radiocommunications-based service involving non-speech, one-way, personal selective calling with a tone, vibration or visual alert. The system may either simply inform the user that somebody is trying, service which provides the subscriber with the facility, by means of portable equipment used in a given area, to receive an alert by radio initiated by any telephone in a public network; the alert can, a one-way radio communication service which by means of a network of transmitters broadcasts the identity code or call sign of a small pocket receiver, or pager. The pager monitors the broadcast chann, a service enabling customers equipped with pocket-sized receivers to be given an audible indication that they are required to take some prearranged action, usually that of calling a particular phone n