METHOD AND ARRANGEMENT FOR SYNCHRONISING DATA STREAMS IN NETWORKS AND A CORRESPONDING COMPUTER PROGRAM AND CORRESPONDING COMPUTER-READABLE STORAGE MEDIUM

• US 20120219019A1
• Filed: 08/19/2010
• Published: 08/30/2012
• Est. Priority Date: 08/19/2009
• Status: Active Grant

• Current Assignee: Lautsprecher Teufel GmbH
• Original Assignee: Raumfeld GmbH
• Inventors: Hirsch, Michael
• Granted Patent: US 8,902,934 B2
• Time in Patent Office: Days
• US Class Current: 370/503
• CPC Class Codes: H04L 65/1106 Call signalling protocols; H.323 and related
• 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 69/28 Timers or timing mechanisms used in protocols

Abstract

The invention relates to a method and arrangement for synchronising data streams in networks and to a corresponding computer program and corresponding computer-readable storage medium which can be used, in particular, for synchronising different audio playback devices (audio adapters) within a home network. Said home network can be a conventional computer network comprising both wireline and wireless components. According to the invention, in order to synchronise the data output in networks in which at least one data stream is transmitted by a network unit to at least two output units of the network, where said stream is outputted, first common time information is made available to at least the output units and the output of the data in the data stream is synchronised at least in terms of the phase and/or frequency on the basis of the first common time information.

Claims

1. A method for synchronising data output in networks, wherein at least one data stream is transmitted by a network unit to at least two output units of the network and is output by at least part of the output units,

wherein

a global time information is at least provided periodically to the at least two output units, and on the at least two output units the global time is approximated by evaluating:

of the global time information and of a local time information, which is provided by a hardware clock of each of the at least two output units, and where the local time information is the instant of time on which the global time information was received by the respective at least two output units,

of the length of time cycles of the global and local clock, and

of the duration of transmission of the global time information from the unit, which provides the global time information, to the at least two output units, where the duration of transmission is determined by taking into account a variance in transfer time between the unit, which provides the global time information, and the at least two output units, and

output of the data of the data stream is synchronised, at least with regard to phase and/or frequency, on the basis of the approximated global time information.

2. The method according to claim 1,

wherein

output of the data of the data stream is synchronised, wherein the local clocks of the output units function independently of the global time information.

3. The method according to claim 1,

wherein

the global time information is provided by transmitting data comprising the global time information through the network layer, transport layer, session layer, presentation layer, application layer of the OSI layer model or a combination of said layers.

4. The method according to claim 1, wherein

the global time information is an absolute time information or a relative time information, referring to a predefinable global reference or starting point.

5. The method according to claim 1, wherein

output of the data is synchronised by compensating for a difference between the global time information and the at least one piece of local time information.

7. The method according to claim 1, wherein

the start of output of the data is synchronised.

8. The method according to claim 1, wherein

the output rate of the data is synchronised.

10. The method according to claim 1,

wherein

the duration of data transmission is determined by transmitting data from at least one of the output units to the unit providing the global time information and returning said data to the at least one output unit and determining the time between transmission and reception of the data in the at least one output unit.

11. The method according to claim 1,

wherein

synchronisation comprises a determination of the number of samples corresponding to the difference between the global time information and the at least one piece of local time information.

12. The method according to claim 1, wherein

synchronisation comprises an adaptation of the clock frequency of at least one of the hardware clocks used in the at least two output units and/or

a resampling of at least part of the data streams.

20. The method of claim 1, further comprising downloading said computer program from an electronic data network to a data processing device that is connected to the data network.

6. (canceled)

9. (canceled)

13. An arrangement comprising at least one network unit and at least two output units, wherein the arrangement is configured in such a manner such that at least one data stream may be transmitted by the network unit to the output units, and is further output by at least part of the output units, the arrangement further comprising computer program means comprising:

means for providing a global time information at least periodically to the at least two output units, and on the at least two output units the global time is approximated by evaluating;

of the global time information and of a local time information, which is provided by a hardware clock of each of the at least two output units, and where the local time information is the instant of time on which the global time information was received by the respective at least two output units,

of the length of time cycles of the global and local clock, and

of the duration of transmission of the global time information from the unit, which provides the global time information, to the at least two output units, where the duration of transmission is determined by taking into account a variance in transfer time between the unit, which provides the global time information, and the at least two output units, and

means for synchronizing output of the data of the data stream, at least with regard to phase and frequency, on the basis of the approximated global time information.

14. An arrangement according to claim 13,

wherein

the arrangement is part of a multi-room audio system.

15. An arrangement according to claim 13,

wherein

data transmission between the at least one network unit and the at least two output units is at least partly wireless.

16. An arrangement according to claim 13,

wherein

the output units comprise audio, video and/or multimedia playback devices.

17. An arrangement according to claim 13,

wherein

the arrangement comprises a network including at least partly wireless communication links.

18. A computer program or a computer-readable storage medium on which the computer program is stored, comprising means for enabling a data processing device to carry out a method for synchronising data streams in networks once it is loaded into storage means of a data processing device, wherein at least one data stream is transmitted by a network unit to at least two output units of the network and is output by at least part of the output units,

wherein the computer program comprises:

means for providing a global time information at least periodically to the at least two output units, and on the at least two output units the global time is approximated by evaluating;

of the global time information and of a local time information, which is provided by a hardware clock of each of the at least two output units, and where the local time information is the instant of time on which the global time information was received by the respective at least two output units,

of the length of time cycles of the global and local clock, and

of the duration of transmission of the global time information from the unit, which provides the global time information, to the at least two output units, where the duration of transmission is determined by taking into account a variance in transfer time between the unit, which provides the global time information, and the at least two output units, and

means for synchronising output of the data of the data stream, at least with regard to phase and frequency, on the basis of the approximated global time information.

19. (canceled)