Research Of Message Scheduling Technology Of Time Scheduling Network

In a non-real-time communication network,if multiple nodes send messages to the same node through the switch at the same time,these messages will be queued within the switch,which will result in an uncertain delay in the message transmission process.In addition,multiple applications on the same node will compete for the link when they send messages at the same time,and cause uncertainty about the message transmission time.For some applications which has strict real-time requirements,non-real-time communication networks can not meet their requirements for real-time and temporal determinism of network message transmission.Real-time communication network with strict end-to-end delay and jitter requirements can meet the strict real-time requirements of applications.The real-time communication network also called Time Scheduling Network(TSN),TSN transmits all messages in the time slot of the message schedule generated offline.Messages transmission in TSN is characterized by no conflicit and time determinism.The message in the TSN is called a Time-Triggered(TT)message,and the TSN communication is called a time-triggered(TT)communication.At present,the main research on TSN is to add the time-triggered communication service on the basis of Ethernet,such as Time-Triggered Ethernet(TTE),but there is little research on the time-triggered communication service of FC network.TTE is a kind of TSN,and if the service of the time scheduling transmission message is added in the Fiber Channel(FC)network,the FC network also becomes a TSN.In this thesis,the scheduling problem of periodic messages in TTE and FC networks is studied,and the message scheduling algorithm and message scheduling software are proposed and implemented.The main work of this thesis are summarized as follows:1.The definition of content of the message schedule and the the method of sending and receiving the message according to the message schedule is proposed.2.The algorithm of the message scheduling table in TSN is proposed,which can be applied to both a simple star network and a complex switched network.The algorithm assigns time slots to each TT message on the entire transmission link in the network,while ensuring the determinism of each TT message transmission time.3.Achived the message schedule software,the main features of the software include:(A)parsing the XML file which saved information of the network;(B)running the message scheduling algorithm on the base of the network information which is parsed and generating the message schedule;(C)display the message schedule in graphical form,and you can see the specific time slot in which each message is transmitted over its link;(D)as a running server to send message schedule generated by the message scheduling algorithm to each device node software;(E)automatically generate the topology of the entire network on the base of the network information which is parsed;(F)manually and automatically configure the entire network information and save it as an XML file.4.The function of each module of the message scheduling software and the performance of the message scheduling algorithm are tested.