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Location based radio operation Disclosure Number: IPCOM000232371D
Original Publication Date: 2013-Nov-04
Included in the Prior Art Database: 2013-Nov-04
Document File: 2 page(s) / 34K

Publishing Venue


Related People

Edkins, Jim: INVENTOR [+2]


This idea provides a method to change the mode of operation of the radio based on location using geo-fense or equivlent location technology. It covers the following use cases: - conventional channel - LMR operating mode (trunking/conventional) - Secure/clear operation This is accomplished in the following manner: - application for drawing geofences and selecting the action desired when a radio enters the Geofence - detection of radios entering a Geofence. This can be one of two ways - by tracking the radios reported location and taking an action when the radio enters a Geofence (e.g. sending a channel change command to the radio) or - by pushing the Geofence to the radio along with the appropriate action to take upon entering the Geofence (e.g. send the fence along with the channel frequency to change to upon entering the fence)

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Location Based Radio Operation

By James G. Edkins, Daniel J. McDonald, George Economy

Motorola Solutions, Inc.



Land Mobile Radio systems, such as ASTRO25, can operate in several modes. One is trunking, where a central computer monitors resources and assigns a traffic channel for voice or data services. The other mode is conventional. These channels are not assigned and are open to any user in coverage of the channel.  

The conventional system relies on user protocol in order to effectively use these channels without interfering with each other. There are also mechanisms in the subscriber radio to mitigate multiple users on a single channel.

One of the key operating precepts for conventional is that the channels are statically deployed. This means that a certain channel/frequency will operate in a geographic area and not change. The user knows this and can select the proper channel when entering the coverage area of the channel. This is a manual process and for the most part rather simple if the number of channels/frequencies is a small quantity.


One of the major issues for conventional is the user must know when to select the proper channel/frequency. This may not be too difficult if the user always remain in coverage of a channel or two. However, for large systems with many channels/frequencies it can be challenging to remember what channel to select.

Customers have looked at several different solutions to address this issue with conventional. One is frequency reuse. Another is vote scan, which is a voted wide area coverage reuse of frequencies. However, these solutions are limited by geography, frequency availability, and cost.

A method is needed in order for the radio to automatically move to the proper conventional frequency when operating in coverage of the channel.


The concept of this invention is to provide information to the radio so it can make an intelligent decision on what channel/mode to select.

This is accomplished by using location. There are several methods on how using location can be used to drive decisions on channel/frequency selection by the subscriber radio.

The first approach is to pre-configure the radio with coordinates of coverage of conventional channels. This information should be available and is typically static. When a radio passes over the coordinates, the radio will move to the conventional channel as programmed. Another term for this type of location information is a “geofence”.

A second method is to periodically broadcast to radios the “geofence” information. The information would contain details of the coverage area (geofence) and conventional channel/frequency to use.


An LMR system can...