Mobile Agent: Emerging Technology

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Mobile Agent: Emerging Technology

Asst. Prof. Rajguru P.V.

Department of Computer Science and IT, Adarsh college, Hingoli (Maharashtra), India

Email: [email protected] Cell. 09822186940

Prof. Dr. Deshmukh S.D.

Department of Physics & Computer Science

JES College, Jalna. (Maharashtra), India. Email: [email protected]

Cell: 09422238695

Abstract–Mobile agent technology has been promoted as an emerging technology that makes it much easier to design, implement, and maintain distributed systems, introduction to basic concepts of mobile agents like agent mobility, agent types and places and agent communication. Then benefits of the usage of mobile agents are summarized and illustrated by selected applications. The next section lists requirements and desirable properties for mobile agent languages and systems. We study the main features, challenges, and open problems of mobile agent technology.

Keywords –Mobile Agent, Mobile Agents, Mobile Agent Platform.

I. I

NTRODUCTION

The term agent comes from Greek ‘agein’, which means to drive or to lead. Today the term agent denotes something that produces or is capable of producing an effect. It can be a chemically, physically or biologically active principle. With this broad scope the term agent can be used for substances (rinsing agent) as well as for human beings (travel agent). With its connotation of driving or leading something, the term is very suitable to describe current trends in computer science away from using the computer as a passive tool towards considering the computer as some more active instrument, in particular an instrument to which work can be delegated. Programming techniques and software that enable a more active role of the computer have been proposed in many different areas of computer science. To distinguish these agents from other types of agents, they are summarized under the term software agents. A possible definition of mobile agents is as follows:

Fig.1. Different Components of a Mobile Agent Framework

“A process that can actively migrate from one host to another host and based on locally computed decisions -can actively migrate to a third host is called a mobile agent.”

A problem with this widely adopted definition is that it is too much focused around the migration, which is only a small part of the functionality a mobile agent has to provide. A mobile agent is a program functions on behalf of a user in a distributed environment, and is able of migrate independently from one node to other to accomplish the assigned task of user.

Mobile Agent = Agent + Mobility

However, mobile agents can migrate to anywhere at any time. Mobile agents are different from Java Applets, since applets can travel only one way from server to client, while mobile agents can move in between the client and the server bi-directionally.[7]

The MuBot Agent

[http://www.crystaliz.com/logicware/mubot.html] "The term agent is used to represent two orthogonal concepts. The first is the agent's ability for autonomous execution. The second is the agent's ability to perform domain oriented reasoning."

Nwana, 1996 An agent is a component of software and or hardware, which is capable of acting exactingly in order to accomplish tasks on behalf of its user.

Jennings, Sycara and Wooldridge, 1998 An agent is a computer system, situated in some environment, that is capable of flexible autonomous action in order to meet its design objectives

The AIMA Agent [Russell and Norvig 1995, page 33] "An agent is anything that can be viewed as perceiving its environment through sensors and acting upon that environment through effectors."

The Maes Agent [Maes 1995, page 108] "Autonomous agents are computational systems that inhabit some complex dynamic environment, sense and act autonomously in this environment, and by doing so realize a set of goals or tasks for which they are designed."

The IBM Agent

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II. M

OBILE

A

GENT

L

IFE

C

YCLE

A. Creating an agent and Disposing

The place where mobile agent is created is called mobile host. There is another agent that resides on the same mobile host. This agent can initiates the creation process or any other agent system can initiate it. There is a need to authenticate this process by providing authority and information that the new agent will process. The creator also provides the initialization arguments for the new agent.

B. Transferring an agent

Mobile agent can move around in any mobile host and this move instruction is provided by mobile agent itself. The transferring process is executed by dispatch process, transfer agent from its current location (origin mobile host) and received by the particular place (destination mobile host).

Fig.2. Life Cycle of Mobile Agent

C. Dispatching an agent

When we want to move mobile agent from one place to another place then it is necessary mobile agent must be able to identify its destination mobile host. If the destination mobile host is not defining then it’s run in default place that is selected by the destination agent. Mobile agent system provides information that agent want to transfer itself to the destination mobile agent.

