Abstract: A hybrid exchange which exchanges the STM data to be transmitted periodically to realize an exchange in unit of the ATM data to be transmitted asynchronously includes asynchronous transmission terminal interface as the interface with an STM terminal, an synchronous transmission terminal interface as the interface with an ATM terminal, an ATM exchange interface as the interface with an ATM exchange, a transmitting unit for transmitting the STM time slot and ATM time slot, and a control unit for controlling the interfaces. The synchronous transmission terminal interface assigns the STM data to be transmitted periodically to the STM time slot, while the asynchronous transmission terminal interface assigns the ATM data to be transmitted asynchronously to the ATM time slot. The STM time slot and ATM time slot are identified by the STM/ATM identifier. The STM time slot is stored by multiplexing a plurality of STM data.

Abstract: An identifier translation apparatus is provided that does not require a prohibitively large memory capacity and that is simple in construction and capable of increasing the speed of processing. Using an address consisting of a VPI and the high-order 6 bits of a VCI, a first-stage table is read to retrieve a block number, and using an address consisting of the retrieved block number and the low-order 6 bits of the VCI, a second-stage table is read to retrieve a routing tag. The routing tag is then appended to a cell.

Abstract: In the present invention, input data are extracted by a clock and compared with the previous input data. A cyclic counter is provided for cyclically counting clock signals in each noise erasure time period (the maximum retaining time of a signal referred to as noise). When a change is detected in input data, the counter value is stored. When the input data indicate no changes, the counter value and the stored counter value are compared. If a non-coincident result is outputted, it indicates that the noise erasure time has not passed since the input data indicated a change. Therefore, the input data are not outputted. If a coincident result is outputted, it indicates that the cyclic counter counted one cycle. That is, the noise erasure time has passed. Therefore, the input data are outputted since the input data are not recognized as noise.

Abstract: A time-multiplexed highway line designating system used in a time divisional electronic switching unit comprises line interface units each being provided corresponding to each line, a storing unit provided in the interface unit for storing time slot information specific to each line processed in a time divisional manner, and a timing generating circuit provided in the interface unit for generating from the time slot information a timing for the line.

Abstract: A compact battery-feed circuit for an exchange, including two feedback circuits provided for two wires, one being a dc feedback circuit for the dc voltage on the two wires, and the other being an ac feedback circuit for the ac voltage signal on the two wires.

Abstract: Battery feed circuit for a pair of subscriber lines includes a voltage drive circuit with an operational amplifier having a predetermined output impedance determined by an alternating current terminal impedance for the pair of subscriber lines. Both voice signals and induced noise signals are terminated by the voltage drive circuit. The voltage drive circuit is connected in parallel with an electronic inductance circuit, between one of the subscriber lines and ground or a direct current voltage supply.