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?
Introduction
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 perspectiveWireless 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 mattersA 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.
ComplexityAnother 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 serviceThis process can literally take days to
complete - a real obstacle for consumers and IS
departments.
PerformanceAssuming 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 messagesTo 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
handheldBecause 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
jdoe@palm.net.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