Setting a Wifi network is easy for a small scale area but to cover a whole building, you need multiple wireless routers which may be ugly at times.
Using LED may solve the problem of aesthetics and at the same time encourages the usage of LEDS which use less energy for lighting.
Chinese scientists demonstrate 2Mbps internet connection over LEDLED data transmission used to be all the rage -- we fondly remember beaming Palm Pilot contacts via IrDA. Then we got omni-directional Bluetooth and building-penetrating WiFi, and put all that caveman stuff behind us.
But now, scientists the world over are looking to bring back line-of-sight networking, and the latest demonstration has Chinese researchers streaming video to a laptop with naught but ceiling-mounted blue LEDs.
The Chinese Academy of Sciences claims to have realized a 2Mbit per second internet connection that transmits data simply by modulating the flicker of the little diodes, and imperceptibly enough to have them serve as room lighting as well.
Like Boston University before them, the Chinese scholars see short-range LED networks controlling smart appliances. It's not quite the gigabit speed you'd get from laser diodes, but this way you'll get more mileage out of those expensive new bulbs, eh?