Optical network unit and optical line terminal

• US 7,415,111 B2
• Filed: 10/07/2004
• Issued: 08/19/2008
• Est. Priority Date: 04/16/1999
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Fujiyoshi, Shinichi, Ryu, Kazuya, Toyoda, Yoshimi, Wakayoshi, Mitsuharu, Uchida, Kazuhiro, Koyanagi, Toshinori, Hirashima, Katsuhiko, Matsuo, Tamotsu, Sakai, Toshiyuki, Miura, Kenji, Monzawa, Takashi, Abiru, Setsuo, Asato, Jun, Shiono, Hideki, Shimaru, Tateo
• Primary Examiner(s): SMITHERS, MATTHEW
• Application Number:
  US10/960,884
• Publication Number:
  US 20050058139A1
• Time in Patent Office: 1,412 Days
• Field of Search: 380/265
• US Class Current: 380/256
• CPC Class Codes: H04B 10/00 Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
• CPC Class Codes: H04L 2012/5605 Fibre
• CPC Class Codes: H04L 2209/04 Masking or blinding
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• CPC Class Codes: H04L 63/068 using time-dependent keys, e.g. periodically changing keys cryptographic mechanisms or cryptographic arrangements for controlling usage of secret information H04L9/088
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 2011/0079 Operation or maintenance aspects

Abstract

An optical network unit and an optical line terminal which efficiently control the data receiving and dechurning processes in a passive optical network. In a churning parameter memory subsystem, a first memory bank stores churning parameters that are currently used, while a second memory bank stores updates made to the churning parameters. Under the control of the churning parameter memory subsystem, those first and second memory banks change their roles with each other at a churning key updating time point. A data dechurning unit receives a data stream consisting of a plurality of frames and dechurns the information contained in the data stream, according to the stored churning parameters. When an update is done to the parameters in a certain frame, the data dechurning unit makes the update effective at the next frame, thus starting data dechurning operations from the next frame.

Claims

1. An optical network unit coupled to an optical access network system, which receives a data stream and dechurns information contained in the received data stream by using a churning key, comprising:

churning parameter memory means for storing churning parameters that indicate which logical connections are churned or not churned; and

data dechurning means for receiving the data stream consisting of a plurality of frames and dechurning the information contained in the data stream according to the churning parameters stored in said churning parameter memory means, the churning parameters being activated at the beginning of each frame, whereby an update having been made thereto in a specific frame becomes effective in the next frame.

2. An optical line terminal coupled to an optical access network system, which transmits a data stream containing information that is churned by using a churning key, comprising:

flag control means for controlling flags when sending the data stream to a receiving end; and

churning parameter transmission control means for controlling transmission of churning parameters indicating which logical connections are churned or not churned based on the status of the flags.

3. The optical line terminal according to claim 2, wherein said flag control means clears an initial parameter delivered flag when the receiving end is in a standby state, and sets the initial parameter delivered flag at the end of an initial parameter delivery process that delivers an entire set of the current churning parameters to the receiving end.

4. The optical line terminal according to claim 2, wherein the flags provided by said flag controlling means include an initial parameter delivery in progress flag that indicates that an initial parameter delivery process is in progress to deliver an entire set of the current churning parameters to the receiving end.

5. The optical line terminal according to claim 2, wherein said flag control means sets a parameter update failure flag when an update of the churning parameters being stored in the receiving end has failed.

6. The optical line terminal according to claim 2, wherein said flag control means sets a parameter update unfinished flag when the receiving end has left an operating state.

7. The optical line terminal according to claim 2, wherein said flag control means sets a churning key updating flag when the optical line terminal is updating the churning key.

8. The optical line terminal according to claim 2, wherein said flag control means sets a parameter update request flag when initiating an update of the churning parameters.

9. The optical line terminal according to claim 8, wherein said flag control means sets the parameter update request flag to initiate an update of one logical connection for one receiving end.

10. The optical line terminal according to claim 2, wherein said flag control means sets a parameter updating flag when the churning parameters are being updated.

11. The optical line terminal according to claim 2, further comprising churning parameter overwriting means for performing a churning parameter overwriting process that resends the churning parameters to the receiving end.

12. The optical line terminal according to claim 11, wherein said churning parameter overwriting means suspends the churning parameter overwriting process when transmitting another message having a higher priority.

13. The optical line terminal according to claim 11, wherein said churning parameter overwriting means suspends the overwriting process while the churning parameters are being updated.

14. The optical line terminal according to claim 11, wherein:

said churning parameter overwriting means comprises a timer that operates at predetermined intervals; and

said churning parameter overwriting means is regularly activated by said timer.

15. The optical line terminal according to claim 14, wherein the interval of said timer is given by an external source.

16. The optical line terminal according to claim 2, wherein:

said churning parameter transmission control means transmits a churning parameter message multiple times to send one of the churning parameters to the receiving end;

when sending the first instance of the churning parameter message, said churning parameter transmission control means performs arbitration between the churning parameter message and other messages; and

after the arbitration is finished, said churning parameter transmission control means automatically transmits the multiple instances of the churning parameter message at predetermined intervals.

17. The optical line terminal according to claim 2, further comprising churning parameter updating means for updating the churning parameters at a churning key updating time point where the churning key is updated.