Mobile Agent

Wireless microsensor networks have been identified as one of the most important technologies for the 21st century. This paper traces the history of research in sensor networks over the past three decades, including two important programs of the Defense Advanced Research Projects Agency (DARPA) spanning this period: the Distributed Sensor Networks (DSN) and the Sensor Information Technology (SensIT) programs. Technology trends that impact the development of sensor networks are reviewed, and new applications such as infrastructure security, habitat monitoring, and traffic control are presented. Technical challenges in sensor network development include network discovery, control and routing, collaborative signal and information processing, tasking and querying, and security. The paper concludes by presenting some recent research results in sensor network algorithms, including localized algorithms and directed diffusion, distributed tracking in wireless ad hoc networks, and distributed classification using local agents.

This paper introduces AntNet, a novel approach to the adaptive learning of routing tables in communications networks. AntNet is a distributed, mobile agents based Monte Carlo system that was inspired by recent work on the ant colony metaphor for solving optimization problems. AntNet's agents concurrently explore the network and exchange collected information. The communication among the agents is indirect and asynchronous, mediated by the network itself. This form of communication is typical of social insects and is called stigmergy. We compare our algorithm with six state-of-the-art routing algorithms coming from the telecommunications and machine learning elds. The algorithms' performance is evaluated over a set of realistic testbeds. We run many experiments over real and arti cial IP datagram networks with increasing number of nodes and under several paradigmatic spatial and temporal tra c distributions. Results are very encouraging. AntNet showed superior performance under all the experimental conditions with respect to its competitors. We analyze the main characteristics of the algorithm and try to explain the reasons for its superiority.

The technologies, architectures, and methodologies traditionally used to develop distributed applications exhibit a variety of limitations and drawbacks when applied to large scale distributed settings (e.g., the Internet). In particular, they fail in providing the desired degree of configurability, scalability, and customizability. To address these issues, researchers are investigating a variety of innovative approaches. The most promising and intriguing ones are those based on the ability of moving code across the nodes of a network, exploiting the notion of mobile code. As an emerging research field, code mobility is generating a growing body of scientific literature and industrial developments. Nevertheless, the field is still characterized by the lack of a sound and comprehensive body of concepts and terms. As a consequence, it is rather difficult to understand, assess, and compare the existing approaches. In turn, this limits our ability to fully exploit them in practice, and to further promote the research work on mobile code. Indeed, a significant symptom of this situation is the lack of a commonly accepted and sound definition of the term "mobile code" itself.

Threat diagnostic, using AND/OR tree (TDT) and risk analysis, is a mechanism to protect mobile agents against malicious host attacks. The method is based on analyzing the probable causes of mobile agent failure to perform its intended function. It uses the symptoms of different types of malicious host attacks and arranges them in a logical order depending on the expected outcomes. We provide a methodical definition of attacks against mobile agents. This approach allows defining a proposed protection scheme that is used to protect mobile agents. The objectives of this paper are twofold: Firstly,, identify the different types of malicious hosts attacks based on their symptoms. Secondly we introduce our approach based on criticality analysis to identify the most critical type of attack and its associated expected failure cost.

Existing authorization mechanisms fail to provide powerful and robust tools for handling security at the scale necessary for today's Internet. These mechanisms are coming under increasing strain from the development and deployment of systems that increase the programmability of the Internet. Moreover, this "increased flexibility through programmability" trend seems to be accelerating with the advent of proposals such as Active Networking and Mobile Agents. The trust-management approach to distributed-system security was developed as an answer to the inadequacy of traditional authorization mechanisms. Trust-management engines avoid the need to resolve "identities" in an authorization decision. Instead, they express privileges and restrictions in a programming language. This allows for increased flexibility and expressibility, as well as standardization of modern, scalable security mechanisms. Further advantages of the trust-management approach include proofs that requested transactions comply with local policies and system architectures that encourage developers and administrators to consider an application's security policy carefully and specify it explicitly. In this paper, we examine existing authorization mechanisms and their inadequacies. We introduce the concept of trust management, explain its basic principles, and describe some existing trust-management engines, including PolicyMaker and KeyNote. We also report on our experience using trust-management engines in several distributed-system applications.

