Abstract: A method for connecting together two twisted pair lines in a LAN so as to avoid common mode current. The invention recognizes that the impedance to ground is different for each wire in the twisted pair line. Moreover, this impedance is different from spool-to-spool for lines having the same purported impedance. A balun is placed at the connection between the lines.

Abstract: A LAN which uses flat telephone cable having at least four conductors. The inner conductors are joined together and the outer conductors are joined together at each node thereby making reversals of the inner and outer conductors, which may occur at connectors, impossible. Each node uses two baluns to provide an unbalanced zone between the baluns for connecting to the DTE.

Abstract: Enhanced collision detection in an Ethernet network, particularly useful for passive nodes using receive mode collision detection. When a transmitting node detects a collision, for example, using transmit mode collision detection, it activates a current sink at the node further reducing the DC potential on the line. This reduced DC potential assists in overcoming the low frequency impedance which may exist between the transmitting node and a remotely located passive node.

Abstract: EMI suppression technique that pseudorandomizes the positive or negative going transitions that are used to represent one binary state in a transmitted digital signal such as in MLT-3 data format. By pseudorandomizing the selection of these transitions, substantial spreading of the spectral energy occurs. Descrambling need not occur since each transition is recognized as the encoded binary state. Thus, the data sender can encode the data and suppress EMI without any changes to the receiver's equipment.

Abstract: A LAN which uses flat telephone cable having at least four conductors. The inner conductors are joined together and the outer conductors are joined together at each node thereby making reversals of the inner and outer conductors, which may occur at connectors, impossible. Each node uses two baluns to provide an unbalanced zone between the baluns for connecting to the DTE.

Abstract: An apparatus for monitoring and testing a twisted pair, particularly useful for an Ethernet network. First and second DC currents alternated with one another are applied to both ends of the line, asynchronously. By monitoring the potential on the line, a determination is made as to the condition of the line. For example, shorted, crossed, improperly terminated or open conditions can be detected. A visual indication of the condition of the line is provided and additionally, the visual indication provides an indication of the traffic level in the network.

Abstract: An apparatus for monitoring and testing a twisted pair, particularly useful for an Ethernet network. First and second DC currents alternated with one another are applied to both ends of the line, asynchronously. By monitoring the potential on the line, a determination is made as to the condition of the line. For example, shorted, crossed, improperly terminated or open conditions can be detected. A visual indication of the condition of the line is provided and additionally, the visual indication provides an indication of the traffic level in the network.