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Various organizations use the RFID technology for linking, tracking and identifying objects in their operative context. Nevertheless, the RFID components cannot yet be considered as mobile, intelligent and communicating elements of the organization's information infrastructure. They are not always used for accomplishing the linkage between the physical world and the adopted Information Technologies (IT) solutions. Therefore, they are not used for enabling organizations to automatically monitor, decide, and take actions. Heterogeneous networked devices and services installed within the organizations, often work independently instead of collaborating for offering a better quality of the daily activities to the end-user. This paper discusses the adoption of a Smart Ubiquitous Platform (SUP) for monitoring and managing the documents circulation by using the RFID technology. Advantages of the adoption of RFID are discussed too. [ABSTRACT FROM AUTHOR]

This paper proposes a new persistent storage to efficiently manage OWL Web ontologies. The Semantic Web is recognized as a next direction for progress of the current Web. To realize the Semantic Web, various technologies have been developed. Especially, OWL (Web Ontology Language) is the most important and state-of-the-art technology toward the ideal Semantic Web. However, most of research is being focused on designing and building OWL documents (OWL Ontology). One of the most important issues is how to efficiently and persistently store a very large OWL data into database management systems. In this paper, we propose a persistent storage system to achieve the purpose. This paper describes the performance evaluation result on the load time. The experiment result explicitly shows that our proposal provides more enhanced performance comparing with the existing systems. [ABSTRACT FROM AUTHOR]

This paper presents a middleware based on SOA (Service-Oriented Architecture) for context-awareness in a home network with ubiquitous computing. The context-awareness middleware addresses design issues such as heterogeneity, dynamicity, and extensibility issues of ubiquitous computing environment. We also suggest a context model supporting semantic level interoperability of context. In this paper, first we model context metadata ontology as well as context information ontology for the context-awareness middleware. Then we explain a service-oriented context-awareness middleware based on the context model which is introduced in this paper. [ABSTRACT FROM AUTHOR]

One of the particulars to be considered for effective servicing of wireless Internet to mobile terminal is the information of terminal environment. It is because time cost is required in producing mobile contents to suit environment of the connected terminal. In other words, in order to provide mobile web service by considering terminal characteristics, methods to minimize response time and server capacity in accordance with transcoding time in server are required. In this paper, response time to occur in the course of mobile web contents servicing was analyzed and, as a solution for this, Pre-Service method was introduced. Also, this paper suggests two methods in Pre-Service process for selecting optimize content in Cache. One is Device Profile Aware Selection using mobile device information. The other is Content Aware Selection using component information of requested content. Performance level of each method proposed was compared through experiment and the result of analysis was described. [ABSTRACT FROM AUTHOR]

Now, the study of UWB signal's propagation attenuation model concentrates mainly on residential indoor environment. In this paper, the monitor of the personnel and equipments in tunnel of coal mine is regarded as application background, the environment in coal mine is looked as a kind of special indoor environment. On the basis of residential indoor UWB propagation model, the tunnel of coal mine is divided into near-field region and far-field region according to Fresnel theory. The propagation mode of UWB signal is mainly multimode in near-field region and mainly waveguide in far-field region. Considering the additional ullage factors that caused by the factors of tunnel, such as personnel and coal transports and slicers etc at the same time, this paper puts forward the UWB signal propagation attenuation model in coal mine. Aiming at the parameter of symbol BER, comparison and analysis that based on the existing residential indoor propagation attenuation model and the model of this paper is done. [ABSTRACT FROM AUTHOR]

In this paper, a speech emotion recognition agent for mobile communication service is proposed. The proposed system can recognize five emotional states - neutral, happiness, sadness, anger, and annoyance from the speech captured by a cellular phone in real time and then it calculates the degree of affection such as love, truthfulness, weariness, trick, friendship of the person who you are interesting to know through the mobile phone. In general, a speech acquired by a cellular phone contains noise due to the mobile network and environmental noise. Thus it can causes serious performance degradation due to the distortion in emotional features of the query speech. In order to alleviate the effect of these noises, we adopt a MA (Moving Average) filter which has relatively simple structure and low computational complexity. Then a feature optimization method is implemented to further improve and stabilize the system performance. For a practical application, we create an agent that can measure the degree of affection from the person who you want to know on the mobile phone. Two pattern classification methods, k-NN and SVM with probability estimates, are compared for estimating the degree of affection. The experimental results indicate that the proposed method provides very stable and successful emotional classification performance as 72.5% over five emotional states and it shows the feasibility of the agent for mobile communication services. [ABSTRACT FROM AUTHOR]

