填空题

The communications explosion is on the scale of the rail, automobile or tele- phone revolution. Very soon you’ll be able to record your entire life electronically- anything a microphone or a camera can sense you’ll be able to store. In particular, the number of images a person captures in a lifetime is set to rise exponentially. The thousand images a year I take of my children on a digital camera are all precious to me. In a generation’s time, my children’s children will have total image documentation of their entire lives-a visual log of tremendous personal value. By then we’ll be wrestling with another question: how we control all the electronic devices connected to the Internet: trillions of PCs, laptops, palm pilots, cell phones and other gadgets. In Cambridge, we’re already working on millimeter-square computing and sensing devices that can be linked to the Internet through the radio network. This sort of connectivity will expand dramatically as microscopic communications devices become dirt-cheap and multiple. Just imagine what the paint on the wall could do if it had this sort of communications dust in it: change colour, play music, show movies or even speak to you.
Falling costs raise other possibilities too. Because launching space vehicles is about to become very much cheaper, the number of satellites is likely to go up exponentially. There’s lots of space up there so we could have millions of them. And if you have millions of low-orbit satellites you can establish a global communications network that completely does away with towers and masts. If the satellites worked on the cellular principle so you got spatial reuse of frequencies, system capacity would be amazing.
How do you characterize the future development of communications