RIM 902M Integrator Manual

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RIM 902M OEM Radio Modem Integrator’s Guide
Last Updated: January 11, 1999

Model No. R902M-2-O

1999, RESEARCH IN MOTI ON LIMITED

©

Research In Motion and RIM are registered trademarks of Research In Motion Ltd.
Mobitex is a trademark of the Swedish Telecommunications Administration.
MS-DOS is a registered trademark, and Windows is a trademark, of Microsoft Corp.

Warning: This document is for the use of licensed users only. Any unauthorised
copying, distribution or disclosure of information is a violation of copyright laws.

While every effort has been made to ensure technical accuracy, information in this
document is subject to change without notice and does not represent a commitment on
the part of Research In Motion Limited.

Researc h In M oti on

295 Phillip Street
Waterloo, Ontario
Canada N2L 3W8
tel. [phone]
fax [phone]

E-mail: [e-mail]
Web sit e : www.rim.net

MOBITEX I nterface, sp ecified

in Specification

LZBA 703 1001,

compatible equipment

FCC Compliance Statement (USA)

FCC Class B Part 15
This devi ce compl ies with Part 15 of FCC Rules. O peration i s subject to

the following two conditions:

1. T his devi c e may not cause harm ful i nterference, and

2. This device must accept any interference received, including
interference that may cause undesired operation.

Warning

Changes or modifications to this unit not expressly approved by the
party responsible for compliance could void the user’s authority to
operate this equi pment.

This equipment has been tested and found t o c omply wit h 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
interf erence i n a residenti al i nstallat ion. T his equipm ent generat es, uses
and can radiate radio frequency energy and, i f not i nstalled and used in
accordance with the manufacture’s instructions, may cause harmful
interference to radi o c ommunications.

There is no guarantee, however, that interference will not occur in a
particul ar installat ion. If thi s equipment does cause harm ful i nterf erence
to radio or t elev ision recepti on, which can be determ ined by tur ning the
equipment off and on, the user is encouraged to try to correct the
interference by one or m or e of the following measures:

x

Re-orient or r elocate the receiv ing antenna.

x

Increase the separation between the equipment and r ec eiv er .

x

Connect the equipm ent int o an outlet on a circ uit di ff erent f rom

that to which t he r ec eiver is connected.

x

Consult the dealer or an experienced radio/TV technician for

help.

Industry Canada Certification

This device complies with Industry Canada RSS 119, under certification
number TBD.

IC Class B compliance

This device complies with the Class B limits for radio noise emissions as set
out in the interference-causing equipment standard entitled “Digital
Apparatus,” ICES-003 of Industry Canada.

Contents

FCC Complia nce S t a tement (USA)
Industry Canada Certification

........................................i

...............................................ii

About this guide....................................................................v

1. Introduction...............................................................1

Radio performance...................................................................... 1

Mobitex network technology....................................................... 4

FCC radio frequency exposure rules............................................ 5

2. Getting started...........................................................9

Test board overview...................................................................10

How to connect the test board.....................................................11

The MENU diagnostics tool.......................................................12

3. Mechanical integration........................................... 21

Environmental properties...........................................................21

Physical properties.....................................................................22

Mounting methods.....................................................................24

Cables and connectors................................................................27

4. Power requirements................................................ 31

Load specifications ....................................................................31

Batteries ....................................................................................32

Plug-in supplies.........................................................................34

Automotive supplies...................................................................34

5. Interface specification............................................. 35

MASC and RAP link-layer protocols .........................................35

Pin descriptions.........................................................................37

How to turn the radio on and off................................................42

Interface to an RS-232 device.....................................................43

Interface to microprocessor........................................................43

6. Antenna selection .................................................... 45

Selecting an antenna..................................................................45

Introduction to antenna terminology..........................................46

Positioning the antenna..............................................................49

Shielding...................................................................................50

Specifications ...................................................................... 51

Glossary of terms................................................................53

Index....................................................................................55

About this guide

This document is a guide to integrating the RIM 902M OEM radio modem into
a variety of devices such as laptop computers, handhelds, vending machines,
point-of-sale terminals, vehicle-based mobile terminals, and alarm system.

Topics covered in this guide include:

x

mounti ng requirements

x

power (battery) characteristics

x

in t er facing to th e RIM 902M

x

antenn a selection and placement

Throughout the guide, there are suggestions and precautions that will ease the
implementation of a wireless communication solution. These recommendations
are based on years of experience integrating wireless modems into a variety of
devices. You are welcome and encouraged to contact RIM if you would like to
discuss the technical implementation of this radio modem.



Introduction

1.

With the in troduction of the RIM 902M, Research In Motion (RIM) has set a
new standard for radio modem performance. The RIM 902M is unr ivaled i n the
key areas of r eceiver sensitivity, ouput efficiency, noise immunity, and power
consumption. Its small size and weight make it suitable for virtually any
wireless data application, including handheld devices and mobile terminals.

The RIM 902M is designed for use with Mobitex wide-area wireless data
networks operating in the 900 MHz range, such as the BellSouth Intelligent
Wireless Network.

RIM radio modems are specifically designed to integrate easily into a computer
or other embedded system. Potential applications include:

x

Laptop computers

x

Point of sale devices

x

Ruggedized terminals

x

Handheld PC’s

x

Parking meters

x

Dispatching

x

Vehicle tracking and location

x

Monitoring and telemetry

x

Vending machines

x

Utility meters

x

Billboards

x

Security alarm panels

Radio performance

The RIM 902M offers the highest performance of any radio modem for
Mobitex wireless data networks:

2 Introduction – Radio performance

Receiver sensitivity

Receiver sensitivity is a measure of how well a radio modem can “hear” a
network base station. This figure is important when a device will be used in
areas where signal strength is weak, such as inside buildings and in locations
that are not close to a base station. A radio modem with good receiver
sensitivity can be used in more places than a radio modem with poor sensitivity.

The RIM 902M has a receiver sensitivity of –118 dBm, or 0.0016 picowatts.
This is the strength of the weakest digital signal that can be interpreted with a
1% bit error rate. Although 1% may seem high, the sophisticated over-the-air
Mobitex protocol corrects these errors before the data is passed to the
application, ensuring error-free communication. This capability is already built
into the radio’s firmware, and does not require any additional software
development.

Noise immunity

The RIM 902M is not de-sensitized by the electromagnetic interference (EMI)
or “noise” that is generated by the electronics of the terminal into which it is
integrated. As a result, no special shielding is required between the radio and
your device.

Noise immunity offers several benefits, including:

x

easier integration

x

longer battery life

x

increased reliability

x

im proved RF perfor mance

x

more coverage from each base station

x

no need for special RF shielding

Powerful and efficient transmitter

When necessary, the RIM 902M can supply a full 2.0 watts to the antenna.
However, the RIM 902M quickly decreases the output power when it is close to
a base station  to as little as 0.06 watt – because a stronger signal is needed
only when far from a base station. By transmitting a strong signal only when
necessary, the RIM 902M conserves battery power.

The RIM 902M provides reliable transmit efficiency across the entire operating
voltage range of 4.15 to 4.75 volts. As a result, batteries can be used even when
nearing depletion. This also maximizes the radio coverage area throughout the
life of the battery.

Integrator’s Guide – RIM 902M OEM Radio Modem

Introduction – Radio performance 3

Low power requirements

If you are planning to integrate the RIM 902M into a handheld or portable
device, battery life is a critical issue: your customers will insist on long lasting
devices without heavy battery packs. The RIM 902M sets a new power
consumption standard for Mobitex radio modems. This ensures efficiency an d
maximizes battery life.

Transmitting data: 1.7 amps or less (at 4.5V), depending on output power

The transmitter is ON for a pulse of between 32 ms and 1 second per
packet, depending on the amount of data transmitted. The maximum
packet size for a Mobitex device is 512 bytes.

Receivin g d ata: 60 mA (at 4.5V)

The radio turns its receiver ON for a 150 ms “window” once every 10
seconds. The base station will only attempt to communicate with the radio
during this window. To minimize latency during rapid two-way
communication, the receiver is also turned ON and kept ON for 10
seconds after any communication (transmit or receive) with the network.

Standby power: 0.3 mA (at 4.5V)

Standby power consumption is very low and occurs when no radio activity
has taken place for at least 10 seconds. The radio and base station are
closely synchronized to ensure that a communication attempt is not missed
when the radio is in standby mode.

Battery life is not a concern for certain applications, such as in-vehicle
applications that draw power from the vehicle battery. For these applications, it
is possible to put the radio in an express operating mode, in which power
consumption is higher than normal but packet transfer latency is reduced to a
minimum.

Small size

Using a single board design, the RIM 902M is very thin, and much smaller
than a business card, at only 42.0 by 67.5 mm. This tiny size allows the
RIM 902M to meet tight space requirements within most applications. The fact
that a single board is used means that the device is much more reliable than
multi-board designs, particularly in high-vibration environments such as
vehicles.

RIM 902M OEM Radio Modem – Integrator’s Guide

4 Introduction – Mobitex network technology

Mobitex network technology

The Mobitex wireless network technology, developed by Eritel in 1984 for
Swedish Telecom, has become an international data communication standard.
Now managed by the Mobitex Operators Association (MOA), which controls
the specification s for this open standard, Mobitex is a secure, reliable, wireless
packet switching network specifically designed for wide-area wireless data
communications.

