"TBR21"是什么？？

答案:2 悬赏:60 手机版

解决时间 2021-02-06 21:35

提问者网友：美人性情
2021-02-06 12:17

TBR21 includes the following countries: Austria, Belgium, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the
United Kingdom.

最佳答案

五星知识达人网友：人類模型
2021-02-06 12:31

TBR21 是欧盟国家的相关专业组织订立的一种通信技术卡接的要求. 上面所说的那些国家应该是统一施行这种标准的欧盟成员国.一下是些稍微具体的介绍.

TBR 21 establishes the minimal technical interface requirements for terminals (except simple telephones) to access the European market.

TBR-21 is concerned with the technical aspects of the TTE/PSTN interface:
Voltage / Current Characteristics
DTMF tone generation
Call progress detection
Return losses and symmetry to Ground
Ring detection
ON/OFF Hook characteristics
Polarity and short interruptions
Busy tone recognition
Distortion and spurious emissions

全部回答

1楼网友：低音帝王
2021-02-06 12:43

95式性能很差，主要是人机效果差，火线高，这是朵英贤一意孤行的结果，至于tar21，95式根本没法和他比，简直就是天与地的差距一样

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