4G technologies are designed to provide IP-based voice, data and multimedia streaming at speeds of at least 100 Mbit per second and up to as fast as 1 GBit per second. 4G LTE is one of several competing 4G standards along with Ultra Mobile Broadband (UMB) and WiMax (IEEE 802.16).
An electrical ballast is a device placed in line with the load to limit the amount of current in an electrical circuit. It may be a fixed or variable resistor.
ballast factor (BF) - The ratio of the light output of a fluorescent lamp or lamps operated on a ballast to the light output of the lamp(s) operated on a standard (reference) ballast. Ballast factor depends on both the ballast and the lamp type; a single ballast can have several ballast factors depending on lamp type.