Full mesh satellite-based multimedia networking system

• US 5,812,545 A
• Filed: 01/23/1996
• Issued: 09/22/1998
• Est. Priority Date: 01/04/1996
• Status: Expired due to Term

• Current Assignee: Orion Atlantic, L.P. (Loral Orion Network Systems, Inc.), ND Satcom Gesellschaft Fur Satellitenkommunikationssysteme Mbh
• Original Assignee: Orion Atlantic, L.P. (Loral Orion Network Systems, Inc.), Nortel DASA Network Systems GmbH & Company
• Inventors: Thaller, Franz, Arens, Heinrich, Liebowitz, Burt, Sweeney, Steven
• Primary Examiner(s): Safourek, Benedict V.
• Assistant Examiner(s): RAO, SEEMA SRINIVAS
• Application Number:
  US08/589,255
• Time in Patent Office: 973 Days
• Field of Search: 370/315, 370/314, 370/316, 370/319, 370/321, 370/322, 370/324, 370/326, 370/328, 370/329, 370/336-338, 370/345, 370/347, 370/348, 370/350, 370/431, 370/442, 370/443, 370/444, 370/501, 370/514, 370/464, 370/468, 370/498, 370/476, 370/474, 340/825.5, 340/825.51, 455/12.1, 455/13.1, 455/13.2, 455/53.1
• US Class Current: 370/337
• CPC Class Codes: H04B 7/18523 Satellite systems for providing broadcast service to terrestrial stations, i.e. broadcast satellite service arrangements specially adapted for satellite broadcast receiving H04H40/90; picture transmission via satellite H04N1/00103; television transmission via satellite H04N7/20
• CPC Class Codes: H04B 7/18582 Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185

Abstract

A satellite communications system is provided for full mesh connectivity between a number of earth terminals via a satellite link. The earth terminals are connected to user access devices to receive and transmit voice, video and data and are operable to generate bursts to transmit user data via a satellite, and to process data received from the satellite and transmit it to the addressed user access devices. The terminals each comprise a programmable computing device which prioritizes data into bursts using a fragmentation protocol. The programmable computing device also organizes bursts in at least one of a plurality of slots constituting a time division multiple access frame in accordance with a burst plan. Each terminal has access to a guaranteed number of the slots. The allocation of the remaining slots among the terminals varies dynamically to increase or decrease the burst transmission rates of the terminals as needed. Dynamic assignment of slots depends on committed information rates, the lengths of data queues in the terminals and the type of data to be transmitted. Terminals need not be assigned consecutive ones of the dynamically assignable slots.

Claims

1. A satellite communication system providing full mesh connectivity among a number of earth terminals via a satellite, the earth terminals being connected to user access devices to receive and transmit at least one of voice, video and other data, each of said terminals comprising:

a processor having a digital memory device and a plurality of ports for connecting to said user access devices, said processor being operable to generate bursts using data received from said user access devices for transmission via the satellite, and to process data received via the satellite and addressed to one of said user access devices for transmission to said user access device;

a modem connected to said processor for modulating said bursts onto radio frequency modulated signals and demodulating downlink carrier signals received from the satellite; and

a radio frequency transceiver connected to said modem for converting said modulated signals to an uplink carrier signal for broadcast to each of said earth terminals via the satellite, and for converting said downlink carrier signals to corresponding modulated signals, respectively;

wherein said processor is programmable to organize said bursts in at least one of a plurality of slots constituting a time division multiple access frame, one of said terminals to which said processor corresponds having access to a selected number of said slots to increase or decrease the rate at which said one of said terminals transmits said bursts via the satellite, said selected number of slots being dynamically variable in accordance with a burst plane stored in said digital memory for assigning said slots in said frame to each of said terminals, said slots being dynamically assignable among said terminals in accordance with said burst plan, said dynamically assignable slots being assigned to respective ones of said terminals based on their respective bandwidth requirements.

