Trimble TRIMTRAC1 User Manual

TrimTrac Locator

Technical Manual

****DRAFT***

Part Number XXXXX-XX-ENG

Draft Revision 1.0

January 2004

Corporate Office

Trimble Navigation Limited
749 North Mary Avenue
Post Office Box 3642
Sunnyvale, CA 94088-3642 U.S.A.
Phone: [phone]
1-800-545-7762

www.trimble.com

Copyright and Trademarks

© 1997–2004, Trimble Navigation Limited.

All rights reserved. Printed in the United States of
America. Printed on recycled paper.

The Circle & Parallelogram and TrimTrac are
trademarks of Trimble Navigation Limited. The
Sextant logo, Globe & Triangle and Trimble are
trademarks of Trimble Navigation Limited, registered
in the United States Patent and Trademark Office. All
other trademarks are the property of their respective
owners.

Release Notice

This is January 2004 release (Revision A) of the
TrimTracTM Locator Technical Manual, Part Number
XXXX-YY-ENG. The following limited warranties
give you specific legal rights. You may have others,
which vary from state/jurisdiction to state/jurisdiction.

Hardware Limited Warranty

Trimble warrants that this Trimble hardware product
(the “Product”) shall be free from defects in materials
and workmanship and will substantially conform to
Trimble’s applicable published specifications for the
Product for a period of one (1) year, starting from the
date of delivery. The warranty set forth in this
paragraph shall not apply to software/firmware
products.

Software and Firmware License, Limited
Warranty

This Trimble software and/or firmware product (the
“Software”) is licensed and not sold. Its use is
governed by the provisions of the applicable End User
License Agreement (“EULA”), if any, included with
the Software. In the absence of a separate EULA
included with the Software providing different limited
warranty terms, exclusions, and limitations, the
following terms and conditions shall apply. Trimble
warrants that this Trimble Software product will
substantially conform to Trimble’s applicable
published specifications for the Software for a period
of ninety (90) days, starting from the date of delivery.

Warranty Remedies

Trimble's sole liability and your exclusive remedy
under the warranties set forth above shall be, at
Trimble’s option, to repair or replace any Product or
Software that fails to conform to such warranty
(“Nonconforming Product”), or refund the purchase
price paid by you for any such Nonconforming
Product, upon your return of any Nonconforming
Product to Trimble in accordance with Trimble’s
standard return material authorization procedures.

Warranty Exclusions and Disclaimer

These warranties shall be applied only in the event and
to the extent that: (i) the Products and Software are
properly and correctly installed, configured,
interfaced, maintained, stored, and operated in
accordance with Trimble's relevant operator's manual
and specifications, and; (ii) the Products and Software
are not modified or misused. The preceding warranties
shall not apply to, and Trimble shall not be responsible
for defects or performance problems resulting from (i)
the combination or utilization of the Product or
Software with products, information, data, systems or
devices not made, supplied or specified by Trimble;
(ii) the operation of the Product or Software under any
specification other than, or in addition to, Trimble's
standard specifications for its products; (iii) the
unauthorized modification or use of the Product or
Software; (iv) damage caused by accident, lightning or
other electrical discharge, fresh or salt water
immersion or spray; or (v) normal wear and tear on
consumable parts (e.g., batteries).

THE WARRANTIES ABOVE STATE TRIMBLE'S

ENTIRE LIABILITY, AND YOUR EXCLUSIVE
REMEDIES, RELATING TO PERFORMANCE OF THE
PRODUCTS AND SOFTWARE . EXCEPT AS
OTHERWISE EXPRESSLY PROVIDED HEREIN, THE
PRODUCTS, SOFTWARE, AND ACCOMPANYING
DOCUMENTATION AND MATERIALS ARE PROVIDED

