Abstract: A circulating switch comprises switch modules of moderate capacities interconnected by a passive rotator. Data is sent from a one switch module to another switch module either directly, traversing the rotator once, or indirectly through at least one intermediate switch module where the rotator is traversed twice. A higher capacity extended circulating switch is constructed from higher-capacity switch modules, implemented as common memory switches and having multiple ports, interconnected through a multiplicity of rotators preferably arranged in complementary groups of rotators of opposite rotation directions. A polyphase circulating switch having a low switching delay is derived from a multi-rotator circulating switch by providing programmable rotators having adjustable relative rotator-cycle phases. A low delay high-capacity switch may also be constructed from prior-art medium-capacity rotator space switches with mutually phase-shifted rotation cycles.

Abstract: A network of global coverage, scalable to hundreds of petabits per second, comprises bufferless switch units each of dimension n×n, n>1, arranged in a matrix of ? columns and ? rows, ?>1, interconnecting a maximum of ?×n edge nodes. Each edge node has ? upstream channels to ? switch units in ? different columns and ? downstream channels from ? switch units in ? different rows. All upstream channels to a switch unit are time-locked to the switch unit, thus enabling coherent switching at the switch unit. The switch units are preferably fast-switching optical nodes. Alternatively, the switch units may comprise fast-switching optical nodes each of dimension m×m, arranged in a first ?×? matrix, and latent space switches each of dimension n×n, n>1, arranged in a second ?×? matrix, ?>1, where ?×m=?×n. An edge node time locks to each optical node and each latent space switch to which it connects.

Abstract: A modular optical switch includes a set of optical switch modules connected in a mesh, a master controller for the whole optical node and a switch-module controller for each of the optical switch modules. The optical switch modules receive optical signals from, and transmit optical signals to, edge nodes based on connection requests received from the edge nodes. The master controller acts to select a path, using a simple or compound time-slot matching process, through the mesh of switch modules for each optical signal related to a connection request. Advantageously, the optical switch modules are fast switching, enabling the use of time-sharing schemes such as TDM, and the modular optical core node is made practical by efficient path selection at the master controller. A hybrid modular switch may include both optical and electronic switch modules, a master controller, and a switch-module controller for each of the switch modules.

Abstract: A time-shared network comprising edge nodes and optical core nodes may be dynamically divided into several embedded networks, each of which covering selected edge nodes. At least one of the edge nodes may host an embedded-network controller operable to form multiple-source flow-rate allocation requests each of the requests specifying flow-rate allocations to a plurality of paths from several source nodes to several sink nodes. A core node may also host an embedded-network controller or several embedded-network controllers. The time-shared network may use both time-division multiplexing and burst switching.

Abstract: A switching node comprises edge nodes interconnected by independent switch units. The switch units are arranged in at least one switch plane and the switch units of each switch plane are arranged in a matrix having several rows and several columns. Each edge node has a channel to a switch unit in each column in each switch plane and a channel from each switch unit in a selected column in each switch plane. Simple paths, each traversing only one switch unit in a switch plane, may be established for any directed edge-node pair. Additionally, several non-intersecting compound paths, each comprising at most two simple paths, may be established for any edge-node pair. A significant proportion of traffic may be routed through simple paths. The switching node employs distributed control scheme and scales gracefully from a capacity of a fraction of a terabit per second to thousands of terabits per second.

Abstract: A circulating switch comprises switch modules of moderate capacities interconnected by a passive rotator. Data is sent from a one switch module to another switch module either directly, traversing the rotator once, or indirectly through at least one intermediate switch module where the rotator is traversed twice. A higher capacity extended circulating switch is constructed from higher-capacity switch modules, implemented as common memory switches and having multiple ports, interconnected through a multiplicity of rotators preferably arranged in complementary groups of rotators of opposite rotation directions. A polyphase circulating switch having a low switching delay is derived from a multi-rotator circulating switch by providing programmable rotators having adjustable relative rotator-cycle phases. A low delay high-capacity switch may also be constructed from prior-art medium-capacity rotator space switches with mutually phase-shifted rotation cycles.

