Mobile Agent Supported on Demand Routing Method to Lessen Link Failure in MANET

A mobile agent is a software program which migrates from a site to another site to perform tasks assigned by a user. For the mobile agent system to support agents in various application areas, the issues regarding reliable agent execution, as well as compatibility between two different agent systems or secure agent migration, have been considered. Some of the proposed schemes are either replicating the agents (Hamidi & Mohammadi, 2005) or check-pointing the agents (Park, Byun, Kim, & Yeom, 2002; Pleisch & Schiper, 2001;) For a single agent environment without considering inter-agent communication, the performance of the replication scheme and the check-pointing scheme is compared in Park et al. (2002) and Silva, Batista, and Silva (2000). In the area of mobile agents, only few works can be found relating to fault tolerance. Most of them refer to special agent systems or cover only some special aspects relating to mobile agents, such as the communication subsystem. Nevertheless, most people working with mobile agents consider fault tolerance to be an important issue (Izatt, Chan, & Brecht, 1999; Shiraishi, Enokido, & Takzawa, 2003). Mobile agents are becoming a major trend for designing distributed systems and applications in the last few years and foreseeable future. It can bring benefits such as reduced network load and overcoming of network latency (Chan, Won, & Lyu, 1993). Nevertheless, security is one of the limiting factors of the development of these systems. The main unsolved security problem lies in the possible existence of malicious hosts that can manipulate the execution and data of agents (Defago, Schiper, & Sergent, 1998). Most distributed applications we see today are deploying the client/server paradigm. There are certain problems with the client/server paradigm, such as the requirement of a high network bandwidth, and continuous user-computer interactivity. In view of the deficiencies of the client/server paradigm, the mobile code paradigm has been developed as an alternative approach for distributed application design. In the client/server paradigm, programs cannot move across different machines and must run on the machines they reside on. The mobile code paradigm, on the other hand, allows programs to be transferred among and executed on different computers. By allowing code to move between hosts, programs can interact on the same computer instead of over the network. Therefore, communication cost can be reduced. Besides, mobile agent (Fischer, Lynch, & Paterson, 1983) programs can be designed to work on behalf of users autonomously. This autonomy allows users to delegate their tasks to the mobile agents, and not to stay continuously in front of the computer terminal. The promises of the mobile code paradigm bring about active research in its realization. Most researchers, however, agree that security concerns are a hurdle (Greenberg, Byington, & Harper, 1998). In this article, we investigate these concerns. First, we review some of the foundation materials of the mobile code paradigm. We elaborate Ghezzi and Vigna’s classification of mobile code paradigms (Ghezzi & Vigna, 1997), which is a collection of the remote evaluation, code on demand, and mobile agent approaches. In the next section, we address the current status of mobile code security. The following section presents the model for fault-tolerant mobile agent. In the next section, security issues of the mobile agent are discussed, and we discuss security modeling and evaluation for the mobile agent in the section after. In the following section, simulation results and influence of the size of agent are discussed. We then conclude the article.

Mobile agent technology has been proposed for use on the Internet. The mobile agent is a software program that acts on behalf of a user or software. It has the following features: (1) it is autonomous; (2) it has one or more objectives; (3) it has a scope of competence; and (4) it may, or may not, collaborate and communicate with other software and users. 3 In order to perform its job, it is able to migrate from a source host to a target host on a network under its own control. 4 However, this may lead to a great deal of security threats and attacks. When a mobile agent moves between a series of hosts, it may happen to encounter either trust-worthy or malicious hosts. A mobile agent must be capable of authenticating legal hosts and other agents to avoid malicious attacks. Ideally, a mobile agent should be versatile, robust, and secure in changing environments. Therefore, the security issue when dealing with mobile agents becomes essential. So far, the research on mobile agent security has been focused on the following topics: 5

In order to share the intelligence among all kinds of mobile nodes, this paper puts forward the intelligence sharing technology based on mobile agents in mobile peer-to-peer (MP2P) system. The MP2P system could build up a common applicable theoretical framework for mobile intelligence management such as mobile intelligence acquisition, query, synchronization, cache, and prefetching. In order to reduce the maintenance cost of intelligence index table for the mobile nodes in the MP2P network, use the edge intelligence of network enough, and parallel process the mobile task of network, we propose the intelligence management technology based on mobile agent (MA), which improves the execution efficiency of security authentication, intelligence distribution, cache prefetching, transaction processing, location service, and task cooperation among the mobile nodes.