The availability of positional information is of great importance in many commercial, governmental, and military applications. Localization is commonly accomplished through the use of radio communication between mobile devices (agents) and fixed infrastructure (anchors). However, precise determination of agent positions is a challenging task, especially in harsh environments due to radio blockage or limited anchor deployment. In these situations, cooperation among agents can significantly improve localization accuracy and reduce localization outage probabilities. A general framework of analyzing the fundamental limits of wideband localization has been developed in Part I of the paper. Here, we build on this framework and establish the fundamental limits of wideband cooperative location-aware networks. Our analysis is based on the waveforms received at the nodes, in conjunction with Fisher information inequality.

The computational power of networks of small resource-limited mobile agents is explored. Two new models of computation based on pairwise interactions of finite-state agents in populations of finite but unbounded size are defined. With a fairness condition on interactions, the concept of stable computation of a function or predicate is defined. Protocols are given that stably compute any predicate in the class definable by formulas of Presburger arithmetic, which includes Boolean combinations of threshold-k, majority, and equivalence modulo m. All stably computable predicates are shown to be in NL. Assuming uniform random sampling of interacting pairs yields the model of conjugating automata. Any counter machine with O(1) counters of capacity O(n) can be simulated with high probability by a conjugating automaton in a population of size n. All predicates computable with high probability in this model are shown to be in P; they can also be computed by a randomized logspace machine in exponential time. Several open problems and promising future directions are discussed.

We introduce a calculus for mobile agents and give its chemical semantics, with a precise de nition for migration, failure, and failure detection. Various examples written in our calculus illustrate how to express remote executions, dynamic loading of remote resources and protocols with mobile agents. We give the encoding of our distributed calculus into the join-calculus.

A good object-oriented design does not necessarily make a good component-based design, and vice versa. What design principles do components introduce? This paper examines component-based programming and how it expands the design space in the context of an event-based component architecture. We present a conceptual model for addressing new design issues these components afford, and we identify fundamental design decisions in this model that are not a concern in conventional object-oriented design. We use JavaBeans-based examples to illustrate concretely how expertise in component-based design, as embodied in a component taxonomy and implementation space, impacts both design and the process of design. The results are not exclusive to JavaBeans-they can apply to any comparable component architecture.

Global Reporting Initiative (GRI) is the best-known framework for voluntary reporting of environmental and social performance by business worldwide. Using extensive empirical data, including interviews and documentary analysis, we examine GRI's organizational field and conclude that since its modest beginnings in 1999 GRI has been by several measures a successful institutionalization project. But the institutional logic of this new entity, as an instrument for corporate sustainability management, leaves out one of the central elements of the initial vision for GRI: as a mobilizing agent for many societal actors. This emergent logic reflects GRI's dominant constituency – large global companies and financial institutions and international business management consultancies – and not the less active civil society organizations and organized labor. We attribute these developments to factors such as building GRI within the existing institutional structures; the highly inclusive multistakeholder process; and the underdeveloped base of information users. From the institutional theory perspective, this case shows how the process of institutionalization is deeply affected by initial strategies of the founders, and how it reproduces existing power relations. From the governance perspective, this case leads us to question the power of commodified information to mobilize civil society and to strengthen governance based on partnerships.

This paper presents coordination algorithms for groups of mobile agents performing deployment and coverage tasks. As an important modeling constraint, we assume that each mobile agent has a limited sensing/communication radius. Based on the geometry of Voronoi partitions and proximity graphs, we analyze a class of aggregate objective functions and propose coverage algorithms in continuous and discrete time. These algorithms have convergence guarantees and are spatially distributed with respect to appropriate proximity graphs. Numerical simulations illustrate the results.

