METHOD, SYSTEM, AND RELAY APPARATUS FOR REALIZING PASSIVE OPTICAL NETWORK REACH EXTENSION

• US 20130230326A1
• Filed: 04/15/2013
• Published: 09/05/2013
• Est. Priority Date: 10/14/2010
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: MA, Teng, LI, Hanguo, HU, Xing, JIANG, Hongli, CHEN, Juan
• Granted Patent: US 9,154,221 B2
• Time in Patent Office: Days
• US Class Current: 398/67
• CPC Class Codes: H04B 10/07 Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04J 3/1652 Optical Transport Network [OTN]
• 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 2011/009 Topology aspects

Abstract

Embodiments of the present invention disclose a method and a system for realizing PON reach extension, and a relay apparatus for realizing this method. The method includes: extracting an overhead in an upstream data stream that is sent by an ONU to an OLT, obtaining a payload in the upstream data stream through de-mapping, and storing it into a buffer; extracting bandwidth authorization information in an downstream data stream that is sent by the OLT to the ONU; and reorganizing a stored payload according to the bandwidth authorization information and inserting a corresponding overhead to generate a new upstream data stream and send it to the OLT.

Claims

1. A method for realizing passive optical network reach extension, comprising:

extracting an overhead in an upstream data stream that is sent by an ONU to an OLT, obtaining a payload in the upstream data stream through de-mapping, and storing it into a buffer; and

extracting bandwidth authorization information in a downstream data stream that is sent by the OLT to the ONU; and

reorganizing the stored payload according to the bandwidth authorization information and inserting a corresponding overhead to generate a new upstream data stream and send it to the OLT.

2. The method according to claim 1, wherein before the extracting the overhead in the upstream data stream which is sent by the ONU to the OLT, the method further comprises:

extracting the bandwidth authorization information in the downstream data stream that is sent by the OLT to the ONU;

forwarding a sequence number request that is regularly sent by the OLT to the ONU;

buffering a sequence number that is returned by the ONU as a response to the sequence number request, and when receiving again the sequence number request that is sent by the OLT, sending the sequence number according to the bandwidth authorization information to the OLT; and

forwarding an identifier that is allocated by the OLT for the ONU.

3. The method according to claim 2, wherein after the forwarding the identifier that is allocated by the OLT for the ONU, the method further comprises:

forwarding a distance measuring request that is sent by the OLT to the ONU;

receiving a distance measuring response message that is returned by the ONU as a response to the distance measuring request;

deducting a delay of transmitting the distance measuring response message in an OTN device from time of receiving the distance measuring response message to generate a new distance measuring response message and send it to the OLT;

forwarding, to the ONU, an equalization delay value that is calculated by the OLT according to arrival time of the distance measuring response message; and

forwarding a reply message that is returned by the ONU to the OLT after the ONU receives the equalization delay value, thereby activating the ONU.

4. The method according to claim 1, further comprising:

in the buffer, allocating a T-CONT buffer area for each T-CONT of the ONU, calculating a new bandwidth requirement according to a size of the T-CONT buffer area and a bandwidth requirement in the overhead, and inserting the new bandwidth requirement into the overhead.

5. The method according to claim 4, wherein the calculating the new bandwidth requirement is taking a maximum value among the size of the T-CONT buffer area and the bandwidth requirement in the overhead as the new bandwidth requirement.

6. A system for realizing passive optical network reach extension, wherein the system comprises an OLT, a relay apparatus, and at least one ONU;

the OLT sends a downstream data stream that comprises bandwidth authorization information to the ONU through the relay apparatus;

the ONU acquires the bandwidth authorization information from the downstream data stream, and sends an upstream data stream according to the bandwidth authorization information; and

the relay apparatus extracts an overhead in the upstream data stream that is sent by the ONU to the OLT, obtains a payload in the upstream data stream through de-mapping, and stores it;

extracts the bandwidth authorization information in the downstream data stream that is sent by the OLT to the ONU; and

reorganizes the stored payload according to the bandwidth authorization information and inserts a corresponding overhead to generate a new upstream data stream and send it to the OLT.

