Central Peripheral Architecture for BLE

As understanding of Bluetooth Low Energy architecture in terms of Central and Peripheral roles is essential to understand how Bluetooth Low Energy devices advertise and connect to each other.

A Central is a device, which scans for Bluetooth devices to connect and utilize the information hosted by them. Usually, Central devices are richer in terms of resources such as computing power compared to the Peripheral devices. Specific to the use case that we will describe in this chapter, the role of a Central will be played by a mobile phone (Android/iOS):

Figure 1: Central and Peripheral Roles in Bluetooth Low Energy; source: developer.apple.com

Peripherals, on the other hand, are devices, which advertise their presence, and it is by virtue of this advertisement that the Central knows that a Peripheral device is nearby and it can connect to enquire...