In order to develop the integrated services LAN, based on the summary of the accessmode of LAN, this thesis put forward a new medium access mode of LAN------DoubleToken and Double Loop that is each loop has its own token.

• 为了发展综合业务局域网,本文在对局域网存取方式综述的基础上,提出了一种新的局域网介质存取方式:双令牌双环(即每个环各有一个令牌)的介质存取方式。