A Survey of Wireless Options for Palm Developers
Arguably there is no aspect of mobile computing that fires the public's imagination more than wireless communications. Indeed, when you contemplate the ability to access the vast wealth of the Internet from the Palm of your hand and communicate with friends and co-workers, anytime, anywhere, it is easy to see why there is so much pent-up excitement surrounding this topic.
It seems like we have been waiting for this marvelous future to happen for quite some time now. I remember just a few years ago attending a wireless and mobile computing tradeshow, and one of the speakers joked that, although many were calling that year the "Year of Wireless," the same tag had been applied to the previous ten years! The truth is that components of the wireless dream are in fact here, but depending on who you are, what your expectations are, and what you want to do with wireless, you might find that the realities of today's wireless capabilities fall short of the promise.
Part of the problem is that, like so many new technologies, wireless has been hyped to the point where it will take a very long time to live up to all the expectations involving pervasive anytime/anywhere fast connectivity. I will say that wireless is one of those few technologies in which the hype is well deserved: wireless will almost certainly fulfill its promise, and change the way we work and live. The problem is not whether it will or won't happen, but when. I think if someone stood up in 1980 and proclaimed that each of us would ultimately have a personal computer on our desk that had a 10GB hard drive and a 2GHz processor, they would clearly have seen their predictions come true, and given a long enough time span for it to occur, it might not have even seemed outlandish to predict. As usual, timing and expectations are so important as we try to forecast the future of computing.
What this article covers
This article provides a brief introduction to the landscape of available wireless communications options for software developers building mobile computing applications.
Specifically, you will learn:
- Which wireless communication options are available
- Hardware and software choices for each option
- How to choose the right option for your application
- The Palm SDK APIs that cover wireless communications
Subsequent articles in this series will build on this information, and provide more in depth, low-level treatments of some of these wireless technologies from the perspective of the Palm developer.
Options for Wireless Communication
There are by now a large number of ways for PDAs to connect wirelessly to other computers. Each method has its pros and cons, and for people new to the industry, these methods can be confusing to understand and choose from. It does not help that there are so many components to the whole solution, including hardware, software, adapters, protocols, carriers, and networks, many of which do not work with one another.
This section lays out the relevant connectivity options available today for Palm OS handhelds. Although it is beyond the scope of this series to explain the entirety of wireless communications (that's a book in and of itself!), you should still be able to get a good starting point for understanding the options.
I (somewhat arbitrarily) divide the options into two categories: short-range wireless communications and wide-area communications. As you'll see, there is some overlap in terms of the capabilities delivered to the users, but it's as good a categorization as any.
This section provides an overview of the short-range wireless communications options available to the Palm programmer. Among them are infrared communications, Bluetooth, and 802.11 (also known as Wi-Fi).
Infrared communications have been bundled with every Palm device manufactured going back to the Palm III. Infrared communications can be used to create one-way and two-way information exchange between two PDAs, or between a PDA and an IrDA-compatible device such as a printer.
Infrared on Palm devices is the shortest and most limited of the short-range communications options. Connections must be "line of sight" (no obstacles blocking the beam), and must be within a range of approximately three feet. (Note that some Sony Clie devices come with an enhanced IR port that can communicate over slightly longer distances such as the width of a living room.)
On the handheld side of things, every PDA has all it needs to support infrared communications. An IR port comes with every device, an IrDA compatible stack is bundled with Palm OS, and the Palm built-in applications are all enabled to beam data to and from other PDAs.
For short-duration tasks, things such as beaming an address book entry from one PDA to another, or printing to an IR-enabled printer, infrared is very reliable. The line-of-sight requirement and the limited range of the beam combine to make this a poor choice for longer duration activities such as Internet communications. Furthermore, on the Palm OS there is no native support for TCP/IP communications over IR.
Infrared can be used for hot-sync, but obviously requires the host computer to have an infrared port.