D. Receiving an agent

Before receiving any mobile agent, the static mobile agent determines whether this agent is acceptable or not. For that the static mobile agent want authentication of coming agent. After that dynamic mobile agent provides it’s authenticated and if it is correct then they execute that dynamic mobile agent.

E. Agent Class Transfer

The mobile agent cannot resume execution in the destination without its class being present. Following are the ways to make the class available for the destination engine.

Class at origin:- if the class is already at destination Class at distention

Code on demand

F. Communication

Agents can communicate with other agents. These other agents may be residing within same place or in other place. Agents messaging are either peer-to-peer or broadcast. In peer-to-peer communication mechanism

only two hosts exchange information. On the contrary broadcasting is one to many messaging scheme. Broadcast mechanism is useful in multi-agent systems.

III. A

RCHITECTURE OF

M

OBILE

A

GENT

The architecture gives the structure of the system, which consists of some components, their individual functionalities and their interrelationship with each other. The basic architecture of the mobile agent can be thought of as a client sends out an agent, which travels the network-visiting servers in order to perform some required action. The architecture consists of :

•

Agent

Manager:

agent manger has few

responsibilities as it Sends agents to and receives agents from remote hosts. Prepares agents for transport by serializing the agent. Reconstructs received agents and creates the agents execution context.

•

Security Manager:

responsibilities of security manager are: Authenticates agents before allowing execution. Automatically invoked when the agents tries to use any system resource or tries for any unauthorized activity. Protects the host and agent from unauthorized access. •

Inter-agent Communication:

it allows the agents to communicate through massage passing mechanism. This part is still under research work where agents from different agent systems can communicate to each other. Till now all those agent system, which follow FIPA (Foundation for Intelligent and Physical Agent) standards are able to exchange messages as they follow a standard format for sending and receiving messages. Inter communication is still an issue among heterogeneous agent system.

Fig.3. Architecture of Mobile Agent

• Directory Manager:

Lists names and addresses of services and agents. Mobile Agent first migrates to remote container and registers itself to the Directory Services. When any other agent needs to find some agent it contacts the Directory Services for help.

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IV. C

LASSIFICATION OF

A

GENTS

The concept of an agent is one that is difficult to define exactly, no individual has thought of a wide-ranging description that fits the myriad of possibilities offered by agents. Because of this lack of a strict definition, AI researchers such as Wooldridge have split the notion of agents into two factions, these being "weak" agency and "strong" agency. [Wooldridge 1995]

a. Interface Agents

Maes' defines interface agents as "computer programs that employ Artificial Intelligence techniques to provide active assistance to a user with computer-based tasks."

b. Mobile Agents

Mobile Agents are software processes capable of moving around networks such as the World Wide Web (WWW), interacting with other hosts, gathering information on behalf of their owner and returning with any information it found that was requested by the owner. Mobility is another way that agents can be classified, i.e. static or mobile [Nwana 96]. Mobile agents have to stop execution in order to move around a network, and only continue executing when they arrive at a host that is capable of re-starting and running the code.

c.Co-operative Agents

A co-operative agent can communicate with, and react to its environment. An agent's view of its environment would be very narrow due to its limited Sensors. Co-operation exists when the actions of an agent achieves not only the agent's own goals, but also the goals of agents other than itself. The fact that these agents communicate to achieve co-operation implies that agents of a similar type will have social interaction, through message passing between agents.

d. Reactive Agents

Reactive agents are a special type of agent, which do not possess internal symbolic models of their environment. Instead, the reactive agent "reacts" to a stimulus or input that is governed by some state or event in its environment. This environmental event triggers a reaction or response from the agent. Reactive agents have the highest level of autonomy as they simply react reliably to events in their environment.

e. Smart Agents

The classification of smart agents is one that is really a future consideration of how "smart" agents will become. If an intelligent information-gathering agent can dictate information to another owner's agent, how does the owner know that the message has not been misinterpreted or lost by either agent's reaction to the information? The real problem with any intelligent agent system is the amount of trust placed in the agent's ability to cope with the information provided by itssensors in its environment.

f.Hybrid Agents

Nwana argues that the agents that have been reviewed so far in this report have different strengths and weaknesses. No one type of agent is completely suitable to an individual task. For this reason, there are benefits of using several classes of agent when considering the

development of an agent-based application (i.e. to combine autonomy with co- operation). This is where Hybrid agents are used. They are simply a union of different agent classes together with an agent control unit, which allows each agent type to inter-operate with each other effectively.

g.Heterogeneous Agents

This type of agent describes "two or more agents that belong to different agent classes" [Nwana 96] and is used primarily to make 2 or more standalone applications inter-operate by using controller agents. These controller agents can facilitate communication between Applications using standard agent communication languages (ACL's) and communication.

