The Research Of Monitoring And Management On IPTV QoS

In this paper, the QoS performance indicators which affect the IPTV QoS are analyzed in detail, and two solutions of QoS problem are given for two important factors in this. According to the monitoring and management on the quality of video streaming, the priority classification method based on PSI packet and the selective retransmission based on audio and video data packets are proposed, in order to improve the quality of user interaction, this paper presents a management method to improve the quality of user interaction based on the channel zapping time.From the point of the management of PSI packets loss, PSI control information is very important for the video decoding, after analysing this importance, according to the defects of the existing data management methods, this paper presents a new data management method based on the priority classification PSI packets. based on the existing priority classification methods, according to the importance of PSI table information, this method gives the PSI data packets a higher priority for transmission, so the PSI packets can be transmitted earlier by the routing node, so that the quality of the terminal video images under the network anomaly can be ensured. The priority classification method complete the management of the data priority from three levels which are the level of the business contents, the level of the TS packets types, the level of the TS packets contents, and it makes the partition of priority that based on the over three level be the poicy set of priority classification mithod. After getting the priority of the packet according to the priority classification strategy, this method mark the priority on the right position from the level of IP packets and the level of TS packets, then the routing nodes complete the distinct processing using the priority queue scheduling policy of multilevel polling according to the identification and analysis of the packet prioritization, such as priority transmitted and priority discarded. Simulated the actual operation of IPTV environment, completing the design of the system and the verification of method, the result of the experiment shows that when the internet occurs abnormal situations such as packet loss, the priority classification method based on PSI packets achieves its purpose to intervene and manage data actively, and ensures the priority transmission of the important data in special situations, certify the quality of the IPTV video images.From the point of the repair of common radio and video packets after damaging, after analyzing the reason that caused data loss and error, this paper makes a in-depth research on three types of video frame which are I frame,P frame,B frame, based on this, according to the defects of the existing IPTV fault-tolerant mechanism, this paper presents a new error resilience method based on the choice and retransmission of radio and video packets. This method judged the loss of packets according to the information such as TS head,frame head and image slice, then it makes the TS packets lost and damaged be choiced and retransmitted, so the management of the IPTV QoS can be completed, ensures the quality of the video images on terminal. Prefered choice and retransmission method regards data error and packets loss as loss events, and it analyzes the packets and then identifies which packets are lost according to the certain rules, then record the healthy data information and the loss data information, put the healthy data into decoding buffer, while select the packets with higher priority from the loss information list for retransmiting and repairing according to the rules of rules set and priority strategies, the method is based on the defects of the existing TCP data retransmission, using the method combined with P2P and HTTP protocol, getting the healthy packets by sending the data retransmission request to the close client or the streaming media server. At last, build and deploy the test environment, complete designing the system and verifying the effectiveness of the method, the result of the experiment shows that, the choice and retransmission method based on the radio and video packet completed intervening and controlling the IPTV business data actively under the situation of packets loss, on the basis of reducing delay and jitter, the method ensured the priority retransmission of the critical data, and certified the qualilty of the terminal video.Channel zapping time can affect the quality of user interaction, so according to the effect, and after analyzing the main factors that affect the channel switching, in order to make up the shortcomings of existing improved methods, this paper presents a new multicast algorithm based on the priority route performance evaluation which maintains the multicast tree. This method takes into the effect of the node performance and the structrue of the multicast tree on the ability to transmit stream, at first, a simple peer performance assessment algorithm was proposed to evaluate the priority of the ability of the peer to forward data, and then using this assessment algorithm as a assessment scale, and using the depth of the candidate parent peer in the multicast tree as a reference, to evaluate the priority performance of the multicast path which the candidate is on, then accroding to the level of the path performance priority to sort the candidate parent peer, and select the optimal parent node from them, then insert the appication node into the multicast tree which requests the media streaming, then the processing of maintaining the mulicast tree is completed. Finally, verify the correctness and efficiency of the algorithm by doing the simulation experiment, and compare and analyze the experimental results, the comparison of the results shows that, the multicast algorithm based on the priority route performance evaluation which maintains the multicast tree reduce the delay of network transmiting media stream, improve the ability of multicast tree forwarding stream, thereby reduce the channel zapping time, ensure the quality of the user interaction, and complete the management of IPTV QoS.