSTN), but the special features of these port SEs are not important to the present invention. SEs can be fixed or mobile. Since mobile SEs are allowed in the system, the NCS may include mobility management software necessary in a mobile wireless communication system.
    Figure 2 shows a block diagram of a subscriber device according to a preferred embodiment of the present invention. Subscriber equipment (SE) 150 includes a transceiver including: GEO antenna 202, GEO deplexer 204, GEO receiver 206, switch 210 for selecting duplexers, LEO antenna system 212, LE0 duplexer 214, LEO receiver 216 , switch 218 for selecting receivers, and transmitter 222. SE also includes a processor comprising: switch 220 for selecting processors, signaling processor 230, service processor 234, and control processor 232, and user interface 236. In a preferred embodiment, at least requires a two-channel SE. For example, SE 150 includes two antenna systems, a fixed high gain GEO antenna, and a two beam controlled LEO antenna subsystem with lower gain.
    The GEO antenna 202 is used to communicate with satellites 110 (Figure 1) and is coupled with GEO duplexer 204. GEO duplexer 204 provides a separate single function port for the transfer function, a separate single function port for the receive function, and a dual function gate for the antenna function. GEO receiver 206 provides the necessary signal conversion to deliver data to the processors. The GEO receiver 206 is permanently connected to the signaling processor 230. The signaling processor 230 processes data used to provide signaling services.
    The LEO antenna system 212 is used to communicate with satellites 120 (Figure 1) and is coupled with LEO duplexer 214. LE0 duplexer 214 is a three-port device used for both separating and combining the transmit and receive functions . One port on the LEO duplexer 214 is connected to the LEO antenna system 212. A second port is connected to the switch 210, and a third port is connected to the LEO receiver 216. The switch 210 connects the transmitter 222 to any of the duplexers. The switch 210 is also coupled to the control processor 232, which determines when the switch 210 switches. In a preferred embodiment, a single transmitter is used, and the transmitter 222 is switched between GE0 duplexer 204 and LEO duplexer 214. In a preferred embodiment, the LEO and GEO transmit frequencies are close to each other, and a single HF section and power amplifier is operated with both constellations.
    The transmitter 222 is also coupled to the switch 220, which is used to select either signaling processor 230 or service processor 234. The switch 220 is used to select what type of signals to send. In one case, signals containing service information are selected, and in another, signals containing signaling information are selected.
    Switch 218 has two input ports connected to GEO receiver 206 and LEO receiver 216. Switch 218 has a single output port that is connected to service processor 234. The service processor 234 is used to process service information from either the GEO receiver 206 or the LEO receiver 216. The control processor 232 is used to control the switching state for the switch 218. The control processor 232 is coupled to the signaling processor 230 and the service processor 234. The user interface 236 is coupled to the service processor 234.
    Figure 3 shows a block diagram for a system control center according to a preferred embodiment of the present invention. System control center 140 includes: GEO antenna 302, GE0 duplexer 304, GEO receiver 306, switch 310 for selecting duplexers, LEO antenna system 312, LEO duplexer 314, LEO receiver 316, switch 318 for selecting receivers, transmitter 322, switch 320 for selecting processors, signaling processor 330, service processor 334, and control processor 332. At least in a preferred embodiment. two-channel SCC required. SCO 140, for example, includes two antenna systems. The first could be a GE0 antenna subsystem with at least two fixed high gain GEO antennas, and the second could be a beam-amplified lower gain LEO antenna. GEO antenna 302 is used to communicate with satellites 110 (Figure 1) and is coupled with GEO duplexer 304. GEO duplexer 304 provides separate single function ports for the transmit function, a separate single function port for the receive function and a dual function port for the antenna function. GEO receiver 306 provides the necessary signal conversion to provide data to the processors. GEO receiver 306 is coupled to the signaling processor 330. The signaling processor 330 processes data used to provide signaling services.
    The LEO antenna system 312 is used to communicate with satellites 120 (Figure 1) and is coupled with LEO duplexer 314-LEO duplexer 314 is a three-port device used both for separating and combining the transmitters. and receive functions. One port on LEO duplexer 314 is connected to LEO antenna system 312. A second port is connected to switch 310, and a third port is connected to LEO receiver 316. Switch 310 is used to connect transmitter 322 to connect one of the duplexers. Switch 310 is also coupled to control processor 332 which determines when switch 310 switches. In a preferred embodiment, a single transmitter is used, and the transmitter 322 is switched between the GEO duplexer 304 and the LEO duplexer 314. In a preferred embodiment, the LEO and GEO transmit frequencies are close to each other, and a single HF section and power amplifier is operated with both constellations.
    The transmitter 322 is also coupled to the switch 320, which is used to select either the signaling processor 330 or the service processor 334. The switch 320 is used to select what type of signals to send. In one case, signals containing service information are selected, and in another, signals containing signaling information are selected.
    Switch 318 has two input ports connected to GEO receiver 306 and LEO receiver 316. Switch 318 has a single output port connected to service processor 334. Service processor 334 processes service information from either GEO receiver 306 or the LEO receiver 316. The control processor 332 controls the switch state for the switch 318. The control processor 332 is coupled to the signaling processor 330 and the service processor 334.
