User's Manual
Table Of Contents
- Introduction
- The Integrator’s Task
- Installing the Modem
- Using the Modem Test Jig
- Testing
- Desense
- Application Development
- Message Routing and Migration
- Appendix A - NCL Interface
- Appendix B - Software Development Kit
- SDK Contents
- System Requirements
- SDK Software Architecture
- NCL Application Programmer’s Interface
- Implementation
- Logical Architecture
- Application Interface
- Opening a Session
- Close Session
- Send Data to a Radio Host
- Receive Data From RPM
- Get RPM Status Information
- Set Configuration ITEMS Within the RPM
- Reset RPM
- Register Event Callback Function
- Enable / Disable Events
- Get Error Description
- Register Wakeup Application
- Deregister Wakeup Application
- Switch RPM On/Off
- Send Generic NCL Command To RPM
- Get Software Version
- SCR Application Programmer’s Interface
- A
- Appendix C – Sample programs
- Appendix D - Wavenet Application Loader
- Appendix E - Numeric Conversion Chart
- Appendix F - Specifications
- Appendix H - Glossary
Boomer II User Manual & Integrator’s Guide __________________________________________________ Desense
BM210012WT27 79 Wavenet Technology
Networks can assist in the desense problem by offering more than one
channel frequency at which to operate. If the radio encounters
interference on a channel, it can then roam to another.
WAN protocols include retry mechanisms that resend messages not
acknowledged from the subscriber device. These protocols can correct
problems from intermittent noise sources by retrying during a time slot
that does not coincide with noise source interference.
At a certain point, desensitising a wireless modem receiver creates
unacceptable coverage in the network. This usually is in the 10dB
range, though it can vary with networks.
Antenna
The Boomer II OEM modem is not equipped with an on-board antenna
and one must be provided externally in the host device or terminal.
Field Strengths from the Antenna
Field strengths from the wireless modem transmitter can reach as high
as 100 V/M for WAN products. Harden the host device to withstand
these levels. LCD displays and switching power supplies are
particularly susceptible to RF. Capacitive decoupling of sensitive areas
is required. Decouple the reference voltage points on power supplies,
reset lines on processors, and keyboard scanning circuitry.
Antenna Interactions
There are two interactions that can impact the performance of the
antenna. The user, by placing a hand near the antenna can detune the
antenna and absorb energy. Accordingly, the antenna must be
positioned such that interaction between the user and the card is
minimized.
The host device might also interact with the antenna. This is
particularly true for WAN modems, which have higher output power.
An imaginary sphere of real estate should be provided for the antenna
to function. Cabling for other peripherals must not interfere with this
region.
Desense Summary
Desense considerations fall into two categories when using a wireless
device and computer as a system:
The impact of the host EMI on system performance
The impact of the RF fields from the wireless device transmitter
on host operation
The latter consideration is not a significant problem. If RFI is assessed
properly, it is usually corrected with little effort and cost.
Because of the need for system coverage, the host EMI interaction with
the radio receiver can be a significant and often elusive problem to