Playback device

Patent metadata

Field	Value
Publication number	US-10747496-B2
Application number	US-201916544900-A
Country	US
Kind code	B2
Filing date	Aug 20, 2019
Priority date	Jul 28, 2003
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

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 as new and desired to be secured by Letters Patent of the United States is:

1. 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, and wherein as part of the time synchronization, the first zone player maintains an adjusted clock time that (i) is different from its local clock time and (ii) tracks a clock time of the third zone player;
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 and the adjusted clock time.

2. The method of claim 1 , wherein the adjusted clock time is based on exchanging timing information with the third zone player.

3. The method of claim 2 , 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.

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

6. The method 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. 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, and wherein as part of the time synchronization, the first zone player maintains an adjusted clock time that (i) is different from its local clock time and (ii) tracks a clock time of the third zone player;
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 and the adjusted clock time.

8. The tangible, non-transitory computer-readable media of claim 7 , wherein the adjusted clock time is based on the exchange of timing information with the third zone player.

9. The tangible, non-transitory computer-readable media 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 tangible, non-transitory computer-readable media 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 tangible, non-transitory computer-readable media of claim 7 , wherein at least the first future time is relative to a clock time of the third zone player.

12. The tangible, non-transitory computer-readable media 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. 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, and wherein as part of the time synchronization, the first zone player maintains an adjusted clock time that (i) is different from its local clock time and (ii) tracks a clock time of the third zone player;
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 informat

Assignees

• Sonos Inc
• Sonos Inc

Inventors

• Millington Nicholas A J

Classifications

• H04L65/75

  Media network packet handling · CPC title

• H04L65/613

  for the control of the source by the destination (control signals issued by the client directed to the server or network components specially adapted for selective content distribution H04N21/637) · CPC title

• H04L65/61

  for supporting one-way streaming services, e.g. Internet radio · CPC title

• H04L67/55

  Push-based network services · CPC title

• H04L65/611

  for multicast or broadcast (systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06) · CPC title