NB module is suitable for outdoor scenes without Wi-Fi signal, such as: manhole cover monitoring, street lamp monitoring, fire hydrant monitoring, water quality monitoring, atmospheric monitoring, building energy consumption monitoring, public bicycles, smart gas meters, smart water meters, smart heat meters, smart parking, smart electricity meters, photovoltaic power generation, Battery monitoring, commercial air conditioning, cargo tracking, electric bicycles, smart greenhouses, smart farming, pipe network monitoring, power distribution facility monitoring, smart home appliances, smart access control, smart home, and healthcare.