Browse Prior Art Database

QUICK CONTROL CHANNEL LOOKBACK SEARCH ON NEW ADJACENT SITE INFORMATION DURING FAILSOFT

IP.com Disclosure Number: IPCOM000008888D
Original Publication Date: 1998-Sep-01
Included in the Prior Art Database: 2002-Jul-22
Document File: 1 page(s) / 64K

Publishing Venue

Motorola

Related People

Dave Forseth: AUTHOR [+3]

Abstract

In a Motorola trunked radio system a subscriber unit (SU) in a failsoft mode of operation will period- ically leave the failsoft channel to perform a control channel (CC) lookback search. The CC lookback search consists of reprogramming the SU to the CC frequencies of sites which are learned either through roaming to the site or through adjacent site informa- tion broadcasts. If CC operation is found on any of the CCs, failsoft operation will be exited and trunk- ing operation will resume. Failsoft CC lookback searches will be performed after a SU programma- ble time period (defaulted to 2 minutes; programma- ble up to 4 minutes) in which no voice transmission has been performed by the user.

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MOTOROLA Technical Developments

QUICK CONTROL CHANNEL LOOKBACK SEARCH ON NEW

ADJACENT SITE INFORMATION DURING FAILSOFT

by Dave Forseth, Steve Van Swol and Gary Hunsberger

INTRODUCTION

OPERATION OF QUICK CC LOOKBACK ALGORITHM

  In a Motorola trunked radio system a subscriber unit (SU) in a failsoft mode of operation will period- ically leave the failsoft channel to perform a control channel (CC) lookback search. The CC lookback search consists of reprogramming the SU to the CC frequencies of sites which are learned either through roaming to the site or through adjacent site informa- tion broadcasts. If CC operation is found on any of the CCs, failsoft operation will be exited and trunk- ing operation will resume. Failsoft CC lookback searches will be performed after a SU programma- ble time period (defaulted to 2 minutes; programma- ble up to 4 minutes) in which no voice transmission has been performed by the user.

  When ASBs are received by a SU in failsoft operation they will be checked against an internal list of currently known adjacent sites. If the broad- cast specifies a site which was not previously known by the SU the quick CC lookback search will be delayed until the end of the call.

  The quick CC lookback search will consist of exiting the failsoft channel and reprogramming to the CC of the new site (or mutiple sites if more than one has been learned since the last lookback). If the SU cannot find trunking operation on this channel it will immediately ret...