Abstract. Ubiquitous Computing advocates the construction of massively dis- tributed systems that help transform physical spaces into computationally active and intelligent environments. The design of systems and applications in these environments needs to take account of ...

In order to fully realise the potential of mobile agent technology to address the needs of the network management domain, it is imperative to establish the conditions where mobile agent-based (MA) NMS or SNMP-based NMS should be employed to achieve the optimal performance in term of overhead traffic generated. This paper presents mathematical models to approximate the overhead traffic created by the MA-based NMS and SNMP-based NMS on the production network, based on the complexity of the management task involved. Through our analysis and experimentation, we establish that there is range (of the number of nodes involved) wherein it is advantageous to use mobile agents. Furthermore, we demonstrate through our analytical model that this range can be estimated a priori, thereby facilitating a decision on when to deploy mobile agents and when not to.

1. ABSTRACT Agent technology is an emerging field and agent-based application design is still a pi o- neering discipline. We are all pioneers, i n- venting and re-inventing sometimes smart but perhaps more not-so-smart solutions to recur- rent problems. It is here that agent design pat- terns can help by capturing good solutions to common problems in agent design. No

obile agents offer a new paradigm for distributed computation, but their potential benefits must be weighed against the very real security threats they pose. These threats originate not just in malicious agents but in malicious hosts as well. 1 For example, if there is no mechanism to prevent attacks, a host can implant its own tasks into an agent or modify the agent's state. This can lead in turn to theft of the agent's resources if it has to pay for the execution of tasks, or to loss of the agent's reputation if its state changes from one host to another in ways that alter its behavior in negative ways. Moreover, if mobile agents ultimately allow a broad range of users to access services offered by different and frequently competing organizations, then many applications will involve parties that may not trust each other entirely. 2 The operation of a mobile agent system will therefore require security services that implement the agreements made by the involved parties, whether declared or tacit. Thus, the agreements cannot be violated, either accidentally or intentionally by the involved parties or by malicious or curious parties not bound by the agreements. Aglets are Java-based mobile agents developed at IBM's Tokyo Research Laboratory. This article describes a security model for the aglets development environment that supports flexible architectural definition of security policies. † Since collaborating on this article, Danny B. Lange has joined General Magic, Inc. .

In the near future, the advent of large-scale networks of mobile agents autonomously performing long-term sensing and communication tasks will be upon us. However, using controlled node mobility to improve communication performance is a capability that the mobile networking community has not yet investigated. In this paper, we study mobility as a network control primitive. More specifically, we present the first mobility control scheme for improving communication performance in such networks. Our scheme is completely distributed, requiring each node to possess only local information. Our scheme is self-adaptive, being able to transparently encompass several modes of operation, each respectively improving power efficiency for one unicast flow, multiple unicast flows, and many-to-one concast flows. We provide extensive evaluations on the feasibility of mobility control, showing that controlled mobility can improve network performance in many scenarios. This work constitutes a novel application of distributed control to networking in which underlying network communication serves as input to local control rules that guide the system toward a global objective.

Wireless sensor networks (WSNs) are difficult to program and usually run statically-installed software limiting its flexibility. To address this, we developed Agilla, a new middleware that increases network flexibility while simplifying application development. An Agilla network is deployed with no pre-installed application. Instead, users inject mobile agents that spread across nodes performing application-specific tasks. Each agent is autonomous, allowing multiple applications to share a network. Programming is simplified by allowing programmers to create agents using a high-level language. Linda-like tuple spaces are used for inter-agent communication and context discovery. This preserves each agent's autonomy while providing a rich infrastructure for building complex applications, and marks the first time mobile agents and tuple spaces are used in a unified framework for WSNs. Our efforts resulted in an implementation for MICA2 motes and the development of several applications. The implementation consumes a mere 41.6KB of code and 3.59KB of data memory. An agent can migrate 5 hops in less than 1.1 seconds with 92% reliability. In this paper, we present Agilla and provide a detailed evaluation of its implementation, an empirical study of its overhead, and a case study demonstrating its use.