This paper attempts to make a summary of current models used to evaluate the performance of IEEE 802.11 DCF and develops a new modeling to analyze the packet delay. The main contribution of this paper is that we found the backoff process of DCF can be considered as a Bernoulli Trials process. The new modeling based on the Bernoulli Trials can be a standard to analyze and validate other analytical methods. It can avoid confusion and conflicting produced by different simulation and calculating methods. In contrast to traditional work in the literature, we use our modeling to calculate the average backoff windows and average packet delay. At the same time, verify the analytical results by Monte Carlo and OPNET. The conclusion shows that the new modeling and analysis are comprehensible, simple and accurate. [ABSTRACT FROM AUTHOR]

The paper constructs a 3-hierarchical resource management model (3-HRMM) in order to adapt to variability of grid resources. We propose resource brokering strategy and adaptive performance task allocation algorithm on 3-HRMM. Resource brokering strategy improves performance through brokering of the application and LRM(Local Resource Manager), a component of 3-HRMM, by performance index and resolves a fault caused by virtual organization by using LRM virtual observer. Under performance evaluation through real-time resource monitoring, adaptive performance task allocation algorithm supports load balancing and fault tolerance. This paper proves feasibility of grid service through the implementation of 3-hierarchical resource management model(3-HRMM), and it shows some results of performance evaluation based on its by using two applications such as image rendering and fractal image processing. [ABSTRACT FROM AUTHOR]

Increasingly advanced ubiquitous systems are becoming possible through advances in technology. This paper reviews the design and deployment of two technologies across an office space of 550m2 to form a pervasive smart environment. The first technology provides ubiquitous location awareness, using ultrasonic tags, and the second provides a pervasive input/output device in the form of an advanced, networked telephone. The paper identifies issues within both deployments and looks at the subsequent usage of both systems. The need for especially high dependability in pervasive smart environments is noted, alongside the need to design with affordances and to include novel feedback channels to the user. The issue of how to select a deployment site is raised, together with the need for maximal logging of events, faults and usage. In analysing usage, we find repetitive trends including novelty periods when users court new applications and smart devices, group-based adoption of services, and an advantage in deploying with a large number of diverse applications. Users take to the technologies well, but must expend great effort in customising them and interest wanes. [ABSTRACT FROM AUTHOR]

Context-aware systems incorporate multimodal information to analyze contextual information in users' environment and provide various proactive services according to dynamic context. In this paper, a novel online context analysis framework is proposed to support context-aware computing in smart meeting room. A novel dynamic context model is presented to model human group interactions. Robust audio and visual modules are integrated for the effective processing of multimodal signals from various sensors, based on which a multi-level dynamic context reasoning mechanism is adopted for the online understanding of group interactions in meeting scenarios. Experimental results show the effectiveness of our framework. [ABSTRACT FROM AUTHOR]

We propose a novel reasoning engine for context-aware ubiquitous computing middleware in this paper. Our reasoning engine supports both rule-based reasoning and machine learning reasoning. Our main contribution is to utilize feature selection method to filter the low-level contexts which are not useful for certain special high-level context reasoning. As a result, rules and learning models in the reasoning engine's knowledge base are refined since useless context have been filtered. The merits of our proposed reasoning engine are described in details in this paper. [ABSTRACT FROM AUTHOR]

The role of location management in mobile communication is to make the seamless packet transmission to the correspondent nodes. Most research imposes mainly on how to reduce the frequency of the binding update messages, how to make the level of the signaling constant notwithstanding the increase in the number of the mobile nodes, and how to minimize the packet loss in transmission. This paper addresses these issues and develops a new technique for optimizing location management in mobile communication. Our proposed method adds a server mobile-node to existing Mobile IPv6 protocol and the server node maintains the functioning of mobile communication and has necessary information. Through these schemes, the lifetime of the mobile nodes can be increased. We provide the usefulness of our proposed method using analytical models and compare the results with the previous researches. [ABSTRACT FROM AUTHOR]