Because the remote medical monitoring system is high distributed, limited to node energy and having a large quantity of process and transmission information, this paper proposes a kind of remote medical monitoring system based on the technology of internet of things and combines the mobile Agent. Ten patients (5 male and 5 female, the age of 18~69 and the average age of 41.8) were given clinical test with this system. It shows the architectural model of the system which consists of wireless sensor nodes, relay nodes, remote monitoring center, etc. To collect the patients’ physiological data, the remote monitoring center in hospital will issue the mobile Agent and run it in the wireless sensor node. After processing the mobile Agent, the center will send it to the relay node, and then send it back to the hospital remote monitoring center through the Internet of things to do comprehensive diagnosis and make decisions. The paper has completed the software and hardware designing and debugging of the each module of system. The result shows that the system is able to monitor the health status of patients who live in different communities in the long term and in time. Further more, the system can achieve optimal utilization of medical resources.

Security in wireless sensor networks is very crucial especially whenever they deployed in military applications. Cryptography is used to protect sensitive information from disclosure. Key management is important component in cryptography. Cryptography is not useful if keys are disclosed to attackers. Designing an efficient key management for WSN is a difficult task because of scarcity of computing, communication, and memory resources. An efficient key distribution approach is proposed by using mobile agent paradigm rather than client–server model. The proposed approach will use good features of both symmetric and asymmetric cryptography. Mobile agents are used to generate public and private key pairs, update keys, and revocation of keys. The proposed scheme in the first level will use mobile agents for key distribution and coordination for asymmetric keys, and in the second level, sensor nodes can involve in constructing symmetric keys for secure communication through mutual authentication and encryption with those keys. The proposed method is implemented using NS2 simulator, and results are compared with existing similar methods in terms of evaluation parameters like communication, computation overhead, memory overhead, and resiliency. The performance of proposed method is improved when it is compared with similar existing methods.

Recently, there has been increasing interest in Mobile Wireless Sensor Networks MWSNs that are constructed by mobile sensor nodes held by ordinary people, and it has led to a new concept called urban sensing. In such MWSNs, mobile sensor nodes densely exist, and thus, there are basically many sensor nodes that can sense a geographical point in the entire sensing area. To reduce the communication cost for gathering sensor data, it is desirable to gather the sensor data from the minimum number of mobile sensor nodes which are necessary to guarantee the sensing coverage or the quality of services. In this paper, to achieve this, we propose a data gathering method using mobile agents in dense MWSNs. The proposed method guarantees the sensing coverage of the entire area using mobile agents that autonomously perform sensing operations, transmit sensor data, and move between sensor nodes. By gathering only sensor data generated by sensor nodes where mobile agents are running, our proposed method can achieve efficient gathering of sensor data.

A Wireless Sensor network (WSN) consists of large number of low cost low power sensor nodes. The nature of wireless sensor networks makes them very attractive to attackers. One of the most popular and serious attacks in wireless sensor networks is sink hole attack and most existing protocols to defend against this attack used cryptographic methods with keys. In sink hole attack a sensor node will have a lot of false neighbors. Wireless Sensor Network has a dynamic topology, intermittent connectivity, and resource constrained device nodes. Researchers over the past years have encouraged the use of mobile agent to overcome these challenges. The proposed scheme is to defend against sink hole attacks using mobile agents. Mobile agent is a program segment which is self controlling. They navigate from node to node not only transmitting data but also doing computation. They are an effective paradigm for distributed applications, and especially attractive in a dynamic network environment. A routing algorithm with multiple constraints is proposed based on mobile agents. It uses mobile agents to collect information of all mobile sensor nodes to make every node aware of the entire network so that a valid node will not listen the cheating information from malicious or compromised node which leads to sink hole attack. The significant feature of the proposed mechanism is that it does not need any encryption or decryption mechanism to detect the sink hole attack. This mechanism does not require more energy than normal routing protocols like AODV. Here we implement a simulation-based model of our solution to recover from a Sinkhole attack in a Wireless Sensor Network. The mobile agents were developed using the Aglet.

