Wireless Communication - Zigbee, Bluetooth - IIIT
Wireless Communication - Zigbee, Bluetooth - IIIT
Wireless Communication - Zigbee, Bluetooth - IIIT
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<strong>Zigbee</strong> Network Reliability<br />
<strong>Zigbee</strong> employs a range of techniques for reliable communication<br />
Channel Selection: On initialization, channels with least activity are<br />
selected<br />
CSMA-CA (Listen Before Sending): Before transmitting, node listens to<br />
the channel to check if it is clear<br />
Data coding: Applies a coding mechanism ensuring higher probability<br />
of successful transmission even in case of simultaneous transfer<br />
Acknowledgements: Receiving device acknowledges the successful<br />
receipt of a message; retransmission if ack is not received in time<br />
Route discovery: In mesh network, possibility of finding an alternate<br />
route if the default route is down<br />
Several mechanisms to ensure security:<br />
Access control lists: Only pre-defined nodes can join the network<br />
128-bit AES based Encryption<br />
Message freshness timers: Timed-out messages are rejected,<br />
preventing message replay attacks<br />
Can you give an example of replay attack?
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