sister "distribution transparancy"

Question :

*We argued that distribution transparancy may not be in place for the
pervasive system. This statement is not true for all types of transparancy.
Give some examples!*


The answer for the question above will be described in the article below :

*Introduction*

Distributed System is the one which hardware or software components located
at networked computer communicates and coordinate their actions only by *passing
message.* The example of the Distributed System is the Pervasive Computing
in which well known also as the Ubiquitous Computing. The Ubiquitous
Computing is the harnessing of many small, cheap computational devices that
are present in user's physical environment, including home, office, or even
the natural setting. The Ubiquitous Computing is almost similar with the
Mobile Computing. But while the mobile computing is concerned with
exploiting the *connectedness of devices that move around* in the everyday
physical world, the Ubiquitous Computing is about exploiting the *increasing
integration of computing devices* with our everyday physical world. The
example of The Ubiquitous Computing is “The Universal Remote Control” that
can control each devices located at home, such as the washing machine, the
cars, the doors, the lamp, and another device that can be installed with
computational devices.

The Construction of Distributed System arise challenges in some fields, that
is : Heterogenity, Openness, Security, Scalability, Failure Handling,
Concurrency, and Transparancy. In this section, We will point only about the
Transparancy.

Transparancy is defined as the concealment from the user and the application
programmer of the separation of components in a Distributed System, so that
*the system is perceived as a whole* rather than as a collection of
independent component. There are at least eight scopes or types of The
Transparancy that have to be resolved by the Distributed System Constructor
or Developer, that is : Access Transparancy, Location Transparancy,
Concurrency Transparancy, Replication Transparancy, Failure Transparancy,
Mobility Transparancy, performance Transparancy, and Scaling Transparancy.

The Access Transparancy enables local or remote resource to be accessed
using identical operation. The Location Transparancy enables resource to be
accessed without knowledge of their physical or network location (for
example, which building or IP address). The Concurrency Trnasparancy enable
several processes to operate concurrently using shared resources without
interfere between them. Replication Transparancy enable multiple instance of
resources to be used to increase reliability and performance without
knowledge of the replicas by user or application programmers. Failure
Transparancy enable the concealment of faults, allowing user and application
programmers to complete their tasks despite the failure of hardware or
software components. Mobility Transparancy allows the movement of resources
and clients within a system without affecting the operation of user or
programs. Performance Transparancy allows to system to be reconfigured to
improve performance as loads vary. Scaling Transparancy allows the system
and applications to expand in scale without change the system structure or
the application algorithms.


*Explanation*

Based on the definition and the structure of The Ubiquitous Computing and
the types of Transparancy, we can make it senses that several types of the
Transparancy can be implemented in the Ubiquitous Computing. For Example, in
the office which has been using the “Smart Card” for accessing every
resources located on its building. The resources include the rooms, devices
such printer, and so on. The Ubiquitous System Constructors may transparent
the location of the database server from the user and the application
programmers, to conceal the complexity of the system itself. They also may
implement the Concurrency Tranparancy and the Replication Transparency to
improve the performance of the system itself. So its possible for the
Constructors to implement several types of the Transparency in the
Ubiquitous System they construct.


*Closing*

Those are our answer for the question above. The conclusion is the
Constructors may implement several types of the Transparency in the
Ubiquitous or Pervasive System they construct. We realize that our
explanation is still lack of the deeper analysis and the illustrations, but
we may advise you to read some references that can help you to understand
better about this topic. The book we advocate is “Distributed Systems,
Concept and Design” (Addison Wesley, 2005).

Thank you.