The Mobile Web | Back | TOC |
PART 1 PART 2
The user base of mobile phones is rising rapidly, thanks to the
competitive market and the promising potential of
the mobile services. The mobile phone has made it possible for us to stay connected to the computer networks
around the world, no matter where we are. The mobile service technology, which includes all hand-held devices like
Palm and the cellular phone, has helped unleash the power of the Internet to the mobile devices. It is now possible
to communicate via the World Wide Web from your mobile phone. We have today what are called Mobile Web
applications that make the Internet communication possible.
The technology for the mobile world comes in several flavors. While all are designed to address the same need, i.e.,
to enable a roaming client to access the web and the telecommunication lines from a single hand-held device, the
approach to make such access possible varies. The variation is considerable, so much so that no single device
today supports the different technologies.
The mobile device has certain characteristics and constraints that the mobile technology must cope with, no matter what flavor it is. The device has limited permanent memory, and a small volatile memory called flash memory. It also has a small display screen that limits how much content you can show, and in what order. To work
around these limitations is a daunting task both to the technology designers and the content developers.
The technologies that have graduated from the laboratory and show promise of wider user base are listed below.
In this article I will focus on the mobile technology that is powered by MIDP. This technology is driven by the specifications from Sun Microsystems. Here you will find Java in the microland. The following table puts the technology in the right perspective.
Servers & Enterprise Computers | Servers & Personal Computers | High-end PDAs, TV set top boxes, Embedded devices | Mobile Phones & Entry level PDAs | Smart Card |
Optional Packages | Optional Packages | Optional Packages | Optional Packages | Java Card |
Java
2 Platform Enterprise Edition (J2EE) |
Java
2 Platform Standard Edition (J2SE) |
Personal Profile | MIDP | |
Personal Basis Profile | ||||
Foundation Profile | CLDC | |||
CDC | ||||
JVM | JVM | JVM | KVM | Card VM |
So we see that there are primarily two virtual
machines (VMs), one for the computing in the large and another for computing in
the small. The KVM supports a device memory stack ranging from 128K to 512K,
such as the one we find in a mobile phone.
The MIDP technology comes like all others with
a set of optional packages, and combined with CLDC, forms the Java runtime environment for today's mobile information devices such as phones
and entry level PDAs.
If you are a user on the move, and wish to have access to your network at all
times, then what you need is a Mobile Web application. Mobile applications can be easily
downloaded to your machine.
Among those who need mobile web applications are the technicians who go from
door to door fixing up appliances, and have to be on the beck and call of
customers all the time.
In the next part we will see how this MIDP
technology works, and conclude in the last part with a small experiment that I
have actually worked on.