Low-power wide-area networkThis needs to include cellular LPWAN technologies such as NB-IoT, LTE-M, Cat-M1 A low-power, wide-area network (LPWAN or LPWA network) is a type of wireless telecommunication wide area network designed to allow long-range communication at a low bit rate between things, such as sensors operated on a battery. The low power, low bit rate, and intended use distinguish this type of network from a wireless WAN that is designed to connect users or businesses, and carry more data, using more power.
Water clockA water clock or clepsydra (; ; water thief) is a timepiece by which time is measured by the regulated flow of liquid into (inflow type) or out from (outflow type) a vessel, and where the amount is then measured. Water clocks are one of the oldest time-measuring instruments. The bowl-shaped outflow is the simplest form of a water clock and is known to have existed in Babylon, Egypt, and Persia around the 16th century BC. Other regions of the world, including India and China, also have early evidence of water clocks, but the earliest dates are less certain.
Atomic batteryAn atomic battery, nuclear battery, radioisotope battery or radioisotope generator is a device which uses energy from the decay of a radioactive isotope to generate electricity. Like nuclear reactors, they generate electricity from nuclear energy, but differ in that they do not use a chain reaction. Although commonly called batteries, they are technically not electrochemical and cannot be charged or recharged.