    Figure 4 shows a flow chart of a method of operating a hybrid constellation satellite communication system according to a preferred embodiment of the present invention. The method 400 starts with step 402. In step 4θ4, a GE0 satellite is used to provide a control channel for initial acquisition and signaling services for a subscriber device. In step 406, a subscriber device requests services through the GE0 satellite through the control channel previously provided.
    In step 408, a system control center selects whether to use at least one GEO satellite or a number of LEO satellites for a communication channel, based on the requested services.
    In step 410, a first communication channel for non-time delay sensitive services between two of the subscriber devices is provided using at least one GEO satellite, when the subscriber equipment requests the communication channel for the non time delay sensitive services.
    In step 412, a second communication channel for time delay sensitive services between two of the subscriber devices is provided using a plurality of LEO satellites, when the subscriber equipment requests the communication channel for the time delay sensitive services.
    An example system could work as described below. An SE monitors downlink channels from a local GEO satellite. A local GEO satellite is one within the field of view of a GEO antenna on an SE. An origin SE sends a randomly accessible channel message. For example, an arbitrarily accessible channel may use a protocol that allows the SE to establish communication with a satellite without having previously co-existed with other SEs or other satellites. A randomly accessible channel is one of many channels that can be established between a GEO satellite and an SE.
    A GEO satellite then receives a message and processes it. The GEO satellite could determine whether the message was processed correctly. If the message was not processed correctly, the sample company would end.
    When the message has been processed correctly, the local GEO satellite could send a confirmation message back to the origin SE and send the message to the network operating system part of SCO.
    When the system operating center receives the sent message, it may process the message to determine the content of the message. If the origin SE is not a valid subscriber, a message is returned to the origin SE by the local GEO satellite, and processing ends. For example, this message could be an access denial message.
    If it is confirmed that the origin SE is a valid subscriber, the SCO locates the destination SE and sends an inquiry to the GEO satellite that is local to the destination SE. The request for information shall be sent using GEO satellites and intersatellite links if the destination SE is not within line of sight of the GEO satellite local to the origin SE.
    The destination SE could then receive the information request and respond to the information request. For example, a destination SE can respond with an unavailable message or a ready message. The destination SE could send a response message to the GEO satellite that is local to the destination SE. The response is sent to the System Control Center using the local GEO satellite using GEO satellites and inter-satellite links if the destination SE is not within the field of view of the System Control Center or within the field of view of the GEO satellite local to the origin SE.
    Continuing with the example, the system control center could determine whether the requested services are delay sensitive. If the requested services are not delay sensitive, the requested services are provided by the GEO satellites and inter-satellite connections, and the sample process ends.
    When the requested services are determined to be delay sensitive, the system control center determines the best LEO satellites to use and selects the best channels to use. In addition, the SCC determines the best routing to use. SCC also sends information to the LEO satellites. This information could include, for example, routing information to be used by the LEO satellites.
    Then, the system control center could send messages to both the origin and destination SEs. These messages contain information about which LEO satellite to use and which channel to use. Both the destination SE and the origin SE could establish communication links with LEO satellites. Information is then exchanged between the originating SE and the destination SE using LEO satellites and inter-satellite connections as required.
    When one of the SEs determines that the LEO satellite it uses for the channel disappears from view, a switch to another LEO satellite is required. SE could send a forwarding message to the SCC. In a preferred embodiment, the message could be sent via the LEO satellites. In an alternative embodiment, the forwarding request message could be sent through the GEO satellites.
    Then, the system operating center could receive the forwarding request message and determine a new LEO satellite to use and a new channel to use. Then the system control center sends messages to both SEs to inform the SEs of the changes. The System Control Center must inform the SE who requested the forwarding which new satellite and channel to use. The system control center also informs the other SE about the routing changes.
    The sample company continues with time-delay sensitive services that are maintained until a termination request is made. The system control center could receive a termination message from either the origin SE or the destination SE. Also, the system operating center could determine whether there is a need to send termination messages to the SEs. For example, the origin SE can send a termination message when all the information it wanted to send to the destination SE has been sent. Also, the destination SE can determine that it no longer needs to exchange information with the origin SE, and it sends a termination message to the system control center. In addition, the system control center may be responsible for determining whether to send a termination message because there is a network problem. A termination notice could be used to terminate processing in the exemplary operating method.
    Figure 5 shows a flow chart of a method for operating a system control center in a hybrid constellation satellite communication system in accordance with a preferred embodiment of the present invention. Method 500 starts with step 502. In step 504, the system control center receives a request from an origin subscriber device to establish a communication channel between the origin subscriber device and a destination subscriber device. In step 506, the system control center determines whether the request requires time-delay sensitive services.
    If step 506 is incorrect, method 500 branches to step 510, in which the system control center provides a communication channel for non-time-delay sensitive services between the originating subscriber equipment and the destination subscriber equipment using a number of GEO satellites.
    If step 506 is true, method 500 branches to step 520 in which the system control center provides a time-delay sensitive communication channel between the origin subscriber equipment and the destination subscriber equipment using at least one LEO satellite.