“AS-IS” AND WITHOUT EXPRESS OR IMPLIED

WARRANTY OF ANY KIND BY EITHER TRIMBLE
NAVIGATION LIMITED OR ANYONE WHO HAS BEEN

INVOLVED IN ITS CREATION, PRODUCTION,
INSTALLATION, OR DISTRIBUTION INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE , TITLE, AND
NONINFRINGEMENT. THE STATED EXPRESS
WARRANTIES ARE IN LIEU OF ALL OBLIGATIONS
OR LIABILITIES ON THE PART OF TRIMBLE ARISING
OUT OF, OR IN CONNECTION WITH, ANY PRODUCTS
OR SOFTWARE . SOME STATES AND JURISDICTIONS
DO NOT ALLOW LIMITATIONS ON DURATION OR
THE EXCLUSION OF AN IMPLIED WARRANTY, SO

THE ABOVE LIMITATION MAY NOT APPLY TO YOU.

TRIMBLE NAVIGATION LIMITED IS NOT
RESPONSIBLE FOR THE OPERATION OR
FAILURE OF OPERATION OF GPS SATELLITES

OR THE AVAILABILITY OF GPS SATELLITE
SIGNALS.

Limitation of Liability

TRIMBLE’S ENTIRE LIABILITY UNDER ANY

PROVISION HEREIN SHALL BE LIMITED TO THE
GREATER OF THE AMOUNT PAID BY YOU FOR THE
PRODUCT OR SOFTWARE LICENSE OR U.S.$25.00.

TO THE MAXIMUM EXTENT PERMITTED BY

APPLICABLE LAW , IN NO EVENT SHALL TRIMBLE
OR ITS SUPPLIERS BE LIABLE FOR ANY INDIRECT,
SPECIAL, INCIDENTAL OR CONSEQUENTIAL

DAMAGES WHATSOEVER UNDER ANY
CIRCUMSTANCE OR LEGAL THEORY RELATING IN
ANY WAY TO THE PRODUCTS, SOFTWARE AND
ACCOMPANYING DOCUMENTATION AND
MATERIALS, (INCLUDING, WITHOUT LIMITATION,
DAMAGES FOR LOSS OF BUSINESS PROFITS,
BUSINESS INTERRUPTION, LOSS OF BUSINESS
INFORMATION, OR ANY OTHER PECUNIARY LOSS),
REGARDLESS WHETHER TRIMBLE HAS BEEN
ADVISED OF THE POSSIBILITY OF ANY SUCH LOSS
AND REGARDLESS OF THE COURSE OF DEALING
WHICH DEVELOPS OR HAS DEVELOPED BETWEEN
YOU AND TRIMBLE. BECAUSE SOME STATES AND
JURISDICTIONS DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR
CONSEQUENTIAL OR INCIDENTAL DAMAGES, THE
ABOVE LIMITATION MAY NOT APPLY TO YOU.

Notices

Class B Statement – Notice to Users. This equipment
has been tested and found to comply with the limits
for a Class B digital device, pursuant to Part 15 of the
FCC rules. These limits are designed to provide
reasonable protection against harmful interference in a
residential installation. This equipment generates,
uses, and can radiate radio frequency energy and, if
not installed and used in accordance with the
instructions, may cause harmful interference to radio
communication. However, there is no guarantee that
interference will not occur in a particular installation.
If this equipment does cause harmful interference to
radio or television reception, which can be determined
by turning the equipment off and on, the user is

encouraged to try to correct the interference by one or
more of the following measures:

– Reorient or relocate the receiving antenna.
– Increase the separation between the

equipment and the receiver.

– Connect the equipment into an outlet on a

circuit different from that to which the
receiver is connected.

– Consult the dealer or an experienced

radio/TV technician for help.

Changes and modifications not expressly approved by
the manufacturer or registrant of this equipment can
void your authority to operate this equipment under
Federal Communications Commission rules.

Regulatory Approvals
CE

The TrimTrac Locator product complies with the
essential requirements of the R&TTE Directive
199/5/EC as stated by the EC Declaration of
Conformity (CE0681) and the EC R&TTE Type
Examination Certificate. The TrimTrac Locator
product complies with the European
Telecommunications Standards Institute
Specifications ETS300-342-1 (EMC for GSM
900MHZ and DCS 1800MHZ Radio Equipment and
Systems).

