This paper analyses the test scenarios of monitoring platforms of DSLAM devices and hand-held test instruments in terms of testing the physical layer parameters for the detection of problems in the functioning of the IPTV service. The paper carries out a comparison of both test abilities and analyses the advantages and disadvantages of each in comparison to the other. The paper also suggests optimal use of both test scenarios at very frequent testing on DSL lines.

This paper examines the actual usefulness and importance of longitudinal balance as one of many electrical parameters of symmetrical copper pairs. Through the results of several experiments on copper pairs with different types of significant faults, but also by measuring longitudinal balance on the real system in practice, this paper attempts to show the actual usefulness and importance of this parameter. In this manner, this paper intends to make the process of measuring the electrical parameters of symmetrical copper pairs more reliable and usable for reliable detection of various types of faults.

This paper analysis the actual usefulness and importance of wideband noise as one of electrical parameters of symmetrical copper pairs. By the results of measuring wideband noise on the real system in practice on copper pairs with different conditions on them, this paper attempts to show the actual usefulness and importance of this parameter. In this manner, this paper intends to make the process of measuring the electrical parameters of symmetrical copper pairs more reliable.

This paper shows an example of estimation and calculation of transfer function of twisted pair channel in DSL environment, from provider point of view, instead of commonly used manufacturers of transceivers ones. A brief overview of twisted pair as communication channel is given. End-to-end transfer function with twisted pair primary parameters as variables is introduced. The results of measurement on cable in commercial exploitation and its comparison with introduced theoretical approach are shown. The 20-pair, 1000-meter-long cable, completely buried, which had been 100% occupied by ADSL2+ signals and operating in rural conditions, is used.

This paper examines the possibility of the implementation and application of new test scenarios for the detection of problems on IPTV services that are delivered over DSL lines. Through a number of specific examples of behaviour that could be related to a significant number of DSL lines that transmit IPTV services in a real system of commercial exploitation, this paper shows the actual possibilities of using this new test scenarios on a significant number of lines. Furthermore, this paper points to some advantages of this test scenarios compared to a similar existing solutions. A pure author's look is presented.

REZIME Faults and disturbances in the fixed access telecommunication networks made of symmetrical copper pairs through which triple-play services are delivered, are common occurrence. These faults and malfunctions can do a greater or lesser extent affect the QoS (Quality of Service) of triple-play services, especially IPTV (Internet Protocol TV) which is far most demanding service. This paper will describe some of the existing methods and tools for the detection of faults and disturbances. Also, this paper will describe some new test scenarios designed for more successful detection of faults and disturbances in order to allow higher quality of tripleplay services.

This paper analyses an influence of some primary parameters on some physical layer parameters for DSL (Digital Subscriber Line) transceivers. Main intention of this paper is to show that some very frequent and very intensive serial and shunt resistive faults in in-house cabling system in some circumstances will not always significantly impact on IPTV (Internet Protocol Television) QoS (Quality of Service) parameters. Detailed description of experiments and results of significant number of testing on a real system in practice are given. The testing is implemented under very different condition in terms of resistive faults and in period of several days. Object of observation is a pair from 1000 pairs copper cable with air-paper insulation, lead sheath and star-quad as stranding elements. The length of observed pair is 1570 metres.

This paper analyses a capability of commonly used copper cable to provide multimedia services over ADSL2+ (Asymmetrical Digital Subscriber Line) technology, with satisfied level of QoS (Quality of Service) and QoE (Quality of Experience). The observed quantities are achieved bit rate and some ADSL line performance parameters, listed in appropriate ITU-T recommendations. They are observed in respect to increase the percentage of active broadband signals on treated cable. A brief theoretical overview, following by practical experiment description is shown. Detailed experimental results, obtained by observation of real system in exploitation conditions are presented. An appropriate discuss observed results is performed also. The twenty pair copper cable, approximately 1000 metres long, is used as real object of analysis.

This paper presents an example of improvement of access network ability to provide triple-play service with satisfied QoE. The improvement is made by copper twisted pair local loop shortening. The local loop shortening is done on real buried copper access network in the rural area. A comparison of parameters before and after loop shortening is shown. Some parameters of the physical layer defined in Recommendation ITU-T G.997.1, such as code violation, forward error correction code and the number of seconds with corrected errors on the observed loops are used for comparison. Of course, the quantities like up/down bit rate, line attenuation, SNR margin, etc. are also analysed. All of experiments are done by observing triple-play services in real ADSL2+ environment.

This paper analyses a dependence of standard definition IPTV service continuity error on code violation block codes. A very reliable method of evaluating of several IPTV QoS parameters by observing the parameters of physical layer of DSL transceivers was introduced. Also, an ability to use the procedures, which have already implemented at common ATU-R and ATU-C ADSL2+ modems for estimation of IPTV QoS parameters, without appropriate performance monitoring system implemented was discussed.

This paper analyses an example of estimation and calculation of channel capacity of twisted pair channel in DSL environment, from point of view of provider, instead of commonly used point of view of manufacturers of terminal equipment. A brief overview of twisted pair as communication channel was given. The channel capacity end-to end with primary parameters as variables was introduced. The results of measurement on real cable in commercial exploitation and its comparison with introduced theoretical approach were shown. The 20-pair, 1000-meter-long cable, completely buried, which had been occupied by 100% by DSL signals and operating in rural conditions, was used.

This paper analyses the behaviour of the adjacent ten DSL local loops in the copper based twisted pair cable with foamed polyethylene insulation. Some parameters of the physical layer defined in Recommendation ITU-T G.997.1, such as code violation, forward error correction code and the number of seconds with corrected errors on the observed DSL lines are analysed. Also, this paper analyses the values of some electrical parameters on those same DSL lines. Based on the values of observed parameters, possibility of simultaneous operation of adjacent DSL lines, even that they carry triple-play services is shown.

This paper gives a short overview of methods of testing performance of triple play services. Also, it explains a simplified scenario of testing DSL lines. By considering and comparing results of simplified testing, it can be noticed that their usage helps in estimation of problems on copper twisted pair. It will be shown that using these results accordingly discovers the location of a fault in delivering of triple play services. All of this can be helpful for operators in decreasing their human resources and material expenditures, respectively.

This paper gives brief overview of possible methods for approximate locating of galvanic faults in cables with symmetrical copper pair cables as well as possible methods of repairing the same ones. The main focus is based on two principal methods of locating faults like the use of measuring instruments that run on the basis of bridge measuring methods and measuring instruments which use time domain impulse reflectometry.