CONVERGED PON FOR TDMA-PON SERVICE BASED ON OFDMA-PON

• US 20130170837A1
• Filed: 12/28/2012
• Published: 07/04/2013
• Est. Priority Date: 12/30/2011
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: KIM, Kwang Ok, LEE, Jie Hyun, MYONG, Seung Il, LEE, Sang Soo, LEE, Jong Hyun, CHO, Seung-Hyun
• Granted Patent: US 9,219,567 B2
• Time in Patent Office: Days
• US Class Current: 398/89
• CPC Class Codes: H04J 14/08 Time-division multiplex systems
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0064 Arbitration, scheduling or medium access control aspects

Abstract

A converged passive optical network (CPON) and a data transmission method are disclosed. The CPON is a combination of a time division multiple access-passive optical network (TDMA-PON) and an orthogonal frequency division multiple access-passive optical network (OFDMA-PON) and is able to dynamically controlling a bandwidth for upstream signal transmission through allocation of multiple subcarriers to each single optical network unit (ONU).

Claims

1. An optical line terminal (OLT) of a converged passive optical network (CPON) that is a combination of a time division multiple access-passive optical network (TDMA-PON) and an orthogonal frequency division multiple access-passive optical network (OFDMA-PON), the OLT comprising:

an OLT interface unit to be matched with an OLT of the TDMA-PON corresponding to each of a plurality of services of the TDMA-PON;

a subcarrier queue transmission unit to process a subcarrier queue corresponding to each of the plurality of services;

an OFDM frame processing unit to process an OFDM frame corresponding to each of the plurality of services; and

an OFDM modem to transmit and receive the OFDM frame.

2. The OLT of claim 1, wherein the subcarrier queue transmission unit comprises:

a downstream subcarrier queue processing unit to transmit a downstream subcarrier queue corresponding to each of the plurality of services;

an upstream subcarrier queue processing unit to transmit an upstream subcarrier queue transmitted from an optical network terminal (ONT) of the OFDMA-PON; and

a frame parser to determine an output port based on a service type of the upstream subcarrier queue.

3. The OLT of claim 1, wherein the OFDM frame processing unit comprises:

a first frame conversion unit to convert a downstream data frame corresponding to each of the plurality of services into an OFDM frame; and

a second frame conversion unit to convert an OFDM frame transmitted from an ONT of the OFDMA-PON into an upstream data frame corresponding to each of the plurality of services.

4. The OLT of claim 3, wherein the OFDM frame processing unit further comprises a subcarrier information processing unit to map subcarrier information of an upstream data frame by each ONT of the OFDMA-PON according to each of the plurality of services.

5. The OLT of claim 1, wherein the OFDM modem comprises:

a modulator/demodulator to modulate or demodulate the OFDM frame;

a parallel-serial conversion unit to convert a signal between a parallel signal and a serial signal;

a digital-analog conversion unit to convert a signal between a digital signal and an analog signal; and

a photoelectric conversion unit to convert a signal between an electrical signal and an optical signal.

6. The OLT of claim 3, wherein the first frame conversion unit converts the downstream data frame into the OFDM frame by adding overhead information to the downstream data frame, the overhead information comprising at least one of start delimiter information and end delimiter information about extraction of the OFDM frame, bit interleaved parity (BIP) information to measure a bit error rate (BER) of a downstream link, bitmap information about a subcarrier usable by an ONT according to the plurality of services, a service type, and an ONT identification (ID).

7. The OLT of claim 3, wherein the second frame conversion unit converts the OFDM frame into the upstream data frame by eliminating overhead information from the OFDM frame, the overhead information comprising at least one of start delimiter information and end delimiter information about extraction of the OFDM frame, bit interleaved parity (BIP) information to measure a bit error rate (BER) of a downstream link, bitmap information about a subcarrier usable by an ONT according to the plurality of services, a service type, and an ONT identification (ID).

