Browse Prior Art Database

METHOD OF SITE SELECTION PERFORMED DURING AUDIO HOLES IN VOICE TRAFFIC

IP.com Disclosure Number: IPCOM000008719D
Original Publication Date: 1998-Jun-01
Included in the Prior Art Database: 2002-Jul-05
Document File: 1 page(s) / 51K

Publishing Venue

Motorola

Related People

Robert Biggs: AUTHOR [+2]

Abstract

In a multisite tnmked radio system, site selection during a voice call is difficult due to the possibility of missing real time voice data while sampling other sites. This need is not apparent on the control channel due to the repeated nature of control channel data. This problem typically only occurs when there is a long duration voice call. A long call can occur when there is a period of heavy dispatch use, or when the user is engaged in a phone patch or a private call. In these cases the conversation tends to be lengthy and the radio will not return to the control channel until the radio is out of range for the site it is using. Dropping the call due to this out of range condition would have been prevented if the radio were able to perform site selection during the long duration call.

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MOTOROLA Technical Developments

METHOD OF SITE SELECTION PERFORMED DURING AUDIO HOLES IN VOICE TRAFFIC

by Robert Biggs and Dale Schaafsma

PROBLEM

  In a multisite tnmked radio system, site selection during a voice call is difficult due to the possibility of missing real time voice data while sampling other sites. This need is not apparent on the control channel due to the repeated nature of control channel data. This problem typically only occurs when there is a long duration voice call. A long call can occur when there is a period of heavy dispatch use, or when the user is engaged in a phone patch or a private call. In these cases the conversation tends to be lengthy and the radio will not return to the control channel until the radio is out of range for the site it is using. Dropping the call due to this out of range condition would have been prevented if the radio were able to perform site selection during the long duration call.

SOLUTION

  The algorithm resides entirely on a subscrib'er unit unlike fixed network equipment solutions such as cellular. TDMA subscribers utilize other user's time slots to perform signal strength mea- surements at other sites. FDMA subscribers present a different problem.

  The subscriber determines when silence/non- voice is present in a conversation, and then mutes the audio. Then the receiver is tuned to the known adja- cent control channels and a signal strength indicator is computed on each channel while staying in bit sync with the...