Method for transmitting time information via a data packet network

• US 7,372,846 B2
• Filed: 06/07/2002
• Issued: 05/13/2008
• Est. Priority Date: 06/07/2001
• Status: Expired due to Fees

• Current Assignee: RingCentral Incorporated
• Original Assignee: Siemens AG
• Inventors: Zwack, Eduard
• Primary Examiner(s): Phan, Man U.
• Application Number:
  US10/163,621
• Publication Number:
  US 20030002483A1
• Time in Patent Office: 2,167 Days
• Field of Search: 370350-354, 370389-394, 370432-458, 370503-516, 709231-236, 709/248
• US Class Current: 370/352
• CPC Class Codes: G06F 1/14 Time supervision arrangements, e.g. real time clock
• CPC Class Codes: H04J 3/0673 using intermediate nodes, e.g. modification of a received timestamp before further transmission to the next packet node, e.g. including internal delay time or residence time into the packet
• CPC Class Codes: H04J 3/0697 Synchronisation in a packet node

Abstract

Time information which is to be transmitted via a data packet network is called up from a time information source and is transmitted to a data packet transmission module. The data packet transmission module controls the transmission time of a data packet in which the time information is transmitted via the data packet network. The transmission time and the calling of the time information are aligned with respect to one another in time by a transmission signal which is generated by the time information source or by the data packet transmission module and indicates the transmission time.

Claims

1. A method for transmitting time information via a data packet network, comprising:

calling time information from a time information source;

sending the time information to a data packet transmission module which times transmission of data packets;

transmitting the time information from a first communications device to a second communications device via a data packet;

using a transmission signal to coordinate transmission of the data packet and calling of the time information with respect to one another, the transmission signal indicating the time of transmission; and

generating a reception signal when a data packet receiving module at the second communications device receives the data packet transmitted via the data packet network, the reception signal initiating a call for reception time information from a time information source in the second communications device wherein

the second communications device passes on the data packet to a third communications device,

pass-on-information indicates the time at which the data packet is passed on to the third communications device, and

the reception time information and the pass-on-information are passed on, with the data packet.

2. The method as claimed in claim 1, wherein the transmission signal is generated by the time information source.

3. The method as claimed in claim 1, wherein the transmission signal is generated by the data packet transmission module.

4. The method as claimed in claim 1, wherein

the data packet transmission module generates the transmission signal while the data packet is being transmitted, and

the transmission signal initiates the calling of the time information.

5. The method as claimed in claim 1, wherein

the time information source generates the transmission signal at a predetermined time, and

transmission of the data packet is initiated by the transmission signal.

6. The method as claimed in claim 1, wherein the data packet is transmitted using a TCP/IP transmission protocol.

7. The method as claimed in claim 1, wherein any relative discrepancy between the time information sources of the first and second communications devices is determined on the basis of the time information of the first communications device and the reception time information of the second communications device.

8. The method as claimed in claim 1, wherein the transmission signal and reception signal are generated by hardware components.

9. The method as claimed in claim 1, wherein the physical layer of the OSI reference model is used for at least one of generating and evaluating the transmission signal and the reception signal.

10. The method as claimed in claim 1, wherein,

when the data packet is received at the third communications device after being passed on, pass-receive-information is called from a time information source in the third communications device, and

any relative discrepancy between the time information sources of the first through third communications devices is determined on the basis of the transmitted time information, the reception time information, the pass-on-information, and the pass-receive-information.

11. The method as claimed in claim 1, wherein the transmission signal is generated by a hardware component.

12. The method as claimed in claim 1, wherein the physical layer of the OSI reference model is used for at least one of generating and evaluating the transmission signal.

13. The method as claimed in claim 5, wherein the data packet is transmitted using a TCP/IP transmission protocol.

14. The method as claimed in claim 13, wherein any relative discrepancy between the time information sources of the first and second communications devices is determined on the basis of the time information of the first communications device and the reception time information of the second communications device.

15. The method as claimed in claim 14, wherein the transmission signal and reception signal are generated by hardware components.

16. The method as claimed in claim 14, wherein the physical layer of the OSI reference model is used for at least one of generating and evaluating the transmission signal and the reception signal.

17. The method as claimed in claim 14, wherein,

when the data packet is received at the third communications device after being passed on, pass-receive-information is called, and

any relative discrepancy between the time information sources of the first through third communications devices is determined on the basis of the transmitted time information, the reception time information, the pass-on-information, and the pass-receive-information.