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This paper presents a simple comparison between line conditions produced by using two types of local loops which operate in VDSL (Very-high-bit-rate speed Digital Subscriber line) environment. The object of observation is copper transmission line that remains in access network after replacing copper wires from CO (Central Office) to DP (Distribution Point) with optical fibres, i.e. after implementing...
This paper shows a review investigation the possibility of increasing the efficiency of existing line test solutions for troubleshooting IPTV over xDSL, by the results of experimental research on real system under commercial exploitation. At the beginning of this paper the main weaknesses of the existing troubleshooting testing are described. In the rest of the paper the parameters of the physical...
This paper introduces a very simple testing scenario for detecting of faults in copper local loop that remains in access network after replacing copper wires from CO (Central Office) to DP (Distribution Point) with optical fibres, i.e. after implementation of FTTB (Fibre to the Building/Basement) solution. The scenario can be useful at first for quick and quite reliable loop troubleshooting, and in...
This paper introduces a very simple model of copper local loop that remains in access network after replacing copper wires from CO (Central Office) to DP (Distribution Point) with optical fibres, i.e. after implementing a FTTB (Fibre to the Building/Basement) solution. The model can be used for quick and quite reliable loop qualification and/or troubleshooting. The first part of the paper gives a...
This paper through the results of experimental research collected in real system under commercial exploitation investigates the significance of recommended ratio for one of physical layer parameter — SNR margin for the needs of loop qualification for IPTV over xDSL. At the beginning of this paper, a short definition and recommended value for SNR margin is given. In the rest of the paper the measured...
This paper introduces a quite simple and comprehensible model of copper local loop in current DSL applications. The model is useful for engineers and other technical staff, who operate on local loop qualification and troubleshooting in order to evaluate its ability to provide reliable triple play service over DSL quickly. An overview of existing local loop model is presented briefly at the beginning...
This paper proposes metrics based on QoS preferences of MNs, and QoS abilities of MAPs, in order to perform a simulative evaluation of the Hierarchical Mobile IPv6 (HMIPv6) network implementation with QoS-aware dynamic MAP selection. The chosen metric meets the desired level of QoS, while retaining MAP load balance, while the DiffServ mechanism ensured the required QoS for HMIPv6 network implementation...
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...
This paper continues already done research on the possibility for implementation and new test scenarios aplication for the problems detection in IPTV services delivered over DSL lines. Compared to the previous paper which research it continues, this paper provides a few specific examples of DSL lines in which, based on the values of physical layer parameters, we can assume with great certainty the...
Smart Grid (SG) communication become very hot topic for smart, intelligent and distributed transmission systems for electric power. However, security issues are still open and this is one of main concerns to the deployment of SG. In order to cope with this challenging concern, we propose secure message exchange protocol in this paper, for secure communication in SG system. Particularly, in the proposed...
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 spite of all efforts within the IPTV system to implement robust protection mechanisms, attackers manage to find a way to retransmit content to users who do not have right on it so they damage service providers for certain part of the their legal incomes. This paper presents practical examples of abuse of IPTV content. Several scenarios are created, which are based on the fact that subscribers of...
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...
This paper describes an implementation of secure RICA (Robustness, Integrity, Confidentiality and Authentication) key exchange protocol. Integrity, confidentiality and authentication are the base for secure message exchange. We propose adding robustness in order to ensure better availability of the system. Robustness of presented implementation is due to Quick Response (QR) code properties. QR codes...
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...
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...
This paper analyses randomness in various video and audio media file types, like: Joint Photographic Experts Group (JPEG), Waveform Audio File Format (WAV), Flash video (FLV), high-quality, free and open video format for the web (WEBM) and MPEG-1 Audio Layer 3 (MP3). Analysis is done by executing different statistical test. Statistical tests are usually used for testing different both True Random...
This paper investigates a usability of several common crosstalk models in respect to DSL loop qualification. Short overviews of both common crosstalk models and testing procedures are introduced. A comparison of crosstalk which is calculated from observing models and obtained by testing of real system is done. Based on that, the possibilities of loop qualification using crosstalk models are discussed.
This paper proposes a cryptographic key establishment method based on set of images shared by sender and receiver. The method is simple, fast and secure. We call it CryptoStego. Possible key sizes are virtually limitless. Proposed method is implemented in C programming language. The implementation is compared with (A)RC4 stream cipher, by comparing CPU time and memory occupation by both algorithms...
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...
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