A Comparative Analysis of Periodic Advertisements and Connections in Bluetooth Low Energy

Bluetooth Low Energy (BLE) periodic advertisements and connections share core protocol mechanisms—synchronized secondary advertising channels, fixed transmission intervals, and channel hopping—despite the former being connectionless. We present the first empirical study directly comparing these two modes for unidirectional data transfer in a single transmitter–receiver setup. Empirical measurements across varying data sizes and transmission intervals show that, even for large 244-byte data, periodic advertisements with two application-layer retransmissions use up to 33% and 62% less energy than connections (even with peripheral latency) at long intervals (80 s) on LE 1M and 2M PHYs, respectively, while maintaining similar data transfer reliability. These findings highlight a previously underexplored potential of periodic advertisements as a compelling alternative for energy-constrained, unidirectional deployments requiring infrequent transfers.