EEC

The TrimTrac Locator product complies with
Directive 72/245/EEC as amended by Directive
95/54/EC (el*72/245*95/54).

FCC The TrimTrac product complies with the FCC
Part 15, FCC Part 24, and Industry Canada
requirements. The TrimTrac product complies with
Part 15 of the FCC rules. Operation is subject to the
following two conditions: (1) This device may not
cause harmful interference, and (2) This device must
accept any interference received, including
interference that may cause undesired operation.
FCC ID: JUPTRIMTRAC1

Contents

About this Manual...............................................................................................................vi

Related Information........................................................................................................vi

Technical Assistance......................................................................................................vii

Safety First .......................................................................................................................... 1

Simple Guidelines ........................................................................................................... 1

Detailed Safety Information................................................................................................ 2

Exposure to Radio Frequency S ignals ............................................................................ 2

Electronic Devices .......................................................................................................... 2

Aircraft............................................................................................................................ 3

Blasting Areas ................................................................................................................. 3

Potentially Explosive Atmospheres ................................................................................ 3

For Vehicles Equipped with an Air Bag ......................................................................... 4

Specific Absorption Rates (SAR) ................................................................................... 4

Overview............................................................................................................................. 6

Introduction..................................................................................................................... 6

TrimTrac Locator............................................................................................................ 6

Global System for Mobile Communications .................................................................. 8

Global Positioning System............................................................................................ 10

TrimTrac Locator Defaults ............................................................................................... 12

Introduction................................................................................................................... 12

Factory Default Settings................................................................................................ 12

Read-Only Parameters .................................................................................................. 13

Security Considerations ................................................................................................ 13

Diagnostics.................................................................................................................... 14

TrimTrac Locator Configuration...................................................................................... 15

Introduction................................................................................................................... 15

Provisioning Mode........................................................................................................ 15

Provisioning Set-up....................................................................................................... 15

Provisioning Commands............................................................................................... 18

Use Guidelines .................................................................................................................. 22

Introduction................................................................................................................... 22

General Guidelines........................................................................................................ 22

Operation........................................................................................................................... 24

Introduction................................................................................................................... 24

Operational State Machine............................................................................................ 24

TrimTrac Application Protocol......................................................................................... 30

Introduction................................................................................................................... 30

Message Format ............................................................................................................ 30

TrimTrac Application Protocol Message Summary..................................................... 32

Application Message Types and Format....................................................................... 32

Troubleshooting ................................................................................................................ 39

Introduction................................................................................................................... 39

Specifications.................................................................................................................... 43

Bibliography...................................................................................................................... 44

Glossary............................................................................................................................ 45

DRAFT TrimTrac Locator Technical Manual iv

List of Tables

Table 1 Factory Default Parameters ................................................................................. 13

Table 2 Read Only Parameters ......................................................................................... 13

Table 3, Summary of Provisioning Commands................................................................ 18

Table 4 AT+CTKP Assignment....................................................................................... 18

Table 5 AT+CTKP Query................................................................................................ 19

Table 6 AT+CTKC Assignment ...................................................................................... 19

Table 7 AT+CTKC Query ............................................................................................... 20

Table 8 AT+CTKG Assignment...................................................................................... 20

Table 9 AT+CTKG Query ............................................................................................... 21

Table 10, Basic Message Format ...................................................................................... 31

Table 11, Message Qualifiers ............................................................................................ 31

Table 12, TrimTrac Application Protocol Messages ........................................................ 32

Table 13, REPORT_POS and STATUS_MSG Messages ................................................ 33

Table 14, SET_APP_CONFIG Message .......................................................................... 34

Table 15, SET_PROV_CONFIG Message ....................................................................... 35

Table 16, SET_GPS_CONFIG Message .......................................................................... 35

Table 17, QUERY_CONFIG Message ............................................................................. 36

Table 18, RESP_APP_CONFIG Message........................................................................ 36

Table 19, RESP_PROV_CONFIG Message .................................................................... 37

Table 20, RESP_GPS_CONFIG Message........................................................................ 37

Table 21, QUERY_LOG Message ................................................................................... 38

Table 22, RESP_QUERY_LOG Message ........................................................................ 38

List of Figures

Figure 1, TrimTrac Operational State Diagram ................................................................ 24

DRAFT TrimTrac Locator Technical Manual v

About this Manual

Welcome to the TrimTracTM Locator Technical Manual. This manual is intended for use
by system integrators, service providers and application developers (collectively,
“Resellers”). It is not intended for end-users of the TrimTrac locator. Any end-user
documentation is to be prepared and furnished by the Resellers.

