Transfer Function Estimation of Telephone Lines from Input Impedance Measurements

Rodrigues, Roberto M.; Sales, Claudomiro; Klautau, Aldebaro; Ericson, Klas; Costa, João Crisóstomo Weyl Albuquerque

doi:10.1109/tim.2011.2157431

Cited by 7 publications

(11 citation statements)

References 21 publications

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“…that is equal to the second equation in the system (5). Hence, this proves that equation (6) is still valid when another part of the network is branched to node 2 so that to find the distance d 1 we need a network admittance measurement at nodes 1 and 2 and apply the first equation in (5). Then, to obtain d 2 we can proceed with a similar reasoning so that we relate according to a similar set of equations Y 2 with Y 3 .…”

Section: Derivation Of Lines' Length With Unknown Topology Graphmentioning

confidence: 99%

“…However, although we have measured all the network admittances, we still do not know the topology graph and therefore we do not know the association between the admittances, i.e., we do not know what nodes/admittances are adjacent and what nodes are not directly connected by a line. It may be believed, at a first glance, that the system of equations (5), and therefore (11), applies to any pair of admittances measured in the network so that we always get a physically meaningful (although wrong) distance. In reality, since all the terms inside the logarithm in (11) are complex, d 1 and d 2 can be complex depending on Y 2 .…”

Section: Derivation Of Lines' Length With Unknown Topology Graphmentioning

confidence: 99%

“…In the context of DSL networks, it is part of the line qualification procedures that are used to assess the ability of a specific wired network to support different DSL services before the actual deployment. A proper knowledge of the network topology allows to compute the channel transfer functions and can also be used for support engineering and maintenance operations [3], [4], [5]. In the context of SMG, not only communication is involved, but also power transmission.…”

Section: Introductionmentioning

confidence: 99%

“…To our knowledge, admittance measurements have already been used in power networks in order to implement efficient fault detection strategies [11], [12], but never for topology estimation. On the other hand, equivalent S-parameter and impedance measurement have been used in DSL to identify the DSL topology [4] and the channel transfer function [5] under ideal conditions. The purpose of this paper is to discuss the role of admittance measurements, the fundamental aspects, the conditions and the assumptions that have to be made to allow the derivation of a wireline network topology via admittance measurements.…”

Section: Introductionmentioning

confidence: 99%

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On the Exploitation of Admittance Measurements for Wired Network Topology Derivation

Passerini

Tonello

2017

IEEE Trans. Instrum. Meas.

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Abstract-The knowledge of the topology of a wired network is often of fundamental importance. For instance, in the context of Power Line Communications (PLC) networks it is helpful to implement data routing strategies, while in power distribution networks and Smart Micro Grids (SMG) it is required for grid monitoring and for power flow management. In this paper, we use the transmission line theory to shed new light and to show how the topological properties of a wired network can be found exploiting admittance measurements at the nodes. An analytic proof is reported to show that the derivation of the topology can be done in complex networks under certain assumptions. We also analyze the effect of the network background noise on admittance measurements. In this respect, we propose a topology derivation algorithm that works in the presence of noise. We finally analyze the performance of the algorithm using values that are typical of power line distribution networks.

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Section: Derivation Of Lines' Length With Unknown Topology Graphmentioning

confidence: 99%

Section: Derivation Of Lines' Length With Unknown Topology Graphmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

On the Exploitation of Admittance Measurements for Wired Network Topology Derivation

Passerini

Tonello

2017

IEEE Trans. Instrum. Meas.

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“…The identification of these sections can be performed through the analysis of line measurements that can be categorized as follows: single-ended line testing (SELT), which requires measurement equipment only in one line end and double-ended line testing (DELT), which requires equipment in both terminals [3]. It should be highlighted that, even if DELT is not available, there exist techniques to estimate the frequency response through SELT measurements [4,5]. Having a reasonable line topology estimate, it is possible to evaluate the characteristics of the connection that may impact the quality of service.…”

Section: Introductionmentioning

confidence: 99%

A wavelet‐based expert system for digital subscriber line topology identification

Lima

Klautau

Costa

et al. 2014

Int J Communication

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This work proposes a new method for automatically identifying topologies of lines with one or more sections in a telephone network. The method is based on the examination of both impulse response and time-domain reflectometry trace of a line under test. They are analyzed using a method based on the wavelet transform that identifies and extracts features that contain information about the line topology. Those features are interpreted by an expert system composed of three sequential modules that estimate, respectively, the type of line makeup (serial or bridge tap), the lengths of the line sections, and the corresponding cable type, which are the parameters that completely identify the topology according to the assumed model. A thorough comparison with two state-of-the-art methods is also presented using several twisted-pair copper cables. The results show that the proposed method provides good accuracy with respect to topology identification at low computational cost.

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Simple and Causal Copper Cable Model Suitable for G.fast Frequencies

Acatauassu

Höst

et al. 2014

IEEE Trans. Commun.

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G.fast is a new standard from the International Telecommunication Union, which targets 1 Gb/s over short copper loops using frequencies up to 212 MHz. This new technology requires accurate parametric cable models for simulation, design, and performance evaluation tests. Some existing copper cable models were designed for the very high speed digital subscriber line spectra, i.e., frequencies up to 30 MHz, and adopt assumptions that are violated when the frequency range is extended to G.fast frequencies. This paper introduces a simple and causal cable model that is able to accurately characterize copper loops composed by single or multiple segments, in both frequency and time domains. Results using G.fast topologies show that, apart from being accurate, the new model is attractive due to its low computational cost and closed-form expressions for fitting its parameters to measurement data.

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Transfer Function Estimation of Telephone Lines from Input Impedance Measurements

Cited by 7 publications

References 21 publications

On the Exploitation of Admittance Measurements for Wired Network Topology Derivation

On the Exploitation of Admittance Measurements for Wired Network Topology Derivation

A wavelet‐based expert system for digital subscriber line topology identification

Simple and Causal Copper Cable Model Suitable for G.fast Frequencies

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