    In addition, the system control center uses at least one of the GEO satellites to provide a control channel for initial acquisition and signaling services for the originating subscriber and destination subscriber equipment. The system control center also monitors the control channel and the communication channel.
    In an example system, the company could be as described below. The system control center monitors the downlink channels of a local GEO satellite. A local GEO satellite is one within the field of view of a GEO antenna at the system control center. An origin SE could send a random access channel message to a system control center.
    Then, a system control center could receive and process the message from the GEO satellite. The system control center could determine whether the originating SE is a valid subscriber. If the origin SE is not a valid subscriber, a message is sent back to the origin SE by the local GEO satellite. For example, this message could be an access denial message.
    When it is confirmed that the origin SE is a valid subscriber, the system control center could locate the destination SE and determine if it is available. For example, the SCC may check an active connection file to determine if the destination SE is busy. If the destination SE is busy, a busy message can be sent to the origin SE via the local GEO satellites. If the destination SE is not busy, the SCC sends a call setup message to the destination SE via the GEO satellite that is local to the destination SE. Then, the system control center could send the call setup message to the destination SE using the GEO satellites and the inter-satellite connections.
    The system control center could then receive the response to the call setting message from the destination SE via the GEO satellites. For example, a destination SE could respond with an unavailable message or a ready message. The response could be sent to the System Control Center by the local GEO satellite using the GEO satellites and the inter-satellite connections if the destination SE is not within the field of view of the System Control Center or within the GEO satellite's field of view local to the origin SE. If an unavailable message is received or if no message is received from the destination SE, the SCC sends the unavailable message to the origin SE and the session ends.
    The sample company continues when a ready message is received. Then the system control center could determine whether the requested services are delay sensitive. If the requested services are not delay sensitive, the system operating center provides the requested service using the GEO satellites and the inter-satellite connections, and the sample company would terminate.
    When the requested services are determined to be delay sensitive, the System Control Center should determine the best LEO satellites to use and select the best channels to use. In addition, the System Control Center could determine the best routing to use and send the information to the LEO satellites. This information could include, for example, routing information to be used by the LEO satellites.
    Then, the system control center could send messages to both the origin and destination SEs. These messages contain information about which LEO satellite to use and which channel to use. The system operating center could monitor the destination SE, the origin SE, the LEO satellites and the communication links between the LEO satellites while exchanging information between the origin SE and the destination SE.
    If the System Control Center receives a forwarding request from one of the SEs, the System Control Center could determine a new LEO satellite and channel to use. In a preferred embodiment, the message could be sent via the LEO satellites. In an alternative embodiment, the forward-on-demand message could be sent through the GEO satellites. Then the System Control Center could send messages to both SEs to inform the SEs of the changes. The system operating center must inform the SE who requested the forwarding which new satellite and which new channel to use. The system control center also informs the other SE of the routing changes.
    If the time delay sensitive services are maintained, the system control center will continue to monitor the SEs and the satellites. The system control center could receive a termination message from either the origin SE or the destination SE. The system operating center could also determine whether there is a need to send termination messages to the SEs. For example, the origin SE can send a termination message when all the information it wanted to send to the destination SE has been sent. Also, the destination SE can determine that it no longer needs to exchange information with the origin SE and sends a termination message to the system control center. In addition, the System Control Center may be responsible for determining whether to send a termination message because of a network problem.
    In response to a termination message, the system operating center may remove the SEs from the active connection file, establish a call record, determine the required billing information, and release the assets used. A termination notice could be used to terminate the company in the sample system.
    Figure 6 shows a flow chart of a method of operating subscriber equipment in a hybrid constellation satellite communication system according to a preferred embodiment of the present invention. The method 600 starts with step 602. In step 604, an origin subscriber device sends a request for a communication channel between the origin subscriber device and a destination subscriber device. The application may be for non-time delay sensitive services or time delay sensitive services. In step 606, the subscriber equipment receives setting information to establish the communication channel. In step 608 is the communication channel for non-time-delay sensitive services, therefore the subscriber equipment communicates with a GEO satellite using the setting information. In step 610, the communication channel is for time delay sensitive services, so the subscriber equipment communicates with an LEO satellite using the setting information. The method 600 ends in step 620.
    In addition, at least one GEO satellite is used to provide a control channel for initial acquisition and signaling services for the originating subscriber and destination subscriber equipment. The subscriber equipment can also monitor the control channel and the communication channel.
    The subscriber equipment can be operated in a wide variety of ways when used in a hybrid constellation satellite communication system. Some of these operating methods are described below. SEs 150 can monitor downlink channels from a local GEO satellite. A local GEO satellite is a satellite within the field of view of the GEO antenna 202 (Figure 2) on SE 150 (Figure 1). An SE may determine to establish a communication channel to another subscriber device. This origin SE sends a message through a randomly accessible channel. A randomly accessible channel is one of many channels that can be established between a GEO satellite and an SE. The message contains information about the type of service being requested and destination SE identification.
