What is BLE? -Bluetooth Low Energy basics

There are various wireless technologies developed for short range applications such as voice, data, audio and video. Bluetooth and Bluetooth Low Energy are among them.

Traditional bluetooth is connection oriented. When a device is connected, a link is maintained, even if there is no data flowing. Here sniff modes allow devices to sleep which reduces power consumption and hence provides months of battery life. Peak transmit current is typically around 25 mA. Even though bluetooth has been independently shown to be lower power compare to other radio standards; it is still not low enough power for the coin cells and energy harvesting applications.

Hence BLE(Bluetooth Low Energy) technology is developed for these low power applications. It is one of the technologies used in IoT(Internet of Things). In IoT, things have data which is needed by Web Services. Bluetooth low energy provides the technology to connect these two. It uses asynchronous connectionless MAC which helps to achieve low latency and fast transactions (e.g. 3ms from start to finish). BLE uses new PHY, new radio and new protocol stack compare to generic bluetooth.

Following are the features of BLE referred as Bluetooth Low Energy:

specification/feature BLE(Bluetooth Low Energy) support
Range Typically 5-10 m, 150 meters can be achieved in open field (implementation specific)
Output power 10 mW (10dBm)
Max. current 15mA (implementation specific)
Latency 3 ms
Data rate(Throughput) 1 Mbps (But it is not optimized for file transfer application)
Topology Star
connections > 2 billion
Modulation GFSK at 2.4 GHz
Robustness Adaptive frequency hopping, 24 bit CRC
Security 128 bit AES CCM
Sleep current Approx. 1 µA (Implementation specific)
Modes broadcast, connection, event data models, reads, writes
RF Band 2400 MHz
Spreading FHSS (2 MHz channel BW)

BLE network topologies

Above figure-1 depicts BLE network topologies. Refer BLE tutorial➤ which describes BLE technology features, BLE(Bluetooth Low Energy) network, BLE channels, BLE messages, BLE protocol stack, BLE Applications (BLE Apps) etc.

Refer difference between bluetooth and Bluetooth Low Energy which compares both and provides the similarities and difference between these technologies.

BLE, Bluetooth related Links

Bluetooth vs BLE   Bluetooth Products   Bluetooth vs Zigbee

What is?

what is RF?  what is wireless ?  what is zigbee?  what is Bluetooth?  what is lightwave RF?  what is z-wave?  what is microcontroller?  what is GSM?  what is GPRS?  what is infrared? 

IoT Wireless Technologies

WLAN    ➤THREAD    ➤EnOcean    ➤LoRa    ➤SIGFOX    ➤WHDI    ➤Zigbee   ➤6LoWPAN   ➤Zigbee RF4CE   ➤Z-Wave   ➤NFC   ➤RFID   ➤Lonworks   ➤CEBus   ➤UPB  

RF and Wireless Terminologies