| 摘要 |
<p>PACKET AND CIRCUIT SWITCHED COMMUNICATIONS NETWORK A telecommunications network being operable as a packet switch and as a circuit switch is comprised of a plurality of units including a call controller unit. Each of the units is connected in common to data, address, and control leads of a bus, the data leads being commonly available for signal transmissions of both call control signals between the call controller unit and the other units and communications signals between calling and called ones of the other units. A bus controller is connected to the units by way of the address and control leads for arbitrating access to the data leads by the units, so that only one unit may transmit at any one time. The bus controller includes, poll circuit for polling the units for asynchronous transmission requests, a grant circuit being responsive to the requests, for granting access to the data leads for an indefinite period of time as required for transmission of a data packet from one of the units, and a synchronous cycle circuit, being responsive to a synchronous request signal from any of the units, for generating a synchronous cycle signal for inhibiting data packet transmission and enabling synchronous data transmission via the data leads during a predetermined period of time.</p> |