    The origin SE can receive an acknowledgment of receipt from the SCC and wait for the SCC to respond with additional information. While the SE is waiting, the SCC locates the destination SE and determines whether or not it is busy and sets it up to receive more information.
    The origin SE can receive a message. In this case, the message could contain the response to a request for establishing a communication link to a destination SE, or the message might contain information about establishing a communication link to a specific satellite. The message may also be received by a destination SE. In this case, the message could contain an information request sent from an origin SE, or the message could contain information about establishing a communication link to a specific satellite.
    The SE can establish a communication channel with the specific satellite previously determined by the SCC. Both the origin and destination SE work as instructed. If the SCC instructed the SEs to establish communication connections to LEO satellites, the subscriber connection 145 (Figure 1) is established by the originating SE and another subscriber connection 145 is established by the destination SE . If the SCC instructed the SEs to establish communication connections to GEO satellites, the subscriber connection 155 (Figure 1) is established by the originating SE, and another subscriber connection 155 is established by the destination SE.
    After both the destination SE and the origin SE establish communication links with the appropriate satellites, information can be exchanged between the origin SE and the destination SE. If the information is delay sensitive, the information will be exchanged using LEO satellites and inter-satellite connections, as required. If the information is not delay sensitive, the information will be exchanged using GEO satellites and inter-satellite connections as required.
    Both the origin and destination SE can monitor LEO satellites to ensure that subscriber connections 145 are not disconnected due to movement between the satellites and the SEs. If one of the SEs determines that the LEO satellite it uses for the channel moves out of sight, the SE will conclude that a switchover to another LEO satellite is required. The SE sends a forwarding message to the SCC. In a preferred embodiment, the message is sent via the LEO satellites. In an alternative embodiment, the forwarding request message could be sent through the GEO satellites.
    The SE can wait for the system control center to respond with the forwarding information, which includes a new LEO satellite to use and a new channel to use. Both SEs can receive messages to inform them of the changes required for forwarding. The System Control Center must inform the SE who requested the forwarding which new satellite and channel to use. The system control center also informs the other SE about the routing changes. The SE can establish the new connection as instructed and release the assets used in the old connection.
    Services can be maintained until a destination application is made. Communication service data is exchanged between an origin SE and a destination SE. As an example, in a one-way data transfer, a destination SE could be instructed not to transmit data.
    Either the origin SE or the destination SE can determine whether there is a need to send termination messages to the SCC. For example, the origin SE can send a termination message when all the information it wanted to send to the destination SE has been sent. Also, the destination SE can determine that it no longer needs to exchange information with the origin SE, and it sends a termination message to the system control center.
    The SE can send a termination notice to the SCC. When this occurs, the SCC releases assets that have been used and removes the SEs from the active connection file.
    Figure 7 shows a block diagram of a GEO satellite according to a preferred embodiment of the present invention. The GEO satellite includes: top control channel 702, top subscriber channel 704, top intersatellite link (ISL) channel 706, and processor 710. Top control channel 702 is for communicating with a system control center when a system control center is available locally. Top subscriber channel 704 is for providing a control channel for initial acquisition and signaling services communicating with a subscriber device, and for communicating with the subscriber equipment for non-time-delay sensitive services. Top inter-satellite link (ISL) channel J06 is for establishing and monitoring an inter-satellite link to another GEO satellite when the other GEO satellite is available.
    The processor 710 processes messages received on arbitrary connections, determines whether the messages contain routing information, retransmits some of the messages, and performs operations using information contained in the messages that are not retransmitted.
    Figure 8 shows a flow chart of a method for operating a GEO satellite in a hybrid constellation satellite communication system according to a preferred embodiment of the present invention. The method 800 starts with step Ö02. In step 804, a GEO satellite provides control link 105 (Figure 1) to SCC ΐ4θ (Figure 1), and the GEO satellite provides the subscriber connection 155 (Figure 1) to SE 150 (Figure 1).
    In step 806, the GEO satellite receives a request to make a call from a subscriber device. In step 8θ8, the GEO satellite forwards the request to a system control center. In step 810, the GEO satellite establishes and monitors a communication channel with subscriber equipment when instructed by a system control center to do so. The system control center has provided information to establish a communication channel for non-time-delay sensitive services.
    The GEO satellite establishes and monitors a control connection to a system control center when the system control center is available locally. The control connection to the system control center is used to retransmit a first type of message to the system control center and to receive a second type of message from the system control center. In addition, the GEO satellite establishes and monitors a subscriber connection to a subscriber device when the subscriber device is available locally. The subscriber connection to the subscriber device is used to receive the first type of message from the subscriber device and to retransmit the second type of message to the subscriber device. For example, the first type of messages could be request messages, confirmation messages, or information messages. The second type of messages could be control messages or setting messages.
    For example, the GEO satellite could receive messages from an origin SE, which are sent through a randomly accessible channel. A randomly accessible channel is one of many channels that can be established between the GEO satellite and an SE. A GEO satellite could send a confirmation message to the SE. The GEO satellite could send the message to the SCO.
    A second GEO satellite that is local to a destination SE can receive a message from the SCO. This second GEO satellite could send the message to the destination SE. The second local GEO satellite can receive a response message from the destination SE. The response may not be available or ready. The second local GEO satellite could send a confirmation message to the destination SE and send the response message to the SCC.
