Method and system for data transfer in a bluetooth low energy network

A Bluetooth Low Energy (BLE) network comprising multiple nodes and being for communicating data between Bluetooth Low Energy devices, the network comprising:

• a first BLE device configured to enter a scan mode when having data to send;
• and
• a second BLE device;
• wherein the first device is configured to determine whether the data to send has been transmitted to the first node from an upstream node or a downstream node, and is further configured such that:
• (i) if the data to send was received from a downstream node, the first node begins a scan mode;
• or
• (ii) if the data to send was received from an upstream node, the first node begins an ADV event.