At&t Bell Laboratories

Lucent Technologies Inc.

Avaya Technology LLC

At+t Corp.

American Telephone & Telegraph Co., At&t Bell Laboratories

At&t Technologies, Inc.

At&t Technologies Inc., At&t Bell Laboratories

Harold Wayne Friesen

Wendell G Nutt

David R Hawkins

Stephen Taylor Zerbs

Richard D Beggs

Daryle Pat Donner

Luc W Adriaenssens

Ian A White

Christopher M Helmstetter

Leslie A Baxter

Clay A Feustel

David M Mitchell

Jane B Clayton

Palmer D Thomas

Philip Nelson Gardner

Kenneth B Parks

Steven Craig Bartolutti

Janice Bilecky Haber

Robert Henry Jackson, Jr

Thomas M Wolterman

A system for cross-connecting network elements of different types through a common universal media. In the system, a media conversion interface is electrically connected to a network element. This media conversion interface passively maps the connector and cable type of the network element to a universal connector type. This media conversion interface is electrically connected to a cross-connect module in a universal distribution frame. This electrical connection uses a universal cable group and universal connectors. This cross-connect module is connected to another cross-connect module, also in a universal distribution frame, using a universal cable group and universal connectors. This second cross-connect module is electrically connected to a second media conversion interface, using a universal cable group and universal connectors. This second media conversion interface is electrically connected to a second network element, and passively maps the connector and cable type of the second network element to the universal connector.

System for providing universal cross-connect connectivity in a central office

A cabling media which is suitable for high performance data transmission includes a plurality of insulated metallic conductor-pairs, each pair including two plastic insulated metallic conductors which are twisted together. More specifically, the introduction of a periodic rotation along the length of each insulated conductor essentially acts to cancel out a large number of the adverse effects which may result due to a lack of conductor concentricity and/or dielectric eccentricity.

Local area network cabling arrangement having improved capacitance unbalance and structural return loss

A local area network cable capable of high speed signal transmission has a plurality of twisted pairs of conductors enclosed within a jacket. Each of the twisted pairs has a different twist frequency than any of the other pairs, and at least one of the pairs has a direction of twist that is different from the other twisted pairs, that is, it may have a right hand twist where the other pairs have a left hand twist. In a four pair cable, two of the pairs, of different twist frequency, have imparted thereto a right hand twist, and two of the pairs have a left hand twist.

High speed transmission local area network cable

A cabling media which is suitable for high performance data transmission includes a plurality of metallic conductors-pairs, each pair including two plastic insulated metallic conductors which are twisted together. The present invention describes how the selection and incorporation of metallic conductors having different diameters within a single communication cable can significantly enhance the operational performance of the cable. More specifically, given a first conductor-pair having a certain conductor diameter and twist length, and at least one other conductor-pair with a different twist length, the present invention purposely selects metallic conductors for this other conductor-pair with a different diameter than that of the first conductor-pair so as to ensure that the insertion loss exhibited by the additional conductor-pair is essentially equal to the insertion loss exhibited by the first conductor-pair. The differing conductor diameters allows compensation for the variance in insertion loss from one conductor-pair to the next due to changes in the twist length employed for the plurality of conductor-pairs. Additionally, it is described herein that the insulation thickness of the conductors may be altered from conductor-pair to conductor-pair to ensure that the characteristic impedance measured for the additional conductor-pair is essentially equal to the characteristic impedance measured for the first conductor-pair. As a result of the particular selection of conductors with differing diameters and/or insulation thicknesses for at least two of the conductor pairs, the operational performance of the resulting cable is improved.

Local area network cabling arrangement

A cabling media which is suitable for data transmission with relatively low crosstalk includes a plurality of metallic conductors-pairs, each pair including two plastic insulated metallic conductors which are twisted together. The characterization of the twisting is important and relates to parameters such as twist length as well as core strand length/lay. More specifically, particular combinations of twist lengths and core strand length/lay are purposely selected for each insulated pair of the cable in order to achieve performance capabilities that significantly surpass those required under TIA/EIA-568A. In one particular embodiment of this invention, a cable comprises as its transmission media, four twisted pair of individually insulated conductors with each of the insulated conductors including a metallic conductor and an insulation cover which encloses the metallic conductor. The twisting together of the conductors of each pair is characterized as specifically set out herein and the plurality of transmission media are enclosed in a sheath system which in a most simplistic embodiment may be a single jacket made of a plastic material. As a result of the particular twist scheme employed for the conductor pairs, operational performance of the resulting cable is improved. Also, the cable of this invention is relatively easy to connect and is relatively easy to manufacture and install.

A cable for use within customer premises that effectively extends outside plant service to within the building. The cable has first and second core assemblies preferably formed of flame resistant material completely isolated from each other and surrounded by a shielding member having a rough FIG. 8 configuration. Each of the cores is completely enclosed within the loops formed by the shielding member and completely isolated from the other core. The shielding member is surrounded by a preferably flame resistant outer jacket.

