No. 4 ESS: Mass Announcement Capability

Public demand exists for expanded new uses of the telephone to provide information and entertainment. Hearing a recorded announcement over a telephone is increasing in popularity. Radio and television stations are encouraging public participation in telethons and call-ins. In the past, the scope of these kinds of services has been limited. More extensive services, such as a presidential call-in, have required special engineering at substantial cost. When the telephone company has not been consulted in advance, peaked traffic caused overloads and widespread congestion in the telephone network. The challenge of the Mass Announcement System (MAS) feature is to provide the mechanism so that sponsors can offer these kinds of announcement-related capabilities on a widespread basis to fulfill existing needs and yet to contribute 1049 significant revenues for the Bell System. High capacity, flexibility, and network protection are key factors because the served area may be large or heavily populated, many different services may be provided simultaneously, and calling may be stimulated by media programming. The MAS is a major part of the 4E5 generic development on the No. 4 ESS. The No. 4 ESS provides a means of recording announcements and the capability to connect a large volume of callers to these announcements. The high terminating capacity of the No. 4 ESS and its position in the Direct Distance Dialing (DDD) network make it a viable switching machine for providing MAS services. The technical architecture inherent in the No.