Abstract: An interconnect apparatus provides for optical and/or electric signal interconnections of a number of input ports from a row of N input ports (11.1-11.N) with a number of output ports from a row of N output ports (13.1-13.N) by way of a signal bus which is capable of being segmented. The apparatus comprises a rack structure (10) having a row of N circuit positions (15.1-15.N) for plugging in circuit modules (16), and a set of such circuit modules provided with signal circuits (22) having various bus functions, such as bus-input, bus-interconnect and bus-output functions. The signal bus comprises one or more disjunct bus segments, with each bus segment being capable of being composed of bus parts (11.j-1) between consecutive module positions (11.j-1, 11.j) and bus parts formed by the signal circuits of circuit modules (16) plugged into the module positions (15.j-1, 15.j) (where j=2, . . . ,N).

Abstract: A passive optical-connection network having a protection configuration consists of at least two subnetworks (1, 2), each comprising an access node (1.1, 2.1), a feed network (1.2, 2.2), and a tree-shapedly branched access network (1.3, 2.3). According to this protection configuration there is coupled an end (1.7, 2.7) of a feed network (1, 2), both over a first set (s1) of switches by way of operational connections (1.22 and 2.22) to access ports (1.14 and 2.14) of the access network of the own subnetwork, and over a second set (s2) of switches by way of protection connections (1.23 and 2.23) to corresponding access ports (2.14 and 1.14) of the access network of another subnetwork. The advantage is that corresponding parts of neighbouring similar subnetworks may be used multiply in failure situations without duplicating costly network parts.

Abstract: In a ring-shaped optical distributive network, provided with a central node and a number (N) of network nodes, distribution signals DS are transmitted in two signal transport directions (F, B) by the central node. For the execution of a drop-and-continue function (DC function), each network node comprises a coupling arrangement (21) provided with an optical 2.times.2 switch (28) and a tapping device (33). The switch and the tapping device are mutually coupled in such a way that the DC function can be carried out in a switchable manner in only one of both signal transport directions simultaneously. The switch (28) is turned over when distribution signals from a signal transport direction in a related network node are no longer received. Such a network is self-healing for a single network failure.

Abstract: An optical coupling device for a node in a self-healing optical network, wherein the number of switching elements is reduced by using a novel type of optical 2.times.2-switch. The switch has two switching states: (i) a bar state (ss1) in which a first and a second main port are optically coupled through to a first and a second secondary port, respectively; and (ii) a half-cross state (ss2) in which the main ports are coupled through to one another and in which the secondary ports are not involved in any through-coupling. An integrated design of the switch is based on two asymmetric Y-junctions coupled to one another via a common side branch in which electrodes are active in order to vary the propagation constant. Accordingly, a compact, integrated version of the optical coupling device with only two switching elements can be achieved.