Integrator’s
Guide
RIM 902M
OEM Radio Modem
RIM 902M OEM Radio Modem Integrator’s Guide
Last Updated: January 11, 1999
Model No. R902M-2-O
© 1999, RESEARCH IN MOTION 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.
Research In Motion
295 Phillip Street |
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Waterloo, Ontario |
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Canada N2L 3W8 |
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tel. (519) 888-7465 |
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MOBITEX Interface, specified |
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fax (519) 888-7884 |
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in Specification |
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E-mail: |
rim902m@rim.net |
LZBA 703 1001, |
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Web site: |
www.rim.net |
compatible equipment |
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FCC Compliance Statement (USA)
FCC Class B Part 15
This device complies with Part 15 of 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.
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 equipment.
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 manufacture’s instructions, may cause harmful interference to radio communications.
There is no guarantee, however, 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:
•Re-orient or relocate the receiving antenna.
•Increase the separation between the equipment and 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.
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 |
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FCC Compliance Statement (USA) .......................................... |
i |
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Industry Canada Certification ................................................. |
ii |
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About this guide....................................................................... |
v |
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1. |
Introduction ................................................................. |
1 |
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Radio performance ......................................................................... |
1 |
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Mobitex network technology.......................................................... |
4 |
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FCC radio frequency exposure rules .............................................. |
5 |
2. |
Getting started ............................................................. |
9 |
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Test board overview ..................................................................... |
10 |
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How to connect the test board ...................................................... |
11 |
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The MENU diagnostics tool......................................................... |
13 |
3. |
Mechanical integration ............................................. |
21 |
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Environmental properties ............................................................. |
21 |
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Physical properties........................................................................ |
22 |
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Mounting methods........................................................................ |
24 |
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Cables and connectors .................................................................. |
27 |
4. |
Power requirements .................................................. |
31 |
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Load specifications....................................................................... |
31 |
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Batteries........................................................................................ |
32 |
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Plug-in supplies ............................................................................ |
34 |
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Automotive supplies ..................................................................... |
34 |
5. |
Interface specification............................................... |
35 |
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MASC and RAP link-layer protocols ........................................... |
35 |
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Pin descriptions ............................................................................ |
37 |
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How to turn the radio on and off .................................................. |
42 |
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Interface to an RS-232 device ...................................................... |
43 |
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Interface to microprocessor .......................................................... |
43 |
6. |
Antenna selection....................................................... |
45 |
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Selecting an antenna ..................................................................... |
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Introduction to antenna terminology............................................. |
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Positioning the antenna................................................................. |
48 |
Shielding....................................................................................... |
49 |
Specifications ......................................................................... |
51 |
Glossary of terms................................................................... |
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Index ....................................................................................... |
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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:
•mounting requirements
•power (battery) characteristics
•interfacing to the RIM 902M
•antenna 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.
1
Introduction
With the introduction of the RIM 902M, Research In Motion (RIM) has set a new standard for radio modem performance. The RIM 902M is unrivalled in the key areas of receiver sensitivity, output 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:
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Laptop computers |
• Vehicle tracking and location |
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• Point of sale devices |
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Monitoring and telemetry |
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Ruggedized terminals |
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Vending machines |
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Handheld PC’s |
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Utility meters |
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Parking meters |
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Billboards |
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Dispatching |
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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:
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easier integration |
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improved RF performance |
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longer battery life |
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more coverage from each base station |
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increased reliability |
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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 |
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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 and 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.
Receiving data: 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 specifications 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:
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Australia |
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Germany |
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Singapore |
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Austria |
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Indonesia |
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Sweden |
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Belgium |
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Italy |
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Turkey |
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Canada |
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Korea |
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United Kingdom |
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Chile |
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Netherlands |
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United States |
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Finland |
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Norway |
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Venezuela |
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France |
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Poland |
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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 includes transmission acknowledgment.
The Mobitex network has a hierarchical structure that allows messages to be routed from sender to receiver along the most direct path possible. Each radio 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 sender and the receiver. For example, one base 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 network service is restored. If the mobile receiver moves outside the coverage 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 |
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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 sending and 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 the same frequency by different users. At the receiving end, all packets are accounted 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 rules
Based on FCC rules 2.1091 and 2.1093(1) and FCC Guidelines for Human 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 body of the user and the transmitting radiated structure, the human exposure to
RIM 902M OEM Radio Modem – Integrator’s Guide
6 Introduction – FCC radio frequency exposure rules
RF radiation can be evaluated in terms of Maximum Permissible Exposure (MPE) limits for field strength or power density in mWatts/cm2.