    In addition, local GEO satellites can receive information on how to set up communication channels. If the services are not delay sensitive, the GEO satellites can provide the communication services.
    When services are delay sensitive, the SCC can send information to both local GEO satellites. One local GEO satellite sends a message to the origin SE. This message contains information about which satellite to use, which channel to use, and the routing to use. The second GEO satellite, which is local to the destination SE, sends a message to the destination SE. This message contains information about which satellite to use, which channel to use and the routing to use.
    The GEO satellite can monitor the control link to the system control center to determine if a forwarding message has been sent. In an alternative embodiment, the forwarding request message could be sent through the GEO satellites. In a forwarding company, the system operating center receives the forwarding request message and determines a new LEO satellite to use and a new channel to use. GEO satellites are used by the SCC to send messages to both SEs to inform the SEs about the changes. In another alternative embodiment, the forwarding information could be sent via the LEO satellites. The system control center must inform the SE who requested the diversion which new satellite and which new channel to use. The system control center also informs the other SE about the routing changes.
    It will be apparent to those skilled in the art that other forwarding techniques are available to operate the SEs with an LEO satellite system. For example, the SCC could calculate all forwarding and forwarding times on the time the first connection is established. The present invention is capable of operating with a variety of transfer procedures, and the present invention does not require a specific transfer procedure.
    The GEO satellite can also monitor the channel with the system control center to determine if a termination message has been sent. In a preferred embodiment, the termination message is sent via the GEO satellites. In an alternative embodiment, the termination message could be sent via the LEO satellites. In a termination company, the system control center receives the termination message or determines the need to terminate the communication services. GEO satellites are used by the SCC to send termination messages to both SEs. The GEO satellites can also perform maintenance tasks. These maintenance tasks may include, for example, monitoring on-board operations and connection quality.
    Figure 9 shows a block diagram of an LEO satellite in accordance with a preferred embodiment of the present invention. The LEO satellite includes: lower control channel 902, lower subscriber channel 904, lower intersatellite link (ISL) - channel 906, and processor 910. The lower control channel 902 is for communicating with a system control center when a system control center is available locally. The bottom subscriber channel 904 is for communicating with a subscriber device upon such instruction by the system control center for time-delay sensitive services. The bottom inter-satellite link (ISL) channel 906 is for establishing and monitoring an inter-satellite link to another LEO satellite when the other LEO satellite is available.
    The processor 910 processes messages received on one or more connections, determines whether the messages contain routing information, retransmits some of the messages, and performs operations using information contained in the messages that are not retransmitted.
    Figure 10 shows a flow chart of a method for operating an LEO satellite in a hybrid constellation satellite communication system in accordance with a preferred embodiment of the present invention. The method 1000 starts with step 1002. In step 1004, the local LEO satellite provides a control connection to a system control center. A local LEO satellite is one within the field of view of the LEO antenna 312 (Figure 3) at system control center 140 (Figure 1).
    In step 1006, a local LEO satellite receives a message from the system control center to establish a subscriber connection to a specific SE. In step 1008, the origin SE establishes a subscriber connection 145 to the LEO satellite that is local to the origin SE. The destination SE establishes a subscriber connection 145 to the LEO satellite that is local to the destination SE. Method 1000 ends in step 1020.
    An LEO satellite can receive a message from the SCO to forward the subscriber connection. In a preferred embodiment, the LEO satellite uses a make-to-break strategy in establishing the new subscriber connection. This means that the new subscriber connection is established before the old subscriber connection is disconnected. When the old connection is terminated, the assets are restored for use in establishing other communication channels.
    An LEO satellite can receive a message from the SCO terminating a subscriber connection. When the subscriber connection is terminated, the assets are restored for use in establishing other communication channels.
    An LEO satellite can perform maintenance tasks. These maintenance tasks may include, for example, on-board operation monitoring and connection quality.
    An important feature of the present invention is that there is no direct interaction between the two satellite constellations. Only the subscriber equipment and the system control centers require knowledge of the two satellite constellations. It will further be understood that the methods and systems of the present invention do not require the two satellite constellations to use the same frequency bands. The operation in two different frequency bands has a small effect on the subscriber equipment. Operation in widely separated frequency bands simplifies the high-frequency coordination between the two satellite constellations.
    The methods and systems of the present invention allow the hybrid constellation satellite communication system to be arranged in stages. For example, the GEO satellites and the system control center can be set up and put into service well before the LEO satellites are in operation. When the LEO satellites become available, the appropriate changes can be made to the software and the delay-sensitive services can be transferred to the LEO satellites.
    The methods and systems of the present invention also allow the joining of two systems originally built to operate independently. Using the signaling and control design of the present invention, it is possible for the two systems to be merged as long as the appropriate changes can be made to the space vehicle software.
    In alternative embodiments of the present invention, the ISLs are not strictly necessary. An alternative system could be developed with answering satellites as long as adequate ground stations and ground connections are provided. Since the LEO satellite system would require a comprehensive global infrastructure to provide adequate connectivity, a more likely alternative implementation would be response transmitting GEO satellites and LEO satellites with ISLs.