This manual covers the TrimTrac locator operating on 900 MHz, 1800 MHz and
1900 MHz GSM networks. Data and Event Reporting support is by Short
Message Service (SMS). This manual describes how to set up, configure, install,
operate, and troubleshoot the product. Even if you have used other GSM or
Global Positioning System (GPS) products before, Trimble recommends that you
spend some time reading this manual to learn about the special features of this
product. If you are not familiar with GSM or GPS, visit Trimble Component
Technologies’ Web site dedicated to the TrimTrac product (www.trimtrac.com) for
a look at the device, GSM and GPS. Trimble assumes that you are familiar with
Microsoft Windows, including HyperTerminal, and know how to use a mouse,
select options from menus and dialogs, make selections from lists, and refer to
online help.

This manual is available in portable document format (PDF) from the following Web
site: http://www.trimtrac.com/support

Related Information

Other sources of related information are:

• TrimTrac Web site at www.trimtrac.com , which is dedicated to application

notes, technical notes, and other useful product information are available
from this site. These documents contain important information about
software and hardware changes.

• Release notes – the release notes describe new features of the product,

information not included in the manuals, and any changes to the manuals.
The release notes are available for download from the above Web address.

• ftp.trimble.com – use the Trimble FTP site to send files or to receive files

such as software patches, utilities, service bulletins, and FAQs.
Alternatively, access the FTP site from the Trimble Web site:

www.trimble.com/support.

DRAFT TrimTrac Locator Technical Manual vi

Technical Assistance

If you have a problem and cannot find the information you need in the product
documentation, please contact your local Trimble Component Technologies sales
office or sales engineer.

DRAFT TrimTrac Locator Technical Manual vii

Safety First

Simple Guidelines

Please follow these guidelines when configuring or using the TrimTrac locator.
Violating these guidelines may be dangerous, illegal or otherwise detrimental.
Further detailed information is provided in this manual.

Do Not Operate Where Prohibited

Do not allow the TrimTrac locator to operate wherever wireless phone use is
prohibi ted or when doing so may cause interference or danger. Examples include
but are not limited to operation in hospitals, aircraft, near blasting sites or
wherever operation can cause interference.

Interference

Like all wireless devices, the TrimTrac locator may encounter electrical
interference that may affect its performance.

Avoid Body Contact with Device During Operation

Do not operate the TrimTrac locator in direct contact with your body. Maintain
minimum separation distance of 0.590 inch (15 mm) between the device and any
parts of your body.

Qualified Service

Except for batteries and Subscriber Identification Module (SIM) card, the
TrimTrac contains no user serviceable or replaceable parts. Non-functioning
units must be returned to an authorized service center for repair or replacement.

Accessories and Batteries

Use only approved accessories or batteries. Do not connect incompatible
products. Risk of explosion if batteries are replaced by an incorrect type.
Di spose of used batteries according to the instructions provided with the batteries.

Water-Resistance

The TrimTrac locator is not waterproof. Even though it is water-resistant, it is
recommended that it be used where it is relatively dry and not subjected to either
water streams or submersion.

DRAFT TrimTrac Locator Technical Manual 1

Detailed Safety Information

Exposure to Radio Frequency Signals

The TrimTrac locator is a low power radio transmitter and receiver. When it is
ON, it receives and also sends out radio frequency (RF) signals.

