As computing devices shrink in size, weight and power, untethering of communication links will make the distinction between communications and computing to be blurred, leading to the new field of personal communication services (PCS). In a PCS environment, computing resources can be used more flexibly because users can be freed from being physically connected to the underlying network. PCS aims at ubiquitous availability of services to facilitate the exchange of information between nomadic end users, independent of time, location and access methods. This enables continuous and transparent network access for portable users. In the hierarchical structure of a PCS network, the total service area is divided into multiple areas each of which contains several cells. This, in turn, makes database management much simpler and easier as well.
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