Mobitex networks are deployed around the world. The technology is presently
available in the following countries:

x

Australia

x

Austria

x

Belgium

x

Canada

x

Chile

x

Finland

x

France

x

Germany

x

Indonesia

x

Italy

x

Korea

x

Netherlands

x

Norway

x

Poland

x

Singapore

x

Sweden

x

Turkey

x

United Kingdom

x

United States

x

Venezuela

Mobitex networks in the United States, Canada, Korea, Chile, and Venezuela
operate in the 900 MHz range, and are therefore directly compatible with the
RIM 902M OEM radio modem. Currently, Mobitex networks in other countries
operate at other frequencies, such as 400 MHz.

Mobitex provides highly reliable, two-way digital data transmission. The
network provides error detection and correction to ensure the integrity of the
data being sent and received, and incl u d es transmission acknowledgment.

The Mobitex network has a hierarchical structure that allows messages to be
rout ed from sen der t o receiver alon g th e most di rect pa th possible. Ea ch r adi o
cell is served by an intelligent base station. Because intelligence is distributed
throughout the network, data is only forwarded to the lowest network node
common to the sen der a n d th e r ecei ver . For exa mp le, on e bas e station is able to
handle all traffic in its coverage area.

The network constantly monitors the location of the mobile users. As a mobile
moves from one area of coverage to another, base stations track its signals,
sending updated mobile location and status information to the network. If the
network goes down at any point in transmission, the message is held until
networ k service is restored . If th e mobile recei ver moves outsi de the cover age
area, the base station stores the data until coverage is re-established, then

Integrator’s Guide – RIM 902M OEM Radio Modem

Introduction – FCC radio frequency exposure rules 5

forwards it to the mobile. This prevents data loss, and increases the reliability
of transmission.

Mobitex is optimized for data communication. It uses a packet switching
technique to provide the greatest flexibility in data transmission. Conventional
cellular phone systems, by contrast, use a circuit-switched network, in which a
physical connection is created between the sen ding an d receiving nodes, and
must be maintained throughout the duration of the transmission. With circuit­switched systems, the set-up time for establishing a connection involves
significant overhead and airtime cost, especially when only a small amount of
data needs to be transferred.

Mobitex packets include information about the origin, destination, size, type,
and sequence of data to be sent. This enables packets to be transmitted
individually, in any order, as traffic permits. Internal to the network, individual
packets may travel along different routes, in any order, without interfering with
other packets sent over th e same fr equency by differen t user s. At t he r eceivin g
end, all packets are accoun ted for, and reassembled into the original message.

Set up time is eliminated and network connection is instantaneous. As a result,
packet-switching makes far more efficient use of channel capacity, typically
allowing 10 to 50 times more users over a radio channel than a circuit switched
network.

FCC radio frequency exposure r ules

Based on FCC rules 2.1091 and 2.1093
Exposure to Radio Frequency Electromagnetic Fields, OET Bulletin 65 and its
Supplement C

(2)

, all integrations of the RIM 902M OEM unit are subject to
routine environmental evaluation for RF exposure prior to equipment
authorization or use.

For portable devices, defined in accordance with FCC rules as a transmitting
device designed to be used within 20 cm of the user body under normal
operating conditions, RF evaluation must be based on Specific Absorption Rate
(SAR) limits in Watts/kg. SAR is a measurement of the rate of energy
absorption per unit mass of body tissue.

For mobile devices, defined as a transmitting device designed to be generally
used such that a separation distance of at least 20 cm is maintained between the

RIM 902M OEM Radio Modem – Integrator’s Guide

(1)

and FCC Guidelines for Human

6 Introduction – FCC radio frequency exposure rules

body of the user and the transmitting radiated structure, the human exposure to
RF radiation can be evaluated in terms of Maximum Permissible Exposure
(MPE) limits for field strength or power density in mWatts/cm

RIM will submit module specific information and test reports for a generic
MPE compliance. For an end product not covered by RIM testing and
submission, the integrator will submit for a separate FCC ID. The submission
should include end product information, end product SAR/MPE test report and
a reference to RIM module FCC ID for all other Part 90 requirements.

SAR and MPE limits

SAR limits for General Population/Uncontrolled exposure is 1.6 W/kg for
partial body exposure, averaged over 1 g of tissue and 4 W/kg for han ds, wrists
and feet averaged over 10 g of tissue. The limits for Occupational/Controlled
exposure are more relaxed, i.e., 8 W/kg for partial body and 20 W/kg for hands,
wrists and feet. The 1.6 W/kg limit applies for most of RIM OEM integrators.

2

The limit for MPE is 0.6 mW/cm

at 900 MHz.

2

.

Guidelines

RF exposure distance is based on normal operating proximity to the user’s
body. This distance is measured from the feed point of the antenna to the
closest body part. A test need to be performed to determine the passing distance
that meets the exposure limits.

Operating manual compliance statement

The integrator should include a statement in their operation/user/installation
manual making the user aware of RF exposure issues and insuring that the
users keep a passing distance from the antenna while transmitting.

Also the integrator should provide instructions or diagrams in the manual for
proper antenna mounting and position, when applicable, to ensure a safe
exposure distance to the operator and nearby persons.

Integrator’s Guide – RIM 902M OEM Radio Modem

Introduction – FCC radio frequency exposure rules 7

Label

If the final device configuration cannot be controlled so as to limit the user
distance to the antenna then the device needs to have an RF radiation hazard
label warning the user to keep away from the antenna by the specified distance.

RIM 902M OEM Radio Modem – Integrator’s Guide



2.

Getting started

RIM is committed to facilitating the integration of the RIM 902M OEM radio
modem. We provide the necessary resources to evaluate the feasibility of
implementing a wireless communication solution, and work closely with our
partners to develop an application in the shortest time possible.

Years of intense R&D have spawned several tools that have been used
internally to help streamline our own development process. We have included
many of these tools with the RIM 902M OEM Developer’s Kit. The pur pose of
the Ki t is to accel erat e rad io int egration and to help system designers evaluate
the RIM 902M. Using the Kit, you can quickly begin interfacing the radio
modem to your computing device.

We’re here for you!

RIM has a team of experienced engineers who can support you in the design
and implementation of your project. If you need help getting started, or if you
have any questions about the radio technology or its integration into your
platform, please contact the RIM 902M engineering development team:

e-mail:
phone:
fax:
web:

[e-mail]
[phone]
[phone]
www.rim.net

10 Getting started – Test board over view

Test board overview

The RIM test board provides a standard RS-232 serial interface between a PC
and the radio modem. It is designed to help you quickly interface the
RIM 902M to a standard PC (through a COM port) or a termi nal device with
an RS-232 serial port. The test board also provides access points to the radio’s
serial communication port, which allows you to monitor activity with a logic
probe, multimeter, or oscilloscope.

The test board includes the followin g components and functionality:

RS-232 interface

The serial (COM) port on a PC and most terminal devices operates at RS-232
signal levels, which are typically r12V. This high voltage would damage the
RIM 902M, which is typically integrated into a device that operates an
asynchronous serial port at 3.0V. The RS-232 interface on the test board allows
you to produce an output from the radio that is easily interpreted by a PC.

Test points

The test board is more than just an RS-232 int erface. It also features debugging
facilities to help you test your application. It provides direct access to each of
the 22 pins on the serial data cable, which allows connectivity to analytical
equipment (e.g. logic probe, multimeter, or oscilloscope) and real-time
indication of data flow.

On/off switch

With the switch in the ON position, the radio will turn on whenever power is
applied to the test board. When th e switch is m oved to the OFF position, the
radio will shut down.

Power supply

The RIM 902M must be provided with a clean, h igh-current power source. In
this case, we use a standard plug-pack to provide the current necessary to

Integrator’s Guide – RIM 902M OEM Radio Modem

Getting started – How to connect the test board 11

operate the radio. The voltage is converted into the necessary levels by the
power supply section on the test board.

LED indicators

The test board includes several LED indicators designed to indicate the flow of
data to and from the host (in real time), the radio power status, power to the test
board, and more.

How to connect the test board

Now that you are familiar with the components and functions of the test board,
you are ready to connect the RIM 902M radio modem to an antenn a and to a
PC (or some other computing device with an RS-232 serial interface). To do
this, you will use the test board and cables supplied with your RIM 902M
Developer’s Kit.

1. Flat serial cable (test board to radio)

The flat serial interface cable carries data between the test board and the
RIM 902M. Control and status signals such as TURNON are also carried on
this cable. Use this cable to connect the RIM 902M’s serial connector to the test
board.

This cable also carries clean, regulated power to the RIM 902M.

When inserting the cable, ensure that the side with the bare pins are in direct
contact with th e pin side of the connector.

2. DB-9 serial cable (test board to PC)

Connect the male end of the straight-through DB-9 serial cable to the test
board.

Connect the female end of the cable to your PC’s COM port.

RIM 902M OEM Radio Modem – Integrator’s Guide

12 Getting started – The MENU diagnostics tool

3. Power adapter (test board to AC outlet)

Plug the 120VAC-to-12VDC power adapter into the wall outlet. Connect the
other end to the p ower jack of the test board.