The growing computational power requirements of grand challenge applications has promoted the need for linking highperformance computational resources distributed across multiple organisations. This is fueled by the availability of the Internet as a ubiquitous commodity communication media, low cost high-performance machines such as clusters across multiple organisations, and the rise of scientific problems of multi-organisational interest. The availability of expensive, special class of scientific instruments or devices and data sources in few organisations has increased the interest in offering a remote access to these resources. The recent popularity of coupling (local and remote) computational resources, special class of scientific instruments, and data sources across the Internet for solving problems has led to the emergence of a new platform called "Computational Grid". This paper identifies the issues in resource management and scheduling driven by computational economy in the emerging grid computing context. They also apply to clusters of clusters environment (known as federated clusters or hyperclusters) formed by coupling multiple (geographically distributed) clusters located in the same or different organisations. We discuss our current work on the Nimrod/G resource broker, whose scheduling mechanism is driven by a user supplied application deadline and a resource access budget. However, current Grid access frameworks do not provide the dynamic resource trading services that are required to facilitate flexible application scheduling. In order to overcome this limitation, we have proposed an infrastructure called GRid Architecture for Computational Economy (GRACE). In this paper we present the motivations for grid computing, resource management architecture, Nimrod/G resource broker, computational economy, and GRACE infrastructure and its APIs along with future work.

We describe the mobile agent paradigm which is becoming increasingly popular for network-centric programming, and compare it with earlier paradigms for distributed computing from which it has evolved. The design of mobile agent systems requires the resolution of several system-level issues, such as the provision of code mobility, object naming, portability, scalability, and a range of security issues that go hand-in-hand with mobile code. Agent programming requires suitable languages and programming models that can support code mobility, and runtime systems that provide some fundamental primitives for the creation, migration and management of agents. We discuss these requirements and describe several mobile agent systems that illustrate di erent approaches taken by designers to address the problems.

Mobile agents represent a promising technology for the development of Internet applications. However, mobile computational entities introduce peculiar problems w.r.t. the coordination of the application components. The paper outlines the advantages of Linda-like coordination models, and shows how a programmable coordination model based on reactive tuple spaces can provide further desirable features for Internet applications based on mobile agents. Accordingly, the paper presents the design and the implementation of the MARS coordination architecture for Java-based mobile agents. MARS defines Linda-like tuple spaces, which can be programmed to react with specific actions to the accesses made by mobile agents. Several examples in the context of a WWW information retrieval application show the effectiveness of the MARS approach.

The purpose of this article was to examine historic institutional autologous stem cell mobilization practices and evaluate factors influencing mobilization failure and kinetics. In this retrospective study we analyzed clinical records of 1834 patients who underwent stem cell mobilization for autologous transplantation from November 1995 to October 2006 at the Washington University in St. Louis. Successful mobilization was defined as collection of $2 Â 10 6 CD34 1 cells/kg. From 1834 consecutive patients, 1040 met our inclusion criteria (502 non-Hodgkin's lymphoma [NHL], 137 Hodgkin's lymphoma, and 401 multiple myeloma [MM]). A total of 976 patients received granulocyte colony-stimulating factor (G-CSF) and 64 received G-CSF plus chemotherapy (G/C) for the initial mobilization. Although the median CD34 1 cell yield was higher in G/C group than in G-CSF alone group, the failure rates were similar: 18.8% and 18.6%, respectively. Overall, 53% of patients collected $2 Â 10 6 CD34 1 cells/kg during the first apheresis with either mobilization regimen. Regardless of mobilization regimen used, MM patients had the highest total CD34 1 cell yield and required less aphereses to collect $2 Â 10 6 CD34 1 cells/kg. Mobilized, preapheresis, peripheral blood CD34 1 count correlated with first day apheresis yield (r 5 .877, P \ .001) and 20 cells/mL was the minimum threshold needed for a successful day 1 collection. For the remobilization analysis we included patients from the whole database. A total of 269 of 1834 patients underwent remobilization using G/C, G-CSF, and/or GM-CSF, and G-CSF plus plerixafor. Only 23% of remobilized patients achieved $2 Â 10 6 CD34 1 cells/kg and 29.7% failed to pool sufficient number of stem cells from both collections. Patients receiving G-CSF plus plerixafor had lowest failure rates, P 5 .03. NHL patients remobilized with G-CSF who waited $25 days before remobilization had lower CD34 1 cell yield than those who waited #16 days, P 5 .023. Current mobilization regimens are associated with a substantial failure rate irrespective of underlying disease. Patients who fail initial mobilization are more likely to fail remobilization. These findings suggest that there is a need for more effective first-line mobilization agents.

