Audio Master Selection

Patent metadata

Field	Value
Publication number	US-2019339932-A1
Application number	US-201916514280-A
Country	US
Kind code	A1
Filing date	Jul 17, 2019
Priority date	Jul 28, 2003
Publication date	Nov 7, 2019
Grant date	—

Abstract

A system is described for maintaining synchrony of operations among a plurality of devices that have independent clocking arrangements. The system includes a task distribution device that distributes tasks to a synchrony group comprising a plurality of devices that are to perform the tasks distributed by the task distribution device in synchrony. The task distribution device distributes each task to the members of the synchrony group over a network. Each task is associated with a time stamp that indicates a time, relative to a clock maintained by the task distribution device, at which the members of the synchrony group are to execute the task. Each member of the synchrony group periodically obtains from the task distribution device an indication of the current time indicated by its clock, determines a time differential between the task distribution device's clock and its respective clock and determines therefrom a time at which, according to its respective clock, the time stamp indicates that it is to execute the task.

First claim

I claim:

1 . A system comprising:
a first set of network devices comprising:
a first network device comprising a first clock that is configured to provide a first local clock time of the first network device;
a second network device comprising a second clock that is configured to provide a second local clock time of the second network device;
a third network device comprising a third clock that is configured to provide a third local clock time of the third network device,
wherein the first, second, and third network devices include respective network interfaces that are configured to facilitate network communication between the first, second, and third network devices via one or more data networks,
wherein the first, second, and third local clock times are different, and
wherein the first set of network devices include at least one processor and data storage having stored therein instructions that, when executed, perform functions including:
receiving, by at least one network device in the first set of network devices, a first control instruction for at least the second network device and the third network device to enter into a synchrony group;
after receiving, by the at least one network device in the first set of network devices, the first control instruction, selecting, by at least one network device in the first set of network devices, the second network device from among a second set of network devices that comprises the second network device and the third network device, to serve as an audio distributor in the synchrony group comprising the second network device and the third network device;
after selection of the second network device to serve as the audio distributor in the synchrony group:
operating, by the second network device and the third network device, as part of the synchrony group, wherein, while operating as part of the synchrony group, the third network device is configured to:
 receive, from the second network device, (a) audio information and (b) playback timing information associated with the audio information, wherein the playback timing information is indicative of at least one future time at which the second network device and the third network device are to engage in synchronized playback of the audio information; and
 engage in synchronous playback of the audio information with the second network device based on at least the playback timing information and the third local clock time of the third network device.

2 . The system of claim 1 , the functions further comprising:
receiving, by the second network device from the third network device, timing information; and generating, by the second network device, the playback timing information associated with the audio information using at least the received timing information.

3 . The system of claim 2 , wherein the received timing information was generated based on the third clock of the third network device.

4 . The system of claim 2 , further comprising a fourth network device, the functions further comprising:
operating, by the fourth network device, as part of the synchrony group, wherein, while operating as part of the synchrony group, the fourth network device is configured to:
receive, from the second network device, (a) the audio information and (b) the playback timing information associated with the audio information; and
engage in synchronous playback of the audio information with the second network device based on at least the playback timing information and a fourth local clock time of the fourth network device.

5 . The system of claim 4 , wherein, while operating as part of the synchrony group, the fourth network device is further configured to:
determine a time differential based on at least the fourth local clock time of the fourth network device, wherein engaging in synchronous playback of the audio information with the second network device based on at least the playback timing information and the fourth local clock time of the fourth network device comprises engaging in synchronous playback of the audio information with the second network device based on at least the playback timing information, the fourth local clock time of the fourth network device, and the determined time differential.

6 . The system of claim 2 , further comprising a fourth network device, the functions further comprising:
sending, by the fourth network device, to the at least one network device in the first set of network devices, the first control instruction.

7 . The system of claim 1 , further comprising a fourth network device, the functions further comprising:
receiving, from the fourth network device by a given one of the second network device or the third network device, a first volume control instruction for the synchrony group; and after receiving the first volume control instruction for the synchrony group, the given one of the second network device or the third network device:
adjusting a respective volume level of the given one of the second network device or the third network device based on the received first volume control instruction; and
sending, to the other of the second network device or the third network device, a second volume control instruction based on the received first volume control instruction.

8 . The system of claim 1 , wherein selecting the second network device from among the second set of network devices to serve as the audio distributor comprises:
selecting the second network device from among the second set of network devices based on at least one of (1) a load of one or more network devices and (2) a network latency.

9 . The system of claim 1 , wherein selecting the second network device from among the second set of network devices comprises:
selecting the second network device from among the second set of network devices based on at least a network performance metric of the second network device.

10 . The system of claim 1 , wherein, while operating as part of the synchrony group, the third network device is configured to:
receive, from the second network device, clock timing information comprising an indication of the second local clock time of the second network device.

11 . A method to be performed by a system comprising a first set of network devices, the method comprising:
receiving, by at least one network device in the first set of network devices, a first control instruction for at least a second network device and a third network device to enter into a synchrony group, wherein the first set of network devices comprises:
a first network device comprising a first clock that is configured to provide a first local clock time of the first network device;
the second network device, the second network device comprising a second clock that is configured to provide a second local clock time of the second network device; and
the third network device, the third network device comprising a third clock that is configured to provide a third local clock time of the third network device, wherein the first, second, and third network devices include respective network interfaces that are configured to facilitate network communication between the first, second, and third network devices via one or more data networks,
after receiving, by the at least one network device in the first set of network devices, the first control instruction, selecting, by at least one network device in the first set of network devices, the second network device from among a second set of network devices that comprises the second network device and the third network device, to serve as an audio distributor in the synchrony group comprising the second network device

Assignees

• Sonos Inc

Inventors

• Millington Nicholas A J

Classifications

• H04L65/1069

  Session establishment or de-establishment · CPC title

• H04H20/26

  Arrangements for switching distribution systems · CPC title

• G06F16/2322

  using timestamps · CPC title

• G11B20/10527

  Audio or video recording; Data buffering arrangements (G11B20/12 - G11B20/18 take precedence) · CPC title

• H04N5/04

  Synchronising (for television systems using pulse code modulation H04N7/56) · CPC title