Abstract: A local area network uses standard ANSI FDDI LAN concentrator stations and a first set of mutually reverse-direction data buses or loops, in conjunction with an additional set of mutually reverse-direction data paths. The standard FDDI protocols when applied in the context of the particular connections of the concentrator station operate in the event of a break in the data path terminating at an input or output port, to reconfigure the station to interconnect the buses in a manner which routes data around even multiple breaks in the buses, to thereby maintain communication integrity.

Abstract: A system for converting sequentially received data words, in the form of successively received groups of data words, into an interleaved output data word sequence, with each group of received data words consisting of T successive series of R data words. The system comprises N memories, each having W words locations, where W.multidot.N.gtoreq.T.multidot.R and where the N memories form a single memory matrix which is employed to process every group of received data words. Writing logic is provided for writing successively received data words of a first group of data words into the N memories in a predetermined sequence. Reading logic is provided for reading from the memories every R.sup.th data word of the first group of data words written into the to leave an available word location in each instance where a data word was read therefrom.

Abstract: Pulse returns received as discrete range samples are averaged, summed with ach new range sample and stored individually in cells of a shiftable register. Undesirable range smearing due to relative movement of the target is avoided by aligning each new range sample with the closest of the previously-stored sums. A control signal is generated to represent the estimated relative movement of the target for a particular interpulse period. Alignment is achieved by then shifting the register responsively to the control signal so that the closest stored range sample is summed or integrated with the new, incoming range sample.

Abstract: A digital processor for discretely sampled information signals, of the type such as radar return signals and communication signals. Means are disclosed for determining the positions and values of extrema and the positions of the leading and trailing edges of extended pulses occurring between sampling instants. Means are also disclosed for determining the duration of such extended pulses.