8. The OLT of claim 1, wherein the OLT interface unit receives a data signal from the OLT of the TDMA-PON and converts the data signal into a downstream data frame, the downstream data frame being a media access control (MAC) frame or a GPON transmission convergence (GTC) frame based on a transmission protocol.

9. An optical network terminal (ONT) of a converged passive optical network (CPON) that is a combination of a time division multiple access-passive optical network (TDMA-PON) and an orthogonal frequency division multiple access-passive optical network (OFDMA-PON), the ONT comprising:

an OFDM modem to transmit and receive an OFDM frame to and from an optical line terminal (OLT) through an optical link;

an OFDM frame processing unit to process an OFDM frame corresponding to each of a plurality of services;

a subcarrier queue transmission unit to process a subcarrier queue corresponding to each of the plurality of services; and

an ONT interface unit to be matched with an ONT of the TDMA-PON corresponding to each of the plurality of services.

10. The ONT of claim 9, wherein the OFDM modem comprises:

a modulator/demodulator to modulate or demodulate the OFDM frame;

a parallel-serial conversion unit to convert a signal between a parallel signal and a serial signal;

a digital-analog conversion unit to convert a signal between a digital signal and an analog signal; and

a photoelectric conversion unit to convert a signal between an electrical signal and an optical signal.

11. The ONT of claim 9, wherein the OFDM frame processing unit comprises:

a first frame conversion unit to convert an OFDM downstream frame transmitted through a subcarrier into a data frame associated with a service of the TDMA-PON; and

a second frame conversion unit to convert a data frame associated with a service of the TDMA-PON into an OFDM frame for upstream transmission.

12. The ONT of claim 11, wherein the first frame conversion unit converts the OFDM frame into the data frame by eliminating overhead information from the OFDM frame, and the second conversion unit converts the data frame into the OFDM frame by adding the overhead information to the data frame.

13. The ONT of claim 12, wherein the overhead information comprises at least one of start delimiter information and end delimiter information about extraction of the OFDM frame, bit interleaved parity (BIP) information to measure a bit error rate (BER) of a downstream link, bitmap information about a subcarrier usable by an ONT according to the services, a service type, and an ONT identification (ID).

14. The ONT of claim 9, wherein the subcarrier queue transmission unit comprises:

a downstream subcarrier queue processing unit to transmit a downstream subcarrier queue associated with a service of the TDMA-PON to a media access control (MAC) transmission unit of the TDMA-PON; and

an upstream subcarrier queue processing unit to receive an upstream subcarrier queue associated with a service of the TDMA-PON from an MAC reception unit of the TDMA-PON.

15. The ONT of claim 9, wherein the ONT interface unit comprises:

an MAC transmission unit to transmit a downstream subcarrier queue to a matched ONT of the TDMA-PON;

an MAC reception unit to receive an upstream subcarrier queue from a matched ONT of the TDMA-PON; and

a subcarrier allocation unit to select a subcarrier based on information about a subcarrier allocated by the OLT of the OFDMA-PON and a status of an upstream subcarrier queue of an ONT.

16. A method of transmitting data performed by an optical line terminal (OLT) of a converged passive optical network (CPON) that is a combination of a time division multiple access-passive optical network (TDMA-PON) and an orthogonal frequency division multiple access-passive optical network (OFDMA-PON), the method comprising:

converting a data signal corresponding to each of a plurality of services of the TDMA-PON into a media access control (MAC) frame or a GPON transmission convergence (GTC) frame based on a transmission protocol;

converting the MAC frame or the GTC frame into an OFDM frame by adding overhead information to the MAC frame or the GTC frame; and

transmitting the OFDM frame to an optical network terminal (ONT) of the OFDMA-PON.

17. The method of claim 16, further comprising:

managing information about a subcarrier usable by the ONT of the OFDMA-PON according to the respective services of the TDMA-PON; and

dynamically allocating an idle subcarrier based on a status of a subcarrier queue of the ONT of the OFDMA-PON.