Sensor node localization is an important issue in wireless sensor networks (WSNs) due to the dynamic nature of sensor deployment. Generally, in wireless sensor network localization, the absolute positions of certain anchor nodes are required based on the use of global positioning systems, then all the other nodes are approximately localized using various algorithms based on a coordinate system of the anchors. This paper proposes a neighbor position-based localization algorithm (NPLA) that can greatly enhance the positioning accuracy when compared with current overlapping connectivity localization. The proposed method localizes the sensor nodes using both the anchors' positions and neighbor node information. However, unlike existing overlapping-based methods, the proposed NPLA does not assume the same radio transmission range. [ABSTRACT FROM AUTHOR]

Reducing power consumption to extend network lifetime with limited energy resource is one of the most important challenges in wireless sensor networks. In addition, the issue of real-time communication is also very important in some practical applications. A directed diffusion algorithm based on link-stabilizing clustering (DDLSC), which is a delay-energy aware routing protocol for wireless sensor networks is proposed in this paper. DDLSC enable a wide range of tradeoffs between delay and energy consumption. The two major components of DDLSC are: a novel stable clustering scheme that forms a wireless sensor network into two layers and the cluster heads construct a virtual backbone for multi-hop communications, and a directed diffusion routing protocol based on the clustering scheme. It is simple, fast to converge, fully distributed and dynamic, and be scalable to the change in network size, density and topology. The performance of DDLSC remains very good even in large-scale sensor networks, and it scales with density. Through analysis and simulation evaluations, we show that DDLSC improves the packet delay and system energy consumption compared to other current data-centric routing protocols. [ABSTRACT FROM AUTHOR]

This paper describes the ubiquitous computing technologies for ship, which is produced and assembled by many steel blocks. It particularly describes the testing of a 2.4 GHz wireless communications platform, especially zigbee, on a number of intelligent devices, with the blocks disturbing the wireless communication. The power line communication that is established in a ship already is also experimented for some data transfer. At last, the RFID technology is applied at the test bed that is composed of three steel containers. In this paper, we implemented some USN technologies in the test bed simulating a ship environment and investigated the basic characteristics of ubiquitous computing technologies. Possible applications of such ubiquitous computing technologies to ships are also introduced here in. [ABSTRACT FROM AUTHOR]

Accurate capacity measures for a path in wireless mesh network can be useful to many applications, including routing protocol design, QoS guarantees, congestion control and other related areas. In this paper, we propose the local virtual probing analytical model. A linear programming problem of both channel assignment and packet scheduling is formulated to determine the capacity of any given path, and hence we propose a path capacity evaluating algorithm based on greedy strategy (PCEAGS) to solve it. Finally, we discuss the impact of several factors, such as hop count of path, amount of packets and numbers of available channels and radios per node, on the accuracy of PCEAGS in detail. The result shows that our algorithm can estimate path capacity accurately in lower average time complexity and also has better expansibility. [ABSTRACT FROM AUTHOR]

Wireless mesh networks provide an easy deployed and extensible solution to access Internet or communicate with each other for both enterprises and individuals. With the help of multi-channel and multi-radio, wireless mesh network can support more traffic load to meet higher and higher bandwidth requirement in this modern time. There have been researches that focus on channel assignment and routing algorithm for IEEE 802.11 multi-channel environment to achieve better network throughout. However, the data rate and transmission range of 802.11 is limited and is not suitable for a large area metropolitan mesh network deployment. This paper presents a rate-adaption channel assignment and routing algorithm for IEEE 802.16 multi-channel multi-radio network in mesh mode which is expected as the last-mile wireless broadband connectivity. We takes 802.16 TDMA characteristic and modulation/rate adaption into consideration. The Simulation results show that our channel assignment procedure uses fewer channels and better channel utilization than the migrated 802.11 greedy approach. Among the three comparing routing protocols, our protocol performs better in multi-rate 802.16 mesh network and results in higher aggregate throughput. [ABSTRACT FROM AUTHOR]

In this paper we discuss research work that enables the development of hybrid systems consisting of communicating plants and artefacts and we investigate methods of creating "interfaces" between artefacts and plants in order to enable people to form mixed, interacting communities. Our research objective is to develop hardware and software components that enable a seamless interaction between plants and artefacts in scenarios ranging from domestic plant care to precision agriculture. This paper deals with the approach that we follow for the development of such hybrid systems and discusses both hardware and software architectural aspects, with a special focus on describing the modular platform for wireless sensor network implemented and the distributed context management process followed. The latter imposes a proactive computing model by looping sensor data with actuators through a decision-making layer. The deployment of the system in a precision agriculture application is also presented. [ABSTRACT FROM AUTHOR]

