使用电脑的离线式多路电话计费软件。一个计费板插在电脑的PCI扩展槽上，多路电话线接入，实施计费。-use computers offline multi-way telephone billing software. Billing a plate inserted in a computer PCI expansion slot, multi-line access, billing implementation.

3U时隙交叉设备原理图，PCB。漫游短信欢迎系统(信令采集设备部分)培训资料-Schematic cross-slot 3U equipment, PCB. Welcome to SMS roaming system (part of the signaling equipment acquisition) training materials

基于散射算法的接收天线的建模，包括天线结构的构成，阻抗矩阵的生成以及表面电流的计算，仿真了偶极子天线、缝隙天线及蝴蝶结天线。-Scattering algorithm based on receiving antenna modeling, including the composition of the antenna structure, generation and computing surface current impedance matrix, simulation of the