Browse Prior Art Database

METHOD FOR OPTIMIZING THE BROADCAST OF PRIORITY GROUP ACTIVE NOTIFICATIONS ON A TRAFFIC CHANNEL

IP.com Disclosure Number: IPCOM000009350D
Original Publication Date: 1999-Jun-01
Included in the Prior Art Database: 2002-Aug-19
Document File: 2 page(s) / 103K

Publishing Venue

Motorola

Related People

Grant Emberson: AUTHOR [+2]

Abstract

Public Safety Customers reqti a feature whereby if a radio user is involved in a low priority group call and a higher priority group call becomes active in the system then the radio user in the low priori- ty cdl is notified of the high priority call so he can leave the existing call and participate in the new call. The mechanism for this notification to the radio user is by the radio infrastructure periodically broadcast- ing group active notifications on the traffic channel. However, there is very limited band- width on the tratIic channel to broadcast these noti- fications and hence the frequency of the broadcast notification of a specific group call is low, especially if there are many group calls active in the system.

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MO7DROLA Technical Developments

METHOD FOR OPTIMIZING THE BROADCAST OF PRIORITY GROUP ACTIVE NOTIFICATIONS ON A TRAFFiC CHANNEL

by Grant Emberson and Gareth Owen

INTRODUCTION

  Public Safety Customers reqti a feature whereby if a radio user is involved in a low priority group call and a higher priority group call becomes active in the system then the radio user in the low priori- ty cdl is notified of the high priority call so he can leave the existing call and participate in the new call. The mechanism for this notification to the radio user is by the radio infrastructure periodically broadcast- ing group active notifications on the traffic channel. However, there is very limited band- width on the tratIic channel to broadcast these noti- fications and hence the frequency of the broadcast notification of a specific group call is low, especially if there are many group calls active in the system.

  This paper proposes a method for optimizing the broadcast of priority group active notifications on a traffic channel with respect to the TETRA air interface.

PROBLEM(S) TO BE SOLVED

  With the TBTRA air interface, group active noti- fications can only be sent when the traffic channel is configured in associated control channel mode. When user traffic (voice) is present on the traffic channel then the only available control channel capacity is on frame 18, which occurs once every 1. 02 seconds. Hence the problem to be solved was to optimize the broadcast of the group active notifica- tions because, if there are many active group calls in the system, then the frequency at which a particu- lar group call active notification can be sent is low. This results in a potential undesirable delay before a radio user can join a higher priority call.

PROPOSED SOLUTlOlrj TO THE PROBLEM(S)

  On power-on, a radio (MS) will register with the TETRA system using the U-LOCATION UPDATE DEMAND PDU and, assuming the MS is valid for that system, the infrastructure (SwMI) will respond with D-LOCATION UPDATE ACCEPT PDU. Within the D-LOCATION UPDATE ACCEPT PDU there will be a list of g&p identities, held by the infrastructure, which are 'valid for that MS, togeth- er with the relative prior$ies of the groups, identi- fied by the 'group...