The University of Tokyo

Hitoshi Aida

Terumasa Aoki

Udomkiat Bunworasate

Takayuki Ohnishi

Thai Thach Bao

Hiroaki Morino

Soichiro Hidaka

An input distribution packet switch network includes a plurality of 2&times;2 switch elements and packet input modules for the switch network. The switch elements are arranged in multistage and connected in accordance with Shuffle type topology to constitute a N&times;N switch network (N&equals;2 , k: integer number of 2 and over). The links of the leftmost and rightmost switch elements are connected to one another so that the N&times;N switch network can have a ring architecture. The packet input modules are distributed laterally in the switch network.

Input distribution type packet switch network and an input distribution type packet switch

There is provided a variable rate digital switching system comprising steps of: arranging a plurality of incoming TDM buses and a plurality of sending TDM buses in lattice form; providing cross-point buffers at cross-points of the incoming buses and the sending buses; connecting the cross-point buffers belonging to respective sending TDM buses to respective scheduler; connecting respective contents analyzer to respective scheduler; checking frame headers of input TDM frames by respective cross-point buffers, thereby buffering only data of time slot of destined and belonged sending bus and transmitting contents of the frame header to the contents analyzer; checking the frame header by the contents analyzer, thereby deciding the contents of data stored in the respective cross-point buffers on the own-belonged sending TDM bus, and informing them to the scheduler; performing the scheduling by the scheduler as for how time slots in the sending TDM frame is allocated in respective cross-point buffers according to the contents of the frame header and an amount of data stored in respective cross-point buffer; and inputting in turn the buffered data in the own-allocated time slots of the sending TDM frame according to the scheduling by respective cross-point buffer, and outputting them from the sending TDM bus.

Variable rate digital switching system

There is provided a variable rate TDM switching system comprising steps of: arranging a plurality of incoming lines and a plurality of sending lines in lattice form; providing time-division gates at cross-points of the incoming lines and the sending lines; connecting time-division temporal switches having a function of transposing the order of time slots in input TDM frames to forward stage of respective incoming lines of the time-division space switches for performing the switching between the incoming lines and the sending lines with time slot unit while holding the multiplexing, by switching these time-division gates; connecting a scheduler for concentratedly controlling the time-division gates and the time-division temporal switches to these gates and time switches; transmitting the headers of the TDM frames to the scheduler in case of inputting the header of TDM frame, and deciding the temporal switching schedule by the scheduler as to the transposition of the order of time slots in the time-division temporal switch, so as to disperse time slots of the same destination temporally; deciding the spatial switching schedule as to the on off of the time-division gates in the time-division temporal switches so as to appear only one time slot of the destination on the same sending line at the same timing; inputting the TDM frames into the time-division temporal switches with temporal switching by the time-division temporal switch in accordance with the temporal switching schedule; and switching respective time slots into the sending lines of respective destinations.

Variable rate TDM switching system

In a method for coding a moving picture image, in which the moving picture image is coded into a digital moving picture stream when the moving picture image is transmitted via a network, the moving picture image is coded in such a manner that a data unit including a synchronous signal corresponds or conforms to a data transmission unit on the network, or, the moving picture image is coded in such a manner that a synchronous signal is included in a position near a head of respective data transmission units on the network. Therefore, in the digital moving picture stream generated according to the invention, the header of the synchronous layer is included in every maximum length of the IP packet in the variable length packet switching method and in every size of the time slots in the variable bit rate TDM.

Method and apparatus for coding moving picture image

In a system for switching high-capacity and variable length packets from m input ports to n output ports, k Banyan networks are connected into a ring by means of at least n parallel lines, said input ports are connected to inputs of said Banyan networks in a dispersed manner by means of m input modules, misroute tag check parts are connected to outputs of said Banyan networks as well as to inputs of n output modules whose outputs are connected to said output ports. Each of plural unit switches constituting a Banyan network is constructed such that when an input packet cannot be sent to a desired output, the relevant packet is outputted to a non-occupied output of the relevant Banyan network. When the misroute tag check part finds that the misroute tag is set, the relevant packet is sent to a next stage Banyan network, but when the misroute check tag is not set, the relevant packet is outputted to an output module connected to a desired output. The input module stores a packet from the input port and a packet from a misroute tag check part and sends one of these packets selectively to a succeeding Banyan network.

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Kawasaki, Japan

Hitoshi Aida