Battery-powered RFID tags are placed on an asset and they communicate with at least three wireless access points inside 将RFID标签贴在要跟踪的物体（资产）上，通过至少三个无线接入点可以确定物体的未知。
Using several different sources forces you to step back and evaluate or triangulate them.使用不同来源的资料可以强迫你综合各方看法，对原材料进行反复推敲和评估。