Abstract: An ATM (asynchronous transfer mode) cell broadcasting system for use in ATM switches comprises switch matrices for exchanging ATM cells inputted from a plurality of input highways and outputting them to a plurality of output highways. The ATM cell broadcasting system further includes tag information adders, provided at respective input terminals of the switch matrices, for adding tag information according to respective identifiers assigned to the ATM cells. Alternatively, ATM-cell-switching identifier determinant memories may be provided for respective switch elements in the switch matrices, for storing determinant data enabling the switch elements to determine, from the identifiers of the ATM cells, which ones of the ATM cells are to switch and output to their respective output highways.

Abstract: An index value output circuit outputs an index value in response to a VCI added to the first signaling cell outputted from a terminal unit. A switching data output circuit outputs switching data for determining a path for signaling cells, based on the index value. Hence, by revising the index value according to a congestion state of an ATM switch, the above path is dynamically changed. The same index value is inserted in the second and subsequent signaling cells outputted from the terminal unit. Because switching data are based on the same index value, all signaling cells from the same terminal units are fed to the same signaling terminator.

Abstract: Disclosed is a call control method for use with an ATM switch for integrating and switching various types of information which differ in traffic characteristics, such as voice, data and motion images, using an asynchronous transmission mode (ATM). When a call is made to the ATM switch, it is accepted only when it is possible to set a path that can guarantee the service requested by the call. When a call is made to the ATM switch, a load representing how much of the capacity of input links and output links of a self-routing module (SRM) constituting the ATM switch is obtained from the average value and peak value of the bit rate of the call. The load is added to each of current loads of the input and output links and buffers of the self-routing module which form a path in the ATM switch. A determination is made as to whether or not the result of the addition exceeds the maximum load of each of the input and output links and buffers. On determination that the maximum value is not exceeded, the call is accepted.

Abstract: A digital switch module for a time division digital switching system includes an encoding law conversion memory and a control memory. The encoding law conversion memory has previously stored therein conversion data for converting between different types of encoding laws. For example, the A-law and .mu.-law encoding laws set forth in CCITT Recommendation G.711 can be converted by a digital switch module according to the present invention. The encoding law conversion memory includes a read only memory having regions for conversion between A-law and .mu.-law encoded data and for nonconversion of both A-law and .mu.-law encoded data. The control memory designates which of the regions in the encoding law conversion memory is to be used during each time slot, thus dynamically controlling whether data passing through the digital switch module is converted or not. The type of conversion or nonconversion designated by the control memory can be determined by the type of data, e.g.

Abstract: A switchboard control system in which a plurality of switchboards are connected to a time division exchange and controlled by the time division exchange. A speech signal and a control signal (a signal for key information, display information, subscriber number information and other information necessary for the exchange operation by a switchboard operator), which are delivered and received by each switchboard and the time division exchange, are transmitted together by a common transmission line on a time-division-multiplexed basis. On the side of the system toward the switchboards are disposed a position controller, by which the signals are multiplexed and separated and the common transmission line and the switchboards are interconnected. For delivering and receiving the signals, common channel signalling equipment is connected to the time division exchange and remote channel signalling equipment is provided in the position controller.