WO2001031813A1 - Demande d'acces dans un reseau de communications par satellites - Google Patents

Demande d'acces dans un reseau de communications par satellites Download PDF

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Publication number
WO2001031813A1
WO2001031813A1 PCT/US2000/027563 US0027563W WO0131813A1 WO 2001031813 A1 WO2001031813 A1 WO 2001031813A1 US 0027563 W US0027563 W US 0027563W WO 0131813 A1 WO0131813 A1 WO 0131813A1
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WO
WIPO (PCT)
Prior art keywords
data
site
communication system
satellite communication
data packet
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Application number
PCT/US2000/027563
Other languages
English (en)
Inventor
James W. Bishop, Jr.
Alan West Miller
Stephen Daniel Magee
Isaac E. Eteminan
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Motorola Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Motorola Inc. filed Critical Motorola Inc.
Priority to AU78635/00A priority Critical patent/AU7863500A/en
Publication of WO2001031813A1 publication Critical patent/WO2001031813A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/1853—Satellite systems for providing telephony service to a mobile station, i.e. mobile satellite service
    • H04B7/18539—Arrangements for managing radio, resources, i.e. for establishing or releasing a connection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/1853—Satellite systems for providing telephony service to a mobile station, i.e. mobile satellite service
    • H04B7/18558—Arrangements for managing communications, i.e. for setting up, maintaining or releasing a call between stations

Definitions

  • This invention pertains to satellite communication systems in general, and to packet data satellite communication systems in particular.
  • the communications may include command data from the host to one or more of the data terminals and/or collection of data from the data terminals by the host.
  • Data from the data terminals is moved in bursts at random times or at scheduled intervals.
  • applications of data terminal/ host configurations can vary widely, they tend to share a need for flexibility to change the data-usage profile over time.
  • the term “machine orientation” is used to signify that the data being moved are produced and consumed by machines rather than by people and the term “human-user orientation” is used to signify data produced for human use.
  • Data terminal data volume ranges from under 20 to 30 bytes per message for many applications to about 8,000 bytes per message for certain other applications.
  • a small subset of applications requires a continuous data stream over an extended period of time.
  • Prior satellite communications systems provide continuous data stream support via a circuit-mode data call.
  • a sizable set of data terminal/host applications exist in which data messages are in the range of 100 to 1000 bytes per-message. For this entire "under 1000-byte" range to be priced competitively, voice-equivalent channel resource usage must be significantly less than the time it takes to establish a voice communication and move the data.
  • FIG. 1 illustrates a simplified block diagram of a satellite communication system to which the present invention may be advantageously applied
  • FIG. 2 illustrates an embodiment of a block diagram of a system operable in accordance with the invention
  • FIG. 3 illustrates an embodiment of an access request format utilized in accordance with the invention
  • FIG. 4 is a message sequence chart for data packet transmission via access request signaling in accordance with the present invention.
  • FIG. 5 is a message sequence chart for data packet transmission via ring alert signaling in accordance with the present invention.
  • FIG. 6 is a message sequence chart for data packet transmission via User to User Signaling in accordance with the present invention.
  • FIG. 7 is a message sequence chart for Extended Simple Packet Service in accordance with the present invention.
  • FIG. 8 is a message sequence chart for General Packet Radio Service in accordance with the present invention.
  • satellites 12 are dispersed over and surrounding the earth in orbits 14.
  • Six polar orbits 14 are used.
  • Each orbit 14 has eleven satellites 12 for a total of sixty-six satellites 12.
  • this satellite constellation is used in the preferred embodiment of the invention, the satellite constellation is not essential because more or fewer satellites 12, or more or fewer orbits 14, can be used.
  • the present invention is advantageously employed when a large number of satellites 12 are being used, it is also applicable with as few as one satellite 12.
  • different orbital configurations can be used.
  • FIG. 1 illustrates only a few satellites 12 of the constellation.
  • each orbit 14 encircles the earth at an altitude of around 785 km, although higher or lower orbital altitudes may be usefully employed.