4. Antenna cable (radio to magmount antenna)

Your developer’s kit includes a high-performance, 6dB-gain magmount
antenna. This antenna is terminated with a screw-on SMA plug. The
RIM 902M radio modem includes a snap-on MMCX jack. The anten na cable
supplied with your developer’s kit connects the antenna’s SMA plug to the
radi o’s MMCX ja ck.

The magmount antenna provides the best RF performance when placed on a
broad metal surface, such as the roof of a car. When used inside a building,
performance is improved if the antenna is located near a window, with few
obstacles (wall, furniture, equipment, etc.) between the antenna and the
window. The antenna performs equally well if it is positioned upside down.

5. Turn the system on

The power switch on t he test board is conn ected to th e TURNON line of the
RIM 902M radio modem. To determine whether the radio is on, look at the
LED marked ONI. It is lit wh en th e radio is on.

The MENU diagnostics tool

Now that you have successfully connected your RIM 902M radio modem to
your PC, you are ready to send a test packet through the Mobitex network.

Your radio modem should be activated by the network operator in order to be
used on the Mobitex network and to establish an airtime agreement. If you have
not already arranged for activation of your radio, contact your network
operator.

Integrator’s Guide – RIM 902M OEM Radio Modem

Getting started – The MENU diagnostics tool 13

The RIM 902M contains a diagnostic utility called MENU. With this utility,
you can set the current network, “ping” your radio modem, or view radio and
network status values.

Setup

The following instructions assume that your RIM 902M is connected to a PC
running a terminal program, such as Windows HyperTerminal. The MENU
utility is based in the RIM 902M’s firmware, so HyperTerminal is the only
software required to use it.

The MENU utility’s user interface is a full-screen text mode interface, and uses
the ANSI cursor command set. Programs like HyperTerminal support the ANSI
codes by default. If you are using a different terminal program that does not
provide ANSI cursor control, the MENU utility will drop into a line-by-line
interface. The appearance of the line-by-line interface is not documented here,
but the commands it uses are the same as those described below.

Select the COM port which communicates with the RIM 902M and configure
for 9600 bps, and either 7E1 (7 bits, Even parit y, 1 stop bit) or 8N1 (8 bits, No
parity, 1 stop bit). If you have set this up correctly, you will see bursts of
characters from the r adio modem such as ^0010B 47E,0:5D. These character
bursts are normal; the represent a MASC B frame, wh ich you can i gnore for
now.

Type the word menu (all in lower case letters only) then press the ENTER key.
You can expect to see a full screen of information. If nothing happens, simply
re-enter me nu until the radio modem responds. The word “menu” itself will
probably not appear on the screen as you type it in.

If you re-enter menu and nothing occurs, ensure that the radio is turned on and
connected to the PC, and that all cables are securely connected. Please contact
RIM for assistance if you are stuck at this point.

Once the utility has been started, the terminal program’s screen will look
similar to the followin g:

RIM 902M OEM Radio Modem – Integrator’s Guide

14 Getting started – The MENU diagnostics tool

RIM 902M Firmware Version 1.0.0

(c) 1999 Research In Motion Limited

Radio Setup Radio Serial Number = 031/11/066300

Command Key Description Networks Available:

----------- ----------- ------------------­Q Quit and reset the radio. 1. RMDUS (B433/B433)

2. CANTEL (C4D7/C4D7)
N Set the current network.
P Ping: Send a Status MPAK to yourself.

Your Choice ?

MAN=16231144 RSSI= 40% 24 dBuV Battery= 97% Network=RMDUS (B433/B433)
Contact=Yes Mode=PowerSave Live Tx=Enabled Active=Yes Group List=Born
UpFreq=02FF DoFreq=0F2F Base/Area=14/0A Status=0080

The screen displays the software version and build date, the radio modem’s
serial number, the list of available Mobitex radio networks, current radio
modem status indicators, the “ping” function, and other relevant information.

RSSI stands for Received Signal Strength Indicator. This is a measure of
network coverage. The higher the number, the better the coverage. The RSSI is
given both as a percentage and in dBPV (decibel microvolts). To obtain the
RSSI in dBm (decibel milliwatts), subtract 113 from the dBPV value. Note that
RSSI= 0% 0 dBPV does not necessarily represent the complete absence of a
signal; in many cases, the radio is capable of communicating with the network
at signal strengths of 0 dBPV or even less. Actual contact with the Mobitex
network would be indicated by the Contact field. The RSSI is updated every
ten s econds, or when ever you press D.

The Battery indicator shows the level of supplied voltage. The battery level is
upda ted once ever y thir ty seconds, or when ever you press D.

Network tells you which network you are currently using. The example shows
RMDUS (BellSouth Wireless Data, formerly RAM Mobile Data, operates a
Mobitex network in the United States) and CANTEL (Cantel AT&T operates a
Mobitex network in Can ada ).

MAN stands for Mobitex Access Number, which is a unique number that
identifies each Mobitex radio modem. The MAN is used for add ressing packets.
The screen will also display a Radio Serial Number, which is unique to each

Integrator’s Guide – RIM 902M OEM Radio Modem

Getting started – The MENU diagnostics tool 15

radio modem. This number is often referred to in other documents as ESN
(Electronic Serial Number) or MSN (Mobitex Serial Number).

Mode shows whether the radio is in powersave mode or express mode. The
default operating mode is powersave, wh ich reduces power consumption by th e
radio but introduces a latency of up to 10 seconds when receivin g p acket s from
the network. This mode may be changed through software.

Tx is an indicator to let you know whether the radio’s transmitter is enabled or
disabled. The transmitter may be enabled or disabled through software, and is
normally enabled. The Mobitex base station may also instruct a radio to shut
down (also referred to as DIE) if it is an illegal device, or not registered, or
causing disruption to the Mobitex network. The word Live on the status line
indicates that the radio is not in a DIE state.

A ra d io modem receives a Group List when it is powered up and registers with
the network base station. Normally, you would see Group List=OK, which
indicates that the radio has successfully signed onto a base station. If you see
Grou p List =Bor n , th en ei th er your devi ce i s out of cover ag e, or it h a s n ot been
activated by your network operator. Note that it can take 30 seconds for a radio
to display Group List=OK.

UpFreq and DoFreq show the channels (in hexadecimal) that you are using to
transmit and receive, respecti vely. If you are i nteres ted in obtaining the exact
current transmit frequency, divide UpFreq by 80 and add to 890. This gives a
value in MHz. Add 39 MHz to obtain the recei ve chan nel . For exa mple, if th e
display reads “UpFreq=02FF DoFreq=0F2F” then convert hexadecimal 02FF to
decimal 767, divide by 80 and add to 890, and obtain 899.5875 MHz, which is
the transmit channel. Add 39 MHz (or repeat the calculation using DoFreq) to
deter min e that th e receive ch annel at 938. 5875 MHz.

Base/Area indicate which base station you are using. Every base station in the
network is assigned a unique Base/Area combin ation. Base stations in the same
geographic area often share an Area address. Contact your network operator if
you want to know the location of network base stations.

Status describes the current state of the radio. Other documentation may also
refer to the Status value as the radio’s internal fault bits. The following table
shows the interpretation of the Status bits. If the Status value displayed on your
screen does not correspond to any of the values below, then determine which
values add together in hexadecimal to give the Status value that you see. For
example, status value B403 would simultaneously describe states A000, 1000,
0400, 0001, and 0002, as described below.

RIM 902M OEM Radio Modem – Integrator’s Guide

16 Getting started – The MENU diagnostics tool

0000 The radio modem status is normal. There are no warnings.
0001 The RIM 902M has been out of coverage for a long time. No adequate base

station was found. Possible causes include lack of network coverage, wrong

network selected, or the battery level is too low.
0002 This is a new RIM 902M being used for the first time. No action is necessary.
0008 The radio modem has exhausted its internal memory. This should not happen

under ordinary use. Turning the radio modem off and back on will resolve this.
0020 The network has issued a DIE command to the radio modem, perhaps because

it is not registered on the network. No data can be sent to the network until a

LIVE command is issued by the network. Contact the network operator for

help.
0040 The modem’s transmitter has been disabled by your software, using either the

MASC “F M0” or RAP “Turn Transmitter Off” command. The transmitter can

be turned back on with the MASC “F M1” or RAP “Turn Transmitter On”

command, or by resetting the radio.
0080 The radio modem has not yet received a grouplist from the network. If this bit

remains set after the modem has been in network coverage for several minutes,

your radio modem is probably not activated. Contact the network operator to

activate your device.
0100 Another device may be using the same MAN number as your device on the

same base station. This should not happen under ordinary use. It may cause

duplicate, dropped, or mixed up packets. Contact the network operator to

determine whether two units have the same MAN number.
0800 The RIM 902M may be having a problem remembering its last base st ation. If

the problem persists, the unit should be returned for repair.
1000 The RIM 902M has received an unknown interrupt and might be having

problems receiving packets. If the problem persists, the unit should be returned

for repair.
2000 The RIM 902M has received an unknown interrupt. No action is necessary.
4000 The RIM 902M has been damaged and cannot be used until this problem is

corrected. The unit should be returned for repair.

How to change to a different network

The RIM 902M radio may be used on different Mobitex networks operating on
different channels in the 900 MHz range. Up to 16 network channel lists may
be programmed by RIM into each radio. If the network shown is not the correct
one, you can choose another from the list of networks available. Press N and
the MENU utility will present an additional prompt for selecting the network,
as shown be low.

