Browse Prior Art Database

AUTOMATIC CHANNEL SELECTION FOR RADIOS

IP.com Disclosure Number: IPCOM000008986D
Original Publication Date: 1999-Jan-01
Included in the Prior Art Database: 2002-Jul-29
Document File: 2 page(s) / 88K

Publishing Venue

Motorola

Related People

Adrian Nickerson: AUTHOR

Abstract

A two-way radio measures the activity on each channel on which it might potentially wish to trans- mit. When the radio's user wishes to transmit, the radio can then select the vacant channel which is most free of interference from neighboring channels.

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MO-LA Technical Developments

AUTOMATIC CHANNEL SELECTIO'N FOR RADIOS

by Adrian Nickerson

ABSTRACT

  A two-way radio measures the activity on each channel on which it might potentially wish to trans- mit. When the radio's user wishes to transmit, the radio can then select the vacant channel which is most free of interference from neighboring channels.

INTRODUCTION

  This paper describes a method by which a radio can select the least active frequency from a set of channels on which it is authorized to operate.

PROBLEM TO BE SOLVED

  In many countries a set of fixed frequencies is allocated for general use with the choice of channel frequency (and PL code) free for the customer to choose. As a consequence of this, interference between adjacent users on the same frequency can occur even though other frequencies may not be in use.

  Radios made for this application are generally low tier products. They have minimal features and are sometimes user configurable. 'Qpically the channel frequency and PL code are selected either using a number of internal switches or by a preset sequence of button presses. Users find this a com- plex process and a degree of manual dexterity is typically required.

PROPOSED SOLUTION TO THE PROBLEM

  The idea is that the radio automatically config- ures its channel. The mechanism for this is that the radio chooses the least used frequency of those allo- cated. The radio also chqoses a suitable PL code.

  The user selects the Auto Channel Selection (ACS) mode and leaves the radio in this state for as long as is practical. The longer the radio is in this mode the better the estimation of frequency activity.

  A suggested method of selecting the ACS mode could be to hold the ptt button depressed during and, for five seconds after, turning the radio on. The radio would turn off any receiver battery...