Recent research has shown that the cooperative diversity can efficiently combat the fading effects caused by the hostile wireless channels just as the multiple-input multiple-output (MIMO) antenna systems do. Besides, due to the inherent cost and size constraints by many small area wireless networks, e.g. wireless ad hoc networks and wireless sensor networks, in such environments, it would be almost impossible to deploy the antenna array in a mobile node. However, cooperative diversity can provide an economical and viable solution by sharing each mobile node’s single-antenna with others to form a virtual antenna array, while it still can maintain significant performance gains similar to MIMO systems. Meanwhile, the adaptive modulation is a proven technique which can significantly increase the spectral efficiency when perfect channel estimation can be achieved, and many wireless standards have adopted it as an implementation option. It also has been shown that combining these two techniques can greatly raise the system efficiency. Nevertheless, in the multiple nodes cooperative communication networks, the randomness of demodulation process at each relay node makes the task of correctly selecting the forwarding relay nodes very complicated. In view of this problem, a novel adaptive node selection algorithm is proposed for the destination node to effectively select the forwarding relay nodes to help the source node transfer the signals. In this paper, the decode-and-forward (DF) protocol is employed as the cooperative diversity signaling, and the constant-power variable-rate M-ary phase shift keying (M-PSK) is adopted as the adaptive modulation scheme. At the destination node, the maximal-ratio-combining (MRC) method is used to combine all of the signals from diversity branches with the main path transmitted directly from the source node. Because of the random phenomenon of the demodulation process, the outage requirement is used as the baseline in the first stage of the proposed node selection algorithm to choose the maximal transmission rate. Hence the maximal overall system throughput in terms of rate can be achieved. In the meantime, the first candidate forwarding sets of the relay nodes which collectively meet the required outage probability are also been chosen. Then in the second stage, we can further refine the number of the relay nodes among the first candidate forwarding sets by using the following criterion — maximum average rate per node. It will screen out the first candidate sets with the minimum number of the relay nodes. If only one candidate set is left at the end of the second stage, it will be the end of the proposed algorithm. However, if the result of the screening still has more than one set, then the final election among the second candidate sets would be the one which can give the minimum outage probability. In the simulation results, our proposed node selection algorithm can even further improve the spectral efficiency while the deleteriously fading effect induced by the wireless channels can also be effectively removed.

Security has become important to mobile ad hoc networks (MANETs) due mainly to their use for many mission and life-critical applications. However, the broadcast nature of inter-node communications and node mobility in MANETs make it very challenging to secure MANETs. Moreover, their constantly changing topology causes network node density and neighbor relationships to change dynamically. This paper presents an intrusion detection system (IDS) for MANETs at the application layer. The IDS utilizes (1) both anomaly and misuse detection schemes to identify attacks in MANETs and (2) mobile agents (MAs) to augment each node's intrusion-detection capability. In particular, each node is equipped with a local IDS, and MAs will be dispatched periodically or on-demand to augment each node's IDS. We present the design of this IDS and the overall network structure, as well as the methods for authenticating and dispatching MAs. We also evaluate the trade-offs between different design parameters of MAs.

How to determine the source-visiting sequence among the target sensor nodes and manage the mobile agent (MA) effectively is the crucial problem in Mobile-Agent-based computing model for wireless sensor networks (WSNs). In this paper, we propose a novel improved Directed Diffusion-based MA mechanism (IDDMA) for WSNs. IDDMA uses an improved gradient generation algorithm to set up multiple optimal gradients among sensor nodes. The source nodes will subsequently send two distinct types of the exploratory data packet to implement the discovery of the sources and build the routing tables for the MA routing, respectively. Then, the MA in target region could choose its next-hop node dynamically according to the established routing table for MA in each source node and achieve the data fusion; finally it will return to the Sink. Simulation results show that the mechanism outperforms two existing routing protocols in end-to-end packet delay and average energy consumption.

In a peer to peer grid computing environment, volunteers are exposed to failures such as crash and link failures. In addition, since volunteers can dynamically join and leave executions and they are not dedicated only to a peer to peer grid computing, the executions of volunteers are stopped or suspended more frequently than in a grid computing environment. These failures result in the delay and blocking of the executions of tasks and even partial or entire loss of the executions. In addition, these failures make it difficult for a volunteer server to schedule tasks and manage the allocated tasks as well as volunteers. Existing peer to peer grid computing systems, however, do not deal with these failures in scheduling mechanisms. Moreover, since existing scheduling mechanisms are performed only by a volunteer server in a centralized way, there is a high overhead.To solve these problems, we propose a mobile agent based adaptive scheduling mechanism (MAASM). We implemented MAASM in Korea@Home and ODDUGI mobile agent system. The MAASM reduces the overhead of volunteer server by using mobile agents in scheduling procedure in a distributed way. In addition, it tolerates the various failures(especially, volunteer autonomy failures) which frequently occur in a peer to peer grid computing environment. Consequently, MAASM guarantees reliable and continuous executions in spite of the failures, so it decreases total execution time.KeywordsMobile AgentTotal Execution TimeVolunteer GroupSchedule MechanismDesktop GridThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

