Systems and methods for synchronizing operations among a plurality of independently clocked digital data processing devices without a voltage controlled crystal oscillator

• US 20070214229A1
• Filed: 05/09/2007
• Published: 09/13/2007
• Est. Priority Date: 07/28/2003
• Status: Active Grant

• Current Assignee: Sonos, Inc.
• Original Assignee: Sonos, Inc.
• Inventors: Ericson, Michael, Millington, Nicholas
• Granted Patent: US 8,020,023 B2
• Time in Patent Office: Days
• US Class Current: 709/208
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G06F 1/00 Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00 architectures of general purpose stored program computers G06F15/76
• CPC Class Codes: G06F 1/12 Synchronisation of different clock signals provided by a plurality of clock generators
• CPC Class Codes: G06F 16/2322 using timestamps
• CPC Class Codes: G06F 16/60 of audio data
• CPC Class Codes: G06F 16/63 Querying
• CPC Class Codes: G06F 16/635 Filtering based on additional data, e.g. user or group profiles
• CPC Class Codes: G06F 16/638 Presentation of query results
• CPC Class Codes: G06F 16/639 using playlists
• CPC Class Codes: G06F 16/68 Retrieval characterised by using metadata, e.g. metadata not derived from the content or metadata generated manually
• CPC Class Codes: G06F 17/00 Digital computing or data processing equipment or methods, specially adapted for specific functions information retrieval, database structures or file system structures therefor G06F16/00
• CPC Class Codes: G06F 3/048 Interaction techniques based on graphical user interfaces [GUI]
• CPC Class Codes: G06F 3/0482 Interaction with lists of selectable items, e.g. menus
• CPC Class Codes: G06F 3/0484 for the control of specific functions or operations, e.g. selecting or manipulating an object, an image or a displayed text element, setting a parameter value or selecting a range
• CPC Class Codes: G06F 3/04842 Selection of displayed objects or displayed text elements G06F3/0482 takes precedence
• CPC Class Codes: G06F 3/04847 Interaction techniques to control parameter settings, e.g. interaction with sliders or dials
• CPC Class Codes: G06F 3/16 Sound input; Sound output speech processing G10L
• CPC Class Codes: G06F 3/162 Interface to dedicated audio devices, e.g. audio drivers, interface to CODECs
• CPC Class Codes: G06F 3/165 Management of the audio stream, e.g. setting of volume, audio stream path
• CPC Class Codes: G06F 3/167 Audio in a user interface, e.g. using voice commands for navigating, audio feedback
• CPC Class Codes: G11B 20/10527 : Audio or video recording; Data buffering arrangements G11B20/12 - G11B20/18 take precedence
• CPC Class Codes: G11B 2020/10592 : specifically adapted for recording or reproducing multichannel signals
• CPC Class Codes: H03G 3/00 : Gain control in amplifiers or frequency changers
• CPC Class Codes: H03G 3/20 : Automatic control H03G3/005 takes precedence; combined with volume compression or expansion H03G7/00
• CPC Class Codes: H04H 20/103 : Transmitter-side switching
• CPC Class Codes: H04H 20/26 : Arrangements for switching distribution systems
• CPC Class Codes: H04H 2201/20 : digital audio broadcasting [DAB]
• CPC Class Codes: H04J 3/0644 : External master-clock
• CPC Class Codes: H04J 3/0664 : unidirectional timestamps
• CPC Class Codes: H04L 12/2854 : Wide area networks, e.g. public data networks
• CPC Class Codes: H04L 65/1069 : Session establishment or de-establishment
• CPC Class Codes: H04L 65/60 : Network streaming of media packets
• CPC Class Codes: H04L 65/61 : for supporting one-way streaming services, e.g. Internet radio
• CPC Class Codes: H04L 65/611 : 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 Class Codes: H04L 65/612 : for unicast
• CPC Class Codes: H04L 65/613 : 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 Class Codes: H04L 65/75 : Media network packet handling
• CPC Class Codes: H04L 65/80 : Responding to QoS
• CPC Class Codes: H04L 67/1095 : Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/12 : specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04L 67/55 : Push-based network services
• CPC Class Codes: H04L 69/28 : Timers or timing mechanisms used in protocols
• CPC Class Codes: H04N 21/4307 : Synchronising the rendering of multiple content streams or additional data on devices, e.g. synchronisation of audio on a mobile phone with the video output on the TV screen
• CPC Class Codes: H04N 21/43076 : of the same content streams on multiple devices, e.g. when family members are watching the same movie on different devices
• CPC Class Codes: H04N 21/43615 : 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 Class Codes: H04N 5/04 : Synchronising for television systems using pulse code modulation H04N7/56
• CPC Class Codes: H04N 9/7904 : using intermediate digital signal processing
• CPC Class Codes: H04R 2227/003 : Digital PA systems using, e.g. LAN or internet
• CPC Class Codes: H04R 2227/005 : Audio distribution systems for home, i.e. multi-room use
• CPC Class Codes: H04R 27/00 : Public address systems circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; monitoring or testing arrangements for public address systems H04R29/007; amplifiers H03F
• CPC Class Codes: H04R 3/12 : for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04W 56/0015 : one node acting as a reference for the others
• CPC Class Codes: H04W 84/20 : Master-slave selection or change arrangements
• CPC Class Codes: H05K 999/99 : dummy group