In August 1996, the Federal Communications Commissions (FCC) adopted RF
exposure guidelines with safety levels for hand-held wireless phones. Those
guidelines are consistent with safety standards previously set by both U.S. and
international standards bodies:

ANSI C95.1 (1992)
NCRP Report 86 (1986)
ICNIRP (1996)

Those standards were based on comprehensive and periodic evaluations of the
relevant scientific literature. For example, over 120 scientists, engineers, and
physicians from universities, government health agencies, and industry reviewed
the available body of research to develop the ANSI Standard (C95.1)

While the TrimTrac locator is not intended for hand-held use, its design
nonetheless complies with the FCC guidelines (and those standards).

Electronic Devices

Most modern electronic equipment is shielded from RF signals. However, certain
electronic equipment may not be shielded against the RF signals from the
TrimTrac locator.

Pacemakers

The Health Industry Manufacturers Association recommends that a minimum
separation of six (6”) inches be maintained between a handheld wireless phone
and a pacemaker to avoid potential interference with the pacemaker. These
recommendations are consistent with the independent research by and
recommendations of Wireless Technology Research.

Persons with pacemakers:

• Should ALWAYS keep the TrimTrac locator more than eight inches from

their pacemaker with the device is operational.

• Should not carry the TrimTrac locator on their person

DRAFT TrimTrac Locator Technical Manual 2

• If there is any reason to suspect that interference is taking place, the

TrimTrac locator battery pack should be removed immediately.

Other Medical Devices

If any other personal medical devices are used in the vicinity of a TrimTrac
locator, consult the manufacturers of the medical devices to determine if they are
adequately shielded from external RF energy. Physicians may be able to assist in
obtaining this information.

Disable operation of the TrimTrac locator by removing the battery pack in health
care facilities when any regulations posted in these areas prohibit the use of
wireless phones or two-way radios. Hospitals and health care facilities may be
using equipment that could be sensitive to external RF energy.

Vehicles

RF signals may affect improperly installed or inadequately shielded electronic
systems in motor vehicles. Check with the manufacturer or its representative
regarding the vehicle. Also consult the manufacturer of any equipment that has
been added to the vehicle.

Posted Facilities

Disable operation of the TrimTrac locator by removing the battery pack in any
facility where posted notices prohibit the use of wireless phones or two-way
radios.

Aircraft

FCC regulations prohibit using wireless phones while in the air. Disable operation
of the TrimTrac locator by removing the battery pack prior to boarding or loading
in on an aircraft

Blasting Areas

To avoid interfering with blasting operations, disable operation of the TrimTrac
locator by removing the battery pack when in a “blasting area” or in areas posted:
“Turn off two-way radio”. Obey all signs and instructions.

Potentially Explosive Atmospheres

Disable operation of the TrimTrac locator by removing the battery pack prior to
entering any area with a potentially explosive atmosphere and obey all signs and
instructions. Sparks in such areas could cause an explosion or fire resulting in
bodily injury or even death.

Areas with a potentially explosive atmosphere are often, but not always marked
clearly. Potential areas may include: fueling areas (such as gasoline stations);
below deck on boats; fuel or chemical transfer or storage facilities; vehicles using

DRAFT TrimTrac Locator Technical Manual 3

liquefied petroleum gas (such as propane or butane); areas where the air contains
chemicals or particles (such as grain, dust, or metal powders); and any other area
where it would normally be advisable to turn off motor vehicle engines.

For Vehicles Equipped with an Air Bag

An air bag inflates with great force. DO NOT place objects, including the
TrimTrac locator, in the area over the air bag or in the air bag deployment area. If
in-vehicle wireless equipment is improperly installed and the air bag inflates,
serious injury could result.

Specific Absorption Rates (SAR)

THE TRIMTRAC LOCATOR MEETS CERTAIN GOVERNMENT
REQUIREMENTS FOR EXPOSURE TO RADIO WAVES.