We describe a typing system for a distributed π-calculus which guarantees that distributed agents cannot access the resources of a system without first being granted the capability to do so. The language studied allows agents to move between distributed locations and to augment their set of capabilities via communication with other agents. The type system is based on the novel notion of a location type, which describes the set of resources available to an agent at a location. Resources are themselves equipped with capabilities, and thus an agent may be given permission to send data along a channel at a particular location without being granted permission to read data along the same channel. We also describe a tagged version of the language, where the capabilities of agents are made explicit in the syntax. Using this tagged language we define access violations as runtime errors and prove that well-typed systems are incapable of such errors.

The TACOMA project is concerned with implementing operating system support for agents, processes that migrate through a network. Two TACOMA prototypes have been completed; this paper outlines our experiences in building and using them. A mechanism for exchanging electronic cash was explored, as well as agent-based schemes for scheduling and fault-tolerance.

Mobile-agent systems must address three security issues: protecting an individual machine, protecting a group of machines, and protecting an agent. In this chapter, we discuss these three issues in the context of D'Agents, a mobile-agent system whose agents can be written in Tcl, Java and Scheme. (D'Agents was formerly known as Agent Tcl.) First we discuss mechanisms existing in D'Agents for protecting an individual machine: (1) cryptographic authentication of the agent's owner, (2) resource managers that make policy decisions based on the owner's identity, and (3) secure execution environments for each language that enforce the decisions of the resource managers. Then we discuss our planned market-based approach for protecting machine groups. Finally we consider several (partial) solutions for protecting an agent from a malicious machine.

Internet applications face challenges that mobile agents and the adoption of enhanced coordination models may overcome. Each year more applications shift from intranets to the Internet, and Internet-oriented applications become more popular. New design and programming paradigms call help harness the Web's potential. Traditional distributed applications assign a set of processes to a given execution environment that, acting as local-resource managers, cooperating a network-unaware fashion. In contrast, the mobile-agent paradigm defines applications as consisting of network-aware entities-agents-which can exhibit mobility by actively changing their execution environment, transferring themselves during execution. The authors propose a taxonomy of possible coordination models for mobile-agent applications, then use their taxonomy to survey and analyze resent mobile-agent coordination proposals. Their case study, which focuses on a Web-based information-retrieval application, helps show that the mobility of application components and the distribution area's breadth can create coordination problems different from those encountered in traditional distributed applications

Public transportation systems are among the most ubiquitous and complex large-scale systems found in modern society. For those unable to drive such as people with cognitive disabilities, these systems are essential gateways for participation in community activities, socialization, and independence. To understand the magnitude and scope of this national problem, we highlight deficiencies identified in an international study by the Transportation Research Board of the National Research Council and present specific cognitive barriers identified in empirical studies of transportation systems in several U.S. cities.

