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今年9月初,北京气象中心和西德气象局采用符合CCITT V.29标准的调制解调器进行了一次高速数据通信试验。这种装有微处理机的调制解调器采用先进的自适应均衡技术和动态分配的多路复用技术。由于采用自适应均衡技术,可以在一条符合M1020标准的普通宽带话路上,不另加任何均衡补偿措施,便能以调幅调相的调制方式完成9600bps的高速数据传输。动态分配的多路复用技术,可以根据需要把一条9600bps的数据通道分割为一个7200bps的子信道和一个2400bps的子信道;或二个4800bps的子信道;或一个4800bps加二个2400bps的子信道;或四个2400bps的子信道。在电路组织上比较灵活。这次试验是采用最后一种分配方案。以一个子信道作2400bps的非编码数字传真;一个子信道作2400bps的误码率测试(该信道将来作数据通信用);另二个子信道和一个辅助信道作75bps的低速电传通信。在为期两天的
In early September this year, Beijing Meteorological Center and West Germany Bureau of Meteorology conducted a high-speed data communications test using a modem conforming to the CCITT V.29 standard. This microprocessor-equipped modem uses advanced adaptive equalization and dynamically allocated multiplexing. Due to the adaptive equalization technology, it is possible to perform 9600bps high-speed data transmission on the basis of an M1020 standard wide-band speech channel without any equalization compensation. Dynamic allocation of multiplexing technology, according to need a 9600bps data channel is divided into a 7200bps subchannel and a 2400bps subchannel; or two 4800bps subchannel; or a 4800bps plus two 2400bps subchannel ; Or four 2400 bps subchannels. In the circuit organization more flexible. This test uses the last distribution plan. One sub-channel for 2400bps non-encoded digital fax; a sub-channel for 2400bps bit error rate test (the channel for data communications in the future); the other two sub-channels and a secondary channel 75bps low-speed telex. In two days