Road intersections have become the places of high road incidents and car collisions. Our hypothesis is that a system can be made aware of dangerous situations at road intersections and warn drivers accordingly. Moreover, over time, the system can learn (or re-learn) such "patterns" of danger for specific intersections given a history of rich collision data collected via sensors (that exist today). Based on the assumption that such a history of sensory data about colliding vehicles can be obtained, we show useful patterns that can be extracted. This paper presents our framework for intersection understanding, presenting simulated results suggesting that a fragment of the world (i.e. intersections) can be more deeply understood by mining appropriate sensor data. The simulated environment of the road intersections forming the basis of a real-world implementation and testing of the framework are discussed here. The recent results of mining traffic and collision data generated by the simulation are also included in this paper. [ABSTRACT FROM AUTHOR]

Ad hoc networks are exposed to numerous security threats that can adversely affect the success of important applications. Security services such as authentication and key management are important to secure the communication between two nodes in the networks. In the existing key pre-distribution schemes, each node is equipped with a weak authentication mechanism to identify neighboring nodes. During the secret key discovery phase, when any two nodes share at least one key information, one node considers the other side to be worthy of confidence and discloses all the shared information to it without a doubt. These schemes are vulnerable to active attack from authorized nodes as well as unauthorized nodes. This paper proposes a novel key management scheme: each node reduces the disclosure of the shared key information and the network provides strong authentication and privacy. Performance and security analyses have proven that our scheme is suitable for ad hoc networks in terms of availability and security aspects. [ABSTRACT FROM AUTHOR]

In this paper, we generalize the problem of multi-classifiers combination by using modified bagging method to detect previously unknown viruses. The detection engine applies two algorithms, Support Vector Machine and BP neural network to virus detection. For SVM classifier, we extract the feature vector from the API function calls by monitor the programs. And the static feature of program, n-gram, is used in the BP neural network classifier. Finally, the D-S theory of evidence is used to combine the contribution of each individual classifier to give the final decision. Our extensive experiments have shown that the combination approach improves the performance of the individual classifier significantly. It shows that the present method could effectively be used to discriminate normal and abnormal programs. [ABSTRACT FROM AUTHOR]

As wireless communication advances, research on location-based services using mobile devices has attracted interest, which provides information and services related to user's physical location. As increasing information and services, it becomes difficult to find a proper service that reflects the individual preference at proper time. Due to the small screen of mobile devices and insufficiency of resources, personalized services and convenient user interface might be useful. In this paper, we propose a map-based personalized recommendation system which reflects user's preference modeled by Bayesian Networks (BN). The structure of BN is built by an expert while the parameter is learned from the dataset. The proposed system collects context information, location, time, weather, and user request from the mobile device and infers the most preferred item to provide an appropriate service by displaying onto the mini map. [ABSTRACT FROM AUTHOR]

Many challenging security-related issues have been studied in wireless sensor networks to provide a demanded quality and security for deliverable data. Yet, one of these issues which are not handled is the secret key revocation. In a semi-dynamic, resource-constrained and long-living sensor network with self organization features, traditional revocation methods are not desirable and somehow impractical. Through this paper, we discuss the rising issue of key revocation due to the pre-distribution and provide several techniques, structures and algorithms for several network and security conditions and requirements. In addition to the saving of the resources represented by the communication, computation and memory, we provide an extension for special-case networks in which our work can provide a higher performance. [ABSTRACT FROM AUTHOR]

After a first phase of great activity in the field of multi-agent systems, researchers seemed to lose interest in the paradigm, mainly due to the lack of scenarios where the highly distributed nature of these systems could be appropriate. However, recent computing models such as ubiquitous computing and ambient intelligence have introduced the need for this type of highly distributed, autonomous and asynchronous computing mechanisms. The agent paradigm can play an important role and can suit the needs of many applications in these scenarios. In this paper we argue that the main obstacle for the practical application of multi-agent systems is the lack of appropriate security mechanisms. Moreover, we show that as a result of recent advances in security technologies, it is now possible to solve the most important security problems of agent-based systems. [ABSTRACT FROM AUTHOR]

To date, there are numerous variants of designated verifier signatures (DVS), including the notion of strong DVS, multi DVS, universal DVS, etc. In this paper, for the first time, we present a generic definition of DVS model. We also explore the related security notions in DVS, including unforgeability, non-transferability and non-delegatability, and study the relationship of these notions against variants of DVS. Furthermore, we classify the multi designated verifier signature schemes into four categories depending on the way the verification and simulation is performed. We also point out some drawbacks on the existing DVS schemes, and finally present a new and efficient constant size multi DVS scheme that produces a constant size signature regardless the size of the receivers' group. Our scheme is proven secure in the standard model. [ABSTRACT FROM AUTHOR]

