Compared with the existing schemes, the proposed scheme can rekey real-time, provide a high level of security and reduce communication overhead at the same time.
Well firstly, because it's found in large organisations, its fixed costs, or overheads as they're known, are low in relation to its output, or what it produces.
Keeping with household expenses and bills, you probably already turn off the lights when you leave a room and unplug gadgets when you aren't using them, right?