  • substantially line- of-sight electromagnetic (e.g., radio, light, etc.) transmission from any one satellite 12 or reception of signals by any one satellite 12 covers a relatively small area of the earth at any instant.
  • satellites 12 travel with respect to the earth at around 25,000 kilometers per hour (km/hr), allowing satellite 12 to be visible to a terrestrial station or radio communication subscriber units (SUs) 26 for a period of approximately nine minutes.
  • SUs radio communication subscriber units
  • Satellites 12 communicate with terrestrial stations, which can include some number of subscriber units 26 and earth terminal controllers (ETCs) 24 connected to gateways (GWs) 22, which provide access to inte rope rating networks such as public switched telephone network (PSTN) and packet switched data networks (PSDN).
  • ETCs earth terminal controllers
  • GWs gateways
  • PSTN public switched telephone network
  • PSDN packet switched data networks
  • FIG. 1 Two of each of gateways 22 and subscriber units 26 are shown in FIG. 1 for clarity and ease of understanding, but this does not constrain the number of such objects in a system represented by FIG. 1.
  • Earth terminal controllers 24 may be co-located with or separate from gateways 22.
  • Earth terminal controllers 24 associated with gateways 22 primarily receive and relay data packets relating to communications in progress between subscriber units 26 and satellites 12.
  • Subscriber units 26 can be located anywhere on the surface of the earth or in the atmosphere above the earth. Subscriber units 26 are preferably communication devices capable of transmitting data to and receiving data from satellites 12. By way of example, subscriber units 26 may be hand-held, portable cellular telephones adapted to communicate with satellites 12.
  • Communication system 10 can accommodate any number, potentially in the millions, of subscriber units 26.
  • subscriber units 26 communicate with nearby satellites 12 via communication links 16.
  • Links 16 encompass a limited portion of the electromagnetic spectrum that is divided into numerous channels. Links 16 may be combinations of L-Band and/or K-Band frequency channels, but are not frequency limited and may encompass Frequency Division Multiple Access (FDMA) and/or Time Division Multiple Access (TDMA) and/or Code Division Multiple Access (CDMA) communications or combinations thereof.
  • Links 16 include traffic channels 17, and signaling channels which include broadcast channel 18, and an access request channel 19. At a minimum, satellite 12 regularly transmits over one or more broadcast channels 18.
  • Subscriber units 26 synchronize to broadcast channels 18 and monitor broadcast channels 18 to detect data messages, such as a ring alert, that may be addressed to them. Subscriber units 26 may transmit messages to satellites 12 over one or more access request channels 19. Broadcast channels 18 and access request channels 19 are not dedicated to any one subscriber unit 26 but are shared by all subscriber units 26 within view of a satellite 12. On the other hand, traffic channels 17 are two-way channels that are assigned to particular subscriber units 26 by satellites 12 from time to time.
  • At least one traffic channel 17 is assigned for each call, and each traffic channel 17 has sufficient bandwidth to support, at a minimum, a two-way voice conversation.
  • a TDMA scheme is desirably used to divide time into frames, preferably in the 10 to 90 millisecond range.
  • Particular traffic channels 17 are assigned particular transmit and receive time- slots, preferably having a duration in the 3 to 10 millisecond range, within each frame.
  • Analog audio signals are digitized so that an entire frame is transmitted or received in a single short high speed burst during an allotted time-slot.
  • each satellite 12 supports up to a thousand or more traffic channels 17 so that each satellite 12 can simultaneously service a large number of independent calls.
  • traffic channels can be formed without this time slot structure and that methods that do not require digitizing the analog voice signal may be employed.
  • the precise method used to form the channels and process the voice communication is not important to this invention.
  • the present invention is not dependant upon any particular satellite constellation arrangement or limitations.
  • Satellites 12 communicate with other nearby satellites 12 through cross-links 23.
  • a communication from a subscriber unit 26 located at any point on or near the surface of the earth can be routed through the constellation of satellites 12 to within range of substantially any other point on the surface of the earth.
  • a communication can be routed down to a subscriber unit 26 on or near the surface of the earth from a satellite 12 using link 16.
