Media access controller having pseudo-static guaranteed time slots

• US 20040013127A1
• Filed: 07/19/2002
• Published: 01/22/2004
• Est. Priority Date: 01/03/2002
• Status: Active Grant

• Current Assignee: North Star Innovations Inc. (Wi-LAN Inc.)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Shvodian, William M.
• Granted Patent: US 6,980,541 B2
• Time in Patent Office: Days
• US Class Current: 370/442
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 74/02 Hybrid access
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A wireless network is provided that uses pseudo-static time slots. These time slots remain fixed in time unless and until a network controller specifically changes them and the network controller subsequently receives confirmation of the change. Times and durations of the pseudo-static time slots are only changed in small steps as each relevant device in the network acknowledges the step. To aid in allowing full coverage even during a change of active devices, when a transmitter and receiver are moved to a new time slot, the receiver is set to listen to both the old and the new time slots until the transmitter confirms that it has made the switch.

Claims

1. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, the transmitter and the receiver both being initially assigned to a starting active time slot chosen from the plurality of active time slots, comprising:

sending a first instruction from a controller to the receiver to listen for signals from the transmitter during both the starting active time slot and a target unused time interval chosen from the one or more unused time intervals, the starting active time slot and the target unused time interval being adjacent to each other;

sending a first acknowledgement from the receiver to the controller that the first instruction was received and acted upon;

sending a second instruction from a controller to the transmitter, after the controller receives the first acknowledgement, to transmit signals to the receiver during an ending active time slot, the ending active time slot being placed in a time period that is entirely contained within one or both of the starting active time slot and the target unused time interval;

sending a second acknowledgement from the transmitter to the controller that the first instruction was received and acted upon;

sending a third instruction from a controller to the receiver, after the controller receives the second acknowledgement, to listen for signals from the transmitter during only the ending active time slot; and

sending a third acknowledgement from the receiver to the controller that the first instruction was received and acted upon,

wherein the transmission time of the transmitter is not changed between the sending of the first instruction and the sending of the second instruction.

2. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 1, further comprising repeating the sending of the first instruction before receiving the first acknowledgement.

3. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 1, further comprising repeating the sending of the second instruction before receiving the second acknowledgement.

4. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 1, further comprising repeating the sending of the third instruction before receiving the third acknowledgement.

5. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 1, wherein the first and third instructions are sent to the receiver in a beacon, and the second instruction is sent to the transmitter in a directed command frame.

6. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 1, wherein the target unused time interval is smaller than the starting active time slot.

7. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 1, wherein the transmitter and the receiver are in a different network than the controller.

8. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, the transmitter and the receiver both being initially assigned to a starting active time slot chosen from the plurality of active time slots, comprising:

sending a first instruction from a controller to the receiver to listen for signals from the transmitter during both the starting active time slot and an ending active time slot, the ending active time slot being formed in a target unused time interval chosen from the one or more unused time intervals;

sending a first acknowledgement from the receiver to the controller that the first instruction was received and acted upon;

sending a second instruction from a controller to the transmitter, after the controller receives the first acknowledgement, to transmit signals to the receiver during the ending active time slot;

sending a second acknowledgement from the transmitter to the controller that the first instruction was received and acted upon;

sending a third instruction from a controller to the receiver, after the controller receives the second acknowledgement, to listen for signals from the transmitter during only the ending active time slot; and

sending a third acknowledgement from the receiver to the controller that the first instruction was received and acted upon,

wherein the transmission time of the transmitter is not changed between the sending of the first instruction and the sending of the second instruction, and wherein the target unused time interval is at least as long in duration as the starting active time slot.

9. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 8, further comprising repeating the sending of the first instruction before receiving the first acknowledgement.

10. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 8, further comprising repeating the sending of the second instruction before receiving the second acknowledgement.

11. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 8, further comprising repeating the sending of the third instruction before receiving the third acknowledgement.

12. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 8, wherein the first and third instructions are sent to the receiver in a beacon, and the second instructions are sent to the transmitter in a directed command frame.

13. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 8, wherein the target unused time interval is separated from the starting active time slot by a set period of time.

14. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 8, wherein the transmitter and the receiver are in a different network than the controller.

15. A method of coordinating transmission times within overlapping first and second wireless networks, comprising:

dividing available transmission time into a plurality of super-frames, each super-frame being of a set duration;

dividing each super-frame into a plurality of primary time slots, including one or more initial primary time slots and one or more additional primary time slots;

assigning the one or more initial primary time slots to one or more primary devices within the first wireless network;

dividing each of the one or more additional primary time slots into one or more secondary time slots; and

assigning the one or more secondary time slots to one or more secondary devices within the second wireless network.

16. A method of coordinating transmission times within overlapping first and second wireless networks, as recited in claim 15, wherein the one or more initial primary time slots are assigned by a primary controller.

17. A method of coordinating transmission times within overlapping first and second wireless networks, as recited in claim 16, wherein the one or more secondary time slots are assigned by a secondary controller.

18. A method of coordinating transmission times within overlapping first and second wireless networks, as recited in claim 17, wherein the primary controller is in the first wireless network.

19. A method of coordinating transmission times within overlapping first and second wireless networks, as recited in claim 18, wherein the secondary controller is in the secondary wireless network.

20. A method of coordinating transmission times within overlapping first and second wireless networks, as recited in claim 15, wherein the primary time slots each have the same duration.

21. A method of coordinating transmission times within overlapping first and second wireless networks, as recited in claim 15, wherein the primary time slots have differing durations.

22. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, the transmitter and the receiver both being initially assigned to a starting active time slot chosen from the plurality of active time slots, comprising:

sending a first instruction from a controller to the receiver to listen for signals from the transmitter during both the starting active time slot and a target unused time interval chosen from the one or more unused time intervals, the starting active time slot and the target unused time interval being adjacent to each other;

sending a second instruction from a controller to the transmitter, after the controller sends the first instruction, to transmit signals to the receiver during an ending active time slot, the ending active time slot being placed in a time period that is entirely contained within one or both of the starting active time slot and the target unused time interval;

sending an acknowledgement from the transmitter to the controller that the first instruction was received and acted upon; and

sending a third instruction from a controller to the receiver, after the controller receives the acknowledgement, to listen for signals from the transmitter during only the ending active time slot,

wherein the transmission time of the transmitter is not changed between the sending of the first instruction and the sending of the second instruction.

23. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 22, wherein the first instruction is sent in a beacon.

24. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 22, wherein the second instruction is sent in a directed command frame.

25. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 22, wherein the third instruction is sent in a beacon.

26. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 22, wherein the receiver does not acknowledge receipt of the first instruction to the controller.

27. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 22, wherein the receiver does not acknowledge receipt of the third instruction to the controller.

28. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, the transmitter and the receiver both being initially assigned to a starting active time slot chosen from the plurality of active time slots, comprising:

sending a first instruction from a controller to the receiver to listen for signals from the transmitter during both the starting active time slot and an ending active time slot, the ending active time slot being formed in a target unused time interval chosen from the one or more unused time intervals;

sending a second instruction from a controller to the transmitter, after the controller sends the first instruction, to transmit signals to the receiver during the ending active time slot;

sending an acknowledgement from the transmitter to the controller that the first instruction was received and acted upon; and

sending a third instruction from a controller to the receiver, after the controller receives the acknowledgement, to listen for signals from the transmitter during only the ending active time slot,

wherein the transmission time of the transmitter is not changed between the sending of the first instruction and the sending of the second instruction, and wherein the target unused time interval is at least as long in duration as the starting active time slot.

29. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 28, wherein the first instruction is sent in a beacon.

30. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 28, wherein the second instruction is sent in a directed command frame.

31. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 28, wherein the third instruction is sent in a beacon.

32. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 28, wherein the receiver does not acknowledge receipt of the first instruction to the controller.

33. A method of controlling a transmitter and a receiver to adjust transmitting and receiving times in a super-frame having a plurality of active time slots and one or more unused time intervals, as recited in claim 28, wherein the receiver does not acknowledge receipt of the third instruction to the controller.