Research On Time Sensitive Network Technologies For Wireless Ad Hoc Network

Because there is no central node and the flexibility of fast networking,the wireless ad hoc network is often used in military,rescue and other fields.In the traditional industrial control field,most devices are deployed and connected in a wired way.Although this method has been proven to have good real-time performance and reliability,the mobility and scalability of the wired network are poor,and it also limits the applicable scenarios of the wired network in the Industrial Internet of Things.Therefore,the industrial field began to turn the research direction to the wireless field.Compared with the wired network,the wireless network can quickly form a network,has good mobility,and has better robustness in some harsh geographical environments.For wireless industrial networks with access points,a series of communication protocols such as Wireless HART,ISA100.11 a,etc.have been proposed,but for wireless ad hoc networks without central control nodes,no solutions suitable for transmitting time-sensitive traffic flows have been proposed.Therefore,for the time-sensitive transmission problem of wireless ad hoc network,the main work content of this thesis is as follows:(1)Propose a TDMA-based communication framework that can be used to transmit time-triggered traffic in wireless ad hoc networks.The time slot calculation model of TDMA is introduced in detail.A time slot is reserved at the beginning of each macrocycle,and flooding is used to synchronize the time of the entire network to complete time slot alignment.By calculating the scheduling table of each node offline,the network will not fail to transmit due to changes in topology or flow set.(2)Model wireless time-sensitive networks according to real-time requirements.Time slot reuse is realized by transmission without collision,maximizing the number of flows that can satisfy real-time transmission(that is,maximizing the network capacity for deterministic real-time transmission).Use SMT incremental scheduling algorithm to evaluate network capacity,and design experiments to compare with existing scheduling methods.(3)On the basis of satisfying real-time performance,in order to improve the reliability of flow transmission,a multi-path selection algorithm is designed,and a multipath reliable and deterministic real-time transmission model is constructed.In the process of building the model,the transmission rules of non-serial parallel paths are designed through redundant time slots,which avoids scheduling deadlock and overcomes the problem of delay jitter caused by multi-path.(4)Finally,this paper designs a wireless ad hoc network node model on the OMNe T++ simulation platform,and implements the time-sensitive communication architecture for wireless ad hoc networks,generates network configurations through(2)and(3)scheduling tools,and simulates and verifies The feasibility of deterministic realtime transmission based on time-triggered transmission mechanism in wireless ad hoc network is demonstrated.