The Design And Implementation Of 200G High Speed Flex Ethernet Interface

With the advent of the 5G era,it has spawned multiple business scenarios such as enhanced mobile bandwidth,high-reliability and low-latency communications,and massive machine-type communications.Diversified services have huge requirements on the bandwidth,delay time and reliability of the bearer network.On the one hand,the fixed-rate ethernet interface defined in IEEE802.3 can not provide more flexible bandwidth granularity for diverse services;On the other hand,the rapid increase of network traffic makes the demand for ethernet speed increasing rapidly.But with the expanding of transmission rate of the optical module,the cost performance and the commercial economic value become lower and lower.In order to meet the needs of high-speed transmission and flexible bandwidth configuration,the Optical International Forum(OIF)proposed the Flexible Ethernet(FlexE)technology.Based on the traditional ethernet architecture,it introduces a new FlexE shim to achieve the decoupling of Media Access Control(MAC)layer and Physical Layer(PHY),making the ethernet interface flexible.In this paper,the FlexE elastic mechanism is introduced to the design of traditional high-speed ethernet interfaces.Through the bonding of physical layer links,flexible scheduling configuration and 5G time slot distribution,it realizes flexible expansion of interface bandwidth.Theoretical analysis and applied research on the principle of FlexE interface technology are carried out in this paper from the aspects of FlexE principles and functions,FlexE client processing,FlexE shim time slot scheduling mechanism,and processing of the PHY layer in FlexE group.Firstly,based on the FlexE function model,the overall architecture of this design is determined.Then,through the analysis of the FlexE shim and the physical coding sublayer of the high-speed flexible ethernet interface,the overall architecture is divided into submodules by the receiving side and the sending side.In order to realize the conversion of frame format of the media-independent interface of FlexE client at different rates,a unified media-independent interface module is introduced,which improves the design feasibility.In order to reserve space for the insertion of overhead and alignment marker,interface buffer module is introduced,by inserting a placeholder idle block at the expected position of the data stream,the placeholder function is realized and the complexity of the hardware design of the physical coding sublayer is simplified.Finally,by building a Universal Verification Methodology(UVM)verification platform,the design is functionally verified.The Field Programmable Gate Array(FPGA)and Spirent network test instruments are used to test the performance of the design.The final verification result shows: the design in this paper implements the functional requirements of the FlexE shim,and at the same time meets the simultaneous transmission of multiple FlexE clients whose sum of signal bandwidths does not exceed 200 Gbps when the clock frequency is 78.125 MHz,and supports the reconfiguration of the calendar to adjust the size of the transmitted FlexE client bandwidth.The hardware design of high-speed flexible ethernet interface implemented in this article makes the ethernet interface rate no longer equal to the physical channel rate,because of the more flexible and universal channel bonding feature.Thereby,it greatly enhances the flexibility of ethernet interface application and meets the requirements of the 5G bearer network for large capacity and network slices.