As bandwidth requirement has a lasting and strong growth

the broadband network has got fast development

traditional Metropolitan Area Network（MAN）becomes the bottleneck of development of broadband data service gradually

traditional SDH technology already unable to meet the fast growing market demand of data service;Metropolitan area WDM network is unable to become the mainstream of the metropolitan area network since he only offer the transparent transmission channel;And because of the restriction of the performance of the network and dependability

LAN relying mainly on IP is unable to duplicate and expand to MAN and WAM directly.A new transmission technology named RPR appeared

he can not only meet the demand of a large number of data service but also prevent the weakness of traditional SDH

this paper discusses mainly how to give a good support to TDM while there is a large amount of data service in RPR.