Networking

Using 802.11b to connect PDAs to WLANs

Options for connecting handheld devices to wireless networks


Until recently, handheld cradles were the only efficient way for most business users to transfer data between a handheld and a PC and/or network. Today, however, IT departments have two options for wirelessly connecting their users' PDAs: Bluetooth or 802.11b technology. (Although 802.11a technology will eventually be offered for handhelds, at the time of this article's writing, 802.11a products were not available.)

Although Bluetooth technology has been around for several years, it has never gained the wide consumer acceptance many thought it would and continues to be an option more suitable for personal rather than corporate use. However, 802.11b technology is growing in popularity; many organizations currently use 802.11b access points and PC cards to connect their laptop and desktops to wireless LANs (WLANs). Now you can do the same with your organization's PDAs.

Palm
Although the majority of Palm users use Bluetooth technology to attach to wireless networks, you can attach a Palm unit to an 802.11b wireless network. The wireless networking components of 802.11b have a much longer range than Bluetooth components—many of which are limited to as little as 30 feet—and are more common in corporate environments.

The only 802.11b product that I could find for Palm units is the Xircom Wireless LAN Module for Palm Handhelds. It claims to be the only 802.11b/Palm product in existence. This unit offers full 11-Mbps connectivity with all of the bells and whistles that you would normally expect from an 802.11b wireless NIC, such as 128-bit WEP encryption. However, unlike typical wireless NICs, the Xircom unit actually straps to the back of your Palm unit.

The Xircom Wireless LAN Module for Palm Handhelds is compatible with the Palm m500 series and the Palm m125. The unit offers a 1,000-foot range in open areas and about a 90-foot range in normal office environments. It costs around $250.

Pocket PC
Generally speaking, there are many more options for attaching a Pocket PC to a wireless network than there are for the Palm. Pocket PCs use a version of the Windows CE operating system, called Pocket PC, which is more widely supported by 802.11b hardware manufacturers than the Palm OS.

Wireless PC cards
When it comes to wirelessly networking a Pocket PC, the actual brand or model of the wireless NIC is irrelevant. What matters is that the NIC has Windows CE drivers available. In my experience, it is no more difficult to install one type of NIC than another. You simply insert the wireless NIC into the Pocket PC’s PCMCIA slot, and then install the wireless NIC’s drivers through the Network icon in Control Panel.

Figure A
Courtesy of Linksys


The real trick is finding wireless NICs with Windows CE drivers. At the time that this article was written, Windows CE drivers were available for the Linksys WPC11, shown in Figure A. This wireless NIC retails for about $60 and offers a 120-meter indoor range.

You can download the Windows CE drivers for this card from Linksys' Web site. Keep in mind that not all Linksys cards include Windows CE drivers. For example, there are no Windows CE drivers available for the Linksys WPC54A Instant Wireless PC Card.

A helpful tip is that if you have a Pocket PC with a PCMCIA slot, look in the unit’s Control Panel before rushing out to buy a Linksys card. Windows CE natively supports some brands of NE 2000-compliant wireless NICs. For example, I own an older HP Jornada that contains drivers for Proxim cards.

Wireless flash type II cards
Another method of attaching a PDA to a wireless network is via a wireless compact flash card, such as the D-Link DCF-650W, shown in Figure B.

Figure B
Courtesy of D-Link


This wireless flash card can be used to connect PDAs, such as the Compaq iPAQ and the Casio 125, to any 802.11b wireless network. Like a standard 802.11b PC card, the D-Link DCF-650W will operate in either infrastructure mode or in ad hoc mode at speeds of 11, 5.5, 2, and 1 Mbps.

This unit consumes minimal power and is compatible with any Pocket PC that has a flash type II interface and runs Windows CE 3.0. In spite of its low power consumption, the flash card offers a 1,300-foot range in open environments. Although this unit lists for $200, I was able to locate several places on the Internet that were selling the product in the $80 range.

Other compact flash devices are available—or soon will be—such as Pretec's soon-to-be-released CompactWLAN card, Symbol's Wireless Networker CompactFlash Card, and Socket's Wireless LAN CF Card. Prices for these devices range from around $100 for the Pretec card to $180 for either the Symbol or Socket card.

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