21 lines
701 B
Markdown
21 lines
701 B
Markdown
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---
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tags:
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- bluetooth
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- networks
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- radio
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---
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# Bluetooth frequency hopping
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Bluetooth transmits on the 2.5GHz frequency band. As this is an unlicenced band
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there can be interference to the signal and interception.
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To get around this, bluetooth engages in **frequency hopping**. It rapidly
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switches its channel of transmission between 79 distinct frequences within the
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2.5GHz band where each channel occupies a bandwidth of 1MHz.
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Each available band is divided into time slots. This allows multiple devices to
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communicate simultaneously without interfering with each other (that much). The
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[master device](./Bluetooth_piconet.md) controls the sequencing and
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synchronisation of the time slots.
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