摘要:
In an ATM switching system, bi-directionally coupling devices establish connections between corresponding interface units and an ATM switching module. The switching module includes a self-routing switch, an input distribution network for establishing connections between the bi-directionally coupling devices and the input ports of the self-routing switch, and an output distribution network for establishing connections between the output ports of the self-routing switch and bi-directionally coupling devices. The bi-directionally coupling devices and the input and output distribution networks are controlled in accordance with data supplied from the interface units indicating the directions of signals passing through the interface units and the operating speed of the interface units.
摘要:
An optical wavelength selection control system in an optical network includes an optical center node device and a plurality of terminal devices each comprised of a work station and an interface. The optical center node device includes a control circuit, a plurality of optical switches and a plurality of tunable wavelength filters. When there occurs a collision among the plurality of terminal devices wherein a plurality of terminal devices send simultaneously optical packets to the same terminal device, the control circuit operates to control the optical switches and the tunable wavelength filters such that they select only one optical packet, based on information relating to, for example, a data length to be transferred. The control circuit sends out an acknowledgment (ACK) signal to the terminal device whose optical packet has been selected. To each of the terminal devices whose optical packets have not been selected, the control circuit sends out, in addition to a not-acknowledgement (NACK) signal, a signal indicating a resending time schedule. There are no possibilities any more for at least these optical packets to be involved in the collision problems, and this ensures an enhancement of the throughput of the network system.
摘要:
An apparatus for discriminating an optical signal from others comprises a circuit for adding one of discriminating signals to a corresponding optical signal. The discriminating signal is of a frequency lower than a band of the optical signal. Therefore, the discriminating signal is easily detected by being passed through, for instance, a low-pass filter.An apparatus for tuning an optical wavelength filter used in apparatus for discriminating an optical signal from others comprises a circuit for frequency-modulating an optical signal by a first discriminating signal and for amplitude-modulating the optical signal by a second discriminating signal having a phase information of the first discriminating signal. An optical wavelength filter is controlled to be tuned to a predetermined wavelength in accordance with a difference between a phase of the first discriminating signal and a phase of a first discriminating signal produced by the second discriminating signal, respectively, included in an output signal of the optical wavelength filter.Alternatively, the apparatus for tuning an optical wavelength filter used in an apparatus for discriminating an optical signal from others comprises a circuit for modulating an optical signal by a discriminating signal of a predetermined period. The optical wavelength filter is controlled to be tuned to a predetermined wavelength in accordance with a difference between a phase of the discriminating signal and a phase of a discriminating signal included in an output signal of the optical wavelength filter.
摘要:
In a commutator of a rotary electric machine, each of commutator segments has a low-resistive layer made of a low-resistive material and a high-resistive layer made of a high-resistive material having a specific resistance higher than that of the low-resistive material. The low-resistive material contains a carbonic material and a binder. The high-resistive material contains a carbonic material, a binder and an inorganic substance such as boron nitride. A mixing ratio of the inorganic material to the high-resistive material is more than 20 wt %. Alternatively, a brush, which makes contact with the commutator segments, can have the high-resistive layer and the low-resistive layer.
摘要:
Optical signals having arbitrary wavelengths of wavelength-multiplex optical signals are separated in an optical add-dorop multiplexer 110. Switching of the signals after separation and an external signal that is input outside is conducted in an ATM switch 170. The signals after the switching by the ATM switch 170 is combined with wavelength-multiplex signals in the optical add-dorop multiplexer 110.
摘要:
In an optical ATM switching system, an optical ATM cell is produced in response to an incoming ATM cell so that it contains an optical routing bit in a timeslot corresponding to the destination of the cell. A first switching stage is provided for routing the cell from one of its inlets to one of its outlets in accordance with the routing bit contained in the cell and generating a routing signal indicative of the position of the outlet to which the cell is routed. A second switching stage is connected to the outlets of the first switching stage for routing the cell to one of optical buffers in response to the routing signal from the first switching stage. Optical combiners are provided, each corresponding to a group of the optical buffers for combining outputs of the corresponding group of optical combiners.
摘要:
An optical switching system for optical wavelength-division and time-division multiplexed signals includes a plurality of tunable wavelength filters each of which selects a signal having a desired wavelength from an optical wavelength-division and time-division multiplexed signal, a plurality of optical memory elements each of which is supplied with an output signal of each of the plurality of tunable wavelength filters. Each optical memory element memorizes a light intensity of the output signal by being applied with a first control voltage and supplies an output port with the output signal which is converted to have a predetermined wavelength in a desired time slot. The tunable wavelength filters and optical memory elements may by replaced by wavelength filters and tunable wavelength optical memories.
摘要:
An optical switching network comprises a plurality of optical splitters coupled respectively to inlet highways for receiving wavelength-time division multiplex (WTDM) signals through the respective inlet highways, each of the multiplex signals comprising a series of WTDM signals each being identified by a unique wavelength and a unique time slot. A like plurality of sets of tunable wavelength filters are provided. The filters of each set are coupled to respective outputs of the splitters for selecting one of the WTDM signals. A like plurality of time-space switches are associated respectively with the sets of the tunable wavelength filters. Each of the time-space switches has input ports and output ports, the input ports of the time-space switch being coupled respectively to outputs of the filters of the associated set for interchanging the time slot of the selected WTDM signal with another time slot and establishing a path for the selected wavelength between the input ports and the output ports. A like plurality of sets of wavelength tunable lasers are provided, the wavelength tunable lasers of each set being coupled to the output ports of an associated one of the time-space switches for generating an optical output according to the WTDM signal from the established path, the optical output having a wavelength different from the wavelength of the selected WTDM signal. A like plurality of optical combiners are provided for coupling the output of the wavelength tunable lasers of different sets to a respective one of outlet highways.
摘要:
A segment of a carbon commutator includes a carbon layer on a surface side and a metallic carbon layer on a bottom side, and the carbon layer and the metallic carbon layer both contain a thermoplastic resin binder.
摘要:
A segment of a carbon commutator includes a carbon layer on a surface side and a metallic carbon layer on a bottom side, and the carbon layer and the metallic carbon layer both contain a thermoplastic resin binder.