Abstract

Exemplary systems and methods include a distribution device that maintains a clock rate and distributes a series of tasks to a group of execution devices. Each task has a plurality of samples per frame associated with a time stamp indicating when the task is to be executed. The execution devices execute the series of tasks at the times indicated and adjust the number of samples per frame in relation to the clock rate maintained by the distribution device.

Claims

1. A system comprising:

a distribution device configured to maintain a clock rate and distribute a series of tasks, each task having a plurality of samples per frame associated with a time stamp indicating when the respective task is to be executed; and

an execution device configured to execute the series of tasks at the times indicated and to adjust the number of samples per frame in relation to the clock rate maintained by the distribution device.

2. The system of claim 1, wherein a rate of change in an audio information buffer is substituted for the clock rate.

3. The system of claim 1, further comprising a plurality of execution devices wherein one of the execution devices is a master execution device configured to control the distribution of tasks by the distribution device.

4. The system of claim 3, further comprising a user interface module configured to control the master execution device.

5. The system of claim 4, wherein the master execution device is configured to enable another execution device to join the plurality of execution devices.

6. The system of claim 1, wherein the tasks are distributed to the execution device using a selected multi-cast transmission methodology.

7. The system of claim 3, wherein the master execution device is configured to transfer the ability to control the distribution device such that another execution device becomes the new master execution device.

8. The system of claim 3, wherein the master execution device is configured to allow migration of the distribution control function to another execution device in the system.

9. A method of operating a system comprising the steps of:

distributing a series of tasks to a plurality of execution devices, each task having a plurality of samples per frame associated with a time stamp indicating when the respective task is to be executed;

associating each of the tasks with a time stamp;

indicating a time, relative to a common clock at which each execution device is to execute the respective tasks; and

within each execution device, adjusting the number of samples per frame in relation to the common clock.

10. The method of claim 9, further comprising the step of enabling at least one of the execution devices to execute each task that it receives at a determined time.

11. The method of claim 9, further comprising the step of enabling an execution device to function as a master execution device.

12. The method of claim 9, further comprising the step of enabling an additional execution device to join the plurality of execution devices.

13. The method of claim 9, wherein the tasks are distributed to the execution devices using a selected multi-cast transmission methodology.

14. The method of claim 9, further comprising the step of migrating the function of the distribution of tasks from one execution device to another execution device.

15. The method of claim 9, further comprising the step of obtaining information associated with the tasks from a source of audio information.

16. The method of claim 9, further comprising the step of distributing tasks to a second group of execution devices.

17. A system comprising:

an execution device configured to maintain a clock rate and to execute a series of tasks; and

a distribution device configured to distribute the series of tasks to the execution device, each task having a plurality of samples per frame associated with a time stamp indicating when the respective task is to be executed, and configured to adjust the number of samples per frame in relation to the clock rate maintained by the execution device.

18. A system comprising:

a distribution device configured to maintain a clock rate and distribute a series of tasks, each task having a plurality of samples per frame associated with a time stamp indicating when the respective task is to be executed; and

an execution device configured to execute the series of tasks at the times indicated and to adjust the number of samples per frame in relation to the clock rate maintained by the distribution device and to send the adjusted samples per frame to an audio reproduction device.

19. A system comprising:

an execution device configured to maintain a clock rate, to execute a series of tasks, and to send the series of tasks to an audio reproduction device; and

a distribution device configured to distribute the series of tasks to the execution device, each task having a plurality of samples per frame associated with a time stamp indicating when the respective task is to be executed, and configured to adjust the number of samples per frame in relation to the clock rate maintained by the execution device.