Abstract: Method and apparatus are presented for the generation and detection of maintenance signals in an optical data network. The maintenance signals are such that they can be read both by high bit-rate and low bit-rate receivers. Detection of the maintenance signals occurs in two stages. In a low bit-rate first stage each nodal input port is sampled in a round robin fashion to detect the presence of a maintenance signal. In a high bit-rate second stage the maintenance signal is verified and read by a high speed receiver, along with other high bit-rate information transmitted with it. One second stage high speed receiver is shared among M input channels for cost and circuit efficiency.

Abstract: A robust nonblocking switch architecture is presented, in the first and final stages made of switch modules which have extra, unallocated, input and output ports beyond those necessary to render the switch architecture nonblocking. Each middle stage has an extra switch module, affording it spare unallocated ports as well. A method of isolating a fault is also presented, given the robust switching architecture. Operating on each stage one at a time, the switching architecture is reconnected so as to bypass either the input, the output, or both the input and the output ports of the switch module in such stage impacted in the faulted signal path. Such method allows the isolation of the faulty switch module, and can be done automatically, with either external apparatus, or integrated fault isolation equipment.

Abstract: A combination money clip and card holder adapted to retain paper currency and to removably store flexible cards such as credit cards. The product is constructed of three extrudeable plastic material parts that are easily assembled to produce a durable, smooth exterior surface. The product is light weight and of a size to be conveniently carried in a pocket or purse.

Abstract: A robust nonblocking switch architecture is presented, in the first and final stages made of switch modules which have extra, unallocated, input and output ports beyond those necessary to render the switch architecture nonblocking. Each middle stage has an extra switch module, affording it spare unallocated ports as well. A method of isolating a fault is also presented, given the robust switching architecture. Operating on each stage one at a time, the switching architecture is reconnected so as to bypass either the input, the output, or both the input and the output ports of the switch module in such stage impacted in the faulted signal path. Such method allows the isolation of the faulty switch module, and can be done automatically, with either external apparatus, or integrated fault isolation equipment.

Abstract: Method and apparatus are presented which define generic cross-connect primitives that enable the implementation of 1+1 protection in a mesh configured optical network. Such primitives are capable of supporting both 1+1 network protection as well as 1+1 client/access protection, or both. Further, the invention supports multicast applications at no additional architectural cost.

Abstract: Method and apparatus are presented for the generation and detection of maintenance signals in an optical data network. The maintenance signals are such that they can be read both by high bit-rate and low bit-rate receivers. Detection of the maintenance signals occurs in two stages. In a low bit-rate first stage each nodal input port is sampled in a round robin fashion to detect the presence of a maintenance signal. In a high bit-rate second stage the maintenance signal is verified and read by a high speed receiver, along with other high bit-rate information transmitted with it. One second stage high speed receiver is shared among M input channels for cost and circuit efficiency.

Abstract: A method and apparatus for providing signaling for disjoint shared protection in a data network are presented. In a preferred embodiment the method utilizes one or more of the same set of finite optical signals used for maintenance purposes in the network, which can be recognized without regard to bit rate or format. Nodes that share a failed link send an alarm signal that reaches the initiator and terminator node, whereupon the initiator node sends a signal that activates a protection lightpath. When the signal sent by the initiator node arrives at the terminator node, it sends back an acknowledge signal. If the acknowledge signal is not received within a certain time protection is voided. Contention for shared protection resources is resolved via a priority scheme.