Warning: For an end product not covered by RIM MPE testing and submission, the integrator will submit for a separate FCC ID. It is mandatory for portable end products such as hand-held and body-worn devices to comply with FCC RF radiation requirements with respect to SAR limit.
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. RIM will submit module specific information and test reports for a generic MPE compliance.
The three specific antennas tested with the RIM 902M radio modem for generic MPE compliance are Larsen NMO 3E 900B with 3 dBd gain, Austin 200160 500C with 0 dBd gain and Eclipse II Magnet Mount 3 dBd gain antenna. The MPE passing distance for the Larsen ground plane bolted antenna adjusted to 6 foot cable length, is 23 cm. And the passing distance for both Austin ground plane bolted and Eclipse II ground magnet mount scaled to 6 ft cable is 20 cm. The vehicular integrators of RIM 902M who use the Larsen, Austin or Eclipse II antennas, will be in compliance with MPE limit, provided that the antennas are installed at least 23 cm for Larsen and 20 cm for Austin or Eclipse II antennas from any edge of a vehicle rooftop.
The vehicular device integrators using these antennas would be required to add a prominent warning in their user manuals to instruct the installer/end user on proper antenna mounting and antenna centering on the vehicle rooftop in compliance with MPE separation distance. Also the operator/user should be warned to maintain the minimum required distance from antenna at all times.
Integrators using the above antennas in the vehicular configurations, do not require separate FCC approval for RF exposure compliance with respect to MPE limits. However, the integrators of vehicular devices who use antennas other than the three tested by RIM or integrators of portable devices, would then be required to do separate MPE testing for vehicular/mobile applications and SAR testing for handheld/portable devices. This would require submitting for a separate FCC ID and going through the appropriate process.
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 hands, wrists, feet and ankles 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,
Integrator’s Guide – RIM 902M OEM Radio Modem
Introduction – FCC radio frequency exposure rules |
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wrists, feet and ankles. The 1.6 W/kg limit applies for most of RIM OEM integrators.
The limit for MPE is 0.6 mW/cm2 at 900 MHz.
Guidelines
RF exposure distance is based on normal operating proximity to the user’s or nearby persons’ bodies. This distance is measured from any part of a radiating structure, which is generally the antenna to the closest body part. A set of test needs to be performed to determine the passing distance that meets the exposure limits with respect to SAR for hand held/body worn/portable devices and MPE for vehicular/mobile devices if antennas other than the three tested by RIM are used.
Operating manual compliance statement
For the mobile/vehicular transmitter, the integrators 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. The integrators of mobile end products, should provide instructions or diagrams in the manual for proper antenna mounting and positioning, when applicable, to ensure a safe exposure distance to the operator and nearby persons.
For portable transmitters, separate FCC approval is required to be in compliance with FCC RF exposure guidelines in respect to the SAR limits.
Label
If the minimum separation distance of the final device configuration can not be met due to occasional non-essential operating conditions or requirements, then the device needs to have an RF radiation hazard label warning the user or nearby persons to keep away from the antenna by the specified distance.
RIM 902M OEM Radio Modem – Integrator’s Guide
Compliance with respect to SAR limits which satisfy MPE limits, would not require warning labels, however, an RF radiation warning label can be used to alert the user or nearby persons about abnormal usage conditions.
Warning to Integrators and Users
To meet the FCC RF exposure requirement for mobile transmitter end products using the Larsen NMO 3E 900B, 3 dBd antenna, ensure that the antenna is at least 23 cm away from the user or nearby persons when transmitting.
This statement should be added by all integrators to their user manual along with proper installation instructions. The installation instructions should include, but are not limited to, the correct mounting procedures on a ground plane, and positioning the antenna such that the minimum 23 cm is kept from any edge of the vehicle rooftop.
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 purpose of the Kit is to accelerate radio integration 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:
10 Getting started – Test board overview
e-mail: rim902m@rim.net phone: +1 (519) 888-7465 fax: +1 (519) 888-7884 web: www.rim.net
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 terminal 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 following 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 ± 12V. 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 interface. 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.
Integrator’s Guide – RIM 902M OEM Radio Modem
Getting started – How to connect the test board |
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On/off switch
With the switch in the ON position, the radio will turn on whenever power is applied to the test board. When the switch is moved to the OFF position, the radio will shut down.
Power supply
The RIM 902M must be provided with a clean, high-current power source. In this case, we use a standard plug-pack to provide the current necessary to 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 antenna 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.
RIM 902M OEM Radio Modem – Integrator’s Guide
12 Getting started – How to connect the test board
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 is in direct contact with the 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.
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 power 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 antenna cable supplied with your developer’s kit connects the antenna’s SMA plug to the radio’s MMCX jack.
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.
Integrator’s Guide – RIM 902M OEM Radio Modem
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