Browse Prior Art Database

SATELLITE SUBSCRIBER LINE INTERFACE ADAPTER APPARATUS AND METHOD

IP.com Disclosure Number: IPCOM000004646D
Original Publication Date: 2001-Mar-15
Included in the Prior Art Database: 2001-Mar-15
Document File: 3 page(s) / 7K

Publishing Venue

Motorola

Related People

Thomas M. Fox: AUTHOR

Abstract

SATELLITE SUBSCRIBER LINE INTERFACE ADAPTER APPARATUS AND METHOD

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SATELLITE SUBSCRIBER LINE INTERFACE ADAPTER APPARATUS AND METHOD

by Thomas M. Fox

INTRODUCTION

The Iridium subscriber unit (ISU) requires an unobstructed line of sight to the satellites for best performance. The ISU is unable to establish a reliable communications link in a building, such as a house or business, or a car because the integral antenna. This publication describes a device that permits the use of the Iridium network inside these structures using a corded or cordless RJl1-based telephone. The Iridium subscriber line interface adapter (ISLIA) can be embodied in the following approaches:

1. An ISU accessory that provides power, an RJ11 interface, and an outside antenna connection;

2. A satellite transceiver with an RJ11, power and antenna interface that is packaged for outdoor use.

ISU ACCESSORY

A top level block diagram is shown in Figure 1. The five major interfaces include the:

1) Satellite phone (ISU),

2) U.S. RJ11 analog telephone,

3) RS232 connector used to update the ISU accessory software,

4) Satellite phone original power supply/charger (mouse) or cigarette lighter adapter,

5) User.

The ISLIA controls the satellite phone through the data-speech control (DSC) bus. The ISU's battery is charged using the ISU internal charging circuit. ISU on/off is controlled via the power control line. The ISU also provides a dock signal that is used to confirm proper connection to the user with the LED. A remote antenna permits usage inside structures such as a building.

An analog touch tone telephone is connected for mobile originated and mobile terminated calls over the Iridium network. The ISU accessory provides the two wire tip and ring interface. The user functions provided over the two wire interface are:

1) Dial tone signal,

2) Busy Signal,

3) Ring,

4) DTMF,

5) Voice.

The telephone initiated DTMF tones are transmitted through the Iridium network when the key presses are made during the audio call.

To start a mobile originated call the user picks up the telephone handset, and listens for a dial tone before starting the call. The user then dials a number using the touch keys. When no additional key presses are detected for 10 seconds, ISLIA causes the satellite phone to dial the number string and connects the telephone and satellite phone audio paths. When the satellite phone is not present a busy signal is presented to the user.

A mobile terminated call begins when the satellite phone receives a satellite call and notifies ISLIA. A ring voltage is supplied to the telephone until it is answered. The audio is then connected between the satellite phone and the handset. The telephone will ring until the calling party terminates the call.

The RS232 connector is used to update the ISLIA software. The user may download the new code from the Internet or possibly receive an update in the mail. The PC containing the update is connected via the RS232 serial interface.

Two files are downloaded and used to update the code. The first file is boot loader code. The second file i...