Abstract: A cable modern termination system (CMTS) having front and rear sides is disclosed. A rear panel receives a plurality of connector cards. At least one first connector card wherein each first connector card has a row of connectors. At least one second connector cards, wherein each second connector card has a row of connectors, wherein connectors on the first connector cards are staggered from connectors on the second connector cards when the connector cards are inserted into the rear panel.

Abstract: Each packet of the present invention is assigned a priority level. The current data packet flow rate is detected. This data packet flow rate is quantized into at least one data rate level. The current buffer circuit depth is determined as is the priority associated with the current data packet. The probability that the current packet is either dropped or used is determined by using the current data packet service flow rate, the data packet priority, and the current buffer circuit depth.

Abstract: Cable data service levels can be upgraded or downgrade automatically, on a subscriber's request, by using the unique identifier preprogrammed into industry-standard-compliant cable modems. A processor adjunct to the CMTS in a cable data system receives and processes service level change requests. Requests that are granted are sent back to the CMTS for subsequent execution. Faster internet access can be provided on a customer's own initiation.

Abstract: A method and apparatus for encoding and decoding m-bit groups of digital data, where m is at least eight, into serial n bit groups such that each encoded serial n-bit group has sufficient data transitions therein to maintain the synchronization of a phase locked loop clock recovery circuit in a high speed serial link of a communication path. Further, this method and apparatus provides a duty cycle that is within an operational range of the ideal 50 percent, which reduces voltage drift of a.c. coupled high speed serial data links, or reduces thermal drift of optically coupled high speed serial data links.

Abstract: A method and apparatus for communicating serial data at very high actual and effective data rates with a high probability of detecting single and multiple bits errors, even burst errors. The method and apparatus generates at least three parity bits which are sent with each serial data word: an even parity bit taken over all the even bits (including bit 0), an odd parity bit taken over all of the odd parity bits, and a third to parity bit that is an even parity bit taken over every fourth data bit. These parity bits are generated and transmitted along with each data word. At the receiving end, the data portion of each received serial word is stored in a register. The parity bit portion of each received serial word is stored in another register within a parity bit checker. The parity bit checker generates three parity bits taken over the received data word in the same manner that the transmitted parity bits were generated.

Abstract: A new dimension for growth is presented for the generalized growable packet switch architecture. That dimension is time and by rolling routing requests around a distributed out-of-band controller ring, ATM cell traffic can be controlled and spread across two time intervals. The rolling of routing requests and the resulting time spreading of the cell traffic through the distribution network averages out bursts and localized hot spots, thereby reducing blocking and improving cell loss probabilities with only small increases in hardware cost and complexity.

Abstract: A physically realizable one terabit or more ATM packet switch that has a large number of input interfaces connected to a single stage switching fabric which is in turn connected to a number of output modules, generally according to the growable packet switch architecture. This ATM packet switch is different from other growable packet switches in that it has a single stage switch fabric controlled by an out-of-band controller, yet it has significantly reduced complexity with respect to comparably sized electronic crossbar switches or their isomorphs.

Abstract: A telecommunications switch which has a central switch fabric made up of multiple crossbars that can be used to switch either circuit switched or packet switch communications as long as appropriate input and output interfaces and controllers are provided. Thus, a large, high throughput telecommunications switch is provided where the expensive switch fabric core can remain the same and the interfaces and control cards changed as the relative demands for circuit switched communications and packet switched communications, such as ATM, evolve. Besides being flexible, this switch may also be fault tolerant.

Abstract: A growable packet switching arrangement where the distribution network blocking probability is substantially reduced because the network has both switch links and chute links, and the network nodes include both a switching element interconnecting successive stage switch links and a plurality of non-switching, chute connections interconnecting successive stage chute links. A network node can transfer a packet, being received on a switch link, to any selected one of the chute connections of that node for transmission on a chute link. The network nodes are relatively simple and inexpensive because they store only the first few bits needed to route an ATM cell. The blocking probability is further reduced when the number of chutes per node is increased. The number of chutes may be based, for example, on the number of switch link inputs per node.

Abstract: A growable packet switching arrangement where the number, S, of distribution network stages is reduced by bounding S according to log.sub.2 (max(L,N))<S+1<[log.sub.2 (max(L,N))].sup.2 /2. Since the distribution network is made up of stages of opto-electronic nodes and interconnecting free-space optical link stages, there is no need to transmit input signals using different frequencies. Input signals are instead distinguished based on their spatial location. Accordingly, there is no receiver tunability restriction on L, the number of inputs. Further, because signals are regenerated at each network stage and there is only a 3:1 power loss (approximate) at a given stage, high signal/noise ratios and corresponding low bit error rates are achieved.