Abstract: A modular optical switch includes a set of optical switch modules connected in a mesh, a master controller for the whole optical node and a switch-module controller for each of the optical switch modules. The optical switch modules receive optical signals from, and transmit optical signals to, edge nodes based on connection requests received from the edge nodes. The master controller acts to select a path, using a simple or compound time-slot matching process, through the mesh of switch modules for each optical signal related to a connection request. Advantageously, the optical switch modules are fast switching, enabling the use of time-sharing schemes such as TDM, and the modular optical core node is made practical by efficient path selection at the master controller. A hybrid modular switch may include both optical and electronic switch modules, a master controller, and a switch-module controller for each of the switch modules.

Abstract: A packet switch that scales gracefully from a capacity of a fraction of a terabit per second to thousands of terabits per second is disclosed. The packet switch comprises edge nodes interconnected by independent switch units. The switch units are arranged in a matrix having multiple rows and multiple columns and may comprise instantaneous or latent space switches. Each edge node has a channel to a switch unit in each column and a channel from each switch unit in a selected column. A simple path traversing only one of the switch units may be established from each edge node to each other edge node. Where needed, a compound path comprising at most two simple paths may be established for any edge-node pair. In a preferred configuration, the switch units connect at input to orthogonal sets of edge nodes. A distributed control system expedites connection-request processing.

Abstract: A switching node comprises edge nodes interconnected by independent switch units. The switch units are arranged in at least one switch plane and the switch units of each switch plane are arranged in a matrix having several rows and several columns. Each edge node has a channel to a switch unit in each column in each switch plane and a channel from each switch unit in a selected column in each switch plane. Simple paths, each traversing only one switch unit in a switch plane, may be established for any directed edge-node pair. Additionally, several non-intersecting compound paths, each comprising at most two simple paths, may be established for any edge-node pair. A significant proportion of traffic may be routed through simple paths. The switching node employs distributed control scheme and scales gracefully from a capacity of a fraction of a terabit per second to thousands of terabits per second.

Abstract: The invention discloses methods and apparatus for regulating the transfer of data bursts across a data network comprising electronic edge nodes interconnected by fast-switching optical core nodes. To facilitate switching at an electronic edge node, data bursts are organized into data segments of equal size. A data segment may include null data in addition to information bits. The null data are removed at the output of an edge node and the information data is collated into bursts, each carrying only information bits in addition to a header necessary for downstream processing. To ensure loss-free transfer of bursts from the edge to the core, burst transfer permits are generated at controllers of the optical core and sent to respective edge nodes based on flow-rate-allocation requests. Null-padding is not visible outside the edge nodes and only the information content is subject to transfer rate regulation to ensure high efficiency and high service quality.

Abstract: A scalable router-switch comprises a plurality of switch units each having consolidation means for data disassembling and reassembling. The switch units are arranged into switch modules and the switch units of each switch module are interconnected through a dual rotator to form a contention-free temporal mesh.

Abstract: A packet switch that scales gracefully from a capacity of a fraction of a terabit per second to thousands of terabits per second has edge nodes interconnected by independent switch units. The switch units are arranged in a matrix having multiple rows and multiple columns. A switch unit is implemented as an instantaneous space switch or as a latent space switch. Each edge node has a channel to a switch unit in each column and a channel from each switch unit in a selected column. A simple path traversing only one of the switch units may be established from each edge node to each other edge node. Where needed, a compound path concatenating at most two simple paths may be established for any edge-node pair. In a preferred configuration, the switch units connect at input to orthogonal sets of edge nodes. A distributed control system expedites connection-request processing.

Abstract: In a first mode of burst communication in a telecommunication network comprising electronic edge nodes interconnected by bufferless core nodes, data bursts are formulated at the edge nodes, respective burst descriptors are communicated to a controller of a core node, and burst-transfer schedules are sent from the core node to respective edge nodes. In a second mode, each burst-stream is allocated a flow rate and a core node determines burst sizes and schedules burst-transfer permits. In a bimodal burst-switching network comprising edge nodes interconnected by core nodes, an edge node selects to send to a core node burst-transfer requests according to the first mode, or flow-rate-allocation requests according to the second mode, depending on proximity, storage capacity at the edge node, and delay-tolerance specifications.