    The present invention has been described above with reference to a preferred embodiment. However, it will be apparent to those skilled in the art that changes and modifications in this preferred embodiment can be accomplished without departing from the scope of the present invention. While a preferred embodiment has been described in terms of using specific webs, other descriptions or methods can also be used. For example, a very low elevation LEO constellation could be used with a higher elevation LEO constellation or an average-Earth orbit (MEO) constellation. Therefore, these and other changes and modifications that are apparent to those skilled in the art are considered to be within the scope of the present invention.
    权利要求:
    Claims (8)
    [1]
    A method of operating a hybrid constellation satellite communication system, comprising the steps of: using a first satellite to provide a control channel for initial acquisition and signaling services for subscriber equipment; using the subscriber equipment to request services via the control channel; using a system control center to select whether to use the first satellite or a number of second satellites to provide a communication channel based on requested services; providing a first communication channel for non-time-delay sensitive services between two of the subscriber devices using at least one first satellite when the subscriber equipment requests the communication channel for the non-time-delay sensitive services; and providing a second communication channel for time-delay sensitive services between two of the subscriber devices using a plurality of second satellites, when the subscriber equipment requests the communication channel for the time-delay sensitive services.
    [2]
    The method of claim 1, wherein the first satellite is a geosynchronous satellite and the second satellites are low Earth orbit satellites.
    [3]
    The method of claim 1, wherein the first satellite is a geosynchronous satellite and the second satellites are medium Earth orbit satellites.
    [4]
    The method of claim 1, wherein the first satellite is an average Earth orbit satellite and the second satellites are low Earth orbit satellites.
    [5]
    Hybrid constellation satellite communication system comprising: a plurality of subscriber equipment, each capable of requesting time delay sensitive services or non time delay sensitive services; a system control center that can receive a request for services from the subscriber equipment and determine whether the time-delay sensitive services have been requested; a number of first satellites located within a first constellation, which can provide a communication channel for the subscriber equipment requesting the non-time-delay sensitive services; and a number of second satellites located within a second constellation capable of providing the communication channel for the subscriber equipment requesting the time-delay sensitive services.
    [6]
    The system of claim 5. wherein the first satellites are geosynchronous satellites and the second satellites are low Earth orbit satellites.
    [7]
    The system of claim 5, wherein the first satellites are geosynchronous satellites and the second satellites are medium Earth orbit satellites.
    [8]
    The system of claim 5. wherein the first satellites are medium Earth orbit satellites and the second satellites are low Earth orbit satellites.
    类似技术:
    公开号 | 公开日 | 专利标题
    NL1007685A1|1998-06-08|Hybrid constellation satellite communication systems and methods with efficient signaling and control.
    CA2675763C|2012-04-17|Automatic satellite/terrestrial mobile terminal roaming system and method
    US5513242A|1996-04-30|Method and apparatus for facilitating the ultimate making of wireless data transfers
    US6253080B1|2001-06-26|Low earth orbit distributed gateway communication system
    US5371898A|1994-12-06|Method for a communication unit to operate in either a trunking or a cellular communication system
    US4337376A|1982-06-29|Communications system and network
    US5485632A|1996-01-16|Method for initiating and determining simulcast transmission of a message
    EP0872966A2|1998-10-21|Low earth orbit distributed gateway communication system
    US5239674A|1993-08-24|Method for transferring private data transmissions from a trunking communication system to a cellular communication
    RU98100255A|2000-01-10|DISTANCE SIGNAL TRANSMITTING CONTROL SYSTEM THROUGH SATELLITE TRANSMITTERS
    JP2863515B2|1999-03-03|Satellite-based telecommunications system using earth station subsystem
    JP4423410B2|2010-03-03|Multi-layer satellite system and method of operation
    JP2000078067A|2000-03-14|Satellite communication system providing multi-gateway diversity for moving user terminal
    JPH10178379A|1998-06-30|Ground station acquisition system for satellite communication
    Johanson et al.1993|Implementation of a system to provide mobile satellite services in North America
    US6353738B1|2002-03-05|Method for implementing a terminal-to-terminal call with an optimal use of radio resources in a mobile satellite system
    WO2001086836A2|2001-11-15|End-to-end aeronautical data network architecture
