Research And Design Of Data Link Layer Scheduling And Adaptation Algorithm Based On FPGA

The data link layer,which is the medium between the physical layer and the network layer,is the second layer in the OSI model.In recent years,more and more devices are connected to the network,which is caused by the development of network technology and communication technology.As a result,the traffic in the network becomes larger and larger,which challenges the delay and reliability of the data link layer.In order to solve the problem of increasing node traffic in data link layer,a new scheduling algorithm,TWRR-BF scheduling algorithm,is proposed in this paper.TWRR-BF algorithm is proposed based on weighted round robin scheduling algorithm combined with TSN protocol cluster IEEE802.1q.According to the requirements of the TAS in time-sensitive networks,TWRR-BF prioritized the data frames in the data link layer of industrial Ethernet.Using the time slot concept of industrial Ethernet,the transmission time can be divided into two different time slots.Periodic real-time data is sent in a dedicated time slot to avoid "conflict" between periodic real-time data and other data,resulting in "congestion".The weighted polling scheduling algorithm is used to perform weighted polling scheduling for non-real-time data transmitted in general time slots.Combined with circular queue forwarding maximum occupancy time slot resources advantages,this paper proposes a secondary queue preemption strategy,using distance "small flow high priority" recent "big flow low priority" data to fill in "small flow high priority" queue and reduce the idle time slots,so as to improve the resource utilization and reduce system of the whole of the whole system time delay.The experimental results based on FPGA show that TWRR-BF can complete the prioritization scheduling of nodes when the data flow with priority changes,and has low delay and high reliability.In order to solve the problem that the transmitting end and the receiving end cannot synchronize frames due to the different data frame protocols of different interface protocols.This paper presents a new adaptive algorithm based on FPGA,W-F Adapter adaptive algorithm.The W-F Adapter adaption algorithm uses a FIFO as a cache to implement the adaption of data frames between interfaces with different protocols and rates.Through the simulation experiment and the adaptation between AOS frame and TLK2711 data frame in satellite optical network engineering,it is proved that the W-F Adapter adaptor algorithm can adapt the data frame flow of different protocols and rates with high reliability,and the adaptation delay is picosecond level.TWRR-BF scheduling algorithm and W-F Adapter adaptation algorithm solve the problem of node traffic scheduling and frame synchronization between devices of different protocols in the data link layer respectively.The low delay and high reliability of data link layer in traffic scheduling and frame synchronization are guaranteed.