  • a communication can be routed down to or up from any of many earth terminal controllers 24, of which FIG. 1 shows only two, through earth links 15.
  • Earth terminal controllers 24 are usually distributed over the surface of the earth in accordance with traffic demands and regulatory requirements.
  • Each satellite 12 may communicate with up to four earth terminal controllers 24 and over a thousand subscriber units 26 at any given instant.
  • One or more earth terminal controllers 24 provide the primary communications interface between gateways 22 and satellites 12.
  • Gateways 22 can perform call processing functions in conjunction with satellites 12, or gateways 22 can exclusively handle call processing and allocation of call handling capacity within communication system 10.
  • Diverse terrestrial-based communication systems such as the PSTN or the Internet, may access communication system 10 through gateways 22.
  • Any satellite 12 may be in direct or indirect data communication with any subscriber unit 26 or earth terminal controller 24 at any time by routing data through the constellation of satellites 12.
  • communication system 10 may establish a communication path for relaying data through the constellation of satellites 12 between any two subscriber units 26, between any two gateways 22 or between subscriber unit 26 and gateway 22.
  • the present invention is advantageously employed in the above described communication system 10.
  • the present invention is also applicable to satellite communication systems in which full coverage of the earth is not achieved (i.e., where there are "holes" in the communication coverage provided by the constellation) and to satellite communication systems having constellations where there may be plural coverage of portions of the typical communication paths between a satellite, subscriber unit, and gateway.
  • a user having a subscriber unit 26 initiates a communication session by monitoring broadcast channels 18 to determine first, if communication services are available and secondly, the spectrum and time slot of access request channel 19.
  • Subscriber unit 26 then proceeds to refine communication parameters such as timing parameters inherent in synchronous TDMA communication systems and transmission frequency offsets injected by Doppler frequencies introduced by high-velocity orbiting base stations such as satellites 12.
  • Satellite 12 evaluates the communication parameters employed by subscriber unit 26 and provides feedback for refining both timing and frequency parameters in broadcast channel 18. Subscriber unit 26 adjusts subsequent transmissions in access request channel 19 until satellite 12 determines that communication parameters are sufficiently refined to non- interferingly operate in a narrow-band traffic channel 17. Satellites 12, through cross-links 23 and earth-links 15, cooperatively with gateways 22 establish a connection from subscriber unit 26 to a terminating party as requested by the user of subscriber unit 26. This connection process from point to point requires that resources be dedicated from subscriber unit 26 to a terminating party for the duration of a communication session.
  • a subscriber unit 26 When a conventional satellite communication is made, a subscriber unit 26 first finds an available satellite 12. Subscriber unit 26 acquires broadcast channel 18 for a satellite and then initiates an access request via access request channel 19. The access request is sent from subscriber unit 26 through the satellite to the user's home gateway 22. Access request signaling for use in satellite communication systems is known to those skilled in the art. When a subscriber unit is being called, ring alert messages are broadcast via broadcast channel 18. The broadcast ring alert messages include addressing information which identify the subscriber unit 26 which is being rung. Ring alert signaling for satellite communication systems is also known to those skilled in the art.
  • otherwise spare bits in conventional access request sent via access request channel 19 and ring alert signaling sent via broadcast channel 18 are used to transfer data packets.
  • a digital format is used to communicate data over signaling channels including broadcast channel 18 and access request channel 19. Including a destination address, this method supports data packets up to 50 bytes long from a data terminal to a host, with low latency. A response packet up to 20 bytes long can be returned in the opposite direction in this same channel.
  • up to 6 ring alert signaling slots can deliver an address and up to 20 bytes of payload from a host to a data terminal. It should be noted that while the packet payload sizes here are applicable in a particular embodiment of the present invention, other sizes may be chosen without deviating from the fundamental principles of the invention.
  • one or more remote application sites 201 may be accessed by host application sites 203, 213 via a gateway site 205 utilizing communication system 10.
  • Communication system 10 is shown schematically in Fig. 2. It will be understood by those skilled in the art that communication system 10 shown in Fig. 2 is substantially that as shown in FIG. 1 including a constellation of satellites 12 and subscriber units 26.
