Jean-Jacques Werner

The HDSL environment (high bit rate digital subscriber line)

The author presents a tutorial on the physical environment in which high bit rate digital subscriber line (HDSL) transceivers will have to evolve and succeed. Special attention is given to the most damaging impairments that are encountered in subscriber lines, such as propagation loss, linear distortion, crosstalk, bridged taps, and impulse noise. Somewhat less important impairments, such as change of gauge, temperature variation, and thermal noise, are also briefly described. The author concludes with a discussion of the capacity of a twisted-pair channel in a crosstalk-dominated environment. >

51.84 Mb/s 16-CAP ATM LAN standard

The paper describes the characteristics and performance of the 16-CAP transmission scheme that has been chosen by the Technical Committee of the ATM Forum as the ATM LAN physical layer interface standard at 51.84 Mb/s for category 3 unshielded-twisted-pair (UTP) wiring. The two most attractive features of the 16-CAP transceiver are its capability of operating in the presence of multiple users in a voice-grade UTP cable and the straightforward way in which it can provide scalability to lower speeds. It is also shown in the paper how the carrierless AM/PM (CAP) modulation scheme used for the ATM LAN standard can be utilized to provide substantially higher data rates than 51 Mb/s when there is only one user in a cable. Under this condition, data rates up to 155 Mb/s can be achieved over category 3 wiring and significantly higher rates can be achieved over high-performance category 5 wiring. >

Bandwidth-efficient digital transmission up to 155 Mb/s over unshielded twisted pair wiring

Techniques for achieving data rates up to 155 Mb/s over unshielded twisted pair wiring in premises distribution systems are described. These high data rates represent an improvement of about an order of magnitude in speed when compared to presently available data rates for local area networks operating over this communication medium. The transmission scheme proposed for achieving these higher data rates is carrierless AM/PM (CAP), which is a bandwidth-efficient two-dimensional passband line code. It is shown that a 32-CAP line code can be used to provide the fiber distributed data interface (FDDI) rate of 125 Mb/s over 100 m of voicegrade unshielded twisted pair (UTP) wiring in a channel bandwidth of 30 MHz, which results in a robust performance and eliminates potential problems with electromagnetic radiation limits above 30 MHz.<<ETX>>

Local distribution for IMTV

The local distribution system for an interactive multimedia television (IMTV) system builds on a fiber-to-the-curb (FTTC) architecture that delivers the IMTV signals to and from the home over telephone wiring and coaxial cable. The downstream IMTV channel, from the curb to the home, operates at a data rate of 51.84 Mbps, and the upstream channel, from the home to the curb, operates at a data rate of 1.62 Mbps.

Broadband access to the home on copper

One of the most promising network architectures for delivering broadband services to the home is the fiber-to-the-curb (FTTC) architecture. In an FTTC network, local broadband access to the home is provided on outside plant unshielded twisted-pair (UTP) wiring and in-house coaxial cables or new UTP wiring. This paper presents a detailed description of the types of challenges encountered in such a transmission environment. It also briefly discusses the tradeoffs between achievable data rate and UTP cable length and provides some performance results for a 16-carrierless-amplitude-phase-modulation (CAP) transceiver, which is capable of delivering 52 Mb/s to the home.

Effect of bridged taps on channel capacity at VDSL frequencies

This paper presents theoretical and numerical results on the effect of bridged taps on the channel capacity of unshielded twisted pair telephone wiring used in very-high-speed digital subscriber line broadband access systems.

Local distribution for interactive multimedia TV to the home

This paper discusses a local distribution system for interactive multimedia TV (IMTV) to the home. The network architecture considered here id fiber to the curb, and local distribution of the IMTV signals to and from the home is provided on telephone wiring and coaxial cable. The downstream IMTV channel, from the curb to the home, operates at a data rate of 51.84 Mb/s, and the upstream channel, from the home to the curb, operates at a data rate of 1.62 Mb/s.

HDSL and ADSL capacity of the outside loop plant for multimedia services to the home

Multimedia services using the recent developments techniques permit real time videophony. The ability to deliver these services depends upon the limitations of the loop plant. The fundamental limits of the outside loop plant to carry high-speed digital (bi-directional HDSL and ADSL) data are reported. The paper focuses on the copper wire loops and drop lengths that convey the data over the last mile to almost all businesses and residences in the US. The major inputs are the data bases portraying the make up of business and residential loops. Business and residential loops are characterized by the distance to the central office or the remote terminal. Their spectral capabilities are computed and their ultimate digital capabilities are reported. The crosstalk limitations are also computed and compared with the loss of signal due the distance and spectral constraints. The minimum signal to noise ratio is retained to evaluate the percentages of loops that support the HDSL and ADSL transmission quality. The objective of the study is to evaluate the feasibility of providing multimedia services over existing unshielded twisted wire pairs in the loop plant.<<ETX>>

A bandwidth-efficient encoding scheme for high-speed data transmission on Category 3 cable

Higher-speed data transmission over the embedded network of cables, specifically, Category 3 unshielded twisted-pair developed primarily for voice communications, is addressed. To provide robust transmission systems at high data rates for distances of 100 m, bandwidth-efficient encoding schemes utilizing adaptive noise cancellation techniques are required. One such scheme, carrierless AM/PM (CAP), is described.<<ETX>>