In this paper, we develop an energy-efficient, fault-tolerant approach for collaborative signal and information processing (CSIP) among multiple sensor nodes using a mobile-agent-based computing model. In this model, instead of each sensor node sending local information to a processing center for integration, as is typical in client/server-based computing, the integration code is moved to the sensor nodes through mobile agents. The energy efficiency objective and the fault tolerance objective always conflict with each other and present unique challenge to the design of CSIP algorithms. In general, energy-efficient approaches try to limit the redundancy in the algorithm so that minimum amount of energy is required for fulfilling a certain task. On the other hand, redundancy is needed for providing fault tolerance since sensors might be faulty, malfunctioning, or even malicious. A balance has to be struck between these two objectives. We discuss the potential of mobile-agent-based collaborative processing in providing progressive accuracy while maintaining certain degree of fault tolerance. We evaluate its performance compared to the client/server-based collaboration from perspectives of energy consumption and execution time through both simulation and analytical study. Finally, we take collaborative target classification as an application example to show the effectiveness of the proposed approach.

Note: OCR errors may be found in this Reference List extracted from the full text article. ACM has opted to expose the complete List rather than only correct and linked references. ... RS Gray, "Agent Tcl: A Flexible and Secure Mobile-Agent System," <i>Proc. Tcl/Tk ...

It was previously reported that treatment with the sulfated polysaccharide fucoidan or the structurally similar dextran sulfate increased circulating mature white blood cells and hematopoietic progenitor/stem cells (HPCs) in mice and nonhuman primates; however, the mechanism mediating these effects was unclear. It is reported here that plasma concentrations of the highly potent chemoattractant stromal-derived factor 1 (SDF-1) increase rapidly and dramatically after treatment with fucoidan in monkeys and in mice, coinciding with decreased levels in bone marrow. In vitro and in vivo data suggest that the SDF-1 increase is due to its competitive displacement from heparan sulfate proteoglycans that sequester the chemokine on endothelial cell surfaces or extracellular matrix in bone marrow and other tissues. Although moderately increased levels of interleukin-8, MCP1, or MMP9 were also present after fucoidan treatment, studies in gene-ablated mice (GCSFR−/−, MCP1−/−, or MMP9−/−) and the ...

This article first surveys existing protocols for supporting IP mobility and then proposes an extension to the Mobile IP architecture, called TeleMIP. Our architecture attempts to achieve smaller handoff latency by localizing the scope of most location update messages within an administrative domain or a geographical region. TeleMIP is intended for use in evolving third-generation wireless networks, and introduces a new logical entity, called the mobility agent, which provides a mobile node with a stable point of attachment in a foreign network. While the MA is functionally similar to conventional foreign agents, it is located at a higher level in the network hierarchy than the subnet-specific FA. Location updates for intradomain mobility are localized only up to the MA; transmission of global location updates are necessary only when the mobile changes administrative domains and/or geographical regions.

Recent years have witnessed great advancements in the science and technology of autonomy, robotics, and networking. This paper surveys recent concepts and algorithms for dynamic vehicle routing (DVR), that is, for the automatic planning of optimal multivehicle routes to perform tasks that are generated over time by an exogenous process. We consider a rich variety of scenarios relevant for robotic applications. We begin by reviewing the basic DVR problem: demands for service arrive at random locations at random times and a vehicle travels to provide on-site service while minimizing the expected wait time of the demands. Next, we treat different multivehicle scenarios based on different models for demands (e.g., demands with different priority levels and impatient demands), vehicles (e.g., motion constraints, communication, and sensing capabilities), and tasks. The performance criterion used in these scenarios is either the expected wait time of the demands or the fraction of demands serviced successfully. In each specific DVR scenario, we adopt a rigorous technical approach that relies upon methods from queueing theory, combinatorial optimization, and stochastic geometry. First, we establish fundamental limits on the achievable performance, including limits on stability and quality of service. Second, we design algorithms, and provide provable guarantees on their performance with respect to the fundamental limits.