  • Each remote application site 201 may include one or more data terminals 207 that are in turn connected to application specific functions 209.
  • Data terminal 207 is a special case of subscriber unit 26, specifically designed for "machine-oriented" applications.
  • the application specific functions may be any of a number of functions including, but not limited to, monitoring or sensing functions which gather, sense, create and/or modify data which may for example relate to ambient conditions, process state or any number of other control and data generating functions. It will be understood by those skilled in the art that the specific applications and related functions do not limit the scope of the invention.
  • four data terminals 207 each associated with corresponding application specific functions 209 are identified as being at a single remote application site 201.
  • the number of data terminals 207 at one site can vary and the number of remote application sites 201 can also vary.
  • a plurality of host application sites 203, 213 can connect to communication system 10 in a variety of ways.
  • Application host site 213, for example, is coupled to the satellite communication system 10 via a data terminal 207. More typically, however, application host sites 203 connect to system 10 via a gateway site 205. Gateway site 205 includes a gateway 22, an earth terminal controller 24 and a service center 28. Service center 28 provides a data network interface to application host sites 203 and, depending on the specific embodiment of the invention, either a circuit network interface or a packet network interface to gateway 22. It is also possible for application host sites 203 to connect directly to gateway 22 by one of its interfaces.
  • Aggregator site 215 is a special case in which service center 217, which is functionally equivalent to service center 28, is situated remotely from gateway site 205; service center 217 uses the same interface to gateway 22 as service center 28, and offers the same interface to application host site 203 as service center 28.
  • data terminal 207 at remote application site 201 first identifies an available satellite 12 and then initiates an access procedure.
  • the access procedure involves sending an access request via access channel 19 through satellite 12 to attach to a home gateway site 205.
  • gateway site 205 the location of data terminal 207 initiating an access request is determined, access permissions are checked and data terminal 207 is either given or not given permission to continue with the call.
  • the access request includes as part of its format a block of data that is optional. This block of data normally carries information elements related to the position calculation.
  • gateway site 205 would detect that there is location computation data in the block of data.
  • Earth terminal controller 24 of the gateway site 205 determines whether there is a need to identify a location and determine if the call can be made.
  • the information elements of the block of data are replaced with packet data, so that a data packet is carried by the access request from a data terminal 207 of a remote application site 201 through a satellite 12 to a home gate way site 205.
  • Earth terminal controller 24 instead of finding location computation data finds a message in the form of a data packet.
  • the data packet is then sent to a service center 28 for forwarding to a destination host application site 203, 213.
  • the host application site 203, 213 may need to respond to the data packet received.
  • Earth terminal controller 24 delays response to the access request until that response is received or a predetermined time period lapses or until it determines that the connection should not be held.
  • an access decision notification is sent back to data terminal 207 acknowledging whether data terminal 207 can proceed with the call or not.
  • this notification terminates the connection and, if host application site 203, 213 has provided a response packet, carries that response packet to data terminal 207.
  • FIG. 3 the access request data format 300 is illustrated with portions shown in detail; portions that are not particularly relevant to the present invention are omitted for purposes of clarity.
  • the access request format 300 includes first data portion 301 that serves as a message type, labeling the data block as an access request; this portion is unchanged from the prior art in order to preserve the conventions programmed in existing satellites 12.
  • a second data portion 303 indicates the reason for the access request; that is, the purpose for which access is being requested. For the purposes of the invention, a new reason - packet data service - is added to the set of possible values this field may indicate.
  • Data portion 305 contains additional fields that are used in the programming of satellites 12 but are not pertinent to the invention.
  • Data portion 307 known as the "source data terminal identity," identifies a data terminal 207 sending the access request; this identifier is preferably an Internet Protocol (IP) address, but may take other forms as appropriate to the applications using this service.
  • Data portion 309, called the response request indicates whether the remote application site 201 expects to receive a response from application host site 203, 213.
  • Data portion 311 identifies to service center 28 the host application site 203, 213 to which the data packet must be sent; this address is preferably an IP address, but make take other forms as appropriate to the applications and service center implementations using this service.
