Voice conference switching in digital telephone exchanges

The authors present several algorithms which could be used to perform conference connections in a digital telephone exchange, including a newly proposed algorithm. These algorithms are analyzed from both the performance and implementation points of view. Finally, the implementation of the conference switching function in TROPICO-RA, the Brazilian medium/large telephone exchange, is described. The conference circuit designed for the TROPICO was tested with conference groups involving up to six speakers and yielded satisfactory results