Presently, one can use services on the Internet. These services require user's sensitive information such as name, address, credit card number, etc. However, various privacy problems such as information leakage cases are becoming serious social concern. Therefore, we propose a framework to protect user's sensitive information. It allows a user to specify the usage of his/her sensitive information and restricts the use of information by an information recipient. The main concept of the framework is that an information recipient can use sensitive information only in the manner considered safe by the information owner. This is realized by a trusted program that implements the manner of information usage trusted by the information owner. The user offers his/her trusted program to an information recipient and requires to make use of the user's sensitive information through the trusted program. In this paper, we propose the approach for trusted program generation. [ABSTRACT FROM AUTHOR]

In this paper we propose a gentle watching over system that considers users' situations and quality/privacy requirements, in ubiquitous information environment. To realize a gentle and safe watching-over, we have to cope with real situation of a watched person. Moreover, social relationships between observers and the watched person should be considered to give adequate privacy level to the services. To do this, we propose a ubiquitous watch-over system "uEyes". In uEyes we introduce a distinguished feature for watching: Social awareness. To realize the feature, environmental information acquired from real world and knowledge on social activities of people are effectively combined. Based on the advanced feature, live video streaming system is dynamically constructed according to the users' situation in runtime. We implemented a prototype of uEyes for watching over elderly people, and performed some experiments based on several scenarios. From the experimental results, we confirmed effectiveness of our proposed system. [ABSTRACT FROM AUTHOR]

Service customization always plays an important role in ubiquitous environment, in which the adaptation of service component according to user requirement is a key problem. Component adaptation is a traditional topic in Component-Based Software Development (CBSD) and Service-Oriented Architecture (SOA) research fields. But most of the existing approaches employ high level abstraction to achieve the adaptation process and usually make it a computation-intensive task, which can hardly be utilized in the ubiquitous environment. In addition, the high level abstraction-based approach is always difficult to understand for normal users. In this paper, based on the analysis of existing approaches, a business area-oriented service component adaptation approach is proposed. The approach employs basic functions of the business area to represent user requirement and service components. Three control structures are introduced to model the interconnection of the functions. Then the adaptation is performed based on the functionality relationships between service components and user requirement. The approach usually causes low computation cost and is easy to be utilized in ubiquitous environment. [ABSTRACT FROM AUTHOR]

In this paper, a novel ubiquitous intelligent environment platform and its multi-agent control system are presented. The platform named Distributed Embedded Intelligence Room (DEIR) has been constructed with embedded sensors, actuators and computing devices. All the devices are interconnected using five different physical networks. This platform aims to facilitate realistic data collection and online system performance evaluation. The multi-agent control system incorporating two machine learning algorithms, fuzzy inference and decision tree, has been designed to conform to DEIR architecture. Devices to be controlled are classified based on their possible output states and modelled separately by fuzzy inference agents and decision tree agents in the system. The multi-agent control system with hybrid intelligence shows 11% improvements on overall control accuracy and 84% improvements on learning time compared to its predecessor control system. The vast improvement on computational time shows suitability of the approach towards real-time, embedded applications. [ABSTRACT FROM AUTHOR]

The sensor nodes of wireless sensor networks (WSNs) have the following abilities such as: sensing, computation, and wireless communication capabilities. Hence, WSNs can be used for various application domains. In this paper, we propose a location mechanism with mobile reference nodes and Global Positioning System (GPS) to help sensor nodes to calculate the coordinate location information. And then sensor nodes deliver the coordinate location to base station through neighboring sensor nodes. By using this mechanism, we can calculate the coordinate location of the target sensor nodes. And then we can apply this mechanism to track or transfer data packets in the WSNs efficiently. [ABSTRACT FROM AUTHOR]

This paper describes an implementation and quantitative evaluation of the UbiMDR framework. The UbiMDR framework has been proposed for consistent semantics management between ubiquitous applications. This framework enables an application field-independent information exchanging sharing and maxmize the usability of ubiquitous applications and data in devices (tags or smart cards). In the previous study, we just proposed the framework at the conceptual level including description of key components. In other words, the previous proposal has no implementation and evaluation. In this paper, we present a prototype implementation of the UbiMDR framework for semantic interoperability on the ubiquitous environment. To show the merits of the framework, we describe comparative evaluations between the conventional ubiquitous framework and the UbiMDR framework. [ABSTRACT FROM AUTHOR]

