Local networks connect seamlessly with each other, with satellite and terrestrial networks, and with a large number and variety of physical devices that can be used to monitor and control the physical world. This makes them more useful and more resilient to failures, load conditions, and resource mobility. Networks route heterogeneous traffic efficiently, in response to application demands, through nodes that differ in connectivity, computational power, and resources. This adaptability is essential for wireless channels, whose peak bandwidth and error characteristics can vary dynamically and unpredictably. RF channels, for example, are affected by terrain, weather, and interference from other transmitters.
Networks respond flexibly to such unpredictability.
Instead of sending all packets at low data rates or broadcasting at high power, they allow applications to trade data rates off against energy consumption. Instead of always using complex and costly error correction, they use only as much as applications require. Instead of being designed to handle unlikely combinations of worst-case conditions, they are designed more economically to handle current or common conditions. Approach Flexible, decentralized networks, called N21s , connect dynamically changing configurations of self-identifying mobile and stationary devices. N21s integrate different wireless, terrestrial, and satellite networks into one seamless internet.