Size Matters: Optimizing Mobile Document Delivery

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Slurping Through a Narrow Straw
The state of wireless networks in the U.S. is another major limitation of handhelds for viewing documents that directly affects how they are distributed. "Even with the current 2.5 and 3G networks, your [mobile] connection speed might be somewhat equivalent to a 14.4 or a 28.8Kbps modem," says RIM's Heit.

In an effort to reduce the strain on limited bandwidth resources when viewing attachments sent with emails, a BlackBerry holds back on sending the delineated contents of a file until explicitly instructed to do so. "What happens is you get the initial email and then a token indicator for the attachments. The first thing you get is the option of getting either the full content or just the table of contents," says Heit. "What our servers can do is open up the attachment, find the table of contents, and then forward that with hyperlinks to the chapters. If it's something like a spreadsheet, it will pick up all the tabs. If it doesn't have a true table of contents, it will look for subject headings and generate one of its own." 

Adobe's Acrobat has utilized a similar approach when handling larger PDFs for quite some time. "We push the content that you need," explains Huq. "When you access the content you see that first page, and as you flip through [the document], the additional pages are accessed. It's similar to pushing content on demand, which maximizes and does not tax the bandwidth."

Besides sending documents piecemeal to devices, files on a BlackBerrry are also streamlined to cut down on the overall file size. "The bulk of the size of a document is the hidden characters used in formatting," says Heit. "Because we support viewing, but not full manipulation, we don't need to send all that stuff. For a spreadsheet or document file, a compression ratio of what we send over the air is well over 95% the source." Word files viewed on a BlackBerry aren't completely devoid of formatting, though; they still include things like bold and italics, and red-lining through text.

palmOS-enabled devices don't download documents piecemeal but instead bring the whole files onto the hard drive from the get-go. "Today's networks are definitely a crutch for mobile document viewing," says Maes. "A faster network is certainly something that we need." In the meantime, palmOne has worked to speed up the connection between handheld and desktop when tethered together, an upgrade that's vital to the file synchronization of palmOne's LifeDrive concept.

Need More Power
But resolving the issue of bandwidth bottlenecks isn't as simple and straightforward as implementing a faster network. "Battery life is the Achilles' heel of wireless," says Heit. "The problem is that as networks get faster and faster, they'll require faster and faster processors with more memory." And while processor speeds and storage capacities have been able to keep up relatively well with consumers' mobile computing demands, the same can't be said for the battery life needed to power them. "Your battery is not something that has followed Moore's Law," says Heit. "Battery capacity increases are measured in small percentages each year." 

The more processor-intensive the applications' a handheld runs are, the faster your battery loses juice. "You have to be careful in managing that problem very well," Heit continues. "You can create all of these wonderful applications, but if your battery life lasts only an hour, nobody will use it. It's kind of counter to what you hear in the press about these faster networks."

It's All a Matter of Intent
Unfortunately, to date, there's no foolproof workaround when it comes to extending battery life. This will be a constant restriction of handheld devices until the next evolutionary leap in battery technology. But even still, this issue of battery capacity also sheds light on another important aspect of mobile document delivery: the role the handheld plays in a user's workflow. 

For RIM, that means recognizing the limitations of its BlackBerry devices and not trying to cram more and more functionality onto the platform. "We are very concerned with preserving that whole equation of longevity versus functionality, but the other element is the convenience versus the functionality," says Heit. "Your usage case is that people aren't typically sitting still. The way I describe this is when I'm waiting for an elevator—can I check three emails in the thirty seconds that I'm waiting? Obviously with a laptop, that's not a simple equation."

With a BlackBerry, this is precisely what it was designed to be: a remote viewing device for referencing emails and documents quickly. While it does include versions of Word and Excel, neither offers full editing capabilities—an intentional move on the company's part. "People are discovering as we work through applications that you really want to make sure you are capturing the essence of what you need when you're mobile and not just replicating the desktop experience," Heit explains. "We didn't think it was necessary to have full attachment-editing capabilities." This approach enables a BlackBerry to conserve energy by not trying to overexert itself running various applications.

Palm-enabled devices and other PDAs, on the other hand, have positioned themselves more directly as laptop replacements or alternatives. "After the calendar and address book, the most used functions are Word and Excel, followed by photos," says Maes. "Originally we thought that most people were using them to view documents." But then they noticed a trend that spoke to the success of Palm-enabled devices in manipulating, as well as viewing, documents. "The wireless keyboard is a very, very popular accessory that we sell," Maes states. "That tells us that people are truly creating and editing." That keyboard, combined with full versions of Word and Excel, can transform a PDA into an ultra-mobile, fully functional workstation. "We haven't slimmed down anything," says Maes. "Can I do everything in Word that I do on a desktop? Not quite, but it's pretty close."     

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