Secondly, the architecture of hardware and operation mechanism ofsystem are described, the focus is on the design of sub-system comprised of L2/3main control board, user access board, environment detecting board and CPE board.

• 接着，介绍系统的总体硬件设计及其工作流程，并着重论述硬件系统的四个重要组成部分的设计，包括二/三层交换的主控制板，用户接入控制板，环境监控板和用户侧设备板。