###### Abstract  
In this paper, attention is focused on the perspective of metallic access networks utilizing homogeneous symmetric lines as a transmission medium. This miscellaneous environment has a strong influence on transmitted Digital Subscriber Line (DSL) signals and hence it is necessary to know its specific parameters in the given case. Fast and precise measurements on homogeneous symmetric lines are still essential, meaningful and imperative for many reasons: solving interference problems, designing advanced signal processing techniques and realizing appropriate simulation models. There are various ways of testing measurements with meaningful differences. In this contribution, we are focusing on the importance of measurements on homogeneous symmetric lines by means of metallic ended line testing. Subsequently, possibilities for new evaluation techniques for Metallic Ended Line Testing (MELT) parameters and for analyzing of DSL service provision are presented. Additionally, the realization of a mobile application functionality for facilitating the jobs of technicians is introduced, together with the possible availability of homogeneous symmetric lines for DSL service provision. n pacs: 14, 3720. +
Footnote †: journal: Applied sciences  
similar to Orthogonal Frequency Division Multiplexing (OFDM). As a result, the DMT efficiently transforms the broadband frequency-selective channel into many frequency-flat narrowband channels. Another important advantage of DMT is the ability to use different modulation for each tone. Thus, tones with a low Signal-to-Noise Ratio (SNR) will use small constellations, such as quadrature phase shift keying with two bits per ton. The operation of individual parts of the transmission over metallic lines is extraordinarily complex and demanding because they are older and often longer. The quality of transmission is influenced by the quality of the metallic transmission medium used. If the properties of metallic conductors are violated due to external influences, breakdowns and outages often occur. Therefore, in many cases, the Digital Subscriber Line Access Multiplexer (DSLAM) device is separated from the Central Office (CO) device and brought closer to the customer, in so-called cabinets. However, in later generations (e.g., VDSL2, G.fast and G.mgfast), metallic loop lengths were effectively shortened by introducing optical fiber into the Distribution Point Unit (DPU). Typical loop lengths for VDSL2, G.fast and G.mgfast are 1200 m, 250 m and 100 m, respectively. Therefore, channel shortening was not used in later DSL generations, which limited their use to Asymmetric DSL (ADSL) technology. Recently, Long-Range VDSL2 (LR-VDSL2) has been designed to provide high data rates (up to 40 Mbps for downstream) and a longer range than conventional VDSL2 (up to 2100 m) for areas where optical fibers cannot be easily deployed (due to geographical or financial barriers). Thus, the need for data transmission over longer loops again motivates the use of time equalization for LR-VDSL2. In addition, Long-Range G.fast (LR-G.fast) is also being considered (as part of the ITU-T standardization). The recent use case proposed under [4] is for G.mgfast, which is also likely the latest DSL standard. In G.mgfast deployments, one of the proposed scenarios is a dual DPU mode to serve G.mgfast for shorter loop lengths and G.fast and LR-G.fast for longer loop lengths [5]. For preliminary design of VDSL2 systems in terms of the bit rate coverage, an analytical framework for the performance evaluation of VDSL2-based access systems is introduced in [6]. There, G.fast is deployed in hybrid optical/metallic access networks to offer ubiquitous low-cost and high-speed broadband. In [7], network modelling and statistical assessment for G.fast's performance is realized on actual network data in four different genotype classes with the aim of improving the network coverage. The degradation of G.fast's performance due to residual Far-End Crosstalk (FEXT) fluctuations after vectoring pre-coding can be relevant.