Definitions of Managed Object Extensions for Very High Speed Digital Subscriber Lines (VDSL) Using Single Carrier Modulation (SCM) Line Coding

This paper presents a study of the effects of bridged taps on very high-speed digital subscriber line (VDSL) transmission systems. It is shown that the short bridged taps; which affect VDSL signals, are much more damaging than the longer bridged taps, which affect other xDSL signals, such as high-rate digital subscriber line (HDSL) and asymmetric digital subscriber line (ADSL). Specifically, short bridged taps introduce a lot of linear distortion in the loop's transfer function. In addition, they also tend to introduce more overall propagation loss than longer bridged taps. The peak-power-to-average-power ratio (PAR) of the signal increases for the loop with short bridged taps, and thus more AID bits are needed in the implementation of a digital VDSL transceiver as compared to the loop with long bridged taps. The performance of various equalizer structures is discussed in the presence of a severe channel distortion caused by the bridged tap.

This paper investigates the effect of radio frequency (RF) interference on the performance of very high-speed digital subscriber line (VDSL) system. It is shown that a blind equalization is extremely difficult in the presence of RF interference. A receiver structure, incorporating an adaptive notch filter (ANF) and hybrid DFE (H-DFE), is proposed to mitigate the effect of RF interference on the VDSL system. The use of an ANF before the DFE yields reliable blind equalization as well as performance improvement. It is also shown that the H-DFE structure employed in the proposed receiver outperforms the conventional DFE or the noise predictive DFE structure in the presence of RF interference.

Recently, a novel transmission technique was proposed for delay-spread channels that guarantees a low peak-to-average power ratio while also having low computational complexity. In this paper, we extend the technique to systems where the symbol length or number of parallel channels is large, such as in very high speed digital subscriber line (VDSL) or multiple-input multiple-output (MIMO) systems respectively. While operational complexity is low, the computational cost of initialisation in a VDSL or MIMO channel appears, at first sight, to be prohibitive. We show that initialisation can be carried out efficiently. Having so enabled the technique, we present simulation results in a MIMO-VDSL environment which demonstrate its superiority in comparison to other popular techniques such as V-DMT and DMMT when clipping in the transmit power amplifier is a dominant consideration

The paper investigates the power control problem in a frequency-selective interference channel. A centralized power control algorithm is developed with the objective of maximizing the achievable rate region given an average power constraint for each user. The proposed algorithm is based on the multi-user discrete bit-loading algorithm that considers the power allocation over frequency and users simultaneously. Simulation results for very high-speed digital subscriber line (VDSL) systems show that the proposed algorithm achieves a larger rate region than that achieved by a power control algorithm based on iterative waterfilling.

Impulse noise is a potential impairment of very-high speed digital subscriber line (VDSL) services. VDSL systems are protected from impulse noise using a combination of Reed-Solomon coding and interleaving. Since there are two competing proposals for VDSL, the first one based on the use of QAM line code and the second one using DMT modulation, it is interesting to compare their performance in terms of immunity to impulse noise. The paper presents a comparison of the behavior of QAM-VDSL and DMT-VDSL in the presence of impulse noise in real configurations. The required interleaving delay to correct all the generated errors for both systems is investigated. It is shown that when no notches are used in the radio-amateur bands, QAM and DMT systems require similar delays in order to achieve the same level of protection against impulse noise. However, when notches are implemented, DMT-VDSL achieves higher rates than QAM-VDSL. Therefore, larger error-correcting code redundancy can be used, which results in lower end-to-end delays for DMT-VDSL systems.

This document defines a Management Information Base (MIB) module for use with network management protocols in TCP/IP-based internets. This document proposes an extension to the GBOND-MIB module with a set of objects for managing ATM-based multi-pair bonded xDSL interfaces, as defined in ITU-T Recommendation G.998.1.

This document defines a Management Information Base (MIB) module for use with network management protocols in TCP/IP-based internets. This document proposes an extension to the GBOND-MIB module with a set of objects for managing multi-pair bonded xDSL interfaces using Time- Division Inverse Multiplexing (TDIM), as defined in ITU-T Recommendation G.998.3.

Key areas of agreement and disagreement in the network management community are presented using the evolving open systems interconnection network management architecture as an informal guide. A key observation is that the open-networking community has apparently settled on a management model that places management information base (MIB) on each network node and manages these MIBs remotely with application level protocols. Various network systems based on this model are examined, along with some systems that use alternative management architectures.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

This memo defines a set of extensions that instrument RADIUS authentication client functions. These extensions represent a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. Using these extensions, IP-based management stations can manage RADIUS authentication clients. This memo obsoletes RFC 2618 by deprecating the MIB table containing IPv4-only address formats and defining a new table to add support for version-neutral IP address formats. The remaining MIB objects from RFC 2618 are carried forward into this document. The memo also adds UNITS and REFERENCE clauses to selected objects. [STANDARDS-TRACK]

This memo defines a set of extensions that instrument RADIUS authentication server functions. These extensions represent a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. Using these extensions, IP-based management stations can manage RADIUS authentication servers. This memo obsoletes RFC 2619 by deprecating the MIB table containing IPv4-only address formats and defining a new table to add support for version-neutral IP address formats. The remaining MIB objects from RFC 2619 are carried forward into this document. This memo also adds UNITS and REFERENCE clauses to selected objects. [STANDARDS-TRACK]

Wireless Sensor Networks (WSNs) have attracted significant research interest in recent years because of their suitability to a wide range of real world applications. The envisioned Internet Protocol (IP) support for WSNs requires interoperability with existing management solutions, like Simple Network Management Protocol (SNMP), in order to provide remote management functionality and assure the correct operation of the WSN. It is essential to provide a network management system that is interoperable with standard network management solutions, customizable, and extensible to various WSN applications. In this paper we present work in progress on our EmNetS Network Management Protocol (EMP), a lightweight and SNMP-compliant IP-based WSN (IP-WSN) management solution. We present detailed operational architecture and a Management Information Base (MIB) which is extensible to IP-WSN applications. We also present implementation details and preliminary results from our laboratory testbed.

This memo defines an extension to the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it defines objects for the management of Parallel-printer- like devices. [STANDARDS-TRACK]

This memo defines a portion of the Management Information Base (MIB), for use with network management protocols in the Internet community. In particular, it describes managed objects for Small Computer System Interface (SCSI) entities, independently of the interconnect subsystem layer. Table of Contents

This memo defines an experimental portion of the Management Information Base (MIB) for use with network management protocols in TCP/IP-based internets.In particular, it defines objects for managing OSPF Version 2. The Network Management FrameworkThe Internet-standard Network Management Framework consists of three components.They are: RFC 1155 which defines the SMI, the mechanisms used for describing and naming objects for the purpose of management.RFC 1212 defines a more concise description mechanism, which is wholly consistent with the SMI.

This document defines a portion of the Management Information Base (MIB) for use with network management protocols in Internet Protocol Version 6 internets. Specifically, this document is the MIB module that defines managed objects for implementations of the Multicast Listener Discovery Protocol [RFC2710].