I am looking for an Advice to connect two BLE devices directly with each other without interference of phone device.I know that in normal scenario watch will connect with mo
BLE protocol only allows the communication between a central and a peripheral device. The wristband surely is a peripheral device that advertises BLE packets and expose some services (for example the heart rate).
You need to figure out if the android watch support BLE in central mode. In that case you will be able to scan for advertisement packets coming from peripheral devices (wristband), and connect to them.