2. A satellite communication system as claimed in claim 1, wherein one of said terminals is programmable to operate as a manager terminal and the remaining ones of said terminals are each programmable to generate and transmit bandwidth messages to said manager terminal relating to the bandwidth required by said terminal, said manager terminal being programmed to generate said burst plan for assigning said slots in said frame to respective ones of said terminals in accordance with said bandwidth messages, said digital memory device in each of said terminals comprising a plurality of data queues for storing data received from corresponding ones of said plurality of ports, each of said terminals being programmable to monitor a corresponding said plurality of queues, said bandwidth messages comprising data relating to the lengths of said data queues and to the type of data received from corresponding ones of said plurality of ports, said type of data selected from the group consisting of voice, video and other data.

3. A satellite communication system as claimed in claim 1, wherein each of said terminals is programmable to store data relating to the amount of data received at each of said plurality of ports, and the type of data selected from the group consisting of voice, video and other data, said burst plan being determined using said stored data.

4. A satellite communication system providing full mesh connectivity among a number of earth terminals via a satellite, the earth terminals being connected to user access devices to receive and transmit at least one of voice, video and other data, each of said terminals comprising:

a processor having a digital memory device and a plurality of ports for connecting to said user access devices, said processor being operable to generate bursts using data received from said user access devices for transmission via the satellite, and to process data received via the satellite and addressed to one of said user access devices for transmission to said user access device;

a modem connected to said processor for modulating said bursts onto radio frequency modulated signals and demodulating downlink carrier signals received from the satellite; and

a radio frequency transceiver connected to said modem for converting said modulated signals to an uplink carrier signal for broadcast to each of said earth terminals via the satellite, and for converting said downlink carrier signals to corresponding modulated signals, respectively;

wherein said processor is programmable to organize said bursts in at least one of a plurality of slots constituting a time division multiple access frame, one of said terminals to which said processor corresponds having access to a selected number of said slots to increase or decrease the rate at which said one of said terminals transmits said bursts via the satellite, said selected number of slots being dynamically variable in accordance with a burst plan stored in said digital memory for assigning said slots in said frame to each of said terminals, said slots being dynamically assignable among said terminals in accordance with said burst plan, said dynamically assignable slots being assigned to respective ones of said terminals based on their respective bandwidth requirements, said burst plan being generated and transmitted to said terminals with the occurrence of each said frame.

5. A satellite communication system as claimed in claim 4, wherein said slots are of fixed duration.

6. A satellite communication system as claimed in claim 4, wherein said slots assigned to one of said terminals can be nonconsecutive within said frame.

7. A satellite communication system as claimed in claim 4, wherein one of said terminals is programmable to operate as a manager terminal and the remaining ones of said terminals are each programmable to generate and transmit bandwidth messages to said manager terminal relating to the bandwidth required by said terminal, said manager terminal being programmed to generate said burst plan for assigning said slots in said frame to respective ones of said terminals in accordance with said bandwidth messages.

8. A satellite communication system as claimed in claim 4, wherein each of said terminals is programmable to generate and transmit bandwidth messages to all other ones of said terminals, and to generate said burst plan to determine which of said slots in said frame are assigned to said terminal using said bandwidth messages from all of said terminals.

9. A satellite communication system as claimed in claim 4, further comprising a manager terminal programmable to receive bandwidth messages generated and transmitted by said terminals, and to generate said burst plan to determine which of said slots in said frame are assigned to each of said terminals using said bandwidth messages.

10. A satellite communication system as claimed in claim 4, wherein data received from respective ones of said user access devices is formatted into frames, said processor being programmable to divide said frames into fragments and to place said fragments in different ones of said bursts.

11. A satellite communication system as claimed in claim 10, wherein said processor is programmable to prioritize said frames from different ones of said user access devices for placement in said bursts, and to generate said bursts by filling said burst with said fragments from said frame having the highest priority before filling in the remainder of said burst with said fragments from said frames having less priority.

12. A satellite communication system as claimed in claim 11, wherein said step of assigning each of said terminals a variable number of slots further comprises the step of classifying as many of said slots in said first slot class as necessary to transmit bursts comprising data requiring transmission with minimal delay.

13. A satellite communication system as claimed in claim 12, wherein said step of assigning each of said terminals a variable number of slots further comprises the step of classifying a number of said slots in said frame which are not in said first slot class in said second slot class to transmit said bursts comprising data that is less sensitive to transmission delay as said slots in said first slot class.

