Foley & Lardner
Switchboard terminal apparatus having a plurality of loop circuits
 In a switchboard terminal apparatus, a plurality of loop circuits are simultaneously handled by a switchboard operator. The number of loop circuits in the apparatus exceeds the capacities of screen displays and keys/lamps. A normal loop circuit controller controls loop circuits up to the capacities as normal loop circuits. A virtual loop circuit controller controls loop circuits exceeding the capacities as virtual loop circuits. A first switching circuit for switching control of the loop circuit, which processes a given call, from the normal loop circuit controller to the virtual loop circuit controller in accordance with a call release request operation of the given call by the switchboard operator. A second switching circuit switches a call being controlled by the virtual loop circuit controller to a call under the normal loop circuit controller when a reentering operation of the switchboard operator occurs by regarding the call as a virtual incoming call to the normal loop circuit. A virtual queue controller controls the call in a virtual incoming call queue state during switching by the second switching circuit. 
NEC Corporation
H H
H04M H04M
additional inventional
Hiroaki Nobuyuki
Kikuchi Sakai