.
Private Packet Radio .
Private packet radio, though not as common as cellular, offers businesses widespread connectivity. The two major private packet radio providers in the U.S. are Ardis and RAM Mobile Data. These services can be connected to from virtually anywhere in the country. Private packet radio offers quick call setup and is well suited to communications that generate short, bursty messages, such as e-mail, database queries and point of sale applications. Since private package radio has been around for several years, there are many applications that use the network. Some of the commercial applications being used handle messaging, scheduling, electronic filing of expense reports, and even allow for insurance agents to process accident claim forms from a customer's house or office (Salamone 96). The disadvantage with private packet radio, like CDPD, is that it is expensive for large file transfers. .
The fundamental problem that wireless communications faces is that none of the major wireless data services is ideal for all applications. The stumbling blocks to widespread adoption of data connections for laptops and personal digital assistants (PDAs) include the lack of compatibility between services, the cost of the services, and the size and price of wireless modems. .
History of Wireless Communications .
Radio telephones have been used for decades, but have not been widely available due to limited system capacity. The breakthrough that addressed this capacity problem was the development of the cellular concept, which allows frequency reuse. Needless to say, the use of wireless communications has increased exponentially since that breakthrough. The evolution of wireless systems can be divided into several stages: 1) the preprevailing stage, 2) the first generation analog system, 3) the second generation digital system, and 4) the third generation system (to be discussed later). The promised services, the required technologies, and the developmental timetable are summarized in Table 1 (see appendix A).
