Wavenet Technology Pty Ltd. BM2900D Benutzerhandbuch

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Integrator’s Task ____________________________________________ Boomer II User Manual & Integrator’s Guide 
Copyright Wavenet Technology © November 2003 
14 
BM210012WT37 
Plan the Product and Create the Design 
To plan the product and create the design, perform the following steps: 
 
Develop a usage model. 
 
Develop a message model. 
 
Define a service strategy. 
 
Investigate and obtain regulatory approval. 
Develop a Usage Model 
The usage model answers the question, “How will the end product be 
used (portable or mobile; 8 hours, 7 days a week; and so on)?” 
Perhaps the most important enabler of success is a clear determination 
of how the final product is to be used. This steers the development 
process, because all design considerations drive toward meeting the 
needs of the final user. For example, design issues related to a mobile 
device, such as alternator noise and vibration, are completely different 
from considerations required for a fixed-point telemetry application 
powered by a solar panel. Defining what is and what is not important to 
the end user helps to make the critical engineering trade-off decisions 
that are inevitable in every product design. 
Develop a Message Model 
The message model defines how many messages are sent/received and 
how often. To create the message model, determine how much and 
how often data will be sent in each of the uplink (terminal to network) 
and downlink (network to terminal) directions. 
Answer the question, “Is there a requirement for the terminal to be on 
and able to receive 8 hours a day, or does the user turn the unit on only 
when making a query to the Enterprise Server Application?” The 
answer has a direct bearing on the battery size and capacity 
requirement for powering the device. The amount of data sent and 
received is relevant in calculating the cost of airtime and deciding on 
which type of network connection to use. In short, the message model 
is required source data for making many engineering design decisions, 
especially in calculating such values as sleep time versus wake time 
and in determining battery capacity requirements. 
For additional information, refer to section “Message Traffic Model” 
on page 46. The typical approach to creating the model is to define the 
peak and average network throughput requirements based on input 
from the user. Wavenet Technology is able to provide current 
consumption figures for each of the various modes of operation 
(receive and transmit, for example) and explain the functionality of the 
network Power Save protocol. 
The network throughput of the host/terminal depends on many factors 
in addition to the raw throughput of the radio channel. For example, in 
addition to the overhead involved in forward error correction and