对于海底电话电线系统来说,频分多路终端设备在总费用中仅占很小一部份。假如此系统(?)提供更多的电话通道,那么即使终端设备的费用增加些和设备复杂些也是节省的。 在给定的线路频谱中提高电话通路密度是可能的。在现在的陆地通信系统中,由于通路带宽小于4千赫和减小通路间隔,对 For subsea telephone wire systems, FDD equipment accounts for only a small portion of the total cost. If this system (?) Provides more telephone channels, even terminal devices are more costly and less complex to implement. It is possible to increase telephone path density in a given line spectrum. In current terrestrial communication systems, due to the path bandwidth of less than 4 kHz and the reduction of path spacing,