14. A satellite communication system as claimed in claim 12, wherein said step of assigning each of said terminals a variable number of slots further comprises the step of classifying said slots which remain unassigned to said first slot class or said second slot class as free slots and to selectively assign said free slots to said terminals in accordance with a method selected from the group consisting of assigning said free slots equally among said terminals, assigning said free slots in proportion to said number of said slots currently assigned to each of said terminals, and assigning said free slots in inverse proportion to said number of said slots currently assigned to each of said terminals.

15. A satellite communication system providing full mesh connectivity among a number of earth terminals via a satellite, the earth terminals being connected to user access devices to receive and transmit at least one of voice, video and other data, each of said terminals comprising:

a processor having a digital memory device and a plurality of ports for connecting to said user access devices, said processor being operable to generate bursts using data received from said user access devices for transmission via the satellite, and to process data received via the satellite and addressed to one of said user access devices for transmission to said user access device;

a modem connected to said processor for modulating said bursts onto radio frequency modulated signals and demodulating downlink carrier signals received from the satellite;

a radio frequency transceiver connected to said modem for converting said modulated signals to an uplink carrier signal for broadcast to each of said earth terminals via the satellite, and for converting said downlink carrier signals to corresponding modulated signals, respectively;

wherein said processor is programmable to organize said bursts in at least one of a plurality of slots constituting a time division multiple access frame, one of said terminals to which said processor corresponds having access to a selected number of said slots to increase or decrease the rate at which said one of said terminals transmits said bursts via the satellite, said selected number of slots being dynamically variable in accordance with a burst plan stored in said digital memory for assigning said slots in said frame to each of said terminals, said slots being dynamically assignable among said terminals in accordance with said burst plan, said dynamically assignable slots being assigned to respective ones of said terminals based on their respective bandwidth requirements; and

a manager terminal programmable to receive bandwidth messages generated and transmitted by said terminals, and to generate said burst plan to determine which of said slots in said frame are assigned to each of said terminals using said bandwidth messages, said manager terminal being programmable to dynamically classify each slot as one of first and second slot classes, said first and second slot classes allowing for at least first and second levels, respectively, of prioritization for assigning said slots to said terminals.

16. A satellite communication system as claimed in claim 15, wherein said manager terminal is programmable to classify as many of said slots in said first slot class as necessary to transmit said bursts comprising data requiring transmission with minimal delay.

17. A satellite communication system as claimed in claim 16, wherein said manager terminal is programmable to classify a number of said slots in said frame which are not in said first slot class in said second slot class to transmit said bursts comprising data that is less sensitive to transmission delay as said slots in said first slot class.

18. A satellite communication system as claimed in claim 17, wherein said manager terminal is programmable to classify said slots which remain unassigned to said first slot class or said second slot as free slots and to selectively assign said free slots to said terminals.

19. A satellite communication system as claimed in claim 18, wherein said manager terminal is programmable to assign said free slots to said terminals in accordance with a method selected from the group consisting of assigning said free slots equally among said terminals, assigning said free slots in proportion to said number of said slots currently assigned to each of said terminals, and assigning said free slots in inverse proportion to said number of said slots currently assigned to each of said terminals.

20. A satellite communication system as claimed in claim 17, wherein said manager terminal is programmable to assign said slots in said second slot class to guarantee a minimum amount of data is transmitted in said frame for corresponding ones of said terminals.

21. A satellite communication system as claimed in claim 20, wherein said manager terminal is programmable to dynamically classify each slot as one of said first and second slot classes, and a third class, and to assign said slots in said third class to said terminals when said terminals need to send data in excess of said guaranteed amount of data.

22. A satellite communication system as claimed in claim 20, wherein said digital memory device comprises a plurality of data queues for storing data received from corresponding ones of said plurality of ports, and said manager terminal is programmable to assign a number of said slots in said second slot class to empty said data queues without exceeding said guaranteed amount of data.

23. A satellite communication system as claimed in claim 22, wherein each of said terminals is programmable to release a selected number of said slots in said second slot class and assigned to said terminal for assignment to other ones of said terminals by said manager terminal when said released slots are not needed to empty said data queues, said released slots being reassigned to said terminal by said manager terminal when needed.