V. A

GENT

L

ANGUAGES

In theory any language can be used to implement mobile agents. The only necessary requirement is that an execution environment on the host supports the language. A wide variety of languages have been used to write mobile agents, some in research systems, and some in prototype commercial systems. Some languages such as Obliq and Telescript have been specifically designed for writing mobile agents. There are also many mobile agents being written in general purpose languages extended with a special library. Below is a brief description of some of the languages that have been used to write mobile agents.

a. Telescript

- A proprietary system developed by General Magic. The Telescript language has been specifically designed for implementing mobile agent systems. Telescript was designed with the vision for the computer network becomes a programmable platform; Telescript is not a scripting language. It is a complete object oriented language. Telescript supports objects, classes and inheritance. The object oriented model and the syntax is in many way similar to that of C++. Telescript has a library of built-in classes for writing mobile agents. There are special classes for agents and locations. Agents are a base class for mobile agents. Locations are objects that represent sites. The Telescript language has a set of built-in commands for agent migration and inters agent communication. The Telescript language has had a great influence on the development of mobile agents, and mobile agent languages. It was General Magic who first coined the term mobile agent.

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procedures. Java has been used as the basis for many implementations of mobile agent systems.

c. Obliq

- is an experimental language under development by Digital Equipment Corporation's Systems Research Center. Obliq is a lexically scoped, object-based, interpreted language that supports distributed computation. The language supports objects, but not classes. It uses the prototype-based model of object-oriented programming. New objects can be created directly, or cloned from other objects. Obliq uses runtime type checking. Obliq has built-in procedures for importbuilt-ing and exportbuilt-ing procedures and objects between machines. When procedures and objects are dispatched to a remote site for execution, any references they contain point to the same objects as on the machine from which they were dispatched.

d. Agent Tcl

- Agent Tcl is a mobile agent system being developed by Dartmouth College. The Agent Tcl language is an extension of the Tool Command Language (Tcl), the language originally developed by Dr. John Ousterhout. The Agent Tcl extensions add commands for agent migration and message passing. The extra commands give Agent Tcl scripts similar mobility capabilities to Telescript. Agent Tcl uses a modified Safe Tcl interpreter to execute scripts.

e.Perl 5

- Penguin is a Perl 5 module with functions enabling the sending of Perl scripts to a remote machine for execution and for receiving perl scripts from remote machines for execution. The scripts are digitally signed to allow authentication and are executed in a secure environment. Mobile agents written in Perl are restricted in that they must always restart execution at the same point. There is also no support for agents saving their state on migration. A new Agent Module v3.0 is being created to give Perl 5 more sophisticated mobile agent capabilities. The extra features include giving agents the ability to save their state on migration.

f. Python

- Python is an object-oriented scripting language. The Corporation for National Research Institution uses Python as a language for implementing Knowbot programs. This is by no means a complete list of the languages being used for mobile agents.

VI. A

DVANTAGES OF

M

OBILE

A

GENT

Danny B.Lange and Mitsuru Oshima had shown the advantages of Mobile Agent programming. Following are the advantages, that provide by the mobile agent architecture is better than other distributed Architecture:

They reduce the network load:

Fig.4. Reduce the Network load

In a distributed system, for completing a task there are multiples number of times information will moves form one node to another node. This is especially true when security measures are enabled. So that the result is a lot of network traffic and size of data will increase because, security thread will add every time when data is sanded. Mobile agents allow us to dispatch all information of the task at a time when agent arrives at destination host the interactions can take place locally rather than transferred over the network. So that Mobile agents are also for removing the raw information (like security thread that is added every time when information migrates) in the network. The objective of mobile agent bases communication is: move the computations to the data rather than the data to the computations.

