Playback Device

Patent metadata

Field	Value
Publication number	US-2020004497-A1
Application number	US-201916544900-A
Country	US
Kind code	A1
Filing date	Aug 20, 2019
Priority date	Jul 28, 2003
Publication date	Jan 2, 2020
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

What is claimed is:

1 . A first zone player comprising:
a network interface that is configured to communicatively couple the first zone player to at least one data network; a local clock that is configured to provide a clock time of the first zone player; at least one processor; a tangible, non-transitory computer-readable medium; and program instructions stored on the tangible, non-transitory computer-readable medium that are executable by the at least one processor such that the first zone player is configured to:
receive, via the network interface, a request to engage in synchronous playback of audio content as part of a synchrony group comprising at least a second zone player that is communicatively coupled to the first zone player via the at least one data network;
after receiving the request to engage in synchronous playback of the audio content as part of the synchrony group:
exchange, via the network interface with a third zone player that is communicatively coupled to the first zone player via the at least one data network, timing information that facilitates time synchronization between at least the first zone player and the third zone player, wherein the third zone player is not a member of the synchrony group;
receive, via the network interface from the second zone player, (i) audio information that is representative of the audio content and (ii) playback timing information associated with the audio information that comprises an indicator of at least a first future time at which the first and second zone players are to engage in synchronous playback of the received audio information; and
engage in synchronous playback of the received audio information with the second zone player using at least the first future time.

2 . The first zone player of claim 1 , wherein the first zone player maintains an adjusted clock time that tracks a clock time of the third zone player as a result of the time synchronization.

3 . The first zone player of claim 2 , wherein the program instructions that are executable by the at least one processor such that the first zone player is configured to engage in synchronous playback of the received audio information with the second zone player comprise program instructions that are executable by the at least one processor such that the first zone player is configured to:
after receiving the request to engage in synchronous playback of given audio content as part of the synchrony group, engage in synchronous playback of the received audio information with the second zone player when the adjusted clock time maintained by the first zone player reaches at least the first future time.

4 . The first zone player of claim 1 , wherein the third zone player is configured to exchange, via the at least one data network, timing information that facilitates time synchronization between the second zone player and the third zone player.

5 . The first zone player of claim 1 , wherein at least the first future time is relative to a clock time of the third zone player.

6 . The first zone player of claim 1 , wherein the playback timing information associated with the audio information comprises a plurality of indicators of a plurality of future times at which the first and second zone players are to engage in synchronous playback of the received audio information, and wherein at least one future time of the plurality of future times is relative to a clock time of the second zone player.

7 . A method performed by a first zone player, the method comprising:
receiving, via a network interface, a request to engage in synchronous playback of audio content as part of a synchrony group comprising at least a second zone player that is communicatively coupled to the first zone player via at least one data network; after receiving the request to engage in synchronous playback of the audio content as part of the synchrony group:
exchanging, via the network interface with a third zone player that is communicatively coupled to the first zone player via the at least one data network, timing information that facilitates time synchronization between at least the first zone player and the third zone player, wherein the third zone player is not a member of the synchrony group;
receiving, via the network interface from the second zone player, (i) audio information that is representative of the audio content and (ii) playback timing information associated with the audio information that comprises an indicator of at least a first future time at which the first and second zone players are to engage in synchronous playback of the received audio information; and
engaging in synchronous playback of the received audio information with the second zone player using at least the first future time.

8 . The method of claim 7 , further comprising:
maintaining an adjusted clock time that tracks a clock time of the third zone player as a result of the time synchronization.

9 . The method of claim 8 , wherein engaging in synchronous playback of the received audio information with the second zone player using at least the first future time comprises:
engaging in synchronous playback of the received audio information with the second zone player when the adjusted clock time maintained by the first zone player reaches at least the first future time.

10 . The method of claim 7 , wherein the third zone player is configured to exchange, via the at least one data network, timing information that facilitates time synchronization between the second zone player and the third zone player.

11 . The method of claim 7 , wherein at least the first future time is relative to a clock time of the third zone player.

12 . The method of claim 7 , wherein the playback timing information associated with the audio information comprises a plurality of indicators of a plurality of future times at which the first and second zone players are to engage in synchronous playback of the received audio information, and wherein at least one future time of the plurality of future times is relative to a clock time of the second zone player.

13 . Tangible, non-transitory computer-readable media having instructions stored therein, wherein the instructions, when executed, cause a first zone player to perform functions comprising:
receiving, via a network interface, a request to engage in synchronous playback of audio content as part of a synchrony group comprising at least a second zone player that is communicatively coupled to the first zone player via at least one data network; after receiving the request to engage in synchronous playback of the audio content as part of the synchrony group:
exchanging, via the network interface with a third zone player that is communicatively coupled to the first zone player via the at least one data network, timing information that facilitates time synchronization between at least the first zone player and the third zone player, wherein the third zone player is not a member of the synchrony group;
receiving, via the network interface from the second zone player, (i) audio information that is representative of the audio content and (ii) playback timing information associated with the audio information that comprises an indicator of at least a first future time at which the first and second zone players are to engage in synchronous playback of the received audio information; and
engaging in synchronous playback of the received audio information with the second zone player using at least the first future time.

14 . The tangible, non-transitory computer-readable media of claim 13 , further comprising:
maintaining a

Assignees

• Sonos Inc

Inventors

• Millington Nicholas A J

Classifications

• H04J3/0664

  unidirectional timestamps · CPC title

• H04H2201/20

  digital audio broadcasting [DAB] · CPC title

• H04N5/04

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

• H04L69/28

  Timers or timing mechanisms used in protocols · CPC title

• H04N21/43615

  Interfacing a Home Network, e.g. for connecting the client to a plurality of peripherals (home Audio Video Interoperability [HAVI] data switching networks H04L12/2805) · CPC title