A methodology for measurements of basic parameters in a xDSL system

Edson Brito, Jr., Lamartine V. de Souza, Éder T. Patrício, Agostinho L. S. Castro, Gervásio P. dos S. Cavalcante, João Crisóstomo W. A. Costa, Klas Ericson, Fredrik Lindqvist, Jaume Rius I Riu, Raj Jain, Benjamin B. Dingel, Shozo Komaki (+1 others)
2006 Broadband Access Communication Technologies  
In order to qualify a subscriber loops for xDSL transmission, basic parameters like transfer function, scattering parameter S 11 and characteristic impedance should be known. The aim of this paper is to present a test methodology for measurements of these basic parameters. The characteristic impedance is measured by open/short method and it is compared with the terminated measurement method defined in IEC (International Electrotechnical Commission) 611156-1. Transfer function and scattering
more » ... and scattering parameter S 11 of DSL loop are also measured on a real cable. The methodology is based on measurements of a 0.4 mm, 10 pairs, balanced twisted-pair cable of 1400 m of length. In order to improve the analysis of results, we compared the measurements from real cable with results from wireline simulators. The measurement of parameters of xDSL copper loop is done in an infrastructure set up in the LABIT (Technological Innovation in Telecommunications Lab) at UFPA (Federal University of Pará), that consist of a wireline simulators, a precision impedance analyzer, and a network analyzer. The results show a difference between the measurements performed with real cables and wireline simulators for transfer function parameter. Characteristic impedance obtained by both methods presented quite similar results. environmental conditions has great influence in final results. Additionally, the wireline simulators meet the requirements of international DSL standards [9], resulting in a natural difference between real cable and wireline simulator measurements for transfer function parameter. ACKNOWLEDGMENT Authors would like to thank the
doi:10.1117/12.686685 fatcat:aujfbszhbrdgvcqxlstc3h4544