Abstract: 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.

Abstract: Data transactions and voice communications are facilitated in a packet switching system including a group of ports each of which is capable of exchanging inter-destined and intra-destined information signals via a packet bus. The packet bus is operated under the direction of a bus controller which communicates with the ports to arbitrate access to the packet bus for packet transmission. Arbitrating access to the packet bus for pseudo-synchronous and asynchronous signal communications includes the steps of polling the ports within a period of time for high and low priority, transmission requirements. In response to each high priority requirement transmission over a predetermined number of consecutive bus cycles is granted by the bus controller within a predetermined period of time for pseudo-synchronous transmission of signals from each of the corresponding ports one after another.