Suitability of PCM transmission for Nairobi Local Network
Onunga, John O
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The suitability of voice and data signals transmission over PCM channels in Nairobi local network is investigated. The method involves determination of the number of PCM systems that can be accommodated in each existing junction cable and the-error rate achievable with modern treated data on PCM codec optimized for voice transmission. Insulation resistance, signal attenuation and eye-opening tests are carried out to determine cable conditions while Near-end-crosstalk, (NEXT) test is used to determine cable fill. The results show that only 5 existing junction cables in Nairobi area can be used for PCM transmission, while the remaining routes need new PCM cables. Further Data Signals can be transmitted over PCM channels using data moderns, provided the modem outputs are adjusted to between -16 dBm and -32 dBm.