Flexible Ethernet (FlexE) Forward Error Correction (FEC) systems and methods include mapping a first set of calendar slots including Ethernet payload clients to a FlexE Time Division Multiplexing (TDM) structure including a plurality of calendar slots; and mapping a second set of calendar slots including FEC data to the FlexE TDM structure, wherein the first set of calendar slots and the second set of calendar slots fill the FlexE TDM structure. In an exemplary embodiment, an overall Physical (PHY) rate of the FlexE TDM structure is kept constant with a reduction in bandwidth for the Ethernet payload clients based on the second set. In another exemplary embodiment, the overall Physical (PHY) rate of the FlexE TDM structure is increased based on the second set of calendar slots, to support a set rate for the Ethernet payload clients with a reduced number of calendar slots.

Embodiments of the present disclosure provide a data transmission method and a device, and the method includes: determining synchronization header indication information indicating a frame header location of a first code stream, where the first code stream is obtained by encoding CPRI service data; decoding the first code stream to obtain a second code stream, where the first code stream is a 10B code stream, and the second code stream is an 8B code stream, or the first code stream is a 66B code stream, and the second code stream is a 64B code stream; inserting frame header indication information indicating a frame header location of the second code stream into the second code stream according to the synchronization header indication information; and mapping the second code stream and the frame header indication information into an OPU in an ODU frame.

A data processing method, a communications device, and a communications system, where in a process of transmitting a packet service, a code block stream carrying the packet service is first obtained, then, rate adaptation is performed on the obtained code block stream, and finally, the rate-adapted code block stream is mapped to an optical channel payload unit (OPU) signal. Compared with a mapping manner in which a Generic Framing Procedure (GFP) is used, the data processing method, the communications device, and the communications system feature low processing complexity and/or high bandwidth utilization.

A method implemented by a first network element (NE) comprises receiving, by a receiver of the first NE, a burst from a second NE, wherein the burst comprises at least one training symbol (TS), storing, by a memory of the first NE, a channel response for a link between the first NE and the second NE, wherein the first NE is communicatively coupled to the second NE, wherein the channel response is based on a current channel response estimated using at least one TS in the burst and a previously stored channel response, and wherein the previously stored channel response is based on a plurality of bursts previously received from the second NE, and compensating, by a processor coupled to the receiver and the memory of the first NE, modulated symbols in the burst using the channel response.

A switch system configured to switch Flexible Ethernet (FlexE) client services includes interface circuitry configured to ingress and egress FlexE clients; and switch circuitry communicatively coupled to the interface circuitry and configured to switch portions of the FlexE clients utilizing a cell switch and Optical Transport Network (OTN) over Packet (OPF) techniques. A method of switching Flexible Ethernet (FlexE) client services includes ingressing and egressing FlexE clients via interface circuitry; interfacing the FlexE clients with switch circuitry communicatively coupled to the interface circuitry; and switching portions of the FlexE clients with the switch circuitry utilizing a cell switch and Optical Transport Network (OTN) over Packet (OPF) techniques.

A master device generates a time synchronization message, performs a first correction on a correction domain of the time synchronization message, and sends it including a first timestamp T1 to a slave device. The slave device performs a second correction on the correction domain of the time synchronization message, adds a second timestamp T2, generates a delay request message, performs a third correction on the correction domain of the delay request message, and sends to the master device the delay request message including a third timestamp T3. The master device performs a fourth correction on the correction domain of the delay request message, adds a fourth timestamp T4, sends to the slave device a delay response message including the correction domain of the delay request message subjected to the fourth correction and the fourth timestamp T4. The slave device performs time synchronization with the master device accordingly.

A Flexible Ethernet (FlexE) switch system configured to switch a FlexE client service includes interface circuitry configured to ingress and egress a plurality of FlexE clients; and switch circuitry configured to switch portions of the FlexE clients based on 64 b/66 b block boundaries between the interface circuitry. A node configured to switch a Flexible Ethernet (FlexE) client service in a network includes one or more line cards configured to ingress and egress a plurality of FlexE clients; and one or more switch fabrics configured to switch portions of the FlexE clients based on 64 b/66 b block boundaries between the one or more line cards.

A transmission apparatus includes: a first plug-in unit including: a clock generator to generate a first clock, a first frame-pulse generator to generate a first frame-pulse-signal based on the first clock; a detector to detect a phase-difference between a first phase of the first frame-pulse-signal and a second phase of a second frame-pulse-signal transmitted from other plug-in unit, and generate phase-difference information based on the phase-difference, and a first transmitter to transmit a control-signal including the phase-difference information to the other plug-in unit; and a second plug-in unit being the other plug-in unit, including: a receiver to receive the control-signal, a controller to control a phase of a second clock of the second plug-in unit, based on the phase-difference information, a second frame-pulse generator to generate the second frame-pulse-signal based on the second clock, and a second transmitter to transmit the second frame-pulse-signal to the first plug-in unit.

A method of providing a path delay asymmetry for time synchronization between a master clock at a first client node and a slave clock at a second client node. The method comprises: mapping a first time protocol signal (TPS) carrying master clock time protocol data (TPD) onto a first signal; determining a forward mapping delay (d.sub.mf); mapping a second TPS carrying slave clock TPD onto a second signal; determining a reverse mapping delay (d.sub.mr); applying FEC to the first signal, determining a forward FEC delay (d.sub.fecf); applying FEC to the second signal; determining a reverse FEC delay (d.sub.fecr); providing d.sub.mf, d.sub.mr, d.sub.fecf and d.sub.fecr to a calculation element; calculating a path delay asymmetry in dependence on d.sub.mf, d.sub.mr, d.sub.fecf and d.sub.fecr; and providing it to a time protocol client at the second client node.

A transmission apparatus includes: a first plug-in unit including: a clock generator to generate a first clock, a first frame-pulse generator to generate a first frame-pulse-signal based on the first clock; a detector to detect a phase-difference between a first phase of the first frame-pulse-signal and a second phase of a second frame-pulse-signal transmitted from other plug-in unit, and generate phase-difference information based on the phase-difference, and a first transmitter to transmit a control-signal including the phase-difference information to the other plug-in unit; and a second plug-in unit being the other plug-in unit, including: a receiver to receive the control-signal, a controller to control a phase of a second clock of the second plug-in unit, based on the phase-difference information, a second frame-pulse generator to generate the second frame-pulse-signal based on the second clock, and a second transmitter to transmit the second frame-pulse-signal to the first plug-in unit.