SELECTIVE SCREENING OF INCOMING CALLS FOR CELLULAR TELEPHONE SYSTEMS

摘要

The prior art deficiencies are solved, in accordance with the disclosureherein, by maintaining a list of caller identities and by determining, via reference tothis list, the type of call treatment that an incoming call should receive. Thistechnique may be termed "divergent call treatment". The caller identities may betelephone numbers. The list of telephone numbers may be stored in the telephonecompany's switching facilities or in the subscriber's telephone instrument. A widerange of call treatment options are provided, and these options can be performedregardless of whether the list is maintained in the telephone company's switchingfacilities or in the subscriber's telephone instrument.In connection with cellular telephones, the divergent call treatmenttechnique of the present invention is used to particular advantage. In accordancewith one of the embodiments disclosed below, for example, the list maintained is alist of accepted callers, and it is maintained by the telephone service supplier. Whena call comes in, a determination is made as to whether the caller is an "accepted"caller. If so, the call is forwarded to the cellular telephone. Otherwise, the caller isoffered the option to pay for the call. A willingness on the part of the caller to payfor the call is indicated by a signal from the caller. This signal may be, for example,the pressing of one or more keys on a standard DTMF touch-tone pad, such as #1. Inresponse to such a signal, the call is forwarded to the cellular telephone. In theabsence of such a signal, the call is disconnected or diverted, for example, to the landline phone of the cellular telephone subscriber.When the list of accepted callers is maintained in the subscriber'stelephone instrument, means are included to attenuate the ringing signal for aninterval sufficient to provide appropriate call treatment for the call and, optionally,means are included for call forwarding, and/or recording of incoming messages.