  • the remainder of the access request data format 300 comprises a 52-byte field, data portion 304, that is not interpreted by satellites 12. In the prior art, it is used to carry location information from subscriber unit 26 directly to earth terminal controller 24. In the present invention, subfields of data portion 304 as defined hereinafter carry information pertinent to the packet data service from data terminal 207 directly to earth terminal controller 24.
  • data portion 313 contains a description of data terminal 207's location in one of several forms well-known to those skilled in the art; this optional field has been carried over from the prior art, and if used by an application it reduces the maximum size of data packets that may be carried by the size of the location information.
  • the remaining portion of field 304 is the packet payload, here termed field 317; this is the actual application data packet, up to 50 bytes of information to be sent from remote application site 201 to host application site 203, 213.
  • FIG. 4 the sequencing steps utilized in a packet data transmission from a remote application site 201 to a host 203 is illustrated. Via data terminal 207, satellite 12 is acquired at sequence step 401.
  • An access request message containing a data packet is transmitted from data terminal 207 to satellite 12 at sequence step 403.
  • Satellite 12 transmits the message containing the data packet to an earth terminal controller 24 at sequence step 405.
  • Earth terminal controller 24 transmits the message to service center 28 at sequence step 407.
  • the message is forwarded to host application site 203 at sequence step 409 to establish a connection.
  • host application site 203 needs to provide a response message to the remote application site 201 , it will provide a response message that is transmitted to service center 28 at sequence step 41 1.
  • Service center 28 forwards the response message to earth terminal controller 24 at sequence step 413.
  • Earth terminal controller 24 in turn embeds the response message in an access decision response signaling message that is transmitted to satellite 12 at sequence step 415 and then to data terminal 207 at remote application site 201 at sequence step 417. Earth terminal controller 24 then at sequence steps 419, 421 , 423 releases the link to clear the channel.
  • a protocol concatenates a number of messages in order to carry a data packet instead of an incoming call notification in a ring alert.
  • Earth terminal controller 24 computes where a user is located, determines which satellite 12 to utilize, and then sends out a series of ring alert messages over channel 18 carrying the broken-up data packet.
  • a sequence of up to six ring alerts is used to carry the address of the remote data terminal and a data packet of up to 20 bytes.
  • the first ring alert message in this sequence provides the address of the data terminal 207 at remote application site 201 , its location, and an indication that packet contents follow.
  • the remaining ring alert messages in the sequence each carry 4 bytes of the data packet.
  • the ring alert messages are placed in a ring alert queue at a satellite 12 and transmitted from satellite 12 to the data terminal 207 at remote application site 201.
  • a host application site 203 initiates a messaging sequence by sending a message for a remote application site 201 to service center 28 at sequence step 501.
  • Service center 28 in turn provides the message to earth terminal controller 24 at sequence step 503.
  • Earth terminal controller 22 initiates a ring alert process via a new path to satellite 12 at sequence 505 and from satellite 12 to data terminal 207 at remote application site 201 at sequence 507.
  • the initial ring alert includes the address of the data terminal 207 at remote application site 201.
  • Spare bits in a series of ring alert indication slots are assembled at earth terminal controller 24 and injected into a series of ring alert messages in sequences 509 and 510, 511 and 512, 513 and 514, 515 and 516, and 517 and 518.
  • the access request and its response in a conventional prior art voice call would be followed by a series of signaling messages that conform with the standard and custom protocols used in communication system 10.
  • Such protocols are well known to those skilled in the art.
  • GSM Global System for Mobile Communications
  • UUS User to User Signaling
  • This service option is also supported in the Call Control protocol of the Integrated Services Digital Network (ISDN), usually referred to as Q.931.
  • ISDN Integrated Services Digital Network
  • the UUS capability is applied to carry packet data between a data terminal 207 at a remote application site 201 and a host application site 203, 213.
  • Data terminal 207 and gateway 22 communicate via the CC protocol; gateway 22 and service center 28 communicate via the Q.931 protocol.
  • gateway 22 and service center 28 communicate via the Q.931 protocol.