Abstract: A low blocking packet distribution network which is implemented in optics. The network has both switch links and chute links, and the network nodes include both a switching devices interconnecting successive stage switch links and a plurality of non-switching, chute connections interconnecting successive stage chute links. A network node can transfer a packet, being received on a switch link, to any selected one of the chute connection means of that node for transmission on a chute links. The network nodes are relatively simple and inexpensive because they store only the first few bits needed to route an ATM cell. The blocking probability is further reduced when the number of chutes per node is increased. The number of chutes may be based, for example, on the number of switch link inputs per node.

Abstract: A multi-stage network which achieves the same overall connectivity as known networks but where individual switching nodes have no input selectivity and no output selectivity. Each node is enabled or disabled to control communication therethrough in response to a single control signal. The functionality of a switching network is achieved by controlling which nodes are enabled rather than specifying connections of particular node inputs and outputs to be effected by the nodes. In a photonic network embodiment, each network node is implemented using a single symmetric self electro-optic effect device (S-SEED).

Abstract: A network comprising a plurality of successively interconnected node stages where each node has an associated data connection state and includes a control element, significantly implemented as part of the node itself, for controlling the data connection state of at least one node of the following stage. The network is well suited for optical implementation and is controlled by shifting bits into the network for storage by the control elements rather than relying on spatial light modulators.

Abstract: A network arrangement and control method where, before any transmission of data occurs for a particular communication, a network controller determines an unused path to provide a connection, advantageously all the way through the network from a given inlet to a given outlet. Once the identity of the unused path is known, the controller determines control information for use in activating that path and transmits that control information into the network, significantly via the network inlets. The network responds by activating the determined path and communication is enabled via the activated path, but only for the single connection and no buffering of information is required within the network. The network is particularly well suited for optical implementation and control is effected without the use of spatial light modulators but rather by means of control elements embedded within the network itself.

Abstract: A multi-stage network which achieves the same overall connectivity as known networks but where individual switching nodes have no input selectivity and no output selectivity. Each node is enabled or disabled to control communication therethrough in response to a single control signal. The functionality of a switching network is achieved by controlling which nodes are enabled rather than specifying connections of particular node inputs and outputs to be effected by the nodes. In a photonic network embodiment, each network node is implemented using a single symmetric self electro-optic effect device (S-SEED).

Abstract: A reduced-blocking system where a perfect shuffle equivalent network having a plurality of node stages successively interconnected by link stages, is advantageously combined with expansion before the node stages and/or concentration after the node stages in a manner allowing the design of a system with arbitrarily low or zero blocking probability. An illustrative photonic system implementation uses free-space optical apparatus to effect a low loss, crossover interconnection of two-dimensional arrays of switching nodes comprising, for example, symmetric self electro-optic effect devices (S-SEEDs). Several low loss beam conbination techniques are used to direct multiple arrays of beams to an S-SEED array, and to redirect a reflected output beam array to a subsequent node stage.

Abstract: Optical apparatus for performing wavelength-dependent beam combination. The apparatus relies on a polarization beam splitter in combination with other optical elements to develop combined beams with the same polarization type and that are therefore suitable for polarization-dependent combination with other beam arrays. A dichroic mirror, which is used as the wavelength-dependent element of the apparatus, is oriented such that the incident beams are substantially perpendicular to the mirror. With this orientation, the dichroic mirror achieves near-ideal performance even with beam arrays having a substantial angular field. The apparatus also uses two plates which, although designed for operation as quarter-wave plates at one of the two wavelights being combined, are oriented with their respective fast axes substantially perpendicular to each other such that polarization conversions, effected by the plates on beams having the other of the two wavelengths, substantially cancel each other.

Abstract: A crossover network implemented using two-dimensional arrays of nodes. The network is a perfect shuffle equivalent network because it is topologically equivalent to a crossover network of one-dimensional arrays of nodes. The two-dimensional arrays are arranged in rows and columns and there are a plurality of link stages interconnecting successive arrays. The network is implemented efficiently in free space optics because the network topology requires optical crossovers in some link stages that interconnect only nodes in the same column of successive arrays and optical crossovers in the other link stages that interconnect only nodes in the same row of successive arrays.

Abstract: An optical switch (100) is disclosed for switching spatially-separated complementary optical signals from a row of a two-dimensional input storage array (132) to a selected row of a two-dimensional ouptut storage array (133). The switch includes an input system (101) for converting temporally-separated information represented by a serial bit stream of complementary optical signals into a spatially-separated format for storage in the input array. An output system 105 is also included for converting the switched, spatially-separated information in the output array into a temporally-separated format for serial transmission on plurality of optical output fiber pairs 160(1)-160(N). The input and output systems enable the switch to perform both time- and space-division switching with only a single stage of switching.