Medical diagnosis and intervention increasingly rely upon medical image processing tools that are bound with high-cost hardware, designed for special diseases, and incapable of being shared by common medical terminals. In this paper, we present our Ubiquitous Context-based Image Processing Engine (UCIPE) for MedImGrid (Medical Image Grid). It encapsulates image processing algorithms as WS (Web Services), and creates virtual algorithm barn to store their metadata. The user contexts are captured by UCIPE clients and used as clues to search the optimal WS from the algorithm barn. UCIPE supports all-weather accesses (anytime, anywhere, with any means) of numerous multiple terminals to guarantee the algorithm resources be accessed transparently. The UCIPE prototype for MedImGrid is based on CERNET2. The performances of UCIPE-based 3D reconstruction verify the feasibility of UCIPE and prove the improvement of IPv6 network to medical gird applications. [ABSTRACT FROM AUTHOR]

Location-based ubiquitous services have evolved significantly during the last years and are reaching a maturity phase, relying primarily on the experience gained and the utilization of recent technologies. This paper proposes a context-aware platform for mobile devices in dynamic environments, which uses Semantic Web technologies to model context information and advanced interactive map-based interfaces for accommodating pedestrians. To test and demonstrate the approach, a prototype has been developed and a number of further extensions are studied. Building and using this system has enabled us to identify the main challenges that need to be addressed for realizing the objectives of next generation semantics-based pervasive information systems. [ABSTRACT FROM AUTHOR]

In the near future many radio access technologies (RATs) will coexist to offer a vast variety of user services at different quality levels. Software-defined radio (SDR) facilitates to flexibly choose the RAT by means of a software-reconfiguration of the SDR terminal. Cognitive radio automates this process, being an ambient aware, intelligent radio resource management system. We extend its scope in that we introduce the cognitive computing resource management. Our cognitive radio system scans the computing environment, decides whether to reconfigure a candidate SDR mobile terminal or not, and learns from the effects of these decisions. The simulations, which model a simplified though realistic case study, show that two simple computing resource management algorithms outperform an algorithm that is unaware of the present computing environment. The paper concludes that a cognitive computing resource management is necessary for providing a ubiquitous wireless access where the user demands are satisfied as a function of the currently available computing resources of their terminals. [ABSTRACT FROM AUTHOR]

As wireless and mobile computing technologies start to penetrate every corner of our life, highly anticipated smart spaces are becoming a reality. Recently, OSGi has proven quite successful in enabling collaboration and interaction among entities within a single space. However, distributed collaboration over a wider area spanning multiple spaces will be more often required, as more spaces turns intelligent. This paper addresses the need of cross-space service discovery and interaction. Our approach is to utilize SLP protocol as a means to bridge isolated OSGi islands together. We have validated our architectural design through prototype implementations and a comparative evaluation study. [ABSTRACT FROM AUTHOR]

This paper addresses a mobility driven vertical handover (M-VHO) scheme to avoid unnecessary handovers for IEEE 802.11e/16e wireless networks. In the M-VHO scheme, the mobility of a mobile station (MS), e.g., an IPTV terminal, can be estimated by the pattern of velocities and directions. As the mobile IPTV traffic strictly needs to be considered for supporting high quality and large scale multimedia services, IEEE 802.11e-based QoS-aware MAC is good to use. Therefore, the proposed M-VHO scheme is operated over IEEE 802.11e/16e networks. Results demonstrate that M-VHO scheme is efficient to supply QoS in various traffic. [ABSTRACT FROM AUTHOR]

Advance in processor, memory and wireless communication technique have led to an increase of economical and small wireless sensor nodes. To provide the right responses quickly for the diverse events, wireless sensor nodes have cooperation with together. For successful cooperation, the time synchronization among sensor nodes is an important requirement for application execution. In wireless sensor networks, message packets are used for the time synchronization. However, the transmission of message packets dissipates the battery energy of wireless sensor nodes. Since wireless sensor nodes works on the limited battery capacity, the excessive use of message packets has a negative impact upon their lifetime. In this paper, reference interpolation protocol is proposed for reducing the number of message packets for the time synchronization. The proposed method performs time interpolation between the time of reference packets and the global time of the base station. The proposed method completes the synchronization operation with only two message packets. Due to the simple synchronization procedure, our method greatly reduces the number of synchronization messages. From the decrease in the transmission of message packets, the convergence time among wireless sensor nodes is shortened and the lifetime of wireless sensor nodes is also prolonged as much as the amount of saved battery energy. [ABSTRACT FROM AUTHOR]

