Mobile Networking Through Mobile IP

A lthough the Inter-net offers access to information sources worldwide, typically we do not expect to benefit from that access until we arrive at some familiar point—whether home, office, or school. However, the increasing variety of wireless devices offering IP connectivity, such as PDAs, handhelds, and digital cellular phones, is beginning to change our perceptions of the Internet. To understand the contrast between the current realities of IP connectivity and future possibilities, consider the transition toward mobility that has occurred in telephony over the past 20 years. An analogous transition in the domain of networking, from dependence on fixed points of attachment to the flexibility afforded by mobility, has just begun. Mobile computing and networking should not be confused with the portable computing and networking we have today. In mobile networking, computing activities are not disrupted when the user changes the computer's point of attachment to the Internet. Instead, all the needed reconnection occurs automatically and noninteractively. Truly mobile computing offers many advantages. Confident access to the Internet anytime, anywhere will help free us from the ties that bind us to our desktops. Consider how cellular phones have given people new freedom in carrying out their work. Taking along an entire computing environment has the potential not just to extend that flexibility but to fundamentally change the existing work ethic. Having the Internet available to us as we move will give us the tools to build new computing environments wherever we go. Those who have little interest in mobility per se will still benefit from the ability to resume previous applications when they reconnect. This is especially convenient in a wireless LAN office environment, where the boundaries between attachment points are not sharp and are often invisible. The evolution of mobile networking will differ from that of telephony in some important respects. The endpoints of a telephone connection are typically human; computer applications are likely to involve interactions between machines without human intervention. Obvious examples of this are mobile computing devices on airplanes, ships, and automobiles. Mobile networking may well also come to depend on position-finding devices, such as a satellite global positioning system, to work in tandem with wireless access to the Internet. Another difference may well be rate of adoption. It took many years for mobile phones to become cheap and lightweight enough to be perceived as convenient. Because wireless mobile computing devices such as PDAs and pocket …