    CN113258987A|2021-08-13|Communication switching method between low-orbit satellite reverse seams
    CN112019255A|2020-12-01|Transparent and processing mixed low-orbit inter-satellite networking communication system and method
    EP0948183A1|1999-10-06|Selective call forwarding on dropout
    JP3185758B2|2001-07-11|Logical connection management method
    EP0987839A1|2000-03-22|Call re-routing from a mobile user to a service provider
    JPH0612884B2|1994-02-16|Satellite circuit switching connection control method
    EP0971487A1|2000-01-12|Method and arrangement for exchanging control information between earth stations of a satellite communication network
    MXPA99003798A|1999-10-14|Dual mode symmetric/asymmetric communication control system
    同族专利:
    公开号 | 公开日
    GB9722726D0|1997-12-24|
    JPH10285100A|1998-10-23|
    GB2320163B|2001-03-28|
    GB2320163A|1998-06-10|
    RU97121430A|1999-10-27|
    IL121906D0|1998-03-10|
    CA2222238A1|1998-06-05|
    BR9705489A|1999-10-05|
    FR2756992B1|2003-10-10|
    US5887257A|1999-03-23|
    ITRM970695A1|1999-05-12|
    IT1296120B1|1999-06-09|
    KR19980063765A|1998-10-07|
    CN1190297A|1998-08-12|
    FR2756992A1|1998-06-12|
    TW444450B|2001-07-01|
    CN1108669C|2003-05-14|
    DE19752876A1|1998-07-02|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    GB8300747D0|1983-01-12|1983-02-16|British Aerospace|Co-operative satellites|
    DE3644176C2|1986-12-23|1989-04-06|Messerschmitt-Boelkow-Blohm Gmbh, 8012 Ottobrunn, De|
    GB8801008D0|1988-01-18|1988-02-17|British Aerospace|Acquisition system for multiple access optical communication system|
    US5287541A|1989-11-03|1994-02-15|Motorola, Inc.|Global satellite communication system with geographic protocol conversion|
    US5218467A|1990-12-28|1993-06-08|Nasa And Laser Data Technology, Inc.|Multi-access laser communications transceiver system|
    EP0510789B1|1991-04-22|1997-03-12|Trw Inc.|Cellular telephone satellite system|
    US6400926B1|1994-06-22|2002-06-04|Ericsson Ge Mobile Communications Inc.|Radiocommunication system using geostationary and non-geostationary satellites|
    US5602838A|1994-12-21|1997-02-11|Lucent Technologies Inc.|Global multi-satellite network|
    JPH08213945A|1995-02-06|1996-08-20|Atr Kodenpa Tsushin Kenkyusho:Kk|Satellite communication system|FR2730369B1|1995-02-02|1997-04-25|Bruno Louis Blachier|PERSONAL COMMUNICATIONS USING GEOSTATIONARY SATELLITES AND LOW ORBIT RUNNERS|
    DE19609235A1|1996-03-09|1997-09-18|Deutsche Telekom Ag|Method and arrangement for improved radio communication in a satellite-based VSAT network|
    US5974316A|1996-12-26|1999-10-26|Motorola, Inc.|System and method for enhancing ring alert terminations|
    JPH10261987A|1997-03-19|1998-09-29|Fujitsu Ltd|Two-layer constitution satellite communication system and its geostationary satellite|
    US6208625B1|1997-06-12|2001-03-27|Motorola, Inc.|Method and apparatus for increasing call-handling capacity using a multi-tier satellite network|
    US5999797A|1997-11-03|1999-12-07|Motorola, Inc.|Method and apparatus for providing private global networks in a satellite communication system|
    US6173156B1|1998-05-04|2001-01-09|Motorola, Inc.|Global message delivery system and method using GEO and Non-GEO satellites|
    US6175340B1|1998-05-04|2001-01-16|Motorola, Inc.|Hybrid geostationary and low earth orbit satellite ground station antenna|
    US6014562A|1998-05-19|2000-01-11|Ericsson Inc.|Radiotelephone communication systems and methods that map an access request into a predetermined random access channel slot to identify a nearest gateway to a radiotelephone|
    DE19836602C2|1998-08-12|2002-02-07|Soc Europ Des Satellites Sa|Modular satellite|
    US6639898B1|1999-05-25|2003-10-28|Motient Communications, Inc.|Wide area mobile communication networks with multiple routing mode options|
    US6556828B1|1999-08-31|2003-04-29|Loral Spacecom Corp.|Network architectures for LEO/GEO satellite-based communications systems|
    US6633745B1|2000-03-29|2003-10-14|Societe Europeenne Des Satellites S.A.|Satellite cluster comprising a plurality of modular satellites|
    US6684056B1|2000-04-10|2004-01-27|Motorola, Inc.|System for providing optimal satellite communication via a MEO/LEO satellite constellation|
    JP3440998B2|2000-04-18|2003-08-25|日本電気株式会社|Satellite communication system for data distribution|
    FR2818056A1|2000-07-27|2002-06-14|Cit Alcatel|SATELLITE TELECOMMUNICATION METHOD AND SYSTEM AND TERMINAL FOR SUCH A SYSTEM|
    US6909896B2|2001-03-20|2005-06-21|Shiron Satellite CommunicationsLtd.|Apparatus and method for two-way data communication via satellite|
    US7738837B2|2005-02-22|2010-06-15|Atc Technologies, Llc|Satellites using inter-satellite links to create indirect feeder link paths|
    CA2607302C|2005-08-09|2014-10-07|Atc Technologies, Llc|Satellite communications systems and methods using substantially co-located feeder link antennas|
    US8078141B2|2006-01-18|2011-12-13|OverhorizonPlc|Systems and methods for collecting and processing satellite communications network usage information|
    US8326217B2|2006-01-18|2012-12-04|OverhorizonPlc|Systems and methods for satellite communications with mobile terrestrial terminals|