  • data terminal 207 In order for data terminal 207 to send a data packet to host application site 203, 213, it initiates the acquisition and access procedures of communication system 10 described previously, then proceeds with the steps of a conventional call setup.
  • the CC Setup message that data terminal 207 sends to gateway 22 contains a phone number which gateway 22 interprets as service center 28.
  • gateway 22 sends a corresponding Q.931 Setup message to service center 28, which in turn maps the phone number to the address of host application site 203 or host application site 213 as appropriate.
  • the Setup message has also included in its UUS service option the data packet being sent from data terminal 207 to host application site 203, 213.
  • Service center 28 therefore extracts that data packet from the Setup message and sends it along to the application host.
  • a response from the application host can be inserted by service center 28 into signaling that closes the transaction and is returned to data terminal 207 via gateway 22.
  • a data packet sent by host application site 203, 213 can be conveyed to remote application site 201 by means of service center 28 initiating a call to data terminal 207 and inserting the data packet in the UUS service option of the Setup message that flows in that direction; the corresponding response is handled similarly.
  • FIG. 6 the sequencing steps utilized in a packet data transmission from a remote application site 201 to a host 203, with a response from host 203 to remote application site 201 , are illustrated.
  • the sequencing steps for packet data transmission in the opposite direction are sufficiently symmetrical to those described here that they will be easily derivable by one skilled in the art upon understanding FIG. 6; they are therefore not illustrated separately.
  • Via data terminal 207 satellite 12 is acquired at sequence step 601.
  • An access request and its corresponding decision are communicated between data terminal 207, satellite 12, and earth terminal controller 24 at sequence step 603.
  • GSM-standard mobility-management preliminaries which include the request for service at sequence step 605, authentication of the calling terminal at sequence step 607, and grant of permission to proceed with service at sequence step 609. It is at sequence step 611 that data terminal 207 sends the aforementioned CC Setup message to gateway 22, containing the instant data packet embedded in the UUS service option; gateway 22 acknowledges receipt of CC Setup by sending CC Call Proceeding at sequence step 612.
  • the resource assignment procedure depicted in sequence steps 613, 614, 615, 616, and 617 is part of the conventional call setup; they are performed here merely to avoid changing the convention, and add nothing to the movement of the data packet.
  • gateway 22 sends the Q.931 Setup at sequence step 619 to service center 28, again carrying the instant data packet in the UUS service option.
  • service center 28 extracts the data packet, determines the proper address, and at sequence step 621 forwards the data packet to application host site 203.
  • Host 203 may optionally provide a response data packet in sequence step 623; if so, service center 28 includes this response data packet in the UUS service option of the Q.931 Disconnect message it sends to gateway 22 at sequence step 625. If host 203 does not provide a response data packet within a time limit, the Q.931 Disconnect at sequence step 625 is sent without a UUS service option.
  • gateway 22 propagates the call release as a CC Disconnect, including the UUS service option if applicable, to data terminal 207, where any response data packet is provided to remote application 209.
  • the remaining sequence steps 630-646 depict one possible order in which the standard protocols being used may complete the tearing-down of the call. As is well-known to those skilled in the art, these standard protocols have options which permit a number of different sequence combinations at this stage; any of these may be followed within the scope of this invention.
  • the above described embodiments of the invention set forth satellite based packet data services that enable subscriber units to send and receive packet data. As is apparent from the foregoing description, data packet information is exchanged between remote application sites 201 and host application sites 203, 213 that are linked via a satellite communication system 10.
  • the data packet exchange between a remote application site 201 and a host application site 203, 213 is carried by a signaling message which had been used in the prior art only as part of establishing a voice call.
  • These services are well suited for data applications that require "bursty" data transmissions, where the time between successive transmissions greatly exceeds the average transfer delay, and "small" data transmissions, where the application's data fits in the payload capacities described above. Additional embodiments of the invention, described in the paragraphs that follow, are suited to data applications that require either more frequent or larger data transmissions. As will be described below, these embodiments abbreviate call setup procedures from the prior art to establish a path on which the application's data packets are transmitted separate from signaling and its payload capacity limitations.
