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.
When it comes to lighting in commercial buildings, ballasts are an essential part of the picture. Ballasts limit the amount of current that enters the lights from power supplies. This protects the light bulbs or lighting tubes from the high levels of current that come from the electricity source. Without ballasts, fluorescent lamps in recessed lighting and track lighting would be destroyed by the standard current.