Communication apparatus, communication system, and communication method

• US 8,923,367 B2
• Filed: 09/12/2012
• Issued: 12/30/2014
• Est. Priority Date: 09/28/2011
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Okuda, Masato
• Primary Examiner(s): Yu, Lihong
• Application Number:
  US13/612,013
• Publication Number:
  US 20130077659A1
• Time in Patent Office: 839 Days
• Field of Search: 375/257
• US Class Current: 375/219
• 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

Abstract

A communication apparatus including: a transmitter that transmits a first message to another communication apparatus, a receiver that receives a second message from the other communication apparatus, and a processor that performs time synchronization using the first message and the second message, wherein the processor generates information regarding a delay in the communication processing of the first message in the transmitter and the second message in the receiver in a communication layer in communication with the other communication apparatus, and the processor performs the time synchronization with the other communication apparatus based on the information regarding the delay in a time synchronization layer above the communication layer.

Claims

1. A communication apparatus comprising:

a transmitter that transmits a first message to another communication apparatus;

a receiver that receives a second message from the other communication apparatus; and

a processor that performs time synchronization using the first message and the second message;

wherein the processor generates information regarding a delay in a communication processing of the first message in the transmitter and the second message in the receiver in a communication layer in communication with the other communication apparatus, and the processor performs the time synchronization with the other communication apparatus based on the information regarding the delay in a time synchronization layer above the communication layer,

wherein the time synchronization includes at least one of subtracting the delay in the communication processing from a receiving time of the second message received by the receiver and adding the delay in the communication processing to a transmitting time in the first message transmitted by the transmitter.

2. The communication apparatus according to claim 1, wherein the information regarding the delay includes information regarding modulation methods and code rates of the first message and the second message.

3. The communication apparatus according to claim 1, wherein the information regarding the delay includes a delay time in retransmitting of the first message and the second message or the number of times that the first message and the second message are retransmitted.

4. The communication apparatus according to claim 1, wherein the first message and the second message include one of a synchronization message and a delay information request message.

5. The communication apparatus according to claim 1, wherein the transmitter transmits a response including a result of one of the subtracting and the adding to the other communication apparatus.

6. The communication apparatus according to claim 1, wherein the time synchronization uses Precision Time Protocol.

7. A communication system comprising:

a communication apparatus including a transmitter that transmits a first message to another communication apparatus;

a receiver that receives a second message from the other communication apparatus; and

a processor that performs time synchronization using the first message and the second message;

wherein the processor generates information regarding a delay in acommunication processing of the first message in the transmitter and the second message in the receiver in a communication layer in communication with the other communication apparatus, and the processor performs the time synchronization with the other communication apparatus based on the information regarding the delay in a time synchronization layer above the communication layer,

wherein the time synchronization includes at least one of subtracting the delay in the communication processing from a receiving time of the second message received by the receiver and adding the delay in the communication processing to a transmitting time in the first message transmitted by the transmitter.

8. The communication system according to claim 7, wherein the information regarding the delay includes information regarding modulation methods and code rates of the first message and the second message.

9. The communication system according to claim 7, wherein the information regarding the delay includes a delay time in retransmitting of the first message and the second message or the number of times that the first message and the second message are retransmitted.

10. The communication system according to claim 7, wherein the first message and the second message.

11. The communication system according to claim 7, wherein the transmitter transmits a response including a result of one of the subtracting and the adding to the other communication apparatus.

12. The communication system according to claim 7, wherein the time synchronization uses Precision Time Protocol.

13. A communication method comprising:

generating information regarding a delay in a communication processing of a first message in a transmitter and a second message in a receiver in a communication layer in communication with another communication apparatus, and

performing time synchronization with the other communication apparatus based on the information regarding the delay in a time synchronization layer above the communication layer,

wherein the time synchronization includes at least one of subtracting the delay in the communication processing from a receiving time of the second message received by the receiver and adding the delay in the communication processing to a transmitting time in the first message transmitted by the transmitter.

14. The communication method according to claim 13, wherein the information regarding the delay includes information regarding modulation methods and code rates of the first message and the second message.

15. The communication method according to claim 13, wherein the information regarding the delay includes a delay time in retransmitting of the first message and the second message or the number of times that the first message and the second message are retransmitted.

16. The communication method according to claim 13, wherein the first message and the second message include one of a synchronization message and a delay information request message.

17. The communication method according to claim 13, further comprising,

transmitting a response including a result of one of the subtracting and the adding to the other communication apparatus.

18. The communication method according to claim 13, wherein the time synchronization uses Precision Time Protocol.