Integrator’s Guide – RIM 902M OEM Radio Modem

Getting started – The MENU diagnostics tool 17

RIM 902M Firmware Version 1.0.0 release

(c) 1999 Research In Motion Limited

Radio Setup Radio Serial Number = 031/11/066300

Command Key Description Networks Available:

----------- ----------- ------------------­Q Quit and reset the radio. 1. RMDUS (B433/B433)

2. CANTEL (C4D7/C4D7)
N Set the current network.
P Ping: Send a Status MPAK to yourself.

Your Choice ? Choose a network from the list (1..2) ?

MAN=16231144 RSSI= 30% 22 dBuV Battery= 97% Network=RMDUS (B433/B433)
Contact=Yes Mode=PowerSave Live Tx=Enabled Active=Yes Group List=Born
UpFreq=02FF DoFreq=0F2F Base/Area=14/0A Status=0080

Change network name

You may now enter a number corresponding to the desired network shown
under Networks Available. When you press Enter, the radio modem will switch
to the selected network, as shown below. If you do not enter a number, or if you
erase the number you have typed, then no change will occur when you press the
Enter key. Pressing the Esc key will cancel the network set-up command.

The screen below shows what would happen if you typed in 2 and then pr essed
the Enter key. The values shown beside Network, UpFreq, DoFreq, and
Base/Area are different.

RIM 902M OEM Radio Modem – Integrator’s Guide

18 Getting started – The MENU diagnostics tool

RIM 902M Firmware Version 1.0.0

(c) 1999 Research In Motion Limited

Radio Setup Radio Serial Number = 031/11/066300

Command Key Description Networks Available:

----------- ----------- ------------------­Q Quit and reset the radio. 1. RMDUS (B433/B433)

2. CANTEL (C4D7/C4D7)
N Set the current network.
P Ping: Send a Status MPAK to yourself.

Your Choice ?

MAN=16231144 RSSI= 45% 25 dBuV Battery= 97% Network=CANTEL (C4D7/C4D7)
Contact=Yes Mode=Fallback Live Tx=Enabled Active=No Group List=Born
UpFreq=030D DoFreq=0F3D Base/Area=1B/09 Status=0080

Radio update was successful.

“Ping” the network: an end-to-end radio test

You can determine whether your radio modem is working on the network by
pressin g P. When you “ping,” you send a message (MPAK – Mobitex data
packet) to yourself via the wir eless network base station. The MENU utility will
display a message indicating that the MPAK was sent. A few seconds later, it
should a lso indicate that the MPAK was r eceived. This confirms that your rad io
modem is operational and active on the network.

If you get the message “Status MPAK cannot be sent – out of coverage”, then
you are not in an area that is covered by the Mobitex network. You can
determine whether you are in coverage by looking at Contact on the status
lines. If you are certain that you are in a coverage area, but are still not able to
communicate with the network, check the antenna to make sure it is connected
properly an d is deployed properly. Signal quality can vary significantly within a
building. Try moving the antenna to a new location, perhaps near a window, to
see if you can get a signal.

If you get the message indicating that the Status MPAK was sent, but you did
not get one th at it was recei ved, th en you ar e in cover age but your RIM 902M
radio modem has probably not been activated by your network operator, and the
network will not send the MPAK back to the radio. Contact the network
operator to activate your design.

Integrator’s Guide – RIM 902M OEM Radio Modem

Getting started – The MENU diagnostics tool 19

RIM 902M Firmware Version 1.0.0

(c) 1999 Research In Motion Limited

Radio Setup Radio Serial Number = 031/11/066383

Command Key Description Networks Available:

----------- ----------- ------------------­Q Quit and reset the radio. 1. RMDUS (B433/B433)

2. CANTEL (C4D7/C4D7)
N Set the current network.
P Ping: Send a Status MPAK to yourself.

Your Choice ?

MAN=16231227 RSSI= 11% 14 dBuV Battery=100% Network=RMDUS (B433/B433)
Contact=Yes Mode=PowerSave Live Tx=Enabled Active=Yes Group List=Born
UpFreq=02FF DoFreq=0F2F Base/Area=14/0A Status=0080

Received MPAK from 16231227 (to 16231227) Type=03(STATUS ) Traffic/Flags=00

If you are unable to communicate with the network, then contact the network
operator to make sure that your device is activated on the network. If the radio
has not been activated, then the network will not send the MPAK back to the
radio. Second, make sure that you are in network coverage. You can determine
whether you are in coverage by looking at Contact on the status lines. If it
shows Contact=NO, then you are not in an area that is covered by your Mobitex
network. You can also determine whether the antenna is connected properly
and is deployed properly. Signal quality in buildings can vary significantly over
short distances. Try moving the antenna to a new location, perhaps near a
window, to see if you can get a signal. If none of these remedies help, contact
RIM for assistance.

Exiting the utility

When you have finished using the utility, you should press Q to quit. This step
is important because it allows the radio to resume accepting commands from
other software. The screen will clear and you will be informed that the radio
has been reset. You can safely disconnect the radio and close your terminal
program once you have seen this message.

RIM 902M OEM Radio Modem – Integrator’s Guide



3.

Mechanical
integration

This chapter provides information about the RIM 902M that will be useful in
determining the physical positioning of the radio modem within an application.
Environmental properties and testing, physical properties, mounting methods,
and connector information are presented.

Environmental properties

During environmental testing, RIM takes samples of its radio modems and
subjects them to a variety of harsh conditions. We measure over a hundred
digital RF calibration parameters, once before and once after each test. The
difference between these measurements precisely reveal any performance
degradation. Each unit in the sample is also inspected visually after testing.
This experience allows us to fine-tune our design and manufacturing process.

Environmental testing ensures that our products are able to withstand both
typical and extreme real-world conditions in which they will be used. RIM does
not sell units that have been subject to environmental testing.

22 Mechanical integration: Physical properties

Storage temperature

The RIM 902M OEM radio modem may be stored at a temperatur e from -40qC
to +85qC (-40qF to +185qF).

Operating temperature

The RIM 902M is designed to operate between -30qC to +70qC (-22qF to
+168qF).

The en d user should be careful not to exceed the upper temperature limit of
+70qC, as performance degradation or damage to the power amplifier may
occur past this point, especially when packets are transmitted frequently.

Physical properties

Weight

The RIM 902M weighs 1.2 oz (35 g), in cluding the case.

Dimensions

The RIM 902M has been designed to meet the most stringent space
requirements. In most cases, there will be sufficient room in an existing
enclosu re to h ou se the radi o m od em .

The overall maximum dimensions of the radio modem, not including cables,
are:

x

Width : 42. 0 m m

x

Length: 67.5 mm

x

Th i ckn ess: 8.4 mm

Integrator’s Guide – RIM 902M OEM Radio Modem

Mechanical integration: Physical properties 23

RIM 902M OEM Radio Modem – Integrator’s Guide

24 Mechanical integration: Mounting methods

Mounting methods

The RIM 902M OEM radio modem may be securely fastened using a var iety of
methods. The operating environment must be carefully considered when
choosing a mounting option. For example, extreme temperature or heavy
vibration may require a special mounting solution. It is important to ensure that
the RIM 902M remains securely attached in the environment where it will be
used.

The following information is presented as a guide, but applications can vary
considerably. A mechanical engineer can help ensure that the mounting method
is suitable for the specific application.

Bolts

The RIM 902M radio modem includes a hole in each corner, which may be
used to bolt the device onto a circuit board, device housing, or other surface.
The mounting hole pattern is four holes in a 62.5 by 36.5 mm rectangle, with
each hole 2.5 mm in diameter.

The following diagram illustrates the radio mounting details.

Integrator’s Guide – RIM 902M OEM Radio Modem

Mechanical integration: Mounting methods 25

Tie wraps

Tie wraps can be used to as a secure but non-permanent means of attaching the
RIM 902M to a surface. Typically, each tie wrap passes through a hole drilled

RIM 902M OEM Radio Modem – Integrator’s Guide

26 Mechanical integration: Mounting methods

into the surface on either side of the RIM 902M. This allows the radio to be
attached to a shell, a PCB, or some other mounting surface.

If using tie wraps, ensure that the surface beneath the RIM 902M is flat.
Otherwise, the mounting surface could push up on the bottom surface of the
radio case while tightening the tie wraps pushes down on the edge of the radio
case. This could cause the metal case of the RIM 902M to flex upward and
short across components inside the radio, causing the radio to malfunction. For
example, thick adhesive foam tape and tie wr aps should not be used together.

Permanent industrial adhesive

The RIM 902M is small and lightweight enough to be attached to the host
device using an industrial adhesive. For some applications, this method of
mounting is preferable to bolts, because adhesive is easier to use in a
manufacturing environment, and is more resistant than bolts to loosening. In
many cases, an effective solution is to adhere the radio modem to the inside
surface of your product’s casing.

An adhesive should be chosen on the basis of its ability to stick to the material
used in the outer casing of the radio modem and in th e surface to which the
radio will be mounted. The bottom casing of the RIM 902M is magnesium.

3M manufactures VHB, a permanent industrial adhesive with excellent long­term holding power. The peel adhesion and tensile holding power of VHB tapes
are extremely high, making this a suitable solution when the radio will not
need to be removed. Choose foam tape for rough surfaces and adhesive tape for
smooth sur faces.

