A Mobile Phone-Based Expert System for Disease Diagnosis - E-Healthcare Systems and Wireless Communications - page 226

using the HTTP framework that has been built
into it (Linkins et al., 1994). With J2ME, Sun has
adapted the Java platform for consumer products
that incorporate, or are based on small computing
devices (“J2ME: Step by step”, see: http://www.
digilife.be/quickreferences/pt/).

• The type of network connection available

to the device.

The configuration defines the basic run-time
environment as a set of core classes and a specific
JVM that runs on specific types of devices. The
profile defines the application; specifically, it adds
domain-specific classes to the J2ME configuration
to define certain uses for devices. The following
graphic in Figure 3 depicts the relationship be-
tween the different virtual machines, configura-
tions, and profiles. It also draws a parallel with
the J2SE API and its Java virtual machine. While
the J2SE virtual machine is generally referred to
as a JVM, the J2ME virtual machines, K Virtual
Machine (KVM) and C Virtual Machine (CVM),
are subsets of JVM. Both KVM and CVM can
be thought of as a kind of Java virtual machine
- it is just that they are shrunken versions of the
J2SE JVM and are specific to J2ME. Connected
Limited Device Configuration (CLDC) is a con-
figuration for small devices while Connected
Device Configuration (CDC) is a configuration
for larger devices. Two profiles have been defined

General J2ME Architecture

J2ME consists of two elements - configurations
and profiles. It uses configurations and profiles
to customize the Java Runtime Environment
(JRE). As a complete JRE, J2ME is comprised
of a configuration, which determines the Java
Virtual Machine (JVM) used, and a profile, which
defines the application by adding domain-specific
classes. A configuration is a specification that
defines the software environment for a range of
devices defined by a set of characteristics that the
specification relies on, and usually things such as
(Linkins et al., 1994):

• The type and memory available.

• The processor type and speed.

Figure 2. Rule-based reasoning (Source: Michael 2002)