摘要:
A cell based network (100) for transmitting ATM user cells (118), including ABR data cells (118.sub.D) and forward control, or RM, cells (118.sub.FRM) at predetermined cell rates from at least one user source (102) in a virtual connection (VC, 110) through at least one ATM switch (120) and at least one transmission link (130) in the network to at least one user destination (104), employs a method and apparatus for controlling a user source (102) transmission cell rate in the presence of congestion in the VC (110). The calculation of a Fair Share cell transmission rate is written into a backward control, or RM, cell (118.sub.BRM) optionally takes place only in the presence of congestion at an ATM Switch (120). The calculation of the Fair.sub.-- Share value is simplified and calculation time is shortened by changing the number of active ABR VCs (N.sub.ABR) to a factor of two (E.sub.NABR) and dividing the maximum cell transmission rate by E.sub.NABR.
摘要:
A method for distributed voice conferencing in a fast packet network packetizes the speech into speech fast packets. The speech fast packets are transmitted to a central conference handier. The conference handier then provides the speech fast packets to the appropriate users. Another method of voice conferencing in a fast packet network is to send the speech fast packets directly to every other user in the voice conference.
摘要:
A digital decimation filter for receiving a stream of input digital samples at an input sample rate, and for delivering a corresponding stream of output digital samples at a different output sample rate stores a plurality of input digital samples, derives samples of the output stream from the stored input digital samples, and makes an output sample available for inclusion in the output stream at all times, whereby the output sample may be delivered with a selectable phase. In other aspects, an analog-to-digital converter has a sigma-delta modulator for generating a high rate stream of digital samples of an analog signal at a rate substantially higher than the Nyquist rate, and a digital decimation filter for receiving the high rate stream and delivering a corresponding stream of filtered output digital samples at a lower rate, the decimation ratio being selectable; and a multiple-mode modem for use with a channel on which a carrier may be modulated in accordance with at least two different possible modulation schemes (the channel being of the kind that induces echo signals, the modulation schemes comprising techniques for avoiding the effects of the echo signals), receives the modulated carrier from the channel and converts it to a corresponding stream of digital samples, using receive circuitry that has an analog-to-digital converter feeding a programmable digital filter for selectively providing filtering functions applicable respectively to the two different modulation schemes, whereby different receive filters applicable to different modulation schemes need not be provided ahead of the analog-to-digital converter.
摘要:
A signal processing apparatus comprises a main unit having a frame, and a plurality of modules for processing analog signals replaceably inserted into said frame. Each of the modules has an analog-to-digital converter for the analog signals and an identification signal generator which generates a module identification signal different for each module. The main unit comprises a signal processing system and a conversion pulse clock generator. The latter one clocks each analog-to-digital converter in each module to convert analog signals to digital data. The digital data are transmitted together with the module identification signal to the signal processing system.
摘要:
The apparatus contains a microprocessor circuit, which comprises a preprocessor which is not DMA-capable in itself and a DMA-capable central processor. Both processors can be made to communicate with each other by means of a main memory. This is performed by temporarily cutting off the communication path between said DMA-capable central processor and said main memory, specifically by an artificial DMA request via the address line of said preprocessor, and by establishing instead a communication path between said preprocessor and said main memory. The communication of said preprocessor with said main memory is started after said central processor has sent a return message signal to said preprocessor, whereby it confirms that its own communication with said main memory is completed.
摘要:
A communication system transmits packetized voice data from a voice source to a voice destination. At the voice destination, the packets are accumulated in a buffer, sequentially played out and the time the packet waits in the buffer is monitored. The time future voice packets are played out is accordingly adjusted.
摘要:
A cell based network (100) for transmitting cells (118), including data cells and control cells at predetermined cell rates from at least one user source (102) in a virtual connection, VC (110), through at least one switch (120) and at least one transmission link (130) in the network to at least one user destination (104) employs a method for controlling a user source (102) transmission cell rate in the presence of congestion in the VC (110). The calculation of a Fair.sub.-- Share value of the Explicit Rate (ER) that is written into a backward control cell takes place only in the presence of congestion at either an Ingress Switch Port (141) or on an Egress Physical Port (162) connected to the Switch (120).
摘要:
A modular shoe rack consisting of a pair of rods extending between, and supported by, a pair of side frames. The side frames are generally rectangular in configuration and are identical in construction. Each side frame includes a groove arrangement in the bottom and a mating tongue arrangement at the top such that plural side frames may be stacked one upon the other in a stable manner. Each side frame also includes a receiving hole at each side thereof sized to receive the rods. As such, the rods may be inserted within the receiving holes of two side frames to define a shoe rack of single unit length. Thereafter, an additional pair of rods may be inserted into the receiving holes on an opposite side of one of the previous side frames, and a third side frame connected to the free ends of these additional rods. With this arrangement, a shoe rack having two units length is provided by using only three side frames, thus saving the material employed to form a fourth side frame, which would be required using prior art devices. The elongated structure is also formed as a single unit which is more structurally sound and aesthetically pleasing than a pair of prior art devices.
摘要:
A composite signal is transmitted via a transmission line to an x, y, z display device. The composite signal contains in each of a plurality of predetermined time intervals an identifiable signal. The first signal of said composite signal is a synchronizing start signal. The other signals contain varying information. In the display device there are generated an x-, a y- and a z-coordinate signal. These coordinate signals are generated such that in said predetermined time intervals with reference to the synchronizing start signal and in predetermined varying combinations two of these three coordinate signals are developed and determined by the display device, whereas the remaining third coordinate signal is developed by the display device, but is determined from one of the other signals of the composite signal received via the transmission line.
摘要:
The system contains a number of monitoring devices, such as bedside units for monitoring parameters of patients, and a central station in star connection. Each monitoring device contains a signal generator and a display device for the display of monitored parameters. The central station contains a central display device and a central multiplexer. The multiplexer has a separate signal input for receiving the output signals of each signal generator, and a first and second number of multiplexer outputs. The output signals of the signal generators each contain undelayed and delayed signal data. The first multiplexer outputs can be connected to the central display device. Thereby, the undelayed signal data contained in the output signals of selected monitoring devices can be displayed in the central station. These signal data represent all parameters monitored by the selected device. The second multiplexer outputs are connected to an intermediate memory for transfer of the delayed signal data of all signal generators thereto. The delayed data stored in the memory can be transmitted in any signal combination for display as a mixed image on the central display device. Thereby, parameters stemming from different monitoring devices can be displayed simultaneously on the central display device.