24. A satellite communication system as claimed in claim 23, wherein said manager terminal is programmable to assign said released slots assigned to a first one of said terminals to a second one of said terminals when said second one of said terminals needs to send data in excess of said guaranteed amount of data.

25. For use in a satellite communications system for providing full mesh connectivity among a number of earth terminals via a satellite link, the earth terminals being connected to user access devices to receive and transmit at least one of voice, video and other data, a method of dynamically assigning bandwidth on the satellite link to a terminal, the method comprising the steps of:

dividing slots which constitute a time division multiple access frame into a first group of slots and a second group of slots;

assigning each of said terminals a predetermined number of said slots in said first group of slots to provide a predetermined minimum bandwidth, and reserving a predetermined number of said slots in said second group of slots for dynamic allocation among said terminals in accordance with a burst plan, each of said terminals being operable to generate and transmit bursts in said slots assigned thereto from said slot first group of slots and allocated thereto from said second group of slots such that said slots need not be consecutive within said frame;

assigning each of said terminals a variable number of slots from said second group of slots in said time division multiple access frame in accordance with said burst plan wherein said assigned slots assigned to respective said terminals from said first group of slots and said second group of slots need not be consecutive within said frame, each of said terminals being operable to generate and transmit bursts during said assigned slots;

storing said burst plan in a digital memory device in each of said terminals;

monitoring data received from said user input devices connected to said terminals to determine when more bandwidth is needed at each of said terminals, each of said terminals being operable to generate bursts to transmit said data via the satellite using said assigned slots;

requesting additional ones of said second group of slots reserved for dynamic allocation for at least one terminal to increase the burst transmission rate thereof when more bandwidth is needed;

modifying said burst plan to reassign selected ones of said second group of slots reserved for dynamic allocation to said terminal; and

storing said modified burst plan in said digital memory device in each of said terminals.

26. A method of dynamically assigning bandwidth as claimed in claim 25, wherein each of said slots in said time division multiple access frame is of fixed duration.

27. A method of dynamically assigning bandwidth as claimed in claim 25, wherein each of said terminals comprises data queues for storing said data from said user access devices, said monitoring step comprising the step of determining the length of said queues.

28. A method of dynamically assigning bandwidth as claimed in claim 25, wherein each of said terminals is assigned a committed information rate corresponding to at least one of said terminal, one of a plurality of ports thereon for connecting to said user access devices, and a virtual circuit connection associated with one of said plurality of ports, said requesting step comprising the step of generating a bandwidth message for requesting bandwidth comprising data relating said committed information rate, the amount of data received at each of said plurality of ports, and the type of data, said data type selected from the group consisting of voice, video and data.

29. A method of dynamically assigning bandwidth as claimed in claim 25, wherein one of said terminals is a manager terminal, and said requesting step further comprises the steps of generating bandwidth messages at each of said terminals, and transmitting said messages to said manager terminal via the satellite, said manager terminal being operable to reassign said slots in said second group of slots in response to said messages.

30. A method of dynamically assigning bandwidth as claimed in claim 25, wherein said modifying step further comprises the step of determining that a portion of the bandwidth for at least one of said terminals is not required.

31. A method of dynamically assigning bandwidth as claimed in claim 30, further comprising the steps of:

generating a message to said manager station from said terminal indicating that a number of said assigned slots are not being used by said terminal;

adjusting said burst plan by reassigning said unused slots to other ones of said terminals; and

transmitting a modified burst plan to said terminals via the satellite link.

32. A method of dynamically assigning bandwidth as claimed in claim 25, wherein data received from respective ones of said user access devices is formatted into frames, and further comprising the steps of:

dividing said frames into fragments; and

placing said fragments in different ones of said bursts.

33. A satellite communication system as claimed in claim 32, wherein said placing step further comprises the steps of:

prioritizing said frames from different ones of said user access devices for placement in said bursts; and

generating said bursts by filling said burst with said fragments from said frame having the highest priority first; and

filling in the remainder of said burst with said fragments from said frames having less priority.

34. A satellite communication system as claimed in claim 33, wherein said step of assigning each of said terminals a variable number of slots comprises the step of classifying each of said second group of slots as one of first and second slot classes, said first and second slot classes allowing for at least first and second levels, respectively, of prioritization for assigning said slots to said terminals.