Can data be sent to a BLE GAP Peripheral at the time when a BLE GAP Central establish a connection to it?

[Rifat Mahmud]

Say, for example, I have a BLE peripheral programmed with S110 on nRF51822. When an Android app connects to it as a BLE GAP central(and becomes GATT client), can any data be sent with the connection packet so that I can perform an authentication?

[endnode]

All what RK said + you could use "resolvable private" Address feature which provides some sort of pre-authentication, although requires some effort and assumptions to implement it (see more details here).

Cheers Jan