    US8713324B2|2006-01-18|2014-04-29|OverhorizonPlc|Systems and methods for tracking mobile terrestrial terminals for satellite communications|
    US20080045146A1|2006-01-18|2008-02-21|Per Wahlberg|Systems and methods for establishing modular and flexible satellite communications networks|
    US20070171932A1|2006-01-20|2007-07-26|General Dynamics C4 Systems, Inc.|System and method for dynamic allocation and routing of resources|
    US20080233866A1|2007-02-21|2008-09-25|Richard Burtner|Satellite aided location tracking and data services using geosynchronous and low earth orbit satellites|
    US8010127B2|2007-02-22|2011-08-30|Skybitz, Inc.|Satellite aided location tracking and data services using geosynchronous and low earth orbit satellites with global locating system|
    US10127295B2|2009-06-05|2018-11-13|Microsoft Technolofy Licensing, Llc|Geographic co-location service for cloud computing|
    CA2716174C|2010-10-01|2019-11-26|Telesat Canada|Satellite system|
    CN103178895B|2013-03-12|2015-12-09|中国空间技术研究院|TT&C system and method between satellite mobile communication constellation star|
    JP2019516321A|2016-04-28|2019-06-13|クラウド コンステレーション コーポレイション|Intermediate satellite network for cross strapping and local network congestion|
    US10954003B2|2016-07-20|2021-03-23|Worldvu Satellites Limited|Constellation configuration for constellations having a large number of LEO satellites|
    US9967732B2|2016-08-15|2018-05-08|At&T Intellectual Property I, L.P.|Method and apparatus for managing mobile subscriber identification information according to registration errors|
    US9838991B1|2016-08-15|2017-12-05|At&T Intellectual Property I, L.P.|Method and apparatus for managing mobile subscriber identification information according to registration requests|
    US10666352B2|2016-08-30|2020-05-26|Worldvu Satellites Limited|Satellite system comprising satellites in LEO and other orbits|
    US10015764B2|2016-09-14|2018-07-03|At&T Intellectual Property I, L.P.|Method and apparatus for assigning mobile subscriber identification information to multiple devices|
    US9794905B1|2016-09-14|2017-10-17|At&T Mobility Ii Llc|Method and apparatus for assigning mobile subscriber identification information to multiple devices according to location|
    US9843922B1|2016-09-14|2017-12-12|At&T Intellectual Property I, L.P.|Method and apparatus for utilizing mobile subscriber identification information with multiple devices based on registration errors|
    US9814010B1|2016-09-14|2017-11-07|At&T Intellectual Property I, L.P.|Method and apparatus for utilizing mobile subscriber identification information with multiple devices based on registration requests|
    US9924347B1|2016-09-14|2018-03-20|At&T Intellectual Property I, L.P.|Method and apparatus for reassigning mobile subscriber identification information|
    US9906943B1|2016-09-29|2018-02-27|At&T Intellectual Property I, L.P.|Method and apparatus for provisioning mobile subscriber identification information to multiple devices and provisioning network elements|
    US9918220B1|2016-10-17|2018-03-13|At&T Intellectual Property I, L.P.|Method and apparatus for managing and reusing mobile subscriber identification information to multiple devices|
    US10070303B2|2016-11-11|2018-09-04|At&T Intellectual Property I, L.P.|Method and apparatus for provisioning of multiple devices with mobile subscriber identification information|
    US10136305B2|2016-12-01|2018-11-20|At&T Intellectual Property I, L.P.|Method and apparatus for using mobile subscriber identification information for multiple device profiles for a device|
    US10341842B2|2016-12-01|2019-07-02|At&T Intellectual Property I, L.P.|Method and apparatus for using temporary mobile subscriber identification information in a device to provide services for a limited time period|
    US10070407B2|2016-12-01|2018-09-04|At&T Intellectual Property I, L.P.|Method and apparatus for using active and inactive mobile subscriber identification information in a device to provide services for a limited time period|
    US10231204B2|2016-12-05|2019-03-12|At&T Intellectual Property I, L.P.|Methods, systems, and devices for registering a communication device utilizing a virtual network|
    US10361773B2|2017-04-24|2019-07-23|Blue Digs LLC|Satellite constellation having multiple orbital inclinations|
    US10374713B1|2017-06-21|2019-08-06|Blue Digs LLC|Satellite system with networked gateways|
    CN107517077A|2017-08-28|2017-12-26|西安电子科技大学|Space networking double layer minipellet model and the routing optimization method of topology control|
    CN113141207A|2021-04-22|2021-07-20|东北大学|Time-sensitive service-oriented spatial information network data transmission method|
    法律状态:
    1998-08-03| AD1A| A request for search or an international type search has been filed|
    2001-12-03| RD2N| Patents in respect of which a decision has been taken or a report has been made (novelty report)|Effective date: 20011023 |
    优先权:
    申请号 | 申请日 | 专利标题
    US76109396|1996-12-05|
    US08/761,093|US5887257A|1996-12-05|1996-12-05|Hybrid constellation satellite comunication systems and methods with efficient signaling and control|
    [返回顶部]