LPWAN stands for low-power wide area network. This IoT technology will pave the way for billions of new connected objects.
Mainstream technologies like WiFi, Bluetooth, and Cellular 3G/4G have not been a valid solution. They just do not have the range, are too power consuming, or bear an overwhelming cost.
For example: Bluetooth range is only about 10 meters
Wifi range is only about 32 meters and would kill a battery source within days.
Cellular 3G/4G is also too power hungry and above all else, there is an overwhelming cost
Rapid technological advances in the past made possible the miniaturization of network devices to meet the cost and power consumption requirements in IoT and M2M scenarios. What is missing in this picture is a radio technology with both long range capability and a very low cost footprint. Existing radio technologies such as 3G/4G or Short Range Radio do not aptly meet the requirements of IoT scenarios because they are either too expensive or are not able to provide the required range. Other wireless technologies are geared towards high bandwidth which is in most cases not a requirement for IoT.
Emerging LPWAN technologies such as LoRAWAN, Weightless-P and Sigfox are poised for filling the gap by providing long range (up to 40km) and low power connectivity. These technologies allow low cost radio devices and operation thus enabling scaling up IoT applications.
source: LPWAN Technologies for Internet of Things (IoT) and M2M Scenarios by Peter R. Egli, Software Engineering Consultant at Zühlke Group and Academic at ZHAW