Xbee Power Saving
Xbee does not have a traditional low power mode while waiting for RF data or serial data. Instead it provides several levels of sleep modes. However, these sleep modes require periodic waking to poll for messages and require a "router" to buffer messages while the module is sleeping. Traditional low power devices have very low power sub-devices that stay awake listening for things like serial or rf data. The sub-devices typically generate an interrupt to wake the main micro controller of the device when serial or rf data is received.