A Consideration on the Minimum Transmission Loss for the Intraoffice Call Path Based on the Listener Echo

수화자 반향을 고려한 자국내 최소 전송손실에 대한 고찰

Listener echos, which arise in multiple 4-wire loop connections(MLC) during the evolving switched telephone network, impare voice-band data signal transmission performance. This paper first shows the calculation method of the total number of listener echo loops over N 4-wire physical loops and presents the additative law for listener echos. It next demonstrates that about 4 dB should be ensured to Eke the transmission loss of intraoffice call path be minimum for the voice-band data service in a digital local switch.