More information about VHB may be obtained by contacting 3M Industrial
Tape and Specialties Division at 1-800-227-5085 (fax: [phone]). The
publication number for the VHB technical data sheet is 70-0702-0266­1(104.5)R1.

Integrator’s Guide – RIM 902M OEM Radio Modem

Mechanical integration: Cables and connectors 27

Cables and connectors

There are two connectors on the RIM 902M radio modem. These connectors
allow interfacing from the radio modem to a serial computing device, a power
supply, and an ant enna.

Serial cable and connector

The RIM 902M serial communication and control signals are carried on a flat
22-conductor 0.30 mm (0.012”) thick flexible printed circuit (FPC) cable in

1.00 mm centerline spacing, which can plug into a matching connector. Since
each application is unique, Molex can create a custom Flat Flex Cable Jumper
in the correct length and the correct connector orientation for your application.
The minimum cable length available is 30 mm (1.181”).

The serial cable supplied with the RIM 902M Developer’s Kit is a Type D 4”
long Flat Flex Cable Jumper in 1.00 mm centerline spacing, as illustrated in
the following mechanical drawing:

RIM 902M OEM Radio Modem – Integrator’s Guide

28 Mechanical integration: Cables and connectors

This cable can plug into a matching 22-position 1.0 [0.039] horizontal FPC
connector. A variety of connectors are manufactured by Molex. More
information about each connector , including mechanical drawings, is available
fro m th e man ufac ture r’s we b site (www.mo lex. com), or you ca n con tac t RIM
([e-mail]) for help with selecting an appropriate connector for your
application.

Contact:

Molex Headquarters Molex Electronics Ltd.
Lisle, IL, USA Toronto, Ontario, Canada
tel: [phone] tel: [phone]
fax: [phone] fax: [phone]

www.molex.com

Antenna cable and connectors

RIM selected the industry-standard MMCX connector for the RIM 902M
because it is a very small connector that has the mating force to withstand
heavy vibration.

Typically, an antenna does not plug directly into a RIM 902M. Instead, an

connector at the outer casing of the device. This allows the antenna to be
removed from the system with out having to open the device, and it eliminates a
source of strain on th e radio’s MMCX connector.

The antenna cable should have low loss, an impedance of 50 :, and an MMCX
jack that mates with the RIM 902M’s MMCX plug. The other end of the cable
can be any connector you choose, as long as it has an impedance of 50 :. An
SMA screw-on connector is suitable and widely available. TNC connectors are
also suitable, but larger than SMA. The antenna cable supplied with the
RIM 902M developer’s kit has an MMCX connector on one end a nd an SMA
connector on the other. The cable is built with strain reliefs to prevent damage.

Huber & Suhner can provide antenna cables and connectors. The parts
described below have an impedance of 50 : and are suitable for use with the
RIM 902M.

Integrator’s Guide – RIM 902M OEM Radio Modem

Mechanical integration: Cables and connectors 29

11MMCX-50-2-1C/111 Straight MMCX connector
16MMCX-50-2-1C/111 Right -a ngle MMCX connector
25SMA-50-2-25/111 SMA connector
EZ Flex 405 Low-loss matching (50 :) cable
133REEZ4-12-S2/1216 8” cable, straight MMCX to SMA
133REEZ4-12-S2/1699 8” cable, right-an gl e MMCX to SMA

The following cable is included with the RIM 902M Developer’s Kit:

Contact:

Huber & Suhner Huber & Suhner
Essex Junction, VT, USA Kanata, Ontario, Canada
tel: [phone] tel: [phone]
fax: [phone] fax: [phone]

www.hubersuhnerinc.com

RIM 902M OEM Radio Modem – Integrator’s Guide



4.

Power requirements

The RIM 902M radio modem must be provided with a clean power source
capable of delivering bursts of high current . This can be provided by a plug-in
power supply unit, a rechargeable battery pack, or single use batteries. RIM has
conducted extensive research and has developed guidelines for integrators to
follow when designing the power supply system for the RIM 902M.

Load specifications

The RIM 902M draws its power in bursts; th e power required chan ges rapidly
depending on whether the radio is transmitting, recei ving , or in st andby. Th e
load profile is given on the followin g page. These specifications can be given
directly to your power supply designer or battery supplier.

Power supply parameters

The RIM 902M requires a clean, stable 4.15 to 4.75 volt source that is capable
of delivering a one-second burst of up to 1.7A when required by th e tr an smitter.
Under non-ideal conditions such as an improperly matched antenna, however,
thi s bur st could be as hig h as 2 .2 A. Th e r ecei ver cur rent con su mp ti on is 66 m A
and the standby current consumption is 0.07 to 0.2 mA. The maximum no-load

32 Power r equirements: Batt er ies

Radio load profile (at 4.5V)

Transmitter ON

at 2.00 W to antenna
worst-case peak instantaneous (due to extreme
temperature, poorly matched antenna, etc.)

1.7 A

2.2 A

Receiver ON

In EXPRESS mode, the receiver is always ON.
In POWERSAVE mode, the receiver is typically

Standby (transmitter and receiver are both OFF)

Standby mode occurs for 9.85 s out of 10 s if in
POWERSAVE mode and no activity has taken
place for previous 10 s

Typical average power-save current consumption

transmit 0.17%, receive 9.74%, standby 90.09%
transmit 1%, receive 5%, standby 94%

Transmit duration

minimum
maximum

Off current consumption

Batteries

When integrated into a handheld device, the RIM 902M can be powered by
batteries. This is a proven technology that is easily available and eliminates the
need for power supply components such as voltage regulators.

ON for 0.15 s then OFF for 9.85 s

57 mA

0.2 mA
to

5.4 mA

5.7 mA

20.0 mA

32 ms
1 s

d

20 PA

Rechargeable batteries

We recommend using rechargeable nickel cadmium (NiCad) batteries to power
vthe RIM 902M radio modem for battery-operated applications that require a
wide operating temperature range. Nickel metal hydride (NiMH) and Lithium
ion (Li+) cells may also be used with good results, but many such cells do not
work very well at temperatures below freezing. Specifications for batteries

Integrator’s Guide – RIM 902M OEM Radio Modem

Power requirements: Batteries 33

should be obtained from the manufacturer. The RIM engineering development
team can help you determine whether a particular battery is suitable for your
application.

The cells chosen must be able to meet the load specifications of the RIM 902M.
Specifically, they must be able to provide 1.7 A (at 4.5V) for transmission.
Rechargeable cells vary considerably, because capacity varies with current
draw. Even if two cells have the same published capacity, one may not be as
efficient as another when the radio transmitter is turned on. This is because
some batteries have a higher equivalent series resistance (ESR) at high current
drain. The ESR should be low enough that the battery can supply the transmit
current required without a large voltage drop.

Rechargeable alkaline batteries are another option. These cells are typically
rated for about 25 discharge cycles, far fewer than NiCads, but they provide
longer life than NiCads. For the first five to ten cycles, you will get about 70 to
80 percent of the battery life you would expect from a single-use alkaline cell.
After 25 discharges, this number may drop to 50 percent. Some precautions
must be taken with this type of battery. These cells are also not intended to be
used to their full capacity, so the actual useful run-time of these cells is closer to
30 to 40 percent of a single-use alkaline cell, and requires the user to pay closer
attention to the state of the batteries. If you fully discharge a rechargeable
alkaline battery, you may only get five recharges before the capacity decreases
to the point where it is useless.

Single-use batteries

Among single-use cells, only alkaline and lithium cells provide the high
current necessary for transmission. In particular, alkaline AA’s are
inexpensive, widely available, and provide an excellent power source. Alkaline
cells typically run about four times longer than similar-size NiCad cells, and
about three times longer than similar-size NiMH cells.

The use of general-purpose carbon-based batteries is not recommended, as this
type of battery is unable to supply th e power required by the transmitter. If this
type of battery is used, the voltage will drop below the minimum power
required under load almost immediately following a radio transmit, which
would reset the radio.

Since carbon cells are generally sold under names like “super heavy duty,” the
best way to be sure that a single-use battery is alkaline is to look for the word

RIM 902M OEM Radio Modem – Integrator’s Guide

34 Power r equirements: Plug-in supplies

“alkaline” on the label, or to use well-known brands such as Duracell or
Energizer. This should be communicated to the user of your product.

Plug-in supplies

A plug-in supply converts normal AC power (usually 110 volts or 220 volts)
into a steady DC source that can be used instead of batteries. The plug-in
supply must be designed to ensure voltage spikes, lightnin g, and other power
fluctuations cannot damage the radio modem. Transient voltage protection
zener diodes, or other spike arrestor circuits, may be added to keep the inputs
within the limits given in the RIM 902M load specifications. These should have
a value of 20 volts and be placed on the supply side of the regulator circuit.

RIM recommends a supply capable of providing 4.5 V and rated for 2.5 A peak
current.

Automotive supplies

If you plan to power the RIM 902M from an automotive supply, extra
protection must be included to protect the radio modem from the intense power
fluctuations experienced when the automobile is started. A circuit comprising
inductors, transorbs and voltage regulators should be used to ensure the radio
modem is protected from these power fluctuations.

Commonly, in automotive applications, voltages may be as high as 70 V on the
battery, especially during starting. Commercial automotive adapters are
available that will safely convert the 12 volt automotive supply to a regulated
supply suitable for operating the RIM 902M radio modem.