They overcoming network latency

Mobile agent can reduce network latency; robots are the example of real time system, which responds in real time scenario. So latencies are not acceptable. A mobile agent provides a solution; mobile agent dispatched all information stored on it and at the destination mobile agent act as controller so the all information’s are directly access form mobile agent.

They encapsulate protocols

In mobile agent system each host have own information and function by which the mobile agent that will migrate and execute. Mobile agents have both data as well as code this technology is known as encapsulation and to provide the security on this have some rules known as protocol. The interpretation of incoming data and robust coding of out going data are part of basic functioning of protocol.

They execute asynchronously and autonomously

One of the most important advantages of mobile agent system is its asynchronous and autonomous execution of agent in wireless networks. Some times mobile devices are expensive for communication or weak network connections or slow speed for communication but some tasks require a continuously open connection between a mobile device and a communication network but its not economically or technically feasible. So with the help of mobile agent we can solve this problem, tasks embedded into mobile agents, and then dispatched it after that; the mobile agent independent of the creating process and can operates asynchronously and autonomously in this time no need establishment of network connection. After completion of task mobile agent need to agene need to communication network.

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They adapt dynamically

Mobile agents sense their execution background and react autonomously to changes if found any optimal solution. Mobile agents have the unique feature cloning by which they distribute themselves to the hosts in the network by this method they achieve the optimal configuration for solving a problem

Local/decentralized task processing

They facilitate high quality, high performance, and economical mobile application. As the mobile agents reach to the remote system to execute, they exhibit high performance as the agents are executing the resources locally. So instead of fetching the data remotely, they process the platform is installed. So any hardware can support the execution of agents where the agent platform can be installed.

Fig.6. robust and fault tolerant capability

They are robust and fault-tolerant

As mention in fifth advantage the mobile agent adapts dynamically, when a critical problem arrives in network, mobile agent adapt dynamic feature and change his path and provides robust and fault tolerant capability. Before the shut down process all the running agents will get warning message with time to dispatch their execution and resume processing on another connected host

VII. D

ISADVANTAGES OF

M

OBILE

A

GENT

Limitations of Mobile Agents There are many tough issues facing mobile agent systems before the applications just described become commercially viable. The most important issues are, in our opinion, knowledge representation and network security. How do agents represent their knowledge and communicate their needs to other agents? The “meeting”and “collaborate” mechanisms available in many of today’s systems are extremely limited. In addition, the static interfaces supported by today’s agent communication mechanisms limit the flexibility and possibilities for agent interaction.

Mobile agents do not perform well Mobile agents are difficult to design. Mobile agents are difficult to develop Mobile agents are difficult to test and debug

Mobile agents are difficult to authenticate and control Mobile agents can be brainwashed Mobile agents cannot keep secrets

Mobile agents lack a ubiquitous infrastructure Mobile agents lack a shared language/ontology Mobile agents are suspiciously similar to worms.

VIII. A

PPLICATION OF

M

OBILE

A

GENTS

There are no mobile agent applications, but there are plenty of applications that benefit from using mobile agents. Several applications clearly benefit from the mobile agent paradigm

a. E-commerce.

Mobile agents are well suited for ecommerce. A commercial transaction may require real-time access to remote resources, such as stock quotes and perhaps even agent-to-agent negotiation. Different agents have different data goals and implement and exercise different strategies to locally after reaching there. This exhibits the higher performance operation.

Automation of processes

Mobile agents perform specific tasks at different places

They are naturally heterogeneous

Mobile agent provides fundamental concept network computing is heterogeneity in both hardware and software. Mobile agents are generally depends on there execution environment and independent from computer-and transport- layer. Agent can work in any system where the agent accomplish them. We envision agents embodying the intentions of their creators, acting and negotiating on their behalf. Mobile agent technology is a very appealing solution for this kind of problem.

b. Personal assistance

Mobile agents’ ability to execute on remote hosts makes them suitable as assistants performing tasks in the network on behalf of their creators. Remote assistants operate independently of their limited network Connectivity; their creators can even turn off their computers. For example, to schedule a meeting with several other people, a user can send a mobile agent to interact with the agents representing each of the people invited to the meeting. The agents negotiate and establish a meeting time.

c. Secure brokering.

