Abstract: Various techniques for connection setup for Bluetooth Low Energy (BLE) devices are disclosed. The various embodiments save power. In one example, an apparatus (such as a BLE slave) includes a controller configured to transmit advertising packets and, based on responses to the packets, and lack thereof, the controller estimates the length of the scan window and scan interval. In another embodiment, an apparatus such as a master device is configured to generate a scan update packet that specifies the scan window length, scan interval, and start and end times for that master. The controller is configured to transmit the packet to one or more slave devices.