Data fusion in sensor networks involves the processing of data from multiple sources. For distributed settings, the fusion operation has to be executed at individual nodes, which makes data synchronization among nodes a crucial task to ensure consistency. If the sensor nodes are mobile, the communication channel between them can sometimes be broken. When communication is re-established, the snapshots of the nodes may no longer be consistent. The challenge is further made more difficult given limited communication bandwidth. In this paper, we propose two algorithms for data synchronization in distributed and constrained mobile sensor networks. The first one uses timestamps to locate data records to be transferred between nodes. The second one employs hash digest and index tree to locate the discrepancy set between two sensor nodes. For the hash-based algorithm, we further investigate the cases for complete and rounded data. The evaluation results show that the timestamp-based algorithm is better if complete data are required for fusion, while the hash-based algorithm can outperform the timestamp-based one if the fusion algorithm can tolerate errors within some given threshold. [ABSTRACT FROM AUTHOR]

Three-dimensional Under-Water Acoustic Sensor Networks (UWASN) are supposed to be deployed for many applications. However, a protocol for sensors' self-localization and time-synchronization in UWASN remains a challenge problem. In this paper, we developed a multilateration algorithm which could reliably localize and synchronize underwater sensor networks by acoustic ranging. To our best knowledge, this is the first scheme which could achieve both them for 3D UWASN simultaneously. Simulation results are also given to illustrate its effectiveness. [ABSTRACT FROM AUTHOR]

Wireless sensor networks are expected to be widely deployed in the future. Due to their unique features, energy-efficient data dissemination from source is getting more and more attention. In this paper, an energy-efficient dissemination framework with multiple gateways (EDF), which can significantly reduce communication costs resulting in prolonged network lifetime and improve the data source management efficiency by integrated with Internet, is proposed. In our scheme, 3-level architecture with a load-balancing node is proposed, and an efficient algorithm to find a nearest gateway among the multiple gateways for detected information is provided. In the algorithm, it mostly consists of several elements: (i) interest, gradients from source to multiple gateways, and exploratory data message, (ii) scheme for deciding nearest gateway, and (iii) reinforcement and aggregation. By EDF, detected information can be sent to the nearest gateway. Our analysis and simulation results reveal that EDF performs better than the existing algorithm in terms of the average dissipated energy.The abstract should summarize the contents of the paper and should contain at least 70 and at most 150 words. It should be set in 9-point font size and should be inset 1.0 cm from the right and left margins. There should be two blank (10-point) lines before and after the abstract. [ABSTRACT FROM AUTHOR]

In wireless sensor networks, an adversary can use compromised nodes or outside jammer to launch selective forwarding attacks in which malicious nodes may refuse to forward certain messages and simply drop them, ensuring that they are not propagated any more. Multipath routing can be used to counter selective forwarding attacks. However, communication overheads in multipath routing increase dramatically as the number of paths increases. In this paper, we propose a fuzzy-based reliable data delivery method to counter selective forwarding attacks. The number of paths for data delivery is determined by a fuzzy logic with consideration of the energy level of the network and the number of malicious nodes. The proposed method uses the propagation limiting method as a means for routing if multipath routing is insufficient for reliable data delivery. [ABSTRACT FROM AUTHOR]

Embedding smart sensors in humans has been a research challenge due to the limitations imposed by these sensors from computational capabilities to limited power. In this paper, a practical WSN application that will enable blind people to see what their neighboring partners can see is proposed. The challenge is that the actual mapping between the input images to brain pattern is too complex and not well understood. We also study the connectivity problem in 3D/2D wireless sensor networks and propose distributed efficient algorithms to accomplish the required connectivity of the system. A novel connectivity algorithm CDCA to connect disconnected parts of a network using cooperative diversity is introduced. Through simulations, the connectivity gains and energy savings provided by this novel form of cooperative diversity in WSNs are analyzed. [ABSTRACT FROM AUTHOR]