7. The system according to claim 6, wherein before the extracting the overhead in the upstream data stream which is sent by the ONU to the OLT, the relay apparatus further executes the following steps:

extracting the bandwidth authorization information in the downstream data stream that is sent by the OLT to the ONU;

forwarding a sequence number request that is regularly sent by the OLT to the ONU;

buffering a sequence number that is returned by the ONU as a response to the sequence number request, and when receiving again the sequence number request that is sent by the OLT, sending the sequence number according to the bandwidth authorization information to the OLT; and

forwarding an identifier that is allocated by the OLT for the ONU.

8. The system according to claim 7, wherein after the forwarding the identifier that is allocated by the OLT for the ONU, the relay apparatus further executes the following steps:

forwarding a distance measuring request that is sent by the OLT to the ONU;

receiving a distance measuring response message that is returned by the ONU as a response to the distance measuring request;

deducting a delay of transmitting the distance measuring response message in an OTN device from time of receiving the distance measuring response message to generate a new distance measuring response message and send it to the OLT;

forwarding, to the ONU, an equalization delay value that is calculated by the OLT according to arrival time of the distance measuring response message; and

forwarding a reply message that is returned by the ONU to the OLT after the ONU receives the equalization delay value, thereby activating the ONU.

9. The system according to claim 6, wherein the relay apparatus further allocates a T-CONT buffer area for each T-CONT of the ONU, calculates a new bandwidth requirement according to a size of the T-CONT buffer area and a bandwidth requirement in the overhead, and inserts the new bandwidth requirement into the overhead.

10. The system according to claim 9, wherein the relay apparatus calculates the new bandwidth requirement is taking a maximum value among the size of the T-CONT buffer area and the bandwidth requirement in the overhead as the new bandwidth requirement.

11. A relay apparatus for realizing passive optical network reach extension, wherein the relay apparatus comprises:

a processing module, an overhead extracting module, a decapsulating module, a buffer, a data stream regenerating module, a sending module, a receiving module, and a bandwidth map extracting module;

the receiving module receives a downstream data stream that is sent by an OLT to an ONU;

the bandwidth map extracting module extracts bandwidth authorization information from the downstream data stream;

the overhead extracting module extracts an overhead from an upstream data stream that is sent by the ONU to the OLT, and sends it to the processing module to store it into the buffer;

the decapsulating module obtains a payload through de-mapping from the upstream data stream whose overhead is extracted, and sends it to the processing module to store it into the buffer; and

the data stream regenerating module reorganizes the payload that is stored in the buffer according to the bandwidth authorization information, inserts a corresponding overhead to generate a new upstream data stream, and sends it to the OLT through the sending module.

12. The relay apparatus according to claim 11, wherein the processing module further executes the following steps:

extracting the bandwidth authorization information in the downstream data stream that is sent by the OLT to the ONU;

forwarding a sequence number request that is regularly sent by the OLT to the ONU;

buffering a sequence number that is returned by the ONU as a response to the sequence number request, and when receiving again the sequence number request that is sent by the OLT, sending the sequence number according to the bandwidth authorization information to the OLT; and

forwarding an identifier that is allocated by the OLT for the ONU.

13. The relay apparatus according to claim 12, wherein the processing module further executes the following steps:

forwarding a distance measuring request that is sent by the OLT to the ONU;

receiving a distance measuring response message that is returned by the ONU as a response to the distance measuring request;

deducting a delay of transmitting the distance measuring response message in an OTN device from time of receiving the distance measuring response message to generate a new distance measuring response message and send it to the OLT;

forwarding, to the ONU, an equalization delay value that is calculated by the OLT according to arrival time of the distance measuring response message; and

forwarding a reply message that is returned by the ONU to the OLT after the ONU receives the equalization delay value, thereby activating the ONU.

14. The system according to claim 11, wherein the processing module further allocates a T-CONT buffer area for each T-CONT of the ONU in the buffer, calculates a new bandwidth requirement according to a size of the T-CONT buffer area and a bandwidth requirement in the overhead, and inserts the new bandwidth requirement into the overhead.

15. The system according to claim 14, wherein, the processing module calculates the new bandwidth requirement is taking a maximum value among the size of the T-CONT buffer area and the bandwidth requirement in the overhead as the new bandwidth requirement.