  • Satellite communication system 10 for its conventional functions, includes such TRAUs in earth terminal controllers 24.
  • this alternate embodiment of the invention differs from a conventional data call is that the call setup procedures are reduced to the resource allocation procedure, eliminating the GSM CC protocol and mobility management preliminaries.
  • this embodiment is represented by noting that gateway 22 does not participate in the procedures; rather, earth terminal controller 24 and service center 28 interact directly via permanent connections through gateway 22.
  • sequence step 716 the resource assignment procedure depicted in sequence steps 714, 715, and 716 is triggered immediately at earth terminal controller 24 by means of the reason for access field 303 of FIG 3, which is included in the access request message from sequence step 703.
  • sequence step 716 a path is established for data packets between data terminal 207 and service center 28 via satellite 12 and earth terminal controller 24. Note that significantly fewer sequence steps are required to establish this path compared to a conventional call in the prior art.
  • sequence step 720 data packets are exchanged in both directions as needed by the applications at remote application site 201 and host application site 203, with service center 28 serving to relay data packets between host application site 203 and the path to data terminal 207.
  • data terminal 207 informs communications system 10 of that event via the channel release message to earth terminal controller 24 shown in sequence step 729.
  • the remaining sequence steps 740-744 then comprise the release of resources in the path between data terminal 207 and service center 28, thus ending the packet data transfer session.
  • the access request, resource assignment, and resource release procedures were retained from the conventional call setup in order to avoid changes to elements of communication system 10, especially satellites 12.
  • the path establishment is further optimized by using a different access protocol with still fewer steps.
  • the access request and resource assignment procedures are combined into a single command from data terminal 207 to satellite 12, providing satellite 12 the same resource information it would conventionally obtain from earth terminal controller 24 during those separate procedures.
  • earth terminal controller 24 and service center 28 interact directly via permanent connections, either through gateway 22 or independent of gateway 22.
  • service center 28 is desirably implemented as a GPRS Serving Node (GSN).
  • GSN GPRS Serving Node
  • FIG. 8 the sequencing steps utilized in establishing and releasing a bi-directional packet data transmission path between a remote application site 201 and a host 203, initiated by remote application site 201 , are illustrated.
  • the sequencing steps by which a host 203 may initiate the establishment of such a bidirectional packet data transmission path are sufficiently symmetrical to those described here that they will be easily derivable by one skilled in the art upon understanding FIG. 8, noting that the conventional paging procedure that begins a call to a subscriber unit 26 in communication system 10 is used here to effect the packet paging procedure of GPRS; they are therefore not illustrated separately.
  • satellite 12 Via data terminal 207, satellite 12 is acquired at sequence step 801.
  • An access command is sent from data terminal 207 to satellite 12, and thence to earth terminal controller 24 at sequence step 803; this command contains the addresses of resources at each end of the path. It should be readily apparent to those skilled in the art that data terminal 207 obtained these addresses during a logon transaction, not further illustrated here, in which the packet data transmission path was established using the FIG. 7 sequence. After sequence step 803, the predetermined path is enabled for data packets between data terminal 207 and service center 28 via satellite 12 and earth terminal controller 24. Note that significantly fewer sequence steps are required to enable this path compared to a conventional call in the prior art, and compared to the embodiment of FIG. 7.
  • sequence step 820 data packets are exchanged in both directions as needed by the applications at remote application site 201 and host application site 203, with service center 28 serving to relay data packets between host application site 203 and the path to data terminal 207.
  • data terminal 207 informs communications system 10 of that event via the channel release message to satellite 12 shown in sequence step 829. This disables the path without canceling the predetermination created by the aforementioned logon transaction. It will be readily apparent to those skilled in the art that a logoff transaction, not illustrated here, would be initiated at an appropriate time by data terminal 207 to release the resources in the predetermined path as shown in FIG. 7.
  • the above described embodiments of the invention set forth satellite based packet data services that enable subscriber units to send and receive packet data.
  • data packet information is exchanged between remote application sites 201 and host application sites 203, 213 that are linked via a satellite communication system 10.
