Method for synchronizing a communication system via a packet-oriented data network

• US 20030035444A1
• Filed: 08/09/2002
• Published: 02/20/2003
• Est. Priority Date: 08/09/2001
• Status: Abandoned Application

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Zwack, Eduard
• Application Number:
  US10/214,938
• Publication Number:
  US 20030035444A1
• Time in Patent Office: Days
• US Class Current: 370/503
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04L 1/205 jitter monitoring
• CPC Class Codes: H04L 41/5003 Managing SLA; Interaction between SLA and QoS
• CPC Class Codes: H04L 41/5009 Determining service level performance parameters or violations of service level contracts, e.g. violations of agreed response time or mean time between failures [MTBF]
• CPC Class Codes: H04L 43/0858 One way delays
• CPC Class Codes: H04L 43/0864 Round trip delays
• CPC Class Codes: H04L 43/106 using time related information in packets, e.g. by adding timestamps
• CPC Class Codes: H04M 2201/14 Delay circuits; Timers
• CPC Class Codes: H04M 2201/22 Synchronisation circuits
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42

Abstract

To synchronize a communication system via a packet-oriented data network, a frequency offset of a time-measuring device is determined by a measuring device using only data packets with approximately the same forward and return times.

Claims

1. A method for synchronizing a communication system via a packet-oriented data network by a measuring device for determining a frequency offset of a time-measuring device, comprising:

determining the frequency offset within the measuring device using only data packets with substantially identical forward and return times.

2. The method as claimed in claim 1, wherein said determining uses only data packets with a transit time of less than 5 ms.

3. The method as claimed in claim 2, further comprising transporting the data packets by transmit devices via at least one nearest NBCS reference clock in the network.

4. The method as claimed in claim 3, wherein said transporting uses an extended Real Time Transport Protocol.

5. The method as claimed in claim 4, further comprising adding a time stamp to each data packet by a receive protocol device disposed within a receive device to identify a receive time.

6. The method as claimed in claim 4, further comprising adding a time stamp to each data packet by a transmit protocol device disposed within a transmit device to identify a transmit time.

7. A transceiver device for synchronizing a communication system via a packet-oriented data network, comprising:

a transmit and receive protocol devices to identify a transmit time of a data packet by adding a respective time stamp to a data area of the data packet, said transmit protocol device including a time-measuring device;

a measuring device to determine a frequency offset of the time-measuring device disposed within said transceiver device; and

a tracking unit to track the time-measuring device depending on the frequency offset.

8. A network device for synchronizing a communication system via a packet-oriented data network, comprising:

at least one transport device, disposed within the network, to forward data packets to at least one nearest NBCS reference clock and to determine a frequency offset within the measuring device using only data packets with substantially identical forward and return times.

9. The network device as claimed in claim 8, wherein the packet-oriented data network is an Internet Protocol-based network.