One or more techniques and/or systems are provided for automatically forming a wireless sensor network, implementing power management for the wireless sensor network, and/or self-healing within the wireless sensor network. For example, hub devices, configured to forward messages through the wireless sensor network to a gateway device having access to a network, may automatically join and configure into the wireless sensor network by locating and connecting to master devices using signal frequencies representing numbers of hops to the gateway device. A hub device may be configured to transition between a low power sleep state for power conservation and an awakened normal operational state for transmitting timing signals according to a duty cycle, and thus the hub device may be capable of operating from a battery. If a hub device determines that a master device has become inoperable, the hub device may automatically search for a new master device.