Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.