And since every cellular market has two carriers, customers have at least some recourse if they don't get the service or pricing they want from a particular supplier. And prices are falling rapidly. The cost to send data once was as high as 50 cents per kilobyte, but many systems now charge just one-tenth that amount and make monthly allowances in their basic rates. Despite its promise, CDPD coverage is relatively limited. Although it is available from cellular carriers in most large U.S. cities, CDPD often covers less than 50 percent of a region.
Speed can also be an issue.
While CDPD's raw data rate is 19.2Kbps, customers can experience latency that reduces throughput, especially during periods of peak voice traffic. That's because the cellular carriers must allocate CDPD bandwidth from their allotment of voice channels. When voice traffic is light, cellular carriers can devote more bandwidth to data. Wireless data services are still in their infancy. Particularly valuable is their ability to hold messages in a queue when the client computer is turned off or out of range.