Research On Transmission Delay Of PTN Real-time Service Based On Numerical Simulation

With the process of smart grid construction accelerated,the power communication network services are facing upgrading from SDH technology to IP packet technology.The emergence of large particles and multitype network business forces time division multiplexing to statistical multiplexing as the core of electric power communication transmission network.That provide a broad application prospect for PTN technology.Usually,the real-time business such as relay protection,the data of security and stability control in power system use time division multiplexing technology to build transport channels,such business has high requirements for delay,that poses a challenge to the real time and reliability.PTN needs plenty of theoretical and simulation support by carrying such real-time services.The research on PTN transmission delay were mainly dominated by network simulation and rarely considered the stochastic problem and delay jitter in the past.The article adopts the method of numerical simulation,studys the transmission delay problems of real-time business.A PTN packet transmission model of random delay is established,which can describe the probability distribution of random transmission delay,and research the effect of package size on transmission delay characteristics.The article proposes random packaging mode and fixed packaging mode,respectively establishes a single node and the serial path end-to-end delay jitter mathematical models.The influence of network parameters,such as background traffic,path node number and router throughput are researched quantitatively by simulation.The advantages and disadvantages of the two kinds of packaging mode are compared.In order to verify the delay jitter model's correctness,a Monte Carlo simulation is programmed.The simulative results show that the stochastic transmission delay probability is growing quickly with the packaging size increasing.The background has a greater influence on the flow of random packaging mode,and has a little influence on fixed packaging mode.The delay jitter will enhance with the increase in the number of nodes,and will recede with the increase of the router throughput.Under the same condition of network parameters,the delay jitter of fixed packaging mode is smaller.The Monte Carlo simulation results verify the accuracy of this model.While the number of packets is in the range between 16 and 32,the real-time business with using unstructured packaging mode has better delay characteristics.By controlling the transmission channel parameters,we can effectively reduce the delayjitter,and provide a basis for the jitter setting of the routers.In the vast majority of cases,the model of fixed packaging has more stronger ability to resist jitter than the model of random packaging.The study provides theoretical support to TDM business carried by PTN,and the results has meaning of technical guidance and reference value in engineering.