Data transmission method, related apparatus, and system

1 . A method implemented by an optical line terminal (OLT), wherein the method comprises:

sending a first code type and a second code type to an optical network unit (ONU);

receiving, from the ONU, uplink burst data comprising a synchronization data block and a payload, wherein the synchronization data block comprises first synchronization data and second synchronization data, wherein the first synchronization data comprises a first preamble and a first delimiter, wherein the first preamble is of the first code type, wherein the second synchronization data comprises a second preamble and a second delimiter, and wherein the second preamble is of the second code type;

recovering a clock based on the synchronization data block;

obtaining an equalization parameter based on the synchronization data block; and

recovering the payload using the clock and the equalization parameter.

2 . The method of claim 1 , wherein the first code type and the second code type are different.

3 . The method of claim 1 , wherein the second synchronization data and the payload have different transmission rates.

4 . The method of claim 1 , wherein the first synchronization data further comprises a first frequency distribution occupying a first bandwidth, wherein the payload comprises a second frequency distribution occupying a second bandwidth, and wherein the second synchronization data further comprises a third frequency distribution occupying a third bandwidth.

5 . The method of claim 4 , wherein the third bandwidth is wider than the first bandwidth.

6 . The method of claim 4 , wherein the third bandwidth is an integer multiple of the first bandwidth.

7 . A method implemented by an optical network unit (ONU), wherein the method comprises:

receiving a first code type and a second code type from an optical line terminal (OLT);

generating uplink burst data comprising a synchronization data block and a payload, wherein the synchronization data block comprises first synchronization data and second synchronization data, wherein the first synchronization data comprises a first preamble and a first delimiter, wherein the first preamble is of the first code type, wherein the second synchronization data comprises a second preamble and a second delimiter, and wherein the second preamble is of the second code type; and

sending, to the OLT, the uplink burst data.

8 . The method of claim 7 , wherein the first code type and the second code type are different.

9 . The method of claim 7 , wherein the second synchronization data and the payload have different transmission rates.

10 . The method of claim 7 , wherein the first synchronization data further comprises a first frequency distribution occupying a first bandwidth, wherein the payload comprises a second frequency distribution occupying a second bandwidth, and wherein the second synchronization data further comprises a third frequency distribution occupying a third bandwidth.

11 . The method of claim 10 , wherein the third bandwidth is wider than the first bandwidth.

12 . The method of claim 10 , wherein the third bandwidth is an integer multiple of the first bandwidth.

13 . An optical line terminal (OLT) comprising:

a transmitter configured to send, to an optical network unit (ONU), a first code type and a second code type;

a receiver configured to receive, from the ONU, uplink burst data comprising a synchronization data block and a payload, wherein the synchronization data block comprises first synchronization data and second synchronization data, wherein the first synchronization data comprises a first preamble and a first delimiter, wherein the first preamble is of the first code type, wherein the second synchronization data comprises a second preamble and a second delimiter, and wherein the second preamble is of the second code type; and

a processor coupled to the receiver and configured to:

recover a clock based on the synchronization data block;

obtain an equalization parameter based on the synchronization data block; and

recover the payload using the clock and the equalization parameter.

14 . The OLT of claim 13 , wherein the first code type and the second code type are different.

15 . The OLT of claim 13 , wherein the second synchronization data and the payload have different transmission rates.

16 . The OLT of claim 13 , wherein the first synchronization data further comprises a first frequency distribution occupying a first bandwidth, wherein the payload comprises a second frequency distribution occupying a second bandwidth, and wherein the second synchronization data further comprises a third frequency distribution occupying a third bandwidth.

17 . An optical network unit (ONU) comprising:

a receiver configured to receive a first code type and a second code type from an optical line terminal (OLT);

a processor configured to generate uplink burst data comprising a synchronization data block and a payload, wherein the synchronization data block comprises first synchronization data and second synchronization data, wherein the first synchronization data comprises a first preamble and a first delimiter, wherein the first preamble is of the first code type, wherein the second synchronization data comprises a second preamble and wherein a second delimiter, and the second preamble is of the second code type; and

a transmitter coupled to the processor and configured to send, to the OLT, the uplink burst data.

18 . The ONU of claim 17 , wherein the first code type and the second code type are different.

19 . The ONU of claim 17 , wherein the second synchronization data and the payload have different transmission rates.

20 . The ONU of claim 17 , wherein the first synchronization data further comprises a first frequency distribution occupying a first bandwidth, wherein the payload comprises a second frequency distribution occupying a second bandwidth, and wherein the second synchronization data further comprises a third frequency distribution occupying a third bandwidth.