Conference call on a personal handy phone system portable station

Abstract

A system that enables a portable station of the personal handy phone system to support a conference call. The present invention provides this capability by empowering a portable station to communicate with up to four cell stations simultaneously enabling the user of the portable station to communicate with the users of four other telecommunication devices. Specifically, the present invention modifies the internal circuitry of a portable station to increase the number of receiving channel circuits to four and the transmitting channel circuits to four while adding a digital signal processor to mix the different received and outgoing voice signals. The increased number of receiving and transmitting channel circuits enables a portable station to utilize all the communication slots located within the frames of the radio communication interface of the personal handy phone system. Communication is time-multiplexed across these slots. The frames each have eight slots, four for receiving data and four for transmitting data. These eight slots enable a portable station implemented with the present invention to support communication with four cell stations simultaneously. To facilitate this type of communication, the slots located within the portable station frames operate in conjunction with the slots located within the cell station frames of the cell stations involved in the conference call thereby creating communication channels. The cell stations involved in the conference call each utilize different communication channels to communicate with the portable station implemented with the present invention.