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Comment by Tepix

8 days ago

From the whitepaper: "bitchat implements a custom mesh networking protocol over BLE"

I wonder why they didn‘t implement the BLE mesh networking standard released in 2017 by the Bluetooth SIG.

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Tepix

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Beretta_Vexee  7 days ago

There are already several open source implementations, but the Bluetooth SIG standard only supports flood propagation.

This is fine for managing a few hundred temperature sensors or lighting controls up to the building's floor concentrator, which is the main use case for this standard, but it is completely unsuitable for sending individual messages from user A to user B.

  • kragen  7 days ago

    Flooding does work for sending individual messages from user A to user B at a small enough scale, but it gets progressively less efficient as the network grows, and at some level it will collapse.

    • Beretta_Vexee  7 days ago

      Flooding works if there is not too much hops between the sender and the recipient. For indoor IoT, it is very rare to have more than 3 hops and the data rates are extremely low and messages are just few bytes (on/off light, temperature).

      It would only take 4 people at 5 hops apart trying to exchange photos of less than a megabyte to completely saturate a network of hundred devices.

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