This paper discusses problems of multicasting and its application. Two ways are proposed to overcome theproblems of multicasting according to the architectures of current networks and the functional requirements of asurveillance System. One is that Winsock API is directly used to implement multicasting on a network supportingmulticasting. The other adopts the technology of proxy server and tunneling on a network not supporting multicast-ing. In addition,this paper discusses some techniques of multicasting,such as sending,resending,auto-adjusting withthe change of the transmission quality of networks,and the management of multicast group and multicast addresses.
This paper introduces the framework of a remote surveillance system and key technologies to implementthe framework. A codec based on MPEG-4 is developed to encode and decode video. Both ratio and speed of compression of the codec are improved through the optimal designs of motion estimation,quatization and rate control. Errorcorrection functions added to entropy coding of the codec minimize the loss of quality of images due to transmission error. With a QoS mechanism of transmission and playback based on a simple RTP protocol,this framework is able to adapt bandwidth and to control congestion.