An interesting application of mobile agents is in collaborations in which not all the collaborators are trusted. The parties could let their mobile agents meet on a mutually agreed secure host where collaboration takes place without risk of the host taking the side of one of the visiting agents.

d. Distributed information retrieval.

Instead of moving large amounts of data to the search engine so it can create search indexes, agent creators can dispatch their agents to remote information sources where they locally create search indexes that can later be shipped back to the system of origin. Mobile agents can also perform extended searches that are not constrained by the hours during which a creator’s computer is operational.

e. Telecommunication networks services.

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systems flexible yet effective.

f. Workflow applications and groupware.

The nature of workflow applications includes support for the flow of information among coworkers. Mobile agents are especially useful here, because, in addition to mobility, they provide a degree of autonomy to the workflow item. Individual workflow items fully embody the information and behavior they need to move through the organization- independent of any particular application.

g. Monitoring and notification.

This classic mobile agent application highlights the asynchronous nature of these agents. An agent can monitor a given information source without being dependent on the system from which it originates. Agents can be dispatched to wait for certain kinds of information to become available. It is often important that the life spans of monitoring agents exceed or be independent of the computing processes that created them.

h. Information dissemination.

Mobile agents embody the so-called Internet push model. Agents can disseminate information, such as news and automatic software updates, for vendors. The agents bring the new software components, as well as installation procedures, directly to customers’ computers where they Autonomously update and manage the software.

i. Parallel processing.

Given that mobile agents can create a cascade of clones in the network, another potential use of mobile agent technology is to administer parallel processing tasks. If a computation requires so much processor power that it must be distributed among multiple processors, an infrastructure of mobile agent hosts can be a plausible way to allocate the related processes.

j. Cloud computing

Load balancing is a legacy application of process migration and mobile agent technologies. In a distributed system, e.g., a grid or cloud computing system, computers tend to be numerous and their computational loads are different. Computers may also be dynamically added to or removed from the system. Tasks should be dynamically deployed at computers, which loads light rather than those lose with heavy loads. Since mobile agents can migrate to other computers, tasks that are implemented as mobile agents can be relocated at suitable computers whose processors can execute the tasks. This is practical in implementing massively multi agent systems that must operate a huge number of agents, which tend to be dynamically created or which terminate, on a distributed system that consists of heterogeneous computers.

k. Mobile computing

Mobile agents use the capabilities and resources of remote servers to process their tasks. When a user wants to do tasks beyond the capabilities of his or her computers, the agents that perform the tasks can migrate

to and be executed at a remote server. Mobile agents can also mask temporal disconnections in networks. Mobile computers are not always connected to networks, because their wired networks are disconnected before they are moved to other locations or wireless networks become unstable or non-available due to deteriorating radio conditions or are not uncovered by the area at all. A stable connection is only requested at the beginning to send the agent, and to take the agent back at the end of the task, but this is not requested during the execution of the whole application execution. When a mobile agent requests a runtime system to migrate itself, the system tries to transmit the moving agent to the destination. If the destination cannot be reached, the system automatically stores the moving agent in a queue and then periodically tries to transmit the waiting agent to either the destination or another runtime system on a reachable intermediate node as close to the destination as possible. These relay runtime systems repeat the process until the agent arrives at its destination.

IX. E

XAMPLE OF

M

OBILE

A

GENT

JADE: JADE is free software and is distributed by TILab, open source software under the terms of the LGPL (Lesser General Public License Version 2). The last version is 2.5 (Feb 2002). JADE has good GUI, accessible use, good documentation and high acceptance. ARA : Ara is a platform for the portable and secures execution of Mobile Agents in heterogeneous networks. Mobile Agents in this sense are programs with the ability to change their host machine during execution while preserving their internal state. This enables them to handle interactions locally which otherwise had to be performed remotely.

CONCORDIA: Concordia is a full-featured framework developed at Mitsubishi Electric Information Technology Center America’s (MEITCA) Horizon Systems Laboratory. It provides for the development and management of network-efficient Mobile Agent applications for accessing information anytime, anywhere, and on both wire-based and wireless device supporting Java.

