Indoor localization is a topic that has been investigated for more than a decade. Yet, no single system exists that is widely adopted as the de facto localization standard. From a research perspective the goal is to obtain a solution that is general, simple and accurate. As the number of devices in the Internet of Things grow, a new set of challenges are appearing: maintainability, low operational costs, and more importantly, energy autonomy. Considering the challenges above, the following problems are (among others) present in large scale indoor localization scenarios. The costs of replacing the batteries of thousands of anchor nodes (beacons, devices sending location inform-ation) and mobile nodes or tags (devices to be localized) is high.