TDMA backbone for a mobile network

• US 7,139,258 B2
• Filed: 03/05/2002
• Issued: 11/21/2006
• Est. Priority Date: 03/05/2002
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Tillotson, Brian Jay
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): ROSE, KERRI M
• Application Number:
  US10/091,672
• Publication Number:
  US 20030169721A1
• Time in Patent Office: 1,722 Days
• Field of Search: 370/314, 370/316, 370/321, 370/326, 370/337, 370/347, 370/442, 370/329, 370/331, 370/341, 370/350, 370/503, 370/508, 370/519, 455/13.3
• US Class Current: 370/337
• CPC Class Codes: H04B 7/2693 Centralised synchronisation, i.e. using external universal time reference, e.g. by using a global positioning system [GPS] or by distributing time reference over the wireline network
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02

Abstract

An apparatus and method for a time division multiple access (TDMA) network backbone comprising a plurality of nodes interconnected by links. Each node has receive antennas and transmit antennas for communicating radio frequency (RF) bursts, and a node control for communicating node information. The receive antennas are operated in accordance with TDMA receiving slots and the transmit antennas are operated in accordance with TDMA transmit slots. A timing reference subsystem provides timing signals for the nodes for efficiently utilizing the transmission links formed between given nodes.

Claims

1. A time division multiple access (TDMA) based network backbone comprising:

a plurality of nodes including a plurality of receive antennas for receiving a plurality of radio frequency (RF) bursts and a plurality of transmit antennas for transmitting said RF bursts, a duration of said RF bursts being shorter than a time of flight (TOF) between said nodes;

a node control for communicating information relating to said nodes;

a timing reference subsystem for providing timing signals to said nodes; and

a plurality of links interconnecting said nodes,

said receive antennas operated in accordance with a plurality of receiving slots and said transmit antennas operated in accordance with a plurality of transmitting slots.

2. The network backbone of claim 1, wherein said timing reference subsystem comprises a global positioning system.

3. The network backbone of claim 1, wherein transmitting times for said RF bursts are aligned to boundaries of said transmitting slots.

4. The network backbone of claim 1, wherein receiving times for said RF bursts are aligned to boundaries of said receiving slots.

5. The network backbone of claim 1, wherein a plurality of said nodes transmit simultaneously.

6. The network backbone of claim 1, wherein each of said nodes further comprises:

a clock for providing backup timing signals.

7. A method of forming a time division multiple access (TDMA) based network backbone, the method comprising:

sending an orderwire message from a first node selected from a plurality of nodes to other nodes of said plurality of nodes, said first node using a node control for sending said orderwire message to said other nodes;

selecting a second node to form a link, said second node having a plurality of second transmit slots and a plurality of second receive slots;

calculating time of flight (TOF) of a transmission from said first node to said second node at said second node using current locations of said first node and said second node;

sending an orderwire message from said first node to said second node offering a plurality of first transmit slots and a plurality of first receive slots to said second node; and

sending a status message from said second node to said first node.

8. The method of claim 7, further comprising the steps of:

forming an acceptable receive list after comparing said first transmit slots with said second receive slots; and

forming an acceptable transmit list after comparing said first receive slots with said second transmit slots.

9. The method of claim 8, wherein said status message comprises an acceptance message if said acceptable receive list and said acceptable transmit list are not empty, said acceptance message including said acceptable receive list and said acceptable transmit list.

10. The method of claim 8, wherein said status message comprises a rejection message if said acceptable receive list is empty.

11. The method of claim 8, wherein said status message comprises a rejection message if said acceptable transmit list is empty.

12. The method of claim 8, further comprising the step of:

applying a user defined rule to said acceptable receive list and said acceptable transmit list.

13. A method for communicating over a time division multiple access (TDMA) based network backbone, the method comprising:

determining a location for each one of a plurality of nodes, a plurality of each of said nodes including a node control for determining node location;

calculating a time of flight (TOF) between a sending node of said plurality of plurality of nodes, and a subplurality of receiving nodes of said plurality of nodes at the subplurality of receiving node of said plurality of nodes;

transmitting a plurality of radio frequency (RF) bursts from said sending node to said receiving nodes using a plurality of transmitting phased array antennas (PAAs) based on the calculated TOF, said transmitting PAAs operating in accordance with a plurality of transmitting slots; and

receiving a plurality of RF bursts from said sending node, using a plurality of receive PAAs, said receive PAAs operating in accordance with a plurality of receiving slots.

14. The method of claim 13, wherein said step of receiving is performed at times so as to be aligned with said receiving slots.

15. The method of claim 13, wherein said step of receiving is performed at times so as to be aligned with said transmitting slots.

16. The method of claim 13, further comprising the step of:

spacing the RF bursts to avoid overlapping one another.

17. The method of claim 13, wherein said step of transmitting further comprises:

managing transmission times so that a single said transmitting PAA is restricted from attempting to simultaneously transmit to any two of said nodes.

18. A method for dynamically adjusting link capacities for a time division multiple access (TDMA) network backbone, the method comprising:

estimating a needed modification in a total plurality of TDMA slots of a given transmission link for adjusting a link capacity of said given transmission link to accommodate a desired transmission link capacity;

sending a modification request from a first node of said given transmission link to a second node of said given transmission link;

updating a current status of said second node to accommodate a desired transmission link capacity by;

using said first node to estimate a plurality of transmit TDMA slots and a plurality of receive TDMA slots to be removed to reduce link capacity;

selecting said transmit TDMA slots and said receive TDMA slots to be removed by said first node based on a user-defined criteria; and

sending to said second node a request for removing certain of said transmit TDMA slots and certain of said receive TDMA slots; and

sending a status message from said second node to said first node.

19. The method of claim 18, wherein said step of updating a current status, comprises:

constructing a send times block by said first node for determining starting times for transmissions from said first node to said second node;

updating a physically acceptable transmit list for additional required TDMA slots on said first node;

sending a request to said second node for additional transmit capacity along with updated said physically acceptable transmit list;

constructing a physically acceptable receive list from a comparison of a plurality of available receive TDMA slots on said second node with said physically acceptable transmit list;

truncating said acceptable receive list to match said request for additional transmit capacity;

sending said acceptable receive list to said first node; and

using additional capacity if said acceptable receive list contains at least one additional slot.

20. The method of claim 18, wherein said step of updating a current status further comprises:

causing said second node to remove said certain TDMA transmit slots and said certain TDMA receive slots by said second node;

sending an acknowledgement of removal of said certain TDMA transmit and TDMA receive slots from said second node to said first node; and

ceasing the use of said certain TDMA transmit slots and said certain TDMA receive slots by said first node and said second node.