A mobile agent offers discrete advantage both in facilitating better transmission as well as controlling the traffic load in Mobile Adhoc Network (MANET). Hence, such forms of network offers maximized dependencies on mobile agents in terms of its trust worthiness. At present, there are various work being carried out towards resisting security breach in MANET; however approaches using mobile agent based mechanism is few to found. Therefore, the proposed system introduces a novel mathematical model where an extensive decision making system has been constructed for identifying the malicious intention of mobile agents in case they go rogues. By adopting multi-tier communication policy and fairness concept, the proposed system offers the capability to resist any form of malicious activity of mobile agent without even presence of any apriori information of adversary. The outcome shows proposed system outshines existing security scheme in MANET.

This paper proposes a new fault-tolerant and scalable mobile agent communication mechanism to address both agent mobility and directory service node failures. The mechanism enables each mobile agent to keep its forwarding pointer only on a small number of its visiting nodes in an autonomous manner. As this desirable feature has every mobile agent’s migration route be very considerably shortened, the time for forwarding each message to the agent becomes much smaller. Also, this feature causes each node to maintain much fewer forwarding pointers of mobile agents on its storage than in the traditional approach. Moreover, the mechanism allows each movement path of a mobile agent to be replicated in an effective way to preserve scalability of our proposed mechanism. This replication may require a little more agent location updating costs, but much more accelerate delivery of each message to the corresponding mobile agent.KeywordsMobile AgentLate LocatorNode FailureDirectory ServiceService NodeThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

A Mobile ad hoc Network (MANET) is an infrastructure less network that permits nodes to make a wireless network with mobility. In MANETs, the node linkages breaks are frequent due to all nodes are in movement. When neighbor nodes travel out of other node communication range connection among both mobile nodes breaks. Thus it makes delay and packet loss in the network. In the present Traffic Control method, several times, since the highest traffic, heavy rain, accidents, or other reasons, there may be probabilities of jam on roads. Thus, people could get delay owing to the highest traffic. Therefore, it is highly preferred to have an effective way to track the traffic on roads and thus select the suitable road that is traffic free. To resolve these problems, the volunteer Nodes of Ant Colony Optimization Routing (VNACO) is proposed. The primary objective of VNACO is to reduce both the delay and routing overhead in Peer to Peer (P2P) MANETs. Here, peer node act as a volunteer node and mobile node for transmitting data from source to destination. During data transmission, the relay node moving out of communication range when the volunteer node overheard the dropped data packet then deliver the data to the corresponding relay node. As a result, minimizes both the delay and packet losses. In VNACO, the volunteer’s nodes are elected based on node aptitude. Node aptitude is calculated by iterating node connectivity, transmission processing time, node energy and available bandwidth. In addition, an ant colony optimization algorithm to finds the optimal route and reduce the routing overhead in P2P MANETs. The significant application of this mechanism is utilized for the traffic management system. Network simulation results indicate that the VNACO mechanism is minimizing 22% delay and reducing 14% packet losses compared to the baseline protocol.

Recently, there has been focus on augmenting Delay/Disruption Tolerant Networks (DTNs) with easily deployable stationary relay nodes making an unconnected infrastructure to facilitate the data delivery by increasing forwarding opportunities. Relay nodes are capable of downloading, storing, and forwarding the data messages from/to the mobile nodes. Placing the relay nodes is an important issue in DTNs as the performance of the network is dependent to their positions. Relay placement is an NP-hard problem hence it makes it a more complicated issue in DTNs. Existing works in the literature are based on simulation which are suffering from computational complexities dictated by simulation. Moreover, they are optimizing the relay placement only based on specific scenarios. In this paper, we propose a generic analytical model in order to evaluate the performance of DTNs in presence of relay nodes. Our model is dependent on the mobile nodes' mobility pattern, and we consider the case when the mobile nodes move according to the random waypoint model. In order to use the proposed model for placing the relays efficiently, we utilize two heuristic approaches. The first approach is based on optimization of the network performance using simulated annealing and the second one relies on a greedy approach to find the best location for each relay one at a time. Our simulation results show that our approaches outperform the simulation based approaches in terms of data delivery performance.