Data transmission method and related apparatus

A data transmission method comprising:

• Receiving, by a second communication apparatus, an ith alignment marker (AM) group sent by a first communication apparatus, wherein the ith AM group is used to align a plurality of logical lanes, and i is an integer greater than or equal to 1;
• receiving, by the second communication apparatus in M time units between the ith AM group and an (i+1)th AM group, first data that is of a plurality of service flows and that is sent by the first communication apparatus by using the plurality of logical lanes, wherein M is an integer greater than or equal to 2;
• determining, by the second communication apparatus, service flows corresponding to data separately carried in the M time units between the ith AM group and the (i+1)th AM group, wherein
• there is a mapping relationship between the plurality of service flows and a slot of a first calendar, wherein the first calendar comprises s slots, and s is an integer greater than or equal to 2;
• and
• the M time units between the ith AM group and the (i+1)th AM group comprise N first counting periods, the first counting period comprises s time units, each time unit of the first counting period corresponds to one slot of the first calendar, different time units of a same first counting period correspond to different slots of the first calendar, and N is an integer greater than or equal to 1;
• and
• receiving, by the second communication apparatus, the (i+1)th AM group sent by the first communication apparatus, wherein a reception time interval between receiving the ith AM group by the second communication apparatus and receiving the (i+1)th AM group by the second communication apparatus is the M time units.

A first communication apparatus comprising:

• a transceiver, configured to:
• send an ith alignment marker (AM) group to a second communication apparatus, wherein the ith AM group is used to align a plurality of logical lanes, wherein i is an integer greater than or equal to 1;
• and
• send first data of a plurality of service flows to the second communication apparatus based on a mapping relationship by using the plurality of logical lanes, wherein the first data is carried in M time units between the ith AM group and an (i+1)th AM group,
• wherein M is an integer greater than or equal to 2, wherein
• the mapping relationship is a mapping relationship between a slot of a first calendar and the plurality of service flows, wherein the first calendar comprises s slots, and wherein s is an integer greater than or equal to 2;
• the M time units between the ith AM group and the (i+1)th AM group comprise N first counting periods, the first counting period comprises s time units, each time unit of the first counting period corresponds to one slot of the first calendar, different time units of a same first counting period correspond to different slots of the first calendar, and N is an integer greater than or equal to 1;
• and
• the first communication apparatus sends the (i+1)th AM group to the second communication apparatus, wherein a transmission time interval between sending the ith AM group by the first communication apparatus and sending the (i+1)th AM group by the first communication apparatus is the M time units.