Browse Prior Art Database

LOCATING MOBILE RADIOS PARTICIPATING IN GROUP CALLS

IP.com Disclosure Number: IPCOM000009898D
Original Publication Date: 2000-May-01
Included in the Prior Art Database: 2002-Sep-26
Document File: 2 page(s) / 115K

Publishing Venue

Motorola

Related People

Mojan Mohajer: AUTHOR [+2]

Abstract

This paper details a method of efficiently locating mobile radios participating in group calls. A priority is assigned to each group address held by a radio. The infrastructure can then locate a mobile radio by utilization of a priority-based search algorithm.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 50% of the total text.

MOTOROLA

Technical Developments

LOCATING MOBILE RADIOS PARTICIPATING IN GROUP CALLS

ABSTRACT

by Mojan Mohajer and Glenn Walton

This paper details a method of efficiently locating mobile radios participating in group calls. A priority is assigned to each group address held by a radio. The infrastructure can then locate a mobile radio by utilization of a priority-based search algorithm.

INTRODUCTION

In order to set up a call involving many parties quickly, a number of mobile radio protocols support the concept of a group call. A group call is normally initiated by sending signaling on a control channel, the signaling specifying an address which is recognized by a group of radios and which causes those radios to transition to the same traffic channel.

Once on the traffjc channel, communication between the radios can commence. A mobile radio may be capable of holding a number of group addresses, these addresses being assigned as a result of initiative by the infrastructure or the radio itself.

PROBLEM(S) TO BE SOLVED

The transition from control to traffic channel is 'unacknowledged'. This means that the radios do not signal to the supporting infrastructure when they move from one channel to the other. This may cause problems in locating a radio if the infrastructore needs to send individually-addressed signaling to it.

These problems are caused by the unacknowledged nature of the call setup in combination with the following aspects of system behavior: the infrastructure may be processing a number of group calls simultaneously, and a radio may be 'holding' a num~ ber of group addresses, so may be participating in anyone of those calls.

Motorola, Inc. 2000

Most mobile radio protocols support non-intrusive paging of a radio but the protocols do not specify in detail how to apply this paging in a manner which is designed to locate radios in an efficient manner. Here 'efficient' means efficient both from the perspective of signaling, and efficient in terms of the time taken to locate a radio.

PROPOSED SOLUTION TO THE PROBLEM(S)

The following solution resolves the stated problem by allocating priorities to the group addresses assigned to a mobile radio, and then using those priorities to facilitate locating the radio. A more detailed description of the solution follows.

I) When a group address is assigned to a mobile radio, an arbitrary priority number is assigned to that group address.

The infrastructure and the radio have a common understanding of the relationship between the priority numbers and the actual priorities e.g. the higher the number, the higher the priority.

The infrastructure, having assigned group addresses plus associated priorities to a radio, retains the mapping of radios to group addresses to priorities.

2) The infrastructure uses the following 'algorithm ' for locating the radio:

(i) If the radio is participating in an a...