Browse Prior Art Database

METHOD TO CONFIRM WHETHER A VOICE TRANSMISSION WAS REPEATED

IP.com Disclosure Number: IPCOM000008855D
Original Publication Date: 1998-Sep-01
Included in the Prior Art Database: 2002-Jul-18
Document File: 2 page(s) / 103K

Publishing Venue

Motorola

Related People

Mark Gonsalves: AUTHOR

Abstract

In a conventional two way radio communication system, when a mobile radio user initiates a voice transmission, there is no way he can vet-ify that his transmission reached the infrastructui-e and was repeated without having another radio standing by on the same channel to confit-m the reception.

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MOTOROLA Technical Developments

METHOD TO CONFIRM WHETHER A VOICE TRANSMISSION

WAS REPEATED

by Mark Gonsalves

BACKGROUND

   In a conventional two way radio communication system, when a mobile radio user initiates a voice transmission, there is no way he can vet-ify that his transmission reached the infrastructui-e and was repeated without having another radio standing by on the same channel to confit-m the reception.

  Here are some of the scenarios where a use! may not have their transmission repeated and not be aware of it.

- Radio may be out of transmission range and the infrastructure is not able to receive the call, there- fore it cannot repeat it.

  Radio may be in a fringe area and the repeated voice call may have a significant number of bit errors making it difficult to understand over the receiving radios.
- Transmission may be preempted by another radio with a stronger signal.
* Another radio with a stronger signal may be already transmitting and the radio may not be able to preempt that transmission.

Transmission may not be repeated by the station

because it does not match certain constraints like network access code, etc.

  This can be accomplished by having mobile radios listen for an acknowledgment from the infra- structure after each transmission. The infrastructure on the other hand, will be responsible for appending a postamble to the end of each repeated transmission indicating status of the repeated call, since the post- amble is appended after the voice call ends. With an appropriate delay in the infrastructure before the postamble begins, the transmitting radio should have enough time to switch back to receive mode and look for the postamble.

  The postamble status will indicate the PTT ID of the initiating radio and whether the call was partially or fully repeated and what the detected Bit Error Ratio of the repeated call was. Since all radios in the system on the same channel will receive this post- amble, only those radios that completed a transmis- sion during a predefined period will attempt to decode it. If the PTT ID matches, only then will it give the user feedback as to the status of the last transmission.

  In case the t...