| 1. | Complex transmission tech : differential signal in fewer channels
多路传输技术：多重信号可以以较少的线路传输。 |
| 2. | The erbium doped fiber amplifier has been tested in the direct amplifier station of institute of fujian telecommunications for the first time in china . the experiment was very successful
并将研制成功的掺铒光纤放大器首次运用到合作单位福建邮电科学研究所的光纤直放机上进行线路传输实验，实验十分成功。 |
| 3. | Let you make phone calls between offices in different cities ( countries ) for free if the offices are already connected with leased lines or the internet . only equipment requirement is pairs of low cost ipanalogy dual function phones
在两地或多地企业驻地安装企业专用ip电话设备，两端ip电话间通过专线或互联网线路传输电话、传真，无须再每月交纳高额电话、传真费用。 |
| 4. | The data process is : manchester decoding , rate changing , hdlc link coding , hdb3 coding , then through the e1 line trasmission . the received data through the negtive process is changed into ethernet data and enters the 10base - t interface
其数据流程为以太网数据经过曼彻斯特解码，码率变换， hdlc链路编码， hdb3线路码编码，进入e1线路传输；由e1线路接收的数据经过反过程变为以太网数据进入10base - t接口。 |
| 5. | Also only pay local phone cost when calling people in a city where you have an office installed with a gateway equipment . this solution is designed for companies that have high long distance phone bills and have already connected with leased lines or to the internet
网完全连接，通过专线或互联网线路传输电话传真，无须再每月交纳高额电话传真费用，与另一驻地同一市区内的用户通话也只需交纳当地市话费用，而节省长途费用。 |
| 6. | Also only pay local phone cost when calling people in a city where you have an office installed with a gateway equipment . this solution is designed for companies that have high long distance phone bills and have already connected with leased lines or to the internet . b
网完全连接，通过专线或互联网线路传输电话、传真，无须再每月交纳高额电话、传真费用，与另一驻地同一市区内的用户通话也只需交纳当地市话费用，而节省长途费用。 |
| 7. | A new terahertz source of folded waveguide traveling - wave - tube which based on vacuum electronics is introduced , which may answer the question for scarcity of small , economical terahertz source with continuous wave of high average power . secondly , transmission characteristics of terahertz wave in the periodic slow wave circuit of folded waveguide traveling - wave - tube have been researched combined with development of micro - fabrication technology . dispersion relation and interaction impedance of the slow wave circuit are deduced by the way of equivalent circuit , and results accounted by theory are close to those simulated by software
其次,结合计算机模拟技术对这种新型太赫兹辐射源的折叠波导慢波线路传输特性进行研究:用等效电路法从理论上推导了慢波电路场、色散关系及线路耦合阻抗,电磁模拟软件计算得出的慢波电路色散曲线与理论计算所得结果基本上一致,表明这种尺寸的慢波电路在太赫兹频段有着色散曲线较平坦以及宽带、低损耗的良好传输特性。 |
| 8. | However , in cdma system there are multi - path interference , multi - access interference and the interference resulted from absence of synchronization which will limit the user content of the system . so based on the theory of complementary series and ond , the essay presents a new type of spread spectrum series - modified complementary series , which has been applied in cdma communication system
然而， cdma系统本身存在着多址干扰，多径干扰以及由于上行线路传输而产生的非同步干扰等等，这些干扰随着系统中用户数量的增多而增加，这将大大限制cdma系统中的用户容量。 |
| 9. | According to the review and comparison of today ' s adsl test instruments , the author finds the lack of the traditional test methods and indicates that easy to use , versatility and extensible are crucial aspects to design an adsl test instruments . the author also bring up a new method , the adaptive test method which can be used to test the adsl ' s transmission characters on the whole band dynamically
通过对国内外现有adsl检测设备的特点进行总结和比较之后，找出了传统测试方法的不足之处,指出易用性、通用性和可扩展性是设计adsl测试仪表的关键，提出了新的adsl线路传输特性的检测方案? ?使用自适应算法实现对adsl整个频段的衰减情况动态测量，并且在matlab上进行了仿真。 |