Integrator’s Guide – RIM 902M OEM Radio Modem



5.

Interface
specification

The asynchronous serial interface on the RIM 902M operates at 3.0V. It is
similar to RS-232 except that 0V represents a “low” and 3V represents a
“high.” This interface can be connected directly to a micro-controller, or
through a UART to a microprocessor data bus.

MASC and RAP link-layer protocols

The RIM 902M requires a serial link-layer protocol to carry data, radio control
instructions, and radio status information between the RIM 902M radio modem
and the computing device to which it is attached. Two protocols are supported:
Mobitex Asynchronous Communication (MASC) and Radio Access Protocol
(RAP).

If you are using a MASC appl ication with another Mobitex radio and are now
migrating to the RIM 902M, you do not need to rewrite the application in RAP
– simply continue using the MASC application. If you are writing a new
application for the RIM 902M, you will need to choose whether to use MASC
or RAP as your link -la yer protocol.

MASC assumes a h igh-n oise environmen t where bit err ors are li kely to occur
on the serial link between the radio modem and the computing device. MASC

36 Interface specification: MASC and RAP link-layer protocols

is designed to be extremely robust and redundant, a nd sh ould be used when the
serial link is unreliable or when the serial cable to the RIM 902M is very long.

Advances in mobile computing technology have helped to ensure that serial
links are short enough to make bit errors extremely unlikely. This is especially
true for smaller devices such as laptops and PDAs. Th e complexit y of MASC is
unnecessary for these applications, and involves complex and lengthy software
development.

RAP was designed to take advantage of the reliability inherent to a short serial
link. The primary benefit of RAP is that it is easy to describe and implement.
As a result, RAP reduces software development time, complexity, and memory
consumpti on. It a lso pr ovides double th e th r ough put of MASC, by usin g bina r y
frame data transfers instead of hex-ASCII encoding.

Since every application is different, the choice of protocol should be made
carefully. The following chart is provided as a guide to comparing the relative
advantag e of e ach protocol.

MASC RAP

Serial cabl e between
RIM 902M and device

Designed for l on g serial
cable prone to bi t errors

Operating environment Withstands harsh, hostile

electrical int erference

Assumes a short, r eliable
serial cable

Best suited for laptops,
PDAs, other small devices

Software co mplexity Complex Simple

Implement at ion time
(typical)

Weeks or m onth s ,
or use third-par t y API’s

Days

Memory requi rements 10 to 50 kilobytes 1 to 3 kilobytes

Hardware flow control RTS/CTS is required RTS/CTS is optional

Throughput at 9600 bps 4800 bps 9600 bps

Cost Free, open specification,

or pay for thir d-pa rty API’s

Integrator’s Guide – RIM 902M OEM Radio Modem

Free, open specification,
sample source code is free

Ther e is n o “best” pr otocol. Th e MASC or RAP pr otocol is u sed st r ictl y for th e
link between the radio modem and the computing device, and does not have
any influence on the speed or reliability of communication between the radio
and the Mobitex network. The RIM engineering development team (e-mail:
rim900@r i m. net) can help you select the protocol most suited to your n eeds.

Pin descriptions

All input and output lines are 3.0 volt logic; however, they will also be able to
drive 3.3 volt systems. Further, all input lines to the serial port are 5.0 volt
tolerant and outputs will be capable of driving 5.0 volt systems provided the V
of these pins is less than 2.5 volts. Pins 1 thr ough 4, the general pur pose I/O
lines, are strictly a 3.0 volt interface; they ar e not 5.0 volt tolerant.

This section describes the purpose of each of the 22 lines that comprise the
serial interface of the RIM 900 OEM radio modem. The symbol ~ before the
label indicates that line is an active low digital signal.

Interface specification: Pin descriptions 37

IH

Pins 1, 2, 3, 4, 13, and 22 are designed for future use and must be left
disconnected. All other unused inputs to the radio should be tied to ground, and
any unused outputs from the radio should be left disconnected.

Pin 5 ~MSG ~Message Waiting

This is an output from the radio.

The active state of this line is low, and indicates that the radio has received a
message (packet) from the network, which has not been delivered to the device
application yet. This line continues to remain active until the application
ackn owled ges recei vi ng the pack et.

When the radi o’s receive buffer is full , th i s lin e will be inactive (high).

RIM 902M OEM Radio Modem – Integrator’s Guide

38 Interface specification: Pin descriptions

Pin 6 ~COV ~Coverage

This is an output from the radio.

The active state of this line is low, and indicates that the radio is in network
coverage, as measured by the presence of a signal from the network base
station.

When the radio does not have contact with the wireless network, this line is
high.

Pin 9 GND Ground

This line should be tied to the system ground of the host unit to ensure proper
operation.

Pin 10 TURNON Turn Radio On

This is an input to the radio.

This line turns on the radio unit. It is a digital signal that eliminates the need
for an on/off switch across the power supply to the radio. Information about the
use of this pin is contained in the next section of this chapter.

Pin 11 ONI On Indicate

This output from the radio that indicates that the radio is on and operational.

This line may be used by a computing device to qualify the handshaking
outputs on the serial interface. If CTS is low, and ONI is high, then the unit is
read y to receive data, but if CTS is low and ONI is low, then the radio is not
read y to receive data because it is off.

When ONI is low, all inputs to the radio should be held low or disconnected.
Otherwise, power will be consumed and wasted.

Integrator’s Guide – RIM 902M OEM Radio Modem

Interface specification: Pin descriptions 39

Pin 12 TRI Transmit Indicate

The active (radio transmitting) state of this line is high.

This output from the radio that is asserted while the RIM 900 is tr ansmitting a
packet to the network base station. TRI can be used to provide real-time visual
feedback to the user that the radio is transmitting packets. If this is not
necessa ry, the line can simpl y be left d isconnected.

This line is low when the Radio is off.

Pin 14 ~RI ~Ring Indicate

This is an output from the radio.

When ~DTR is not asserted (high), the RIM 900 asserts ~RI (low) to indicate
that it has data waiting for the computing device. The radio will not transfer the
data until ~DTR is asserted (low). This line can be used to wake up a
suspended computing device when the radio needs to communicate with it. If
~DTR is already asserted (low) wh en the radio has data to send the computing
device, ~RI will not be asserted.

For MASC impl ementations in normal serial mode, this line indicates that the
radio has any MASC frame to transfer to the computing device. For MASC
implementations in interactive serial mode, this line indicates that the radio has
received an MPAK from the Mobitex network, and has a MASC M frame
containing the MPAK to tran sfer t o the computing device.

For RAP implementations, ~RI is not used and should not be connected. This
line should also be disconnected if your application does not use it.

Pin 15 ~CTS ~Clear To Send

This line is an output from the radio modem. The active (clear to send) state of
this line is low.

All MASC implementations require this line. This line is optional for RAP
implementations. To use hardware flow control with RAP, the radio must be in
interactive serial mode (see pin 10). Do not connect ~CTS if your application
does not require it.

RIM 902M OEM Radio Modem – Integrator’s Guide

40 Interface specification: Pin descriptions

This is an output from the RIM 900 to the computing device. This line is
asserted low by the RIM 900 to indicate that it i s ready to receive data from the
computing device. When this line is high, any data sent from the computing
device to the RIM 900 may be lost. This is a flow control mechanism th at is
normally reacted to by the UART in your serial communication system.

When the radio is turned off, this line will be low from inside the radio modem
with an impedance of at least 20 k:.

Pin 16 ~RTS ~Request To Send

This line is an input to the radio. Its active (request to send) state of this line is
low.

All MASC implementations require this line. This line is optional for RAP
implementations. Connect ~RTS to ground if your application does not require
it.

This is an i nput to the RIM 900 from the computing device. This l ine should be
asser ted low by the computi n g device t o in dica te th at it i s r eady to r eceive dat a
from the RIM 900. This is a flow control mechanism that is normally handled
by the UART in your serial communication system.

Pin 17 ~DSR ~Data Set Ready

This line is an output from the radio.

The active (data set ready) state of this line is low.

When the RIM 900 is off, this line will be low from inside the radio modem
with an impedance of at least 20 k:.output from the RIM 900 that in di cates t he
state of DTR.

Pin 18 GND Ground

This line should be tied to the system ground of the host unit to ensure proper
operation.

Integrator’s Guide – RIM 902M OEM Radio Modem

Interface specification: Pin descriptions 41

Pin 19 ~DTR ~Data Terminal Ready

This line is an input to the radio.

The active (data terminal ready) state of this line is low, and indicates that the
comput in g device i s rea dy to r eceive d ata from the RIM 900. De-asserting this
line high will turn communication off; the RIM 900 would not attempt to
deliver data to the computing device until ~DTR is again asserted low.
Assertin g this lin e low will cause the radio to send a MASC B frame to the
computing device if MASC is the protocol being used, and will allow
communication to resume.

If you do not intend to use ~DTR, tie it to ground to ensure that it is always
asserted during radio operation.

This line should be driven low wh en the radio is off. Driving ~DTR high when
the radio is off will consume unnecessary power.

Pin 20 TX Transmit

This line is an input to the radio. Its idle (no data) state is high.

This is an asynchronous serial input to the radio unit, and should be connected
to the computing device’s Transmit Data output. This line carries data at 9600
bits per second. MASC parameters are 7 bits, Even parity, 1 stop bit. RAP
parameters are 8 bits, No parity, 1 stop bit.