Abstract: An operating network comprising a large number of nodes interconnected by links determines potential link-capacity enhancement with the help of a companion phantom network. In one embodiment, the operating network and the phantom network are topologically coincident and each node participates in seeking an actual-connection setup through the operating network and a phantom connection through the phantom network for each connection request. Each node associates with each of its output links an operating capacity, a phantom capacity, an operating vacancy, and a phantom vacancy. The phantom vacancy data is used for link provisioning. In another embodiment, nodes may be added to or deleted from the operating network and the phantom network may not topologically coincide with the operating network.

Abstract: A polyphase rotating-access switch consists of a set of latent space switches connecting a set of ingress switch modules to a set of egress switch modules. Each latent space switch has a primary rotator connecting each ingress switch module to each transit memory device of a bank of transit memory devices during a rotation period and a secondary rotator connecting each transit memory device to each egress switch module during the rotation period. Each latent space switch provides paths from each ingress switch module to all egress switch modules characterized by switching delays having values between zero and a rotation period. For each pair of ingress and egress switch modules, the set of latent space switches provides paths of different delays having values between zero and a rotation period. Thus, a connection from an ingress switch module to egress switch module may select an available path of least switching delay.

Abstract: A scalable router-switch comprises a plurality of switch units each having consolidation means for data disassembling and reassembling. The switch units are arranged into switch modules and the switch units of each switch module are interconnected through a dual rotator to form a contention-free temporal mesh.

Abstract: An N-dimensional lattice network that scales to capacities of the order of a Yotta bits per second (1024 bits per second) includes a plurality of sub-nets of edge module switches interconnected by an agile switching core. The agile core may be distributed. In the N-dimensional lattice network, each edge module 408 is connected to N core stages, each core stage having an associated dimensional indicator. The input/output ports of each edge module are divided into (N+1) port groups. One of the port groups serves local sources/sinks while the remaining port groups are respectively connected to core stages in each of the N dimensions. This structure permits virtually unlimited capacity growth and significantly simplifies the routing and forwarding functions. The edge modules are addressed using logical coordinates, one coordinate being assigned for each of the N dimensions. This simplifies routing and permits each edge module to compute its own routing tables.

Abstract: A multi-grained network includes edge modules that switch high-variance multi-rate data traffic, and independent core modules that switch paths having different granularities. The core may include core modules that switch fixed-size data blocks, core modules that switch channels or bands of channels, core modules that switch entire links, and core modules that cross-connect channels or links. To simplify the control functions, the core modules operate independently from each other. Direct link, band or channel connections may be established for selected ingress-egress edge module pairs, if traffic volumes warrant. The use of graded granularity in the core simplifies the control function and reduces network cost.

Abstract: A transit memory assembly of a rotator-based switching node is logically partitioned into two sections, one operated as a common-memory switch fabric and the other as a time-shared space-switch fabric. The composition of data received at input ports of the switching node determines adaptive capacity division between the two sections. Based on an indication of traffic type, a controller of at least one input port selects one of the two sections. The space-switch section enables scalability to a high transport capacity while the common-memory section enables scalability to a high processing throughput. The switching node includes rotators and a bank of transit-memory devices that facilitate the incorporation of any mixture of periodic, aperiodic, contention-free exclusive-access, concurrent-access, and multicast switching.

Abstract: Switch elements, each receiving data from external sources and transmitting data to external sinks, are interconnected through a single rotator to form a switching node. The single rotator has a number of inlets equal to the number of switch elements and a number of outlets equal to the number of switch elements. A first set of channels connects the switch elements to inlets of the rotator and a second set of channels connects the outlets of the rotator to the switch elements. The connectivity pattern of the second set of channels is a transposition of the connectivity pattern of the first set of channels in order to preserve sequential data order of switched data. A controller communicatively coupled to the switch elements exchanges timing data with external nodes of a time-coherent network and schedules data transfer among the switch elements.