In my last article, we considered network alternatives for wireless PDAs, including Bluetooth Wireless PANs, Wi-Fi Wireless LANs, and CDMA2000/GPRS Wireless WANs. After you've identified the kind(s) of wireless that you require, you'll need to acquire that network connectivity. In this article, we consider hardware alternatives for adding PDA wireless PAN, LAN and WAN services.
Embedded or add-on
My last article identified several PDAs that now ship with embedded wireless - for example, HP's iPAQ H2200 (Bluetooth), Palm's Tungsten C (Wi-Fi), and RIM's BlackBerry 6710 (GPRS). PDAs with embedded wireless are on the rise, but there are many wireless adapters that can be added to your PDA. If you're buying a new PDA, which should you choose?
Embedded wireless has the edge for convenience, weight, ease of use, and (sometimes) power consumption. Dragging around an adapter makes a PDA heavier and increases the chance that you'll forget or misplace your adapter. If you buy a PDA with built-in GPRS or CDMA2000, it will integrate seamlessly with a particular carrier's "3G" wireless service, and you may even ditch that old cell phone by carrying one multi-function device instead.
But add-on adapters do have advantages - notably flexibility and upgradeability. For example, PDAs with embedded Wi-Fi now support 802.11b. In six months, if you want to upgrade to 802.11g, you'll need an adapter anyway. If you buy a PDA with embedded Bluetooth, you may still want to add Wi-Fi. Or your employer may require a specific vendor's adapter for support and security. Purchasing a PDA with expansion slots will leave you in a good position to add or upgrade later.
What kind of add-on?
So, you've decided to add wireless by coupling a third-party network adapter to your PDA. Expansion features vary widely, so considering this is important when you purchase your PDA. Common alternatives include the following:
PC cards: PC card (PCMCIA) slots are universal on laptops, but some PDAs can also be used with PC cards - usually by slipping the PDA into an adapter sleeve. This is handy to use one card in both your laptop and PDA. But it's also the bulkiest option, and consumes more power. Not all vendors supply PDA drivers for their cards, so you'll need one that supports your PDA's operating system (odds are best for Pocket PC 2002.) Also note that cardbus PC cards won't work with PDAs. PC cards that can be added to PDAs include 3Com's Wireless Bluetooth PC Card, Cisco's Aironet 350 Series 802.11b PC Card, Novatel's Merlin G100 card for T-Mobile (GRPS), Sierra Wireless' AirCard 710 for AT&T (GPRS), and the Aircard 550 for Sprint (CDMA/1XRTT).
Compact Flash (CF) cards: There are two kinds of CF cards. Type I cards are about 1 5/8" square, with a smallish protrusion at the top. Type II cards are a bit thicker and bigger across the top, but still more compact than PC cards. CF slots are very common on today's PDA, but look for Type II slots so that you can use either Type I or Type II CF cards. Examples include Socket's WL6000320 802.11b (Type I), Linksys' WCF11 802.11b (Type II), Sprint's CF2031 CDMA/1xRTT (Type II), Belkin's F8T020 Bluetooth CF, and Anycom's Bluetooth CF-2001.
Secure Digital Input/Output (SDIO) cards: SD cards are widely used to add memory to PDAs, but the SDIO variation has been used to provide network connectivity. SD slots and wireless cards are less common than CF slots and cards, but that's expected to change over time. SDIO cards are smaller (24mm x 50mm) and may consume less power. Examples include Socket's Bluetooth SDIO Connection Kit for WinCE, Palm's Bluetooth card SDIO card, and SyChip's WLAN6060SD 802.11b SDIO card for WinCE and Palm.
There are also expansion options for PDAs that have somewhat unique connectors. For example, Sony PDAs can accept Memory Stick Input/Output (MSIO) cards, Palm m-Series PDAs can be outfitted with "sleds" and Handspring PDAs use SpringPort expansion cards. In such cases, you'll have fewer options, but you DO still have options. Examples include Intel's Xircom WLAN Module for Palm, Red-M's Blade Bluetooth module for HandSpring, and Hagiwara's HNT-MSW1 Memory Stick WLAN card (3Q03).
Mix and match carefully
No matter which kind(s) of wireless you choose, there are additional factors to consider. If your PDA has just one expansion slot, you may be forced to choose (or alternate) between added storage and wireless. Many adapters support Pocket PC 2002, but support for other PDA operating systems is spottier, and there may also be model restrictions. Check to see if the adapter works with your specific PDA before you buy. There can also be software binding limitations, so do your homework if you're hoping to use wireless with a particular application. Adding wireless to a PDA isn't that difficult, but a little up-front planning can save you heartache in the long run.
Do you have comments about this article, or suggestions for Lisa to write about in future columns? Let us know!
