Spread Spectrum Communication; Notes For Wireless Operations - Denso BHT-200Q User Manual

3.1 Spread Spectrum Communication

3.1.1 Notes for Wireless Operations

The BHT-200QW supports spread spectrum communication.
• If there are too many communications errors, first make sure that the BHT-200QW points directly at an
access point because the 2.4-GHz band requires a more or less straight line path. Note also that the
low-power radio waves have trouble passing through human bodies and other obstacles along that
path.
• This link will not operate properly in the vicinity of microwave ovens, industrial heaters, high-frequency
medical equipment, and other sources of radio waves in the 2.4-GHz band.
• Electromagnetic noise from personal computers, refrigerators, and other home appliances can also
interfere with link operation.
• Environmental factors that can also interfere with link operation include large metallic objects, metallic
dust, or metallic walls in the vicinity of the path and vibration at either end.
To System Designers:
• Before developing the application, make sure that the intended environment is free of the
interference factors above and thus actually capable of supporting link operation.
• Assume that there will be communications failures requiring robust retry capabilities in the
software.
• When introducing the BHT link operation into an environment where equipment using radio waves
in the 2.4-GHz band operates or when introducing such equipment after the introduction of the
BHT link operation, be sure to confirm that the BHT radio link operates properly with all
equipment being in operation beforehand.
• If the environment of the radio communications system is changed after the introduction (e.g.,
newly installed household appliances and movement/addition of shelves or objects), then confirm
that the radio link operates properly again before the actual use.
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