The basics of Bluetooth Low Energy (BLE): Page 5 of 7

October 20, 2016 //By Abhishek Gupta and Imran Mohammed, Cypress Semiconductor
Bluetooth technology has revolutionized wireless communications between devices with its ubiquitous and simple characteristics. It allows devices to communicate without cables while maintaining high levels of security. Because of its low power and low cost, Bluetooth has played a pivotal role in the evolution of applications from high-speed automotive devices to complex medical devices.

Technical Details

Data transfers – BLE supports very short data packets (8 octet minimum up to 27 octets maximum) that are transferred at 1 Mbps. All connections use advanced sniff-sub rating to achieve ultra-low duty cycles to keep energy consumption to a minimum.

Frequency hopping – BLE uses the AFH common to all versions of Bluetooth technology to minimize interference from other technologies in the 2.4 GHz ISM Band. Efficient multi-path benefits increase link budgets and effective operating range as well as optimize energy consumption.

Host control – BLE places a significant amount of intelligence in the controller. This allows the host to sleep for longer periods of time and be woken up by the controller only when the host needs to perform some action. This allows for the greatest current savings since the host processor typically consumes greater power than the BLE controller.

Latency – BLE can support connection setup and data transfer in as quickly as 3 msec. This enables an application to establish a connection and transfer authenticated data in just a few milliseconds for a short communication burst before quickly tearing down the connection.

Range – An increased modulation index allows for a maximum range for BLE of over 100 metres.

Robustness – BLE uses a strong 24-bit CRC on all packets to ensure the maximum robustness against interference.

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