Received signal strength indication Received signal strength indication In telecommunications, received signal strength indicator (RSSI) is a measurement of the power present in a received radio signal. RSSI is usually invisible to a user of a receiving device. However, because signal strength can vary greatly and affect functionality in wireless networking, IEEE 802.11 devices often make the measurement available to users. RSSI is often derived in the intermediate frequency (IF) stage before the IF amplifier. In zero-IF systems, it is derived in the baseband signal chain, before the baseband amplifier. RSSI output is often a DC analog level. It can also be sampled by
Timeline of United States inventions (1946–91) polypropylene or polyester film and fiberglass filaments embedded to add high tensile strength. Filament tape was invented in 1946 by Cyrus Woodrow Bemmels. In 1949, it was placed on the market and was an immediate success. 1946 Credit card 1946 Diaper (waterproof) 1947 Transistor In electronics, a transistor is a semiconductor device commonly used to amplify or switch electronic signals. Because the controlled output power can be much larger than the controlling input power, the transistor provides amplification of a signal. The transistor is the fundamental building block of all modern electronic devices, and is used in radio, telephone, computer,