Push-to-talk over cellular communication system for taxi central office, has server unit to transmit list of additional communication service client units that fulfill criterion to client unit, which provides service e.g. taxi service

摘要

The system has a communication service client unit (401) to generate messages which contain a criterion, and a set of communication service client units, which acts subscribers of a communication service upon fulfilling the criterion. A server unit (402) generates a list of additional communication service client units that fulfill the criterion and transmits the list to the client unit, which provides the service e.g. taxi service. An independent claim is also included for a method for operating a push-to-talk over communication system.