This article presents Agilla, a mobile agent middleware designed to support self-adaptive applications in wireless sensor networks. Agilla provides a programming model in which applications consist of evolving communities of agents that share a wireless sensor network. Coordination among the agents and access to physical resources are supported by a tuple space abstraction. Agents can dynamically enter and exit a network and can autonomously clone and migrate themselves in response to environmental changes. Agilla's ability to support self-adaptive applications in wireless sensor networks has been demonstrated in the context of several applications, including fire detection and tracking, monitoring cargo containers, and robot navigation. Agilla, the first mobile agent system to operate in resource-constrained wireless sensor platforms, was implemented on top of TinyOS. Agilla's feasibility and efficiency was demonstrated by experimental evaluation on two physical testbeds co...

The provisioning of Web services over the wireless Internet introduces novel challenging issues for service design and implementation: from user/terminal mobility during service execution, to wide heterogeneity of portable access devices and unpredictable modifications in accessible resources. In this scenario, there are frequent provision-time changes in the context, defined as the logical set of accessible resources depending on client location, access terminal capabilities, and system/service management policies. The development of context-dependent services requires novel middlewares with full context visibility. We propose a middleware for context-aware resource management, called CARMEN, capable of supporting the automatic reconfiguration of wireless Internet services in response to context changes without any intervention on the service logic. CARMEN determines the context on the basis of metadata, which include declarative management policies and profiles for user preferences, terminal capabilities, and resource characteristics. In addition, CARMEN exploits the mobile agent technology to implement mobile middleware components that follow the provision-time movement of clients to support locally their customized service access. The proposed middleware shows how metadata and mobile agents can favor component reusability and automatic service reconfiguration, by reducing the development/ deployment complexity.

Recently, mobile agents have been proposed for efficient data dissemination in sensor networks. In the traditional client/server-based computing architecture, data at multiple sources are transferred to a destination; whereas in the mobile-agent based computing paradigm, a taskspecific executable code traverses the relevant sources to gather data. Mobile agents can be used to greatly reduce the communication cost, especially over low bandwidth links, by moving the processing function to the data rather than bringing the data to a central processor. This paper proposes to use the mobile agent paradigm for reducing and aggregating data in a planar sensor network architecture. The proposed architecture is called mobile agent based wireless sensor network (MAWSN). Extensive simulation shows that MAWSN exhibits better performance than client/server communications in terms of energy consumption and the packet delivery ratio. However, MAWSN has a longer end-to-end latency than client/server communications in certain conditions. Index Terms-mobile agent, energy efficient, aggregate, data dissemination, wireless sensor networks received the BS, MS and Ph.

Software deployment is an evolving collection of interrelated processes such as release, install, adapt, reconfigure, update, activate, deactivate, remove, and retire. The connectivity of large networks, such as the Internet, is affecting how software deployment is performed. It is necessary to introduce new software deployment technologies that leverage this connectivity. The Software Dock framework creates a distributed, agent-based deployment framework to support the ongoing cooperation and negotiation among software producers themselves and among software producers and software consumers. This deployment framework is enabled by the use of a standardized deployment schema for describing software systems, called the Deployable Software Description (DSD) format. The Software Dock also employs agents to traverse between software producers and consumers in order to perform software deployment activities by interpreting the descriptions of software systems. The Software Dock infrastructure allows software producers to offer their customers high-level deployment services that were previously not possible.

There is an increasing number of Internet applications that attempt to optimize their network communication by considering the network distance across which data is transferred. Such applications range from replication management to mobile agent applications. One major problem of these applications is to efficiently acquire distance information for large computer networks. This paper presents an approach to create a global view on the Internet, a so-called network distance map, which realizes a hierarchical decomposition of the network into regions and which allows to estimate the network distance between any two hosts. This view is not only a single snapshot but is dynamically adapted to the continuously changing network conditions. The main idea is to use a certain set of hosts for performing distance measurements and to use the so gained information for estimating the distance between arbitrary hosts. A hierarchical clustering provides the notion of regions and allows to coordinate the measurements in such a way that the resulting network load is minimized.