Bluetooth Low Energy (also called Bluetooth Smart)

Named after a tenth-century Danish king who unified several fractious tribes, Bluetooth is a familiar technology to most consumers. The specification is maintained by an organization called the Bluetooth Special Interest Group (SIG) made up of 25,000 companies. Bluetooth Low Energy (BLE) is a newer implementation that is not directly compatible with Bluetooth classic (of mobile phone headset fame). It was designed for low power needs and a less frequent data exchange rate. The following chart represents the network protocol stack for BLE:

A BLE device is either a master or a slave in the network. A master acts as an advertiser in the connection while the slave acts as receiver. A master can have several slaves connected to it while a slave can link to only one master. The network group involving the slaves connected to a master is called a piconet.

To make data available for analytics, the master device passes it over the internet using one of the data messaging protocols that will be discussed later in this chapter. There is typically a gateway device that is both part of the bluetooth network and also linked to the internet. It translates data reported from BLE nodes into the appropriate format for data messaging over the internet. It is commonly an unconstrained device that does not need to worry much about power.

Bluetooth 5.0 specification released mid-2016 promises to double the speed, quadruple the range, and bring an eight-fold increase in the capability for data broadcasting for low-power scenarios.