Avoidance of collisions and connection loss in network device serving multiple networks

Patent metadata

Field	Value
Publication number	US-10694359-B2
Application number	US-201816035482-A
Country	US
Kind code	B2
Filing date	Jul 13, 2018
Priority date	Mar 10, 2016
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

A network device serving two or more networks using periodic times slots for transmission events is configured to determine that one of the periodic time slots on one of the networks has or soon will collide with one of the periodic time slots on the other network by processing time stamps for events on each network. Either of the periodic time slots may be occasionally shifted by a time shift amount to avoid a collision between the periodic time slots on each network. Shifting the periodic time slots may be performed by transmitting a Bluetooth connection parameter update packet.

First claim

What is claimed is:

1. A method for operating a device on multiple networks, the method comprising:
establishing a connection on a first network, in which the device is assigned a first set of periodic time slots for performing transactions on the first network, in which a first interval time is specified as a time between each one of the first set of periodic time slots based on a first reference clock;
establishing a connection on a second network, in which the device is assigned a second set of periodic time slots for performing transactions on the second network, in which a second interval time is specified as a time between each one of the second set of periodic time slots based on a second reference clock, in which the first reference clock and the second reference clock have a relative drift rate;
determining that one of the first set of periodic time slots has or soon will collide with one of the second set of periodic time slots by processing time stamps for events on the first network and on the second network; and
requesting a shift of either the first set of periodic time slots or the second set of periodic time slots by a selected time shift amount to avoid a collision between the first set of periodic time slots and the second set of periodic time slots.

2. The method of claim 1 , further including selecting an optimum time shift from a plurality of tentative time shifts, in which each of the plurality of tentative time shifts is calculated by predicting a number of collisions that would result from a different time shift over a period of time, and in which the optimum time shift would produce a minimum number of collisions over the period of time.

3. The method of claim 1 , in which the device is a Bluetooth device, and in which the first network and the second network are piconets.

4. The method of claim 3 , in which requesting shifting of the first set of periodic time slots or the second set of periodic time slots is performed by transmitting a Bluetooth connection parameter update packet.

5. The method of claim 1 , further including determining a drift rate for the first interval time based on the time stamps for events on the first network.

6. The method of claim 5 , further including predicting actual times of future time slots on the first network using the first interval time and the determined drift rate.

7. The method of claim 1 , in which the processing time stamps for events on the first network and on the second network is performed by determining a collision if a sum of a width of a first slot of the first set of periodic time slots and a width of a second slot of the second set of periodic time slots exceeds a time between a start of the first slot and an end of the second slot.

8. A device for operating on multiple networks, comprising:
a transmitter and receiver configured for coupling to the multiple networks;
processing logic coupled to the transmitter and the receiver, in which the processing logic is operable to decode signals received by the receiver, in which the device is assigned a first set of periodic time slots for performing transactions on a first network, in which a first interval time is specified as a time between each one of the first set of periodic time slots based on a first reference clock, and in which the device is assigned a second set of periodic time slots for performing transactions on a second network, in which a second interval time is specified as a time between each one of the second set of periodic time slots based on a second reference clock, in which the first reference clock and the second reference clock have a relative drift rate; and
in which the processing logic is configured to determine that one of the first set of periodic time slots has or soon will collide with one of the second set of periodic time slots by processing time stamps for events received by the receiver on the first network and on the second network, and to request a shift of either the first set of periodic time slots or the second set of periodic time slots by a time shift amount to avoid a collision between the first set of periodic time slots and the second set of periodic time slots.

9. The device of claim 8 , in which the processing logic is further configured to select an optimum time shift from a plurality of tentative time shifts, in which each of the plurality of tentative time shifts is calculated by predicting a number of collisions that would result from a different time shift over a period of time, and in which the optimum time shift would produce a minimum number of collisions over the period of time.

10. The device of claim 8 , in which the processing logic is further configured to determine a drift rate for the first interval time based on the time stamps for events received by the receiver on the first network.

11. The device of claim 10 , further including predicting actual times of future time slots on the first network using the first interval time and the determined drift rate.

12. The device of claim 8 , in which the device is a Bluetooth device, and in which the first network and the second network are piconets.

13. The device of claim 12 , in which the processing logic requests a shift of the first set of periodic time slots or the second set of periodic time slots by configuring the transmitter to transmit a Bluetooth connection parameter update packet.

14. The device of claim 8 , in which the processing logic is configured to determine that one of the first set of periodic time slots has or soon will collide with one of the second set of periodic time slots if a sum of a width of a first slot of the first set of periodic time slots and a width of a second slot of the second set of periodic time slots exceeds a time between a start of the first slot and an end of the second slot.

15. A non-transitory computer readable medium storing software instructions that, when executed periodically by a processor of a device that is serving two Bluetooth piconets, cause a method for avoiding slot collisions to be performed, the method comprising:
determining that one or more of a first set of periodic time slots assigned to the device on a first piconet has or soon will collide with one or more of a second set of periodic time slots assigned to the device on a second piconet by processing time stamps for events on the first piconet and on the second piconet; and
requesting a shift of either the first set of periodic time slots on the first piconet or the second set of periodic time slots on the second piconet by a time shift amount to avoid a collision between the first set of periodic time slots on the first piconet and the second set of periodic time slots on the second piconet.

16. The non-transitory computer readable medium of claim 15 , in which the method further includes selecting an optimum time shift from a plurality of tentative time shifts, in which each tentative time shift is calculated by predicting a number of time slot collisions that would result from a different time shift over a period of time, and in which the optimum time shift would produce a minimum number of collisions over the period of time.

17. The non-transitory computer readable medium of claim 16 , in which the method further includes determining a drift rate for an interval between the periodic time slots assigned to the device on the first piconet based on the time stamps for events on the first piconet.

18. The non-transitory computer readable medium of claim 17 , in which the method further includes predicting actual times of futur

Assignees

• Texas Instruments Inc

Inventors

• Ben-Shachar Matan
• Eshel Omri
• Jakira Yuval
• Brecher Liran
• Ziv Dotan
• Loewy Chen

Classifications

• H04W72/0446

  Resources in time domain, e.g. slots or frames · CPC title

• H04W4/80 Primary

  Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication · CPC title

• H04W74/085

  collision avoidance · CPC title

• H04W84/18

  Self-organising networks, e.g. ad-hoc networks or sensor networks · CPC title