Browse Prior Art Database

Method to Support Multiple Audio Formats per Call in a Wide Area Communication System

IP.com Disclosure Number: IPCOM000169411D
Original Publication Date: 2008-Apr-15
Included in the Prior Art Database: 2008-Apr-15
Document File: 3 page(s) / 185K

Publishing Venue

Motorola

Related People

Daniel J. McDonald: INVENTOR

Abstract

Wide area communication networks such as Motorola ASTRO 25 systems have the need to support multiple audio formats to allow for interaction between subscriber units of different capability. By enabling the support of different audio formats within a common system, radios that support different audio formats can communicate seamlessly. This paper will describe how a communication system can support this multiple audio format functionality.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Method to Support Multiple Audio Formats per Call in a Wide Area Communication System

By Daniel J. McDonald

Motorola, Inc.

Government and Public Safety Business

 

ABSTRACT

Wide area communication networks such as Motorola ASTRO 25 systems have the need to support multiple audio formats to allow for interaction between subscriber units of different capability.  By enabling the support of different audio formats within a common system, radios that support different audio formats can communicate seamlessly.  This paper will describe how a communication system can support this multiple audio format functionality. 

PROBLEM

Communication systems such as Motorola ASTRO 25 systems may support multiple air interfaces connected to a common core infrastructure to allow radios with different air interfaces to intercommunicate.   For example, an ASTRO 25 system may support the existing Project 25 air interface as well as the legacy Motorola SmartZone air interface.  Given a system such as this, there is a need for radios that utilize the Project 25 air interface to interoperate with radios that utilize the Motorola SmartZone air interface.

SOLUTION

In order for radios utilizing different air interface audio formats to communicate, a mechanism is needed to route the correct audio format to the correct radio frequency (RF) Site in the system for transmission over the specific air interface.  One solution to this problem is to create multiple copies of the received audio in different audio formats and route the audio to the correct endpoint using multicast technology.

For example, on a Motorola ASTRO 25 system that contains RF Sites that support the Project 25 air interface and RF Sites that support the SmartZone air interface, an interoperability solution is needed.  In this case, if, for example, analog audio is received over the SmartZone air interface, two copies of the audio would be created by the sourcing RF Site, potentially by standalone duplication device.  One copy of the audio would be in a format usable by other SmartZone RF Sites in the call (e.g. analog audio format) and a second copy (e.g. Improved Multi-Band Excitation (IMBE) audio format) would be utilized by RF Sites that supports the Project 25 air interface. 

When routing the audio from the source RF Site to the destination RF Sites, only the necessary copy of audio suited for the particular RF Site would be routed to that RF Site.  A reasonable method for routing each audio format copy would be to utilize multicast IP technology with each audio format copy utilizing a different multicast addres...