Patent ID: 9131344
Filing Date: 2015-09-08
Classification: H04L,H04W

Abstract:
1. A method of automatic establishment of a location-based talk group call with reduced messaging overhead, in a wireless radio communication system comprising a plurality of subscriber units, the method comprising, responsive to detecting an input requesting that a new location-based talk group call be established: determining, by a first one of the plurality of subscriber units, a geographic reference location and generating location data representative of the geographic reference location; broadcasting, by the first subscriber unit, a location-based talk group call header including the location data and including a location-based talk group call identifier field set to a value that causes other subscriber units in the plurality receiving the call header to receive and output subsequent data associated with the call header responsive to each of the other subscriber units determining that its current geographic location satisfies the location criterion of the call that is at least partly defined by the location data included in the call header; subsequently transmitting the data associated with the call header; and wherein the location data representative of the geographic reference location is GPS location data, and wherein the location data representative of the geographic reference location is compressed location data generated by removing one or more most significant bits of a GPS-determined latitude location of the first subscriber unit and one or more most significant bits of a GPS-determined longitude location of the first subscriber unit.