Indoor communication cable

A fire-resistant cable (20) which is suitable for the transmission of high frequency signals in a local area network includes a core which comprises a plurality of twisted pairs (22,22) of insulated conductors (24,24) and a jacket (35). Each insulated conductor of each pair includes an elongated metallic member (26) and an insulation system (28). The insulation system which is characterized by a suitable low dissipation factor includes dual layers, an outer one of which includes a flame-retardant plastic material. Also, the insulation system is characterized by a suitably low dielectric constant and by compatibility with a relatively short pair twist scheme. In one embodiment, the insulation system includes an inner layer (30) of a polyolefin plastic material and an outer layer (32) of a flame-retardant polyolefin plastic material. The jacket comprises a plastic material characterized by a suitably low dissipation factor and dielectric constant and in a preferred embodiment comprises a flame-retardant polyolefin plastic material. Preferably, the twist length of each pair does not exceed the product of about forty and the outer diameter of an insulated conductor of each pair.

Fire-resistant cable for transmitting high frequency signals

A balanced mode transmission system (20) for use in a local area network includes at least one twisted pair of insulated metallic conductors (27--27) which at its end is connected through a transformer to a transmitting computer and to a receiving computer (48). Each pair of conductors adjacent to the transmitting end and optionally adjacent to the receiving end is provided with a longitudinal choke (56,57). Also, a longitudinally extending metallic wire (60) is included in the system and is connected possibly through a resistor to ground at each end. The combination of the longitudinal choke at least adjacent to the transmitting end and the longitudinally extending metallic wire is superbly effective in suppressing electromagnetic interference notwithstanding the absence of shielding.

Communications transmission system including facilities for suppressing

In a system (20) for transmitting voice and data signals, insulated metallic conductor pairs (44--44) which transmit data signals and insulated metallic conductor pairs (46--46) which are capable of transmitting voice signals are enclosed in a common sheath system of a single cable (40). User pickup of station apparatus (34) during the generation of a ringing voltage on a voice conductor pair causes that pair to become disturbing and to impart impulse noise to a closely coupled data pair. The data pair is designated a disturbed pair and the signals transmitted thereby may be affected adversely. This problem is overcome by providing a circuit (80) comprising in parallel a resistance and an inductance and being in series with the station apparatus. Such an arrangement reduces substantially that frequency content of any disturbing signal which appears on the disturbing pair and which is in the range of the data signal spectrum. This reduces the magnitude of crosstalk between the voice and data pairs and results in substantially error-free transmitted data.

Methods of and apparatus for providing substantially error-free

A cable (20) which is particularly suited to the transmission of substantially error-free data at relatively high rates over relatively long distances includes at least two pairs of individually insulated conductors (42--42). The pairs of individually insulated conductors are enclosed in a tubular member (51) comprising a plastic material. A metallic shield (54) may or may not enclose the tubular member, and in a preferred embodiment, a plastic jacket (58) is provided. The twist length of each pair of insulated conductors does not exceed a value equal to the product of about forty and the outer diameter of the plastic insulation. Further, the twist lengths among the conductor pairs are varied in accordance with a twist frequency scheme modulated by non-uniform increments of twist frequency.

A cable (20) which is particularly suited to the transmission of substantially error-free data at relatively high rates over relatively long distances includes at least two pairs of individually insulated conductors (42--43). Each pair of individually insulated conductors is enclosed individually in its own tubular member (51) comprising a plastic material. A metallic shield (60) encloses the tubular members, and in a preferred embodiment, a plastic jacket (80) encloses the shield. In the preferred embodiment, two pairs of voice communications conductors are disposed at opposed locations between the shield and the jacket. The thickness of the tubular member is such that each insulated conductor of each twisted pair is caused to be spaced from the shield a distance which is not less than one half the diameter of the metallic wire portion of each pair enclosed by the tubular member.

Local area network cable

A parallel data transmission system (20) comprises a cable (40) which is capable of balanced mode transmission but which is driven in an unbalanced mode. The cable includes a plurality of twisted pairs of individually insulated conductors (42--42) enclosed by a metallic shield (54). The twist lengths are relatively short to cause the pairs to be decoupled sufficiently from one another to allow substantially error-free, parallel transmission over relatively long distances. Interposed between the core and the shield is a spacing member (52) which has a relatively low dielectric constant. Receiving facilities are provided for detecting whether the level of transmitted signals is above or below predetermined threshold values and for converting the received signals into one of two or more logic levels. Advantageously, this system increases substantially the distances over which substantially error-free transmission in an unbalanced mode can be accomplished.

Growing community of inventors

Dunwoody, GA, United States of America

Harold Wayne Friesen