International Journal of Emerging Technology and Advanced Engineering Website: www.ijetae.com (ISSN 2250-2459, Volume 2, Issue 5, May 2012) Mobile Agent Technology and its repercussion in Wireless Sensor Networks Madhuri Rao1, K.Vinod Kumar2 Department of Computer Science & Engineering, Institute of Technical Education & Research, S.O.A University, Bhubaneswar, Orissa RPC laid the path for Process Migration which allows a partially executed process to be relocated to another node. In this scenario execution state of the process is migrated, i.e Stack, memory, program counter, state of open files. Locus (UCLA), Sprite (UC Berkeley), Condor (Wisconsin) is some such examples which with the help of process migration could achieve load balancing. Remote Evaluation model by Stamos and Gifford (MIT) (1990) presented yet another technique of Remote programming and Code Mobility. This was further enriched by Java Sun Microsystems in 1995 as they presented code migration across heterogeneous platforms. Abstract— Mobile Agent is the computer program which can automatically move among different network hosts and perform the user's operations. A Mobile Agent characteristic is being automatic, cooperative, mobile, secure and intelligent. These are agents that can physically travel across a network, and perform tasks on machines that provide agent hosting capability. It allows processes to migrate from computer to computer, for processes to split into multiple instances that execute on different machines, and to return to their point of origin. Unlike remote procedure calls, where a process invokes procedures of a remote host, process migration allows executable code to travel and interact with databases, file systems, information services and other agents. Significant research and development into mobile agency has been conducted in recent years, and there are many mobile agent architectures available today. However, mobile agency has failed to become a sweeping force of change, and now faces competition in the form of message passing and remote procedure call (RPC) technologies. The strategies it flavors could be an alternate choice for routing mechanism in various networks especially wireless sensors networks which could have a specific function only to be invoked and then migrate while intelligently compressing and processing data that is collected for the sink to receive. This certainly would reduce network traffic and congestion in wireless sensor networks. In section II some early category of Process migration is outlined. Section III briefs the aspects of Mobile Agent Technology research .Mobile Agents in Wireless Sensor network is explained in Section IV. In section V two algorithms are proposed for Sensor Nodes which are designed on the basis of Mobile Agent Technology. II. PROCESS MIGRATION : Process migration is achieved to fulfill the following goals. 1. Exploitation of resource locality 2. Accessing more processing power 3. Resource sharing Keywords: Mobile Agent, Process Migration, Wireless Sensor Network, Load Sharing 4. Fault resilience 5. System administration I. INTRODUCTION 6. Mobile computing An Agent is a software component (object) which can perform one or more tasks in some predefined manner. The characteristics of an agent are mobility, autonomy, being deliberative and it possesses an element of learning. It is a loosely coupled process having cooperation in catering to a common goal. It borrows its evolution from what is known as Remote Procedure Call (RPC), where a client invokes a code that resides on a server which then manipulates and returns results to the client. Some widely known examples of RPC is Courier at Xerox PARC in 1980, Sun RPC 1984, DCE, CORBA late 1980’s. Table 1. below outlines some examples of process migration conceptualized so far. Viruses is also sometimes understood as a code that could migrate. Mobile agents derived from two fields namely Artificial Intelligence & Distributed Systems which is an area of immense potential. Some Aspects of Mobile Agent research is explained in the next section. 423 International Journal of Emerging Technology and Advanced Engineering Website: www.ijetae.com (ISSN 2250-2459, Volume 2, Issue 5, May 2012) Sl. No Category Example a. Code mobility, safety, programming constructs 1. Early Work XOS, Worm, Butler, DEMOS/MP b. Agent communication languages 2. Transparent migration in Unixlike systems Locus, OSF/1 AD, MOSIX, Sprite 3 OS with Messagepassing interface Charlotte, Accent, V Kernel 4 Microkernels RHODOS, Arcade, Chorus, Amoeba, Birlix, Mach 5 User-space migrations Condor, Migratory PVM, LSF 6 Applicationspecific migrations Freeman, Skordos, Bharat & Cardelli (Migratory Applications 7 Mobile objects Emerald, SOS, COOL 8 Mobile agents: derived from 2 fields- AI and Distributed Systems. Telescript, Agent Tcl, TACOMA, Mole 3) The element of intelligence is imbibed in it by the possibilities in Artificial Intelligence Research with: a. Focus on intelligence, learning, and cooperation IV. MOBILE AGENTS IN WIRELESS SENSOR NETWORK The wireless sensor network is a technology which employs a large finite number of unattended, intelligent sensor nodes with ubiquitous sensing, processing, computing and with wireless communication capabilities, to implement complicated tasks dynamically in the specified sensing field or environment. As these are battery powered sensor nodes functioning in hostile, unattended sensing environment