Trilithic公司的监督系统 :HFC反向回路的维护设备产品简介图２但当反向服务开始加入反向回路时 ,操作者只能由被反向服务信号所占用的频带间之空白频谱侦测入侵干扰图３最后当反向频带被反向服务所占满时 ,则会导致没有频谱可供监督系统侦测入侵干扰。Ｔｒｉｌｉｔｈｉｃ的Ｔ Trilithic’s supervisory system: HFC reverse loop equipment Figure 2 But when the reverse service starts to join the reverse loop, the operator can only detect the white space from the frequency band occupied by the reverse service signal. Interference Figure 3 Finally, when the reverse frequency band is occupied by the reverse service, no spectrum will be available for the surveillance system to detect intrusion. Trilithic’s T