MOLE: Mole is the first Mobile Agent System that has been developed in the Java language. The first version has been finished in 1995, and since then Mole has been constantly improved. Mole provides a stable environment for the development and usage of Mobile Agents in the area of distributed applications.

VOYAGER: Voyager is 100% java Agent-enhanced Object Request Broker (ORB) created by Object Space Company. Goals of this product to provide programmer to create state of the art distributed programs quickly, and easily while providing a lot of flexibility and extensibility for the products that are being created with the voyager system.

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X. C

ONCLUSION

& F

UTURE

W

ORK

Mobile agent technology can offer a new paradigm for communication over heterogonous network channels. A number of advantages of using mobile agent computing paradigms have been proposed and identified. These advantages include: overcoming network latency, reducing network load, executing asynchronously and autonomously, adapting dynamically, operating in heterogeneous environments, and having robust and fault-tolerant behavior. However, the security and standardizing issues still represent a significant obstacle. The main conclusion which can be drawn from our findings and investigation is that mobile agent technology has the potential in increasing the performance of networks as well as for software adopting Mobile Agent System.

We survey & study the Mobile Agent, evaluated performance of Mobile Agent. The greatest performance of Mobile Agent will be used for implementing our Research Project i.e. Distance Evaluation Model by using Mobile Agent Technology.

R

EFERENCES

[1] “Security Of Mobile Agents “ by Prabhat Singh S. Indian Institute of Information Technology, Allahabad

[2] “Comparison and Performance Evaluation of Mobile Agent Platforms“by Raquel Trillo, Sergio Ilarri and Eduardo Mena [3] Is it an Agent, or just a Program? A Taxonomy for

Autonomous Agents byStan Franklin and Art Graesser Third International Workshop on Agent Theories, Architectures, and Languages, Springer-Verlag, 1996.

[4] “Languages for Mobile Agents” by Steven Versteeg August, 1997 available at http://www.cs.mu.oz.au/~scv/thesis.html [5] "Seven Good Reasons for Mobile Agents ", Danny B. Lange &

Mitsuru Oshima March 1999.,Communications of ACM , vol. 42, no. 3,

[6] “Mobile Agents and the Future of the Internet”,David Kotz and Robert S. Gray. ACM Operating Systems Review, 33(3):7-13, August 1999.

[7] “Autonomous Agents For Systems Management With In An Windows NT Environment”by Jim Holmes May 2001

[8] “Agent Platform Evaluation” Kalle Burbeck, LIU Date: 9th April 2003

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[12] “Mobile Agents: Are they a good idea?”, David M. Chess, Colin G. Harrison, and Aaron Kershenbaum. IBM Research Report.

[13] “Security on Mobile Agent Based Communication System” by Abhishek Pandey July 2007

[14] “Mobile Agent-based Applications: a Survey” by Abdelkader Outtagarts IJCSNS International Journal of Computer Science and Network Security, VOL.9 No.11, November 2009

[15] David M. Chess, Colin G. Harrison, and Aaron Kershenbaum. “Mobile Agent Based Distributed System Computing In Network” by Prof. S. N. Gujar1, Prof. G.R.Bamnote2, at all. International Journal of Recent Trends in Engineering, Vol 2, No. 4, November 2009

[16] “Applications of Mobile Agents: A Canvas” by Pooja Arora, Ritu Gupta International Journal of Advanced Research in Computer Science Vol.1, No.3, Sept-2010

A

UTHORS

P

ROFILE

Lect. Rajguru Prakash Vithoba

received the M.C.M. from Dr. Babasaheb Ambedkar Marathwada University, Aurangabad and M.Phil in Computer Science from Algappa University Karikudi, and B.ED from S.R.T.M.U, Nanded in 2005 and 2008 & 2011 respectively. From 2005 he is working as Asst. Prof. of Computer Science in Adarsh Education Society’s, Hingoli. He is also doing Ph.D. from JJT University Rajasthan. He attended many National and International Conferences, Workshops and Seminars. He is having five International & three National Publication in Standard International Journals. One Research paper in title Book “Development of Social Sciences” of Karanataka University. His areas of interest are Mobile Agent, Computing Distance Evaluation, Human Computer Interaction, Green Computing, and ICT.

Mobile Agent: Emerging Technology