RIM 902M OEM Radio Modem – Integrator’s Guide

42 Interface specification: How to turn the radio on and off

Pin 21 RX Receive

This is an output from the radio. Its idle (no data) state is high.

This line is an asyn chronous serial output from the radio unit, and should be
conn ected to th e host t ermin al’s Receive Data input. This line carries data at
9600 bits per second. MASC parameters a re 7 bits, Even parity, 1 st op bit. RAP
parameters are 8 bits, No parity, 1 stop bit.

How to turn the radio on and off

The TURNON pin is a digital signal that turns the raido on and off. It
eliminates the need for a power switch across the power supply to the radio.

Turning the radio on

To turn the RIM 902M on, the software should first check the ONI pin. If ONI
is high, but TURNON is being held low, then your application has recently
requested the radio to shut down, and the radio is performing shutdown
operations and should not be disturbed. Wait for ONI to go low before
continuing.

If ONI is low, thi s in di cates t h e ra dio is t ur n ed off. Set t h e T URNON lin e h i gh
to turn the radio on. The ONI pin will respond by going high, typically within 2
seconds. Once the ONI pin is high, other handshaking and communication
signals can begin.

If the radio fails to respond to a high TURNON line, the radio may require
service, or the power supplied to the radio may be too low for proper operation.

Turning the radio OFF

To turn the RIM 902M off, your software sh ould de-assert the TURNON line
by setting it low. The radio will then begin shutdown operations, and the ONI
pin will remain active until all shutdown operations are complete.

Integrator’s Guide – RIM 902M OEM Radio Modem

Interface specification: Interface to an RS-232 device 43

Shutdown will normally require several seconds to complete, and the radio
should not be disturbed while it is shutting down. Attempting to communicate
with the radio during shutdown may extend the time taken to perform
shutdown operations. The ONI signal will be de-asserted (low) when the radio
has shut down.

All serial inputs to the radio should be low when the radio is turned off. This
ensures that power consumption will be reduced to the lowest possible levels.
Note that if any line is left in the high state, as much as 5 mA may flow into the
radio modem.

MPAK data that has been received by the RIM 902M from the Mobitex
network, but which has not been transferred to the computing device, will not
be saved. The MPAKs will be lost when the unit enters shutdown or is turned
off.

A controlled shutdown is necessary to allow the RIM 902M to tell the Mobitex
network that it is off air.

Interface to an RS-232 device

The RIM 902M serial interface operates at 3.0V, making it compatible with
many existing system designs. In most cases, the RIM 902M can be connected
directly to a micro-controller without any additional interface logic. If the radio
modem is to be connected directly to a PC or other RS-232 device, an in terface
must be provided.

Interface to microprocessor

The RIM 902M can be controlled by a wide variety of microcontrollers and
microprocessors, such as th e Int el 8051 or 80386, or Motorola 68000.

A standard 8250 Universal Asynchronous Receiver/Transmitter (UART)
interface may be used as the means for communicating with the
microprocessor’s data bus.

RIM 902M OEM Radio Modem – Integrator’s Guide

44 Interface specification: Interface to microprocessor

Integrator’s Guide – RIM 902M OEM Radio Modem



6.

Antenna selection

The antenna is one of the most important components of a wireless
communication system. The right antenna will maximize the coverage area of
the RIM 902M.

The antenna that you choose should complement the needs of your specific
project. There are many different antenna types and options that will meet your
engineering and user requirements while remaining within budget constraints.
We strongly recommend the use of an experienced antenna provider in order to
realize the highest gain possible. A well-designed antenna solution will
maximize efficiency, coverage area, and battery life.

Selecting an antenna

Antenna manufacturers have designed and manufactured a wide variety of
antennas for use on the Mobitex network, and for other RF systems operating in
the 900 MHz range. RIM does not recommend specific antennas because the
choice of antenna is application dependent.

The performance of an antenna depends on its configuration and environment:
the same antenna will behave differently in one device than in another device,
even if both devices use the same RIM 902M radio modem. For example,
magmount antennas include a magnetic base that allows the antenna to clamp
onto a metal surface. This surface is called a ground plane, and reflects
electromagnetic radiation that would otherwise be lost to the antenna. This

46 Antenna selection: Introduction to antenna terminology

effectively doubling the length of the antenna by creating a virtual “mirror
image” of the antenna beneath the plane.

Antenna requirements

The following are the minimum requirements of the antenna system used with
the RIM 902M.

Impedance: 50

Center frequency: 913.5 MHz, r5 MHz (O=32.8 cm, r0.2 cm)

Frequencies of operation: 896 to 902M MHz (transmit)

Accepta bl e return loss: VSWR < 2.0 or RL < 10 dB (minimum)

:

this is deliberately biased toward transmit in order
to help balance the two-way link between the radio
modem and the network base station

935 to 941 MHz (receive)

VSWR < 1.5 or RL < 14 dB (recommended)

required across all frequencies of operation

Introduction to antenna terminology

This section introduces some of the terminology that is used to describe
antennas, and expands on the summary of antenna requirements, above.

Gain and ERP

Antennas produce gain by concentrating radiated energy in certain areas, and
radiating less energy in other directions. The amount of gain depends on the
radiation pattern, antenna match, and antenna efficiency. Antenna gain is
given as a rating of the maximum increase in radiated field energy density
relative to an ideal isotropic radiator, expressed in decibels (dB) of power gain .

Integrator’s Guide – RIM 902M OEM Radio Modem

Interfacing and Controlling the RIM 902MAntenna selection: Introduction to antenna
terminology 47

An isotropic radiator a 100% efficient point source radiator with a spherical
radiation pattern. Its field energy density is identical in any direction from the
radiator at each fixed distance from the radiator. An isotropic radiator cannot
exist in practice; it is an unrealisable theoretical reference for measuring
antenna gain and radiation patterns.

The power output of the RIM 902M is 62 mW to 2.0 W at the antenna port, a nd
the antenna gain (or loss) will result in an increase (or decrease) in th is value.
The actual output is called the Effective Radiated Power, or ERP. For example,
if the RIM 902M is putting out 2.0 W of power to a 2.3 dB gain antenna, the
ERP is 2.0 u 10^(2.3y10) = 3.4 W, the actual power radiated by the antenna in
the direction of maximum gain and polarization.

Impedance matching, return loss, and VSWR

The antenna, cables, and connectors in a radio frequency system must all
possess the same impedance. The impedance required by the RIM 902M is
50 :, which is a widely-available industry standard. Any deviation from this
value may result in impedance mismatch.

Impedance mismatch can be caused by cable connections, cable lengths, and
imperfections in the cables and connectors. The mismatch causes some of the
radio frequency energy to be reflected back from the location of the mismatch.
This interferes with the signal and reduces its amplitude, resulting in a power
loss.

Antenna mismatch can be expressed as a return Loss (RL), which is simply the
ratio of reflected power to the incident power, expressed in decibels.

RL

u

1010log

Equation 1: Return Loss

§

P

¨
¨

©

reflected

output

P

·
¸

¸
¹

The Voltage Standing Wave Ratio (VSWR) is another way of expressing the
ratio of incident power (from the RIM 902M) to reflected power (into the
RIM 902M).

RIM 902M OEM Radio Modem – Integrator’s Guide

48 Antenna selection: Introduction to antenna terminology

P

reflected



1

P

VSWR

Equation 2: VSWR

1 -

output

P

reflected

P

output

VSWR = 1 or RL = f dB is a perfect match. In practice, there will always be
imperfections, which means that VSWR will be greater than 1 and RL will be a
negative number.

VSWR and RL normally vary as a function of frequency. The RIM 902M’s
frequency range includes 896 to 902M MHz (transmit) and 935 to 941 MHz
(receive). The minimum acceptable match across this range must be
VSWR < 2.0 or RL < 10 dB. For best performance, the recommended antenna
match at these frequencies is VSWR < 1.5 or RL < 14 dB.

Antenna size

The optimal antenna radiation efficiency is produced by an antenna measuring
one wavelength, O. The value of O for the RIM 902M is 32.8 cm, and is
calculated by dividing the speed of light c = 3 x 10
f = 913.5 MHz. Because the RIM 902M’s receiver is so sensitive, this value
includes a 5 MHz bias toward the transmit frequencies to help balance the
uplink and downlink between the radio modem and the network base station.

Antenna lengths of O/2, O/4, and O/8 also work well, and usually result in a
relatively well matched antenna. O/2 or O/4 can be electrically “shortened” by
adding load matching elements to control the antenna match. However, this
shortening will reduce the antenna efficiency and therefore the effective
radiated power.

8

m/s by the center frequency

Integrator’s Guide – RIM 902M OEM Radio Modem

Interfacing and Controlling the RIM 902MAntenna selection: Positioning the antenna 49

Positioning the antenna

Proper positioning of the antenna will maximize the gain provided by the
antenna. In determining the proper position, the designer must carefully
consider the environment in which the device will be used. Physical devices can
vary significantly, and incorporating the antenna is an integral part of a
successful design.

The Mobitex network is based on vertically polarized radio-frequency
transmission. Therefore, the antenna should ideally be oriented so that it
provides vertical polarization. This is achieved by positioning the antenna
vertically upward when the RIM 902M is in use. In small, hand-held devices, it
may be convenient to design the unit in such a way th at th e antenna folds out of
the way when not in use.

