One set of messages of the society we live in is: Consume. Grow. Do what you want. Amuse yourselves. The very working of this economic system, which has bestowed these unprecedented liberties, most cherished in the form of physical mobility and material prosperity, depends on encouraging people to defy limits.
-Susan Sontag (b. 1933), U.S. essayist. (1989).
The American Heritage Dictionary of the English Language4.1 gives the following two definitions for "Mobility".
1. The quality or state of being mobile.
2. The movement of people, as from one social group, class, or level to another.
However this entry does not identify the relationship between the two definitions. In today's world, upward mobility is often closely tied with physical mobility. Moreover, high productivity often associated with upward mobility means that there is a demand for continuous contact and communications while mobile.
The best example of this is evidenced in the incredible adoption of cellular telephones by the business community. Nowadays, a successful business person without a cellular telephone or a pager is indeed an endangered animal! With increased dependence on data access, the need for mobile communications has now entered the data arena.
In this chapter we discuss the first of the aspects of mobility - mobility management - in CDPD systems. Chapter 5 will cover CDPD network access, the second aspect of mobility.