email article printer friendly more resources

Overcome Device Diversity Challenges
Understanding the issues associated with launching wireless applications can smooth deployment and make the process less intimidating.
by Derek Ferguson

For this solution: Visual Studio.NET, Mobile Internet Toolkit, .NET Compact Framework and Smart Device Extensions

One of the biggest challenges to creating functional and useful mobile software is the enormous diversity among mobile devices on the market today. In many ways, the landscape for mobile devices is best compared to the personal computer market of the early 1980s. Before the IBM PC, there was no de facto standard in personal computing: Some people had Ataris, some had TI-99s, and others had Commodore 64s. The problem was that no single platform was capable of capturing more than a thin slice of the overall computing market—and they were all completely incompatible. This created an enormous challenge for software manufacturers, because they had to choose which platform(s) to target carefully. Each additional platform required a considerable additional investment to port applications onto it.

In some ways, the mobile device landscape of the early 21st century is even more diverse than the personal computing market of the early 1980s. At least back then most devices had approximately the same level of capabilities: 64K, 1 or 2 MHz of processor power, a keyboard, and a TV for a monitor. Today, mobile devices vary widely in speed, memory, and user interfaces. In this article, I'll explain the differences between most of the popular mobile computing platforms available today, such as the Pocket PC and Palm. Then I'll suggest how your developers can use .NET to minimize the complexity of creating applications for such a diverse assortment of devices.

Speed is one of the most widely divergent characteristics among the devices. At the low end of the spectrum, some cell phones contain processors capable only 7 or 8 MHz in processing power. This is approximately comparable to the speed of the first IBM PCs. The Palm OS and similar devices fall in the middle ground. They clock in at around 33 MHz, which is approximately what the 386 era of Intel chips were able to manage. It should be noted, however, that Palm's plans for version 5 of their platform call for an upgrade to the Intel StrongARM processor, which will make their speed capabilities comparable to Pocket PCs.

You probably find the Pocket PCs most interesting given the focus on .NET computing. The StrongARM processors in current Pocket PCs process at approximately 233 MHz. They're miniaturized versions of the computers of just a few years ago. Plans have also just been unveiled to add even faster processors to Pocket PCs, which will more than double their current processing power (see Resources).

The same pattern plays itself out when you evaluate memory. Most cell phones have memory measured in terms of K, and 64K is a common amount. Palm OS devices currently average approximately 8 MB of memory. Pocket PCs tend to have 32 MB and Pocket PC 2002s tend to have 64 MB, though some Pocket PCs prior to 2002 had 64 MB, and there are a few Pocket PC 2002s that have only 32 MB.

Differences in memory and speed can present obvious obstacles to the performance of the applications your developers create. However, user interface (UI) diversity can determine whether an application works at all on a given platform. For example, most cell phones have only a few lines of display screen and no keyboard for input. Instead, users must enter an arcane series of keystrokes on their keypads to enter text. Clearly, this disqualifies such devices for being seriously considered as a platform for deploying the next great word processing application.

Palm devices have a larger display screen and users can enter text using its brand of handwriting recognition, known as Graffiti. You can typically learn it in a few minutes and master it within a few days. Pocket PCs have a similar size display, and although they offers handwriting recognition software, most people prefer to use their built-in, pop-up, on-screen keyboards.