Before the communicating the communication terminal device communication possible conditional conference set mode

摘要

PURPOSE:To decide a charging load side before the communication start between caller and called communication terminal equipments by providing a caller signal transmission means and a called signal transmission means. CONSTITUTION:An operator of a caller terminal equipment 1 operates a caller operation reception device 16 to send a call to a called terminal equipment 3 with a signal sequence added with information part representing a negotiation request from a caller signal transmission reception circuit 12. Upon the detection of the negotiation request with a called signal transmission reception circuit 13, the called terminal equipment 3 uses a signal sequence automatically to inform it that, e.g. the called terminal equipment 3 accepts the charging burden to the caller terminal equipment 1. After the signal sequence is once terminated, the called side signal transmission circuit 13 is again started and a normal setup signal is sent to the caller terminal equipment 1 and then the caller terminal equipment 1 traces the signal sequence sent normally to the called terminal equipment 3 to enter the communication state. Thus, it is possible to negotiate by the communication terminal equipments as to which of them shares the communication charge before the start of communication.