constrained in energy supply, it is of tremendous significance to investigate energy optimization methods to prolong the WSN lifetime. Target detection and location tracking is a typical WSN application that calls for effective and efficient energy management. It would also be cost effective if the network could map to multiple sink nodes with load and network sharing capabilities. Computing capacity of each sensor node though limited, when collaborated with multiple sensor nodes, offers much more resources than an individual one. Distributed computation in the sensor nodes is therefore always encouraged. IN [6] an approach is suggested based on behavior of mobile agents which could be a criteria to choose a mobile agent. Mobile agents have been found useful in facilitating efficient data fusion & dissemination in Wireless Sensor Network [1-4]. The following scenarios is considered in conceptualizing Mobile Agents in Wireless Sensor Networks. Table I: Examples of process migration III. ASPECTS OF MOBILE AGENT RESEARCH: There are three dimensions of Mobile Agent. 1) Its distributed nature cultivates much research possibilities. Like as follows a) Focus on system architectures and protocols for managing executions of mobile agent objects. b) Security, fault tolerance. 2) How one could program this technology makes an avenue for - Programming Languages Research and it could further be specific in : Figure 1: Model of WSN with base station , data collectors and sensor node. 424 International Journal of Emerging Technology and Advanced Engineering Website: www.ijetae.com (ISSN 2250-2459, Volume 2, Issue 5, May 2012) Here, the Base Station (BS) node receives the surveillance report every few minutes. Based on the coordinated information that is collected by Data Collector (DC) nodes, a task is issued or a counter mechanism is brought to happen. To ensure that nodes do not have to communicate over long distances expending huge amount of energy in routing, multiple Base Stations could be placed. After the few initial minutes, these sink nodes would also issue status packets that move in backward position to the data packets and track the status of active nodes, sleeping nodes and dead nodes. Its also finds the most used path. This information in this status packet when read by a sensor node is utilized to facilitate easy and quick and dynamic routing. The beauty of this technique is observed over a period of time, especially when the nodes in a network are getting worn of energy. We introduce the term Mobile multi agent for the piece of code that acts as an agent in each of these sensor nodes. The agent is triggered every clock cycle to compare with values noted in every last cycle. The nodes are multi-capable and can read more than one analog feeling. Each of the analog feeling is considered as a separate entity [19]. Each entity needs to be transmitted separately. The motivation for using Mobile Agents in Wireless Sensor networks has been extensively studied in [17]. Transmit to one of the six neighbors or the cluster head node Cluster head Reads status packet and know nearest active neighbor and preferable path End if end for end for Algorithm 2: Status packet routing initiated and each sink node If data received in sink node is more than 5 entries broadcast status packet with id and hop number to all nearest neighbors If battery of sensor node is less than 50% Discard status packet and set to only transmit mode end if If battery of sensor node is more than 50% hop count ++ Forward packet to neighbor node with sink id and new hop count V. PROPOSED ALGORITHMS. end if The proposed Mobile agent here is expected to transmit its state when there is change in any of its entities. Hence the number of packets and the number of transmissions is reduced, which obviously enhances the life time. This Mobile agent checks for a status packet every clock cycle when its power is more than 50%, reads the information of closest sink node and number of hops to it. If the power contained in a sensor node is less than 50% it would not receive the status packet. In this manner the network holds the information of nodes that should be involved in routing by camouflaging the ones that should not. Therefore, our heuristics form the basis of a simple and practical yet nearoptimal cooperation strategy for sensor nodes. end if VI. CONCLUSION: Mobile agency has yet to achieve widespread acceptance, and there are significant barriers to be overcome before it does. Competing technologies, increasing network bandwidth, and barriers to mobile agency make it unlikely that mobile agency will leave the domain of research and enter the domain of electronic commerce. This is not to say that mobile agency does not have its place - specialized situations and environments will continue to use and develop mobile agents. Load sharing across a network of agent hosts, and delegation of tasks to agents for offline processing hold great potential. Additionally, as more research and development into mobile agency is made, the picture may become brighter for other applications. Some recently developed mobile agent technology adds a new dimension to distributed computing. Experts suggest that mobile agents will be used in many Internet applications in the years to come. However there still exist many technical hurdles that need to be tackled, the most important of them being security. 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