  • the data packet exchange between a remote application site 201 and a host application site 203, 213 is carried by a data transmission path that is established using significantly fewer signaling messages than are required during the establishment of a voice call.
  • These services are well suited for data applications that require frequent data transmissions, where the time between successive transmissions exceeds the time required to establish the transmission path but is not necessarily correlated in any way with the average transfer delay.
  • These services are also well suited for data applications that require data transmissions of any size or duration.

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  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

Des transmissions de paquets de données sont effectuées dans un réseau de communications par satellites (10) entre un site d'application à distance (201) et un site d'application hôte (203, 213). Les paquets de données provenant d'un site d'application à distance ou d'un site d'application hôte sont transmis par l'intermédiaire d'un réseau de communications par satellites en utilisant plusieurs techniques basées sur l'ajout d'un paquet de données à un message de signalisation habituellement utilisé pour établir un appel. Dans un autre mode de réalisation, les paquets de données provenant d'un site d'application à distance ou d'un site d'application hôte sont transmis par l'intermédiaire d'un réseau de communications par satellites utilisant plusieurs techniques basées sur l'établissement d'un trajet de transmission en moins d'étapes par rapport au nombre d'étapes requises pour établir un appel.
PCT/US2000/027563 1999-10-22 2000-10-05 Demande d'acces dans un reseau de communications par satellites WO2001031813A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU78635/00A AU7863500A (en) 1999-10-22 2000-10-05 Access request in a satellite communication system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US42680799A 1999-10-22 1999-10-22
US09/426,807 1999-10-22

Publications (1)

Publication Number Publication Date
WO2001031813A1 true WO2001031813A1 (fr) 2001-05-03

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PCT/US2000/027563 WO2001031813A1 (fr) 1999-10-22 2000-10-05 Demande d'acces dans un reseau de communications par satellites

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AU (1) AU7863500A (fr)
WO (1) WO2001031813A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3386117A1 (fr) * 2017-03-17 2018-10-10 Harris Corporation Communications par satellite basées sur un protocole alternatif non standard
CN109039434A (zh) * 2018-09-13 2018-12-18 上海微小卫星工程中心 一种用于安全卫星通信的方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998018280A2 (fr) * 1996-10-18 1998-04-30 Telefonaktiebolaget Lm Ericsson (Publ) Acces selectif a un systeme de telecommunications mobile
GB2319699A (en) * 1996-11-21 1998-05-27 Motorola Inc Packet data communication in a satellite telecommunication system
EP0866569A2 (fr) * 1997-03-18 1998-09-23 Globalstar L.P. Système de communication radio ayant une allocation distribuéee d'utilisateurs et de ressources avec des interfaces terrestres
US5930679A (en) * 1994-10-03 1999-07-27 Motorola, Inc. Satellite-based ring alert apparatus and method of use

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5930679A (en) * 1994-10-03 1999-07-27 Motorola, Inc. Satellite-based ring alert apparatus and method of use
WO1998018280A2 (fr) * 1996-10-18 1998-04-30 Telefonaktiebolaget Lm Ericsson (Publ) Acces selectif a un systeme de telecommunications mobile
GB2319699A (en) * 1996-11-21 1998-05-27 Motorola Inc Packet data communication in a satellite telecommunication system
EP0866569A2 (fr) * 1997-03-18 1998-09-23 Globalstar L.P. Système de communication radio ayant une allocation distribuéee d'utilisateurs et de ressources avec des interfaces terrestres

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3386117A1 (fr) * 2017-03-17 2018-10-10 Harris Corporation Communications par satellite basées sur un protocole alternatif non standard
US10440776B2 (en) 2017-03-17 2019-10-08 Harris Corporation Non-standard alternate protocol based satellite communications
CN109039434A (zh) * 2018-09-13 2018-12-18 上海微小卫星工程中心 一种用于安全卫星通信的方法
CN109039434B (zh) * 2018-09-13 2021-02-09 上海垣信卫星科技有限公司 一种用于安全卫星通信的方法

Also Published As

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