Cable modelling comparison for twisted-pair copper plant in Malaysia

Abstract

For over two decades, digital subscriber line (DSL) technology has played an important role in bridging the information highway from Malaysia to the rest of the world. Current copper twisted pair cables deployed to the customer premises in Malaysia are mainly consist of Category 3 copper cables which are meant to operate only up to 16 MHz frequency. The new gigabit fast access to subscriber terminals (G.fast) standard aims to operate beyond ADSL2+ (less than 2 MHz) and VDSL (less than 30 MHz) which G.fast can operates up to 106 MHz frequency, thus a study need to be done to characterize the existing copper cables to observe whether the current copper cable can support the new standard at a shorter distances (below 250 meters). Scattering Parameters (4 port S-Parameters) measurements on the Telekom Malaysia's (TM) twisted-pair copper cable were done to obtain the channel transfer function or the insertion loss of the cable up until 350 MHz. The cable bundle contains 50 pairs of twisted pair copper cable with Fully-Filled cable construction which is meant to be used for underground cabling. Based on the transfer function measurement, 3 cable models, the RLCG, the TNO 6-Parameters and the MAR models were selected to be curve fitted to the measured result to get the best fit for the transfer function. The curve fitted models will then be used to predict the maximum achievable attainable rate for G.fast technology at 106 MHz. This paper will attempt to do a benchmarking for the available cable model to best represent the TM's twisted pair cable in terms of channel transfer function.