Wireless Internet access for PDAs

Attaining truly mobile data transfer for PDAs has always involved a long shopping list. The all-in-one solution is almost upon...

Attaining truly mobile data transfer for PDAs has always involved a long shopping list. The all-in-one solution is almost upon us, but is it as easy as it sounds?


As the Internet has grown, so has usage of its resources. People spend hours at their desktop computers accessing and using the seemingly unlimited content available ( everything from news to stock quotes, telephone directories, restaurant lists, airline schedules, reference materials and enterprise data. But, as mobile employees move from meeting to meeting or travel the country, taking them away from their desks, this wealth of information is inaccessible. The solution to this problem is wireless data and Internet access.

Historical perspective

Wireless data access has alternately been called the "saviour" and "failure" of handheld computing. Before palm computing introduced the first palm computing connected organisers, industry analysts suggested the "handheld" market had failed because no company had successfully incorporated two-way wireless capability into its products. In fact, the list of companies which have attempted handheld two-way wireless products reads like a who's who in technology: AT&T, IBM, Motorola, Apple Computer, Ericsson, Nokia and even 3Com, among others.

Size matters

A pocket-sized handheld is simply more convenient and accessible than a device pulled from a briefcase. Until now, wireless data solutions required connecting two devices - a handheld and a mobile phone or a handheld and a power hungry wireless PC card modem - or were bulky integrated devices. None of these combinations or products is convenient to activate, carry or use.


Another obstacle to success has been the requirement that the end user or the IS department do a significant amount of system integration. In a scenario where the handheld device has a PC card slot and wireless connectivity is achieved with an add-on wireless modem card, the user has to:

  • Buy the device
  • Buy the wireless modem, likely from a different vendor
  • Download drivers for the wireless modem, since it was likely designed for laptop use
  • Install those drivers on the handheld
  • Choose and activate a wireless service
  • Potentially sign up for separate ISP service
  • Sometimes even sign up for an additional wireless email service

This process can literally take days to complete - a real obstacle for consumers and IS departments.


Assuming the end user overcomes the complexity of set-up, the user is then faced with slow Internet access over these slow baud rate, high latency wireless networks. The performance of most of the two-way wireless networks today ranges from 8Kbit/s to 19.2Kbit/s. Simply put, the design of Internet protocols and most Internet content were not created with the slower speed of wireless access in mind.

Thus, "browsing" the web from a wireless device is a slow and expensive experience. A second performance hurdle is battery performance. To meet the form factor and convenience goals, many handheld products today run on alkaline batteries. Yet, running two-way wireless radios can drain alkaline batteries in even a few minutes of use. Reduced battery life means reduced portability, thereby defeating the purpose of selecting the handheld in the first place.

One solution to the problems that have plagued two-way wireless data predecessors is the Palm VII handheld from 3Com. It has a built-in two-way wireless radio with integrated antenna. For wireless Internet access, the Palm VII has two new software applications:

  • Web clipping, which enables instant access to Internet information
  • iMessenger software - wireless Internet messaging for sending and receiving brief Internet messages

To achieve the goals of long battery life, low service cost and Internet-like performance without Internet-like bandwidth, Palm Computing took a different approach to accessing information on the World Wide Web. The "browsing" metaphor doesn't make sense for a handheld platform device with a small screen and low bandwidth. Palm Computing felt accessing content on a Palm VII device should be analogous to clipping an article out of a newspaper - you get only the part you really need, nothing more.

So Palm Computing named the concept "web clipping". Web clipping is based on a simple idea - less data transferred results in a more efficient system. To accomplish this, Palm Computing conceived two design principles:

  • All user interaction is based on a simple query and response rather than on a system of hyperlinks
  • Application partitioning, where the query portion is stored locally on the handheld

Because the query portion of the application is stored locally, the user enters data into a request form ( e.g. for a stock symbol, news topic or name to look up ( without even going online. Once the user submits a query, the resultant page or web clipping is very small. On a typical application, about 50 bytes is sent as part of the query and less than 500 bytes is returned (compressed). Because the web clipping concept operates so efficiently, the desired information usually appears on the screen in less than 10 seconds. As a result, the user's actual airtime is minimal.

Palm VII handhelds also come with iMessenger - wireless Internet messaging software that allows users to send and receive messages directly from their Palm VII handheld. Each user receives a personal Internet messaging account on Palm.Net, such as [email protected]

As with web clipping, iMessenger software is a streamlined version of the traditional PC-Internet exchange email. iMessenger strips attachments, compresses the text and delivers the first 500 characters in a message. If the entire message is more than 500 characters, the user decides whether to download the next segment or retrieve the entire message.

iMessenger lets users send notes from virtually anywhere in the US. Schedule changes, new equipment orders or memos can be sent immediately. Retrieving messages works like voice-mail: the user simply raises the antenna and presses a button to download the messages waiting in the queue.

The user's Palm.Net service account is not intended as a forwarding address for all of a user's desktop mail because of the cost and impact on battery life. Instead, users may use the features of their desktop e-mail system to filter and forward messages based on urgency or other criteria.

The full text of this white paper can be found at 3Com's website.

Compiled by Richard Pitt

Read more on Wireless networking