The TrimTrac locator is a radio transmitter and receiver. It is designed and
manufactured not to exceed the emissions limits fro exposure to radio frequency
(RF) energy set by the Federal Communications Commission of the U.S.
government when used in accordance with the instructions set forth in this
manual. These limits are part of comprehensive guidelines and establish
permitted levels of RF energy for the general population. The guidelines are
based on standards that were developed by independent scientific organization
through periodic and thorough evaluation of scientific studies. The standards
include a substantial safety margin designed to assure the safety of all persons,
regardless of age and health.

The exposure standard for wireless mobile phones employs a unit of measurement
known as the Specific Absorption Rate, or SAR. The SAR limit set by the FCC is

1.6W/kg.1 Tests of SAR are conducted using standard operation positions
specified by the FCC with the phone transmitting at its highest certified power
level in all tested frequency bands. Although the SAR is determined at the
highest certified power level, the actual SAR level of the phone while operating
can be well below the maximum value. This is because the phone is designed to
operate at multiple power levels so as to use only the power required to reach the
network. In general, the closer the device is to a wireless base station antenna, the
lower the power output.

Before a phone is available for sale to the public, it must be tested and certified to
the FCC that it does not exceed the limit established by the government-adopted
requirement for safe exposure when used in accordance with manufacturer
instructions. The tests are performed in positions and locations (e.g. near or on
the body) as required by the FCC for each model. The SAR value for the
TrimTrac locator is less than 1.6 W/kg measured at a minimum separation
distance of 0.590 inch (15 mm). The TrimTrac locator is not to be body-worn.

1

In the United States and Canada, the SAR limit for mobile phones used by the public is 1.6 watts/kg
(W/kg) averaged over one gram of tissue. The standard incorporates a substantial margin of safety to give
additional protection for the public and to account for any variations in measurement.

DRAFT TrimTrac Locator Technical Manual 4

The FCC has granted an Equipment Authorization for the TrimTrac locator with
all reported SAR levels evaluated as in compliance with the FCC RF guidelines
for devices not worn on the body. SAR information on the TrimTrac locator is on
file with the FCC and can be found under the Display Grant section of

http://www.fcc.gov/oet/fccid after searching on FCC ID: JUPTRIMTRAC1.

Additional information on Specific Absorption Rates (SAR) can be found on the
Cellular Telecommunications & Internet Association (CTIA) Web site at

http://www.phonefacts.net

DRAFT TrimTrac Locator Technical Manual 5

Overview

Introduction

This manual covers the TrimTrac locator operating on 900 MHz, 1800 MHz and
1900 MHz GSM networks. As used in this manual, the term GSM shall include
any and all of these frequencies.

Regulatory Approvals

CE

The TrimTrac product complies with the essential requirements of the
R&TTE Directive 199/5/EC as stated by the EC Declaration of Conformity
(CE0681) and the EC R&TTE Type Examination Certificate.

The TrimTrac product complies with the European Telecommunications
Standards Institute Specifications ETS300-342-1 (EMC for GSM 900MHZ
and DCS 1800MHZ Radio Equipment and Systems).

EEC

The TrimTrac product complies with Directive 72/245/EEC as amended by
Directive 95/54/EC (el*72/245*95/54). 1.1.2

FCC

The TrimTrac product complies with the FCC Part 15, FCC Part 24, and
Industry Canada requirements.

The TrimTrac product complies with Part 15 of the FCC rules. Operation is
subject to the following two conditions:

(1) This device may not cause harmful interference, and
(2) This device must accept any interference received, including

interference that may cause undesired operation.

TrimTrac Locator

The TrimTrac locator is housed in a single, compact enclosure that simplifies
installation and leads to greater reliability. The standard TrimTrac locator has four
end-user replaceable alkaline AA batteries and there are no external antennas or
other external connections. This package is a mobile communications and

DRAFT TrimTrac Locator Technical Manual 6

positioning system module ideally suited for high volume automotive and asset
management applications requiring a low-cost, battery or externally powered
tracking device. It operates over the GSM cellular networks and allows simple,
fast, and efficient transfer of information between a mobile asset and an
application hosted either on a server or on an end-user PC.

