Research And Realization Of IEEE 1588v2 Time Synchronization Technology In P-OTN

In recent years,with the rapid development of mobile telecommunication,IPTV,etc,transmission network is under great pressure that traffic growth brings.In order to adapt to the rapid growth of the traffic flow and the needs of carrying differentiated traffic better,Mainstream operators and equipment manufacturers pay more and more attention in exploring the evolution of transmission technology,hoping to realize network integration and whole traffic operations.P-OTN(Packet Enhanced Optical Transport Network)brings packetized into OTN technology,enables uniform crossover and flexible scheduling of multi-traffic and multi-particle size,through uniform crossover matrix.It also provides different levels OAM(Operation Administration and Maintenance)in view of the different traffic.At the same time,diversification and combined traffic,especially the rapid growth of mobile communication,demands higher time synchronization performance to the network.The current method is the applications of GPS satellite receiver installing in each base station side to solve the synchronization problems.However,the GPS satellite system brings a safety hazard,high cost and difficult construction problems,etc.Thus,it is need to look for relevant alternatives actively.On current network architecture and service model,it adopts satellite substitution and transmission substitution to solve these problems.That is the use of Beidou satellite navigation system and IEEE 1588 v2 protocol published by the IEEE in 2008.PTP(Precision Time Protocol)is early applicated in the field of industrial automation,and now it is still the research focus in the field of telecommunications.Based on the discuss of characteristics of P-OTN and the theory of IEEE 1588 v2 protocol,this thesis first proposed the necessity for the network time synchronization,and discusses the synchronization scheme in P-OTN,and the problem needed to be solved,including the methods of carring PTP messages or other signals to realize synchronization in OTN network.After comparing the different synchronization schemes in P-OTN,thispaper chooses the one using the reserved overhead bytes to carry PTP messages based on MFAS.Then this thesis puts forward the corresponding system design scheme including the encapsulation of PTP messages,and the realization of the function of hardware and software,finally does the network test.The test results confirm that feasibility of high precision time synchronization in P-OTN network can achieve demands for high precision time in the future mobile communication,and can meet the current and future five years of service development needs.