Method, apparatus or computer program for changing from scheduled to unscheduled communication modes

1. A method comprising:

detecting, by an apparatus, while in a first communication mode that uses scheduled communication windows that are a sequence of a plurality of periodic windows of variable duration, with each periodic window including a first occurring portion having a first occurring interval and a second occurring portion having a second occurring interval, with communications during the second occurring portion being dependent upon preceding communications during the first portion, with a communication device in the periodic windows, when a number of packets communicated in the first occurring interval within the first portion, exceeds a threshold;

changing, by the apparatus, the communication mode from the first communication mode to a second communication mode that uses unscheduled communication with the communication device, if the number of packets communicated in the first occurring interval within the first occurring portion exceeds the threshold, and

remaining, by the apparatus, in the first communication mode, if the number of packets communicated in the first occurring interval within the first occurring portion does not exceed the threshold.

2. A method according to claim 1 , further comprising: while in the first communications mode, intermittently activating communication circuitry according to a schedule.

3. A method according to claim 1 , wherein the first communication mode uses scheduled windows for communication.

4. A method according to claim 3 , wherein the scheduled windows have starting positions that occur periodically.

5. A method according to claim 3 , wherein the windows are positioned to avoid periods reserved for synchronous communication.

6. A method according to claim 3 , wherein the windows have a duration comprising a constant component.

7. A method according to claim 6 , wherein adjacent windows are separated by a period greater than the constant component.

8. A method according to claim 3 , wherein asynchronous communication is prevented outside the scheduled windows.

9. A method according to claim 3 , wherein communication circuitry is activated during the scheduled windows and deactivated for at least part of the time lying outside the scheduled windows.

10. A method according to claim 1 , wherein in the first communication mode, communication is allowed for only a limited duration following a preceding communication.

11. A method according to claim 1 , wherein in the first communication mode has a reduced duty cycle compared to the second communication mode.

12. A method according to claim 1 , wherein in the second communication mode provides on-demand communication of data.

13. A method according to claim 1 , wherein in the second communication mode communication circuitry is activated for an increased number of reception slots compared to the first communication mode.

14. A method according to claim 1 , wherein the interval and the threshold are programmable.

15. An apparatus comprising:

radio transceiver circuitry configured to operate according to a schedule with a communication device when the apparatus is in a first communication mode that uses scheduled communication windows that are a sequence of a plurality of periodic windows of variable duration including a first occurring portion having a first occurring interval and a second occurring portion having a second occurring interval, with communications during the second occurring portion being dependent upon preceding communications during the first occurring portion, with the communication device in the periodic windows, and configured to operate without a schedule with the communication device when the apparatus is in a second communication mode;

a mechanism configured to detect when a number of packets communicated with the communication device in the first occurring interval within the first portion, exceeds a threshold; and

circuitry configured to change a communication mode from the first communication mode to the second communication mode if the detected number of packets communicated in the first occurring interval within the first occurring portion, exceeds the threshold and configured to maintain the first communication mode if the detected number of packets communicated in the first occurring interval within the first occurring portion, does not exceed the threshold.

16. An apparatus according to claim 15 , wherein the first communication mode uses scheduled windows for communication.

17. An apparatus according to claim 16 , wherein the radio transceiver circuitry is activated during the scheduled windows and deactivated for at least part of the time lying outside the scheduled windows.

18. A non-transitory computer-readable medium encoded with instructions that, when executed by a computer in an apparatus, perform steps, comprising:

starting, in the apparatus, a timeout period in a first occurring portion of a periodic window in a sequence of a plurality of periodic windows, the periodic window including the first occurring portion having a first occurring interval and a second occurring portion having a second occurring interval, with communications during the second occurring portion being dependent upon preceding communications during the first occurring portion after a communication with a communication device;

counting, by the apparatus, communications with the communication device during the timeout period in the first occurring interval within the first occurring portion;

determining, by the apparatus, when the count of communications during the timeout period in the first occurring interval within the first occurring portion, exceeds a threshold; and

enabling exit from a first communication mode that uses scheduled communication windows of variable duration dependent upon preceding communications during the first occurring interval within the first occurring portion, with the communication device in the periodic windows, to enter a second communication mode that uses unscheduled communication with the communication device, if the count of communications during the timeout period in the first occurring interval within the first occurring portion, exceeds a threshold and enabling maintenance of the first communication mode if the count of communications during the timeout period in the first occurring interval within the first occurring portion, does not exceed the threshold.

19. A method of controlling a low power radio transceiver comprising:

commencing, by the radio transceiver, a scheduled communication mode that uses scheduled communication windows that are a sequence of a plurality of periodic windows of variable duration including a first occurring portion having a first occurring interval and a second occurring portion having a second occurring interval, with communications during the second occurring portion being dependent upon preceding communications during the first occurring portion, with a communication device in the periodic windows; and

delaying, by the radio transceiver, after the commencement of data communication in the scheduled communication mode with the communication device, an exit from the scheduled communication mode to an unscheduled communication mode with the communication device, until a predetermined data transfer condition is satisfied wherein a number of packets communicated in the first occurring interval within the first occurring portion exceeds a threshold.

20. A radio transceiver apparatus comprising:

circuitry configured to commence data communication according to a schedule with a communication device when the radio transceiver apparatus is in a scheduled communication mode that uses scheduled communication windows that are a sequence of a plurality of periodic windows of variable duration including a first occurring portion having a first occurring interval and a second occurring portion having a second occurring interval, with communications during the second occurring portion being dependent upon preceding communications during the first occurring portion, with the communication device in the periodic windows;

a mechanism configured to delay, after the commencement of data communication with a the communication device, an exit from the scheduled communication mode to an unscheduled communication mode with the communication device, until a predetermined data transfer condition is satisfied wherein a number of packets communicated in the first occurring interval within the first occurring portion exceeds a threshold.