Standard Features

The TrimTrac locator integrates the following into a single package:

• GSM 900/1800/1900 MHz

• High-sensitivity, 12-channel GPS receiver

• Internal GSM and GPS antennas

• TrimTrac application firmware and other integrated functions

• Password-protected data communications

• Support for limited data logging that allows the TrimTrac locator to store

up to 128 position or status records for subsequent download

Subscriber Identity Module (SIM)

You must install a SMS-enabled Subscriber Identity Module (SIM) that
has been initialized by your GSM service provider.

Optional Plug-In Modules

The following options are available as plug-in modules that replace the
standard TrimTrac locator batteries:

• Provisioning Module. Allows configuration of the TrimTrac locator via

a USB connection to a PC

• Vehicle Adapter Module. Allows connection to an external 9-32 VDC

power supply and provides 2 open/closed switch-monitoring connections.

DRAFT TrimTrac Locator Technical Manual 7

Global System for Mobile Communications

Cellular mobile telephone systems are widely available throughout the world.
However, because cellular mobile telephone systems are regulated at the national
level, these systems are not generally compatible with each other. To resolve the
dilemma of being able to communicate from almost anywhere, but only within
your own system, the European telecommunications operators—the Conference
of European Postal and Telecommunications Administration (CEPT)—designed a
new mobile telephone network.

This network has evolved into GSM, and CEPT has turned over management of
GSM to the European Technical Standards Institute (ETSI). GSM is the
predominant mobile communications system throughout the world. Outside the
United States, most GSM systems operate at 900 MHz, 1800 MHz or both and
services provided by these networks are generally referred to as Digital
Communication Services (DCS). The United States GSM system operates at 1900
MHz and is generally referred to as Personal Communication Service (PCS).

GSM Cellular Phone System

The Global System for Mobile (GSM) protocol offers a variety of data services
that allow users to send and receive data at rates of up to 9600 bps. Data can be
delivered over ISDN, Packet Switched or Circuit Switched Data Networks (PSDN
or CSDN) and via the Short Message Service (SMS). The TrimTrac locator uses
SMS, which is a store-and-forward service for the bi-directional exchange of
alphanumeric messages of up to 160 characters.

Architecture of the GSM network

Any asset tracking or management system on GSM consists of several distinct
components. The TrimTrac locator is the mobile unit that is installed in the
vehicle, equipment or other mobile asset and contains the Subscriber Identity
Module (SIM). The SIM card contains a unique International Mobile Subscriber
Identity (IMSI) number. This enables the network to identify the user and
therefore allow the terminal to have access to specific, subscriber services.

DRAFT TrimTrac Locator Technical Manual 8

The GSM system is made up of two sections:

• The Base Station Subsystem that controls the radio link with the mobiles

through local cells

• The Network Subsystem that controls the switching of calls between the

network users, mobile to mobile, and between mobile and fixed lines

The Network Subsystem stores all administrative information including the
current cell being used by the mobile unit that allows call routing and the roaming
ability of GSM. An important feature of GSM is this ability to move across
international and network borders, a feature that is described as “roaming.” If
arrangements have been made with the service provider, the SIM card will be
enabled for roaming.

• Mobile Station (MS)

o The TrimTrac locator includes a radio transmitter and receiver.
o Subscriber Identity Module (SIM) – an electronic card containing a

computer chip. The chip contains the subscriber information and
operating system parameters. SIMs provide authentication,
encryption, information storage, and subscriber account protection
services (including Personal Identity Number or PIN, and Pin
Unblocking Key or PUK). GSM users can move the SIM from one
TrimTrac locator to another.

• Other network components (part of the GSM network)

o Short Message Service Center (SMSC)
o Delivers text messages (up to 160 characters) to GSM users.

GSM Operational Overview

The TrimTrac locator operates in accordance with the state diagram more fully
described the Operation chapter beginning on page 24 of this manual.

Whenever the TrimTrac locator has a new position or status to report, it updates
its Status Message. The TrimTrac locator then enters the GSM Transmit State
and automatically searches for a GSM network using a set of tables on the SIM
card to determine which GSM network the phone should try to reach.

DRAFT TrimTrac Locator Technical Manual 9