The antenna should be located as far from the active electronics of the
computing device as possible. In general, metal construction in the case of the
computing device and its internal components may attenuate the signal in
certain directions. This is not desirable, as it would reduce the sensitivity and
transmit performance of the radio modem when the computing device is held or
positioned in certain orientations. However, the judicious use of metal in the
construction of a ground plane for an antenna can significantly improve the
antenna gain and the coverage area of the system.

If the computing device is designed to sit on a surface, then the an tenna should
be as far from the bottom of the device as possible. This will reduce RF
reflections whenever the device is placed on a metal surface.

When the computing device is hand-held or is worn next to the body of the
user, the antenna should be positioned to radiate away from the body.
Otherwise, the body will absorb the radiated energy an d the effective coverage
area of the radio will be reduced.

For best results, the antenna should be connected directly to the antenna cable.
If an extension cable is required, it should be low loss, as short as possible, and
have an impedance of 50 :. It is important that a proper matching connector
be used, as each connector in the signal path introduces a return loss and
redu ces performan ce.

RIM 902M OEM Radio Modem – Integrator’s Guide

50 Antenna selection: Shielding

Shielding

The electrical design of the RIM 902M provides high immun ity to RF noise.
The metal casing also acts as a shield to help minimize the effect of RF
interference originating from the computing device to which it is attached, and
to prevent the RIM 902M from emitting RF energy into the computing device
and disrupting the computing device’s operation.

Consequently, you do not need to provide any additional RF shielding between
the RIM 902M and a computing device. In fact, it would be more important for

!

the power supply to the RIM 902M to be free of high-frequency electrical noise,
than to provide additional RF shielding.

The antenna must be positioned in such a way that the radiated energy is
directed away from the computing device. If this is not possible, then RF
shielding may be required between the antenna and the computing device.

Note that circuits with a high impedance, and sensitive analog circuits, are
especially vulnerable to nearby radio frequency emissions, and may need to be
shielded. Typically affected circuits include CRTs and LCD display drivers.

Integrator’s Guide – RIM 902M OEM Radio Modem

Specifications

The following is a summary of the RIM 902M OEM radio modem
specifications.

Power supply & typical current usage

x

Single power supply; operating range: 4.1 to 4.75V DC

x

Single 3.0V logic line to turn on/off

x

Typical off current consumption: less than 10PA

x

Battery save stand-by mode: 0.2 mA (at 4.5V)

x

Receive / express stand-by mode: 57 mA (at 4.5V)

x

Transmit mode: up to 1.7A (at 4.5V, output 2.0W)

x

Average current usage: 20 mA (at 4.5V, based upon 94% standby, 5% receive, 1%
transmit)

RF properties

x

Transmit frequency: 896 to 902M MHz

x

2.0 W nominal maximum transmit power at antenna port

x

Transmitter can reduce output power to 0.06 Watts (-15 dB) when it is close to the
base station, to balance radio link

x

Receive frequency: 935 to 941 MHz

x

Receive sensitivity: -118 dBm at 0.01 bit err or rate ( BER)

x

8000 bps 0.3 BT GMSK

x

FCC Parts 15 & 90

x

Industry Canada RSS 122

Serial communications

x

3.0V asynchronous serial port

x

7 bit with parity (MASC) or 8 with no parity (RAP)

x

Link speed: 9600 bps

x

Link leve l pr otocols :

i

Radio Access Protocol ( RAP)

i

Mobitex Asynchronous Communication (MASC)

52 Specification s: Shie lding

Other features

x

A simple-to-use firmware utility displays serial number, MAN, RSSI level, battery

strength, and network parameters. It can also select different Mobitex networks or
"ping" the network to test the radio modem.

x

Software can activate radio

x

Hardware flow control

x

Radio parameters stored at power down

x

Terminal devices may power-down while radio-modem remains operational

x

Certified by RAM Mobile Data to meet Mobitex Interface Specifications (MIS)

including the following features:

i

Personal subscriptions

i

ESN verification

i

Switching between different Mobitex networks

i

Frame and continuous modes

Mechanical & environmental properties

x

Weight: 1.2 oz (35 g), including case

x

Footprint: 42 by 69.5 mm

x

Thickness: 8.4 mm

x

3.0V serial connector: 22 pin FPC (Flexible Printed Circuit) connector

x

Antenna cable connector: MMCX

x

Tested to IEC 68-2-6 Part 2 for vibration

x

Metal case, available in a variety of materials

x

Operating temperature tested to: -30°C to +70°C

(at 5-95% relative humidity, non-condensing)

x

Storage temperature: -40°C to +85°C

Integrator’s Guide – RIM 902M OEM Radio Modem

Glossary of terms

Term: Meaning:

c The speed of light.
dB decibel. A measure of power, based on a logarithmic scale.
Embedded System A computer without the normal display, keyboard, and

disk drives of a PC.

FPC

Gain In this document, refers to increase/decrease in radiated

MAN

MASC

MMCX The connector on the RIM 902M to which an antenna

Mobitex A radio network and its communication protocols, created

MPAK

Network Operator The corporation or agency which installs, maintains and

F

on the RIM 902M is made using this type of flat multi­conductor wiring.

power.

M

one unique MAN. A MAN is a 24-bit number. The
network operator will assign a MAN to each radio modem
when they authorize its use on their Mobitex network.

M

layer protocol exchanged via an asynchronous full-duplex
serial channel between a data terminal or computing
device and the RIM 902M OEM Radio Modem.

cabl e is connected.

by Ericsson and the Swedish Telecommunications
Administration.

M

between the Mobitex network and the radio modem.

authorises use of a Mobitex network in a given area,
usually within one country.

P

lexible

obitex

obitex

obitex Data

rinted Circuit. The serial communication cable

A

ccess Number. Each Mobitex radio modem has

A

synchronous Serial Communications. The link

Pa

cket. A parcel of data transferred

Noise Refers to undesired, random interference combining with

the signal. If the device is not immune to noise, the
interference must be overcome with a stronger signal
strength. Noise can be produced by electronic components.

54 Glossary of terms: Shielding

Term: Meaning:

OEM

Original E

quipment Manufacturer. Usually implies that

the “OEM product” is re-labelled with another
manufacturer’s name. The RIM 902M is designed to be
embedded in OEM terminals, PCs and data gathering
equipment, and as such the equipment it is embedded in
will not normally carry RIM’s name.

OSI

The Open S

ystems Interconnection model allows different

systems, following the applicable standards, to
communicate openly with each another.

Polarity Direction of current flow. Connecting some cables with the

wrong polarity (i.e. backward) may damage the device.

Radio Modem

A device which provides modulation and dem

odulation for

a radio frequency communications system.

Radiation In this document, “radiation” refers to the emission of

electromagnetic energy in the radio frequency (RF) band.
Do not confuse this with radioactive particle emissions
caused by nuclear reactions.

RAP

Radio A

ccess Protocol. An alternative to the MASC

protocol, found on the RIM 902M. Provides simpler

implementation and faster, reliable operation.
Return Loss A measure of antenna matching.
RF

Radio F

requency.

RS-232 The standard asynchronous serial communications

interface used by most existing personal computers and

mini-computers. Usually refers to both the

communications protocol and the electrical interface.
SMA An RF connector type.
TTL

Transistor-T

ransistor Logic. Used in digital circuits. Low

(0) is represented by ~0 V and High (1) is ~5 V.
Type Approval s Th ese appr ovals are r equ ir ed by mos t gover nmen ts b efore

radio transmitters and equipment containing radio

transmitters can be used. In the USA, a device must be

tested and certified by an independent lab which is

recognized by the FCC.
UART

Universal A

synchronous Receiver/Transmitter. Used as an

interface between a microprocessor and a serial port.
VSWR

Voltage S

tanding Wave Ratio. A measure of antenna

matching. See Chapter 5, Antenna Integration.

Integrator’s Guide – RIM 902M OEM Radio Modem

Index

A

Antenna

efficiency • 4 8
gain • 46
gain, maximizing • 48
physical location • 49
return loss • 47, 54
shielding • 49
SMA connector • 54
VSWR • 47, 54

C

Cables

serial • 27, 53

E

Embedded system • 53

I

Industry Canada Certification • ii
Interface

about • 35
connecting to • 27
connecting to an RS232 device • 43
pin descriptions • 37
UART • 54

Interface and Test Board

LED indicators • 11

M

MAN • 53
MASC • 53
MOA • 4
Mobitex • 53

overview • 4
packet switching • 5

Mounting

permanent • 26
requirements • 24

MPAKs • 5

N

Noise

FCC compl ian ce statemen t • i, ii

noise immunity • 2
shielding • 49

O

OEM • 54

P

Power supply

about • 31
alkaline batteries • 33
automotive supplies • 34
load specifications • 31
plug-in supply • 34
rechargeable batteries • 32

56 Index: Shielding

R

Reliability

noise immunity • 2

RIM 900

battery life • 3
controlling • 43
features • 1
output power • 2
physical size • 3, 22

RS232 • 54

S

Schematics

8250 serial interface • 44
Shutdown • 42
Startup

turning the radio on • 42

TURNON • 38

T

Temperature range • 22

Integrator’s Guide – RIM 902M OEM Radio Modem