US 5,506,837 AGranted

Cellular radio communication system which is selectively convertible into a trunked radio communication system for group calls

AssigneeU.S. Philips Corporation

InventorsMichael Sollner, Alfons Eizenhofer

Life of this patent

Estimating the term…

Loading patent…

Abstract

Cellular mobile radio systems provide full-duplex communication between base stations and mobile stations and with the fixed public service network. Also known are trunked mobile radio systems wherein a group of mobile users can exchange information with each other in the half-duplex mode over a common channel, only one user transmitting to the others at any time. It has been proposed to provide mobile radio sets which are especially adapted to be switched for use in either of such systems. The present invention avoids the need for specific adaptation of a mobile radio set for that purpose. Instead, it enables a cellular mobile radio system to be selectively converted into a trunked mobile radio system by providing for the base station to couple an up-link radio channel of any mobile user to down-link radio channels of a selected group of mobile users. One or more such user groups can be formed, only one radio channel being used for each group.

Claims14

Dependent claims

A cellular radio communication system comprising a plurality of base stations respectively for respective regional cells and wherein for communicating with a plurality of mobile user stations in any particular cell the base station for said cell provides down-link radio channels for transmission from the base station to mobile user stations and up-link radio channels for transmission from mobile user stations to the base station, the up-link and down-link channels being paired so as to establish a duplex channel for any mobile user station with which communication is to be established with the base station;

a common radio signalling channel also being provided between the base station of a cell and mobile user stations therein in order to provide for exchange of control information and channel assignments;
characterized in that said system is adapted to be selectively converted into a trunked radio communication system which provides a common group channel for transmission of a one-way group call from a requesting mobile user station to a specified group of other mobile user stations, said selectable conversion being provided by programmable control means (RTC) comprised in each base station and which in response to a group channel request from a requesting mobile user station couples the up-link channel of said requesting station to a common group channel assigned as a down-link channel to each of a group of mobile user stations specified in the group channel request.

Dependencies are inferred from the claim text.