The integration of wireless sensor networks and grid computing is an emerging and promising area of research. Sensor grids extend the grid computing paradigm to the sharing of sensor resources in wireless sensor networks. By combining the complementary strengths of sensor networks and grid computing, sensor grids can support applications that require real-time information from the physical environment and vast amount of computational and storage resources. One of the major challenges in the design of sensor grids is how to efficiently schedule sensor jobs across the collection of sensor resources in a sensor grid. In this paper, we design an integrated and flexible scheduler for a sensor grid testbed. The scheduler makes use of several scheduling and load balancing algorithms to suit the characteristics of sensor jobs. We performed extensive evaluations to characterize the behaviour and performance of these scheduling and load balancing algorithms. Our performance results indicate that the sensor grid scheduler can provide a good tradeoff betweeen performance objectives such as sensor resource utilization, sensor job throughput, and sensor grid lifetime. [ABSTRACT FROM AUTHOR]

The coverage problem in wireless sensor networks (WSNs) is to determine the number of active sensor nodes needed to cover the sensing area. The purpose is to extend the lifetime of the WSN by turning off redundant nodes. In this paper, we propose a mathematical method for calculating the coverage fraction in WSNs. According to the method, each active node can evaluate its sensing area whether covered by its active neighbors. We assume that the network is sufficiently dense and the deployed nodes can cover the whole monitored area. In this scenario, if a node's sensing area is covered by its active neighbor nodes, it can be treated as a redundant node. Based on this idea, we propose a lightweight node scheduling (LNS) algorithm that prolongs the network lifetime of the sensor network by turning off redundant nodes without using location information. Simulation study shows that LNS scheme can save considerable energy for data gathering while meeting the desired coverage fraction imposed by application. [ABSTRACT FROM AUTHOR]

The ability to discover services offered in Mobile Ad-Hoc Networks (MANETs) is the major prerequisite for effectively utilizing these services. Caching service advertisements is an essential component in service discovery protocols for MANETs. To fully utilize the advantage of the cached service advertisements, the cached service description can be advertised with the local service description in a vicinity, which however will increase packet size. To reduce packet size, a better solution is to representing the cached service advertisements with a meta service description. In this paper, we introduce a fine-grained group-based meta service description scheme and propose an efficient service discovery protocol: Meta Service Description Assisted Service Discovery Protocol (MSDASDP) for MANETs, where the number of forwarding nodes of request packets is minimized with the help of the fine-grained meta service description. Simulation results both show that MSDASDP is an effective, efficient, and prompt service discovery protocol for MANETs. [ABSTRACT FROM AUTHOR]

Recently in-network aggregation has gained much attention for effectively reducing energy consumption over sensor networks. In this paper, we present CASA, a clustering-based approximation scheme for in-network aggregation, which significantly reduces the overall energy consumption while maintaining user-specified data quality. We explore two ideas to support the approximation scheme. First, we propose a clustering-based framework to effectively utilize temporal coherency tolerance (tct) in conjunction with in-network aggregation to save communication cost over sensor network. Secondly, we propose an adaptive tct-reallocating technique to further reduce communication cost and maintain load balance. Our experiment results indicate that significant benefits can be achieved by using our CASA approximation scheme. [ABSTRACT FROM AUTHOR]

Internet and multimedia services are widely-provided in All-IP based networks. There has been growing demand for mobile users to get those services. The Wireless Mesh Network (WMN) extends communication range and provides Internet connectivity to mobile users with low upfront investment. In WMN, the traffic usually passes through the gateway and makes it become the common destination of the traffic. Conventional multipath routing protocols in the ad hoc networks do not allow intermediate nodes to reply the route request messages, so the flooding messages make the area near the gateway become congested and degrade the performance. In this paper, we proposed Gateway Zone Multi-path Routing (GZMR) protocol. GZMR uses node around the gateway to form a Gateway Cooperative Zone and ceases the routing control messages flooding from outside the zone. Border nodes in the zone can help replying gateway information to reduce route discovery delay. Our simulation results show that by lowering routing overheads and utilizing multiple paths from source to gateway, GZMR can shorten average end-to-end delay and improve the packet delivery in WMNs. [ABSTRACT FROM AUTHOR]

Broadcast has been widely used in wireless sensor networks to disseminate information to all reachable nodes. The simplest way of realizing broadcast is via omnidirectional flooding. However, it generates an excessive amount of redundant traffic and exaggerates interference in the shared medium among the neighboring nodes. In order to mitigate these problems, this paper proposes an efficient flooding scheme with directional antennas, called BDF (Bi-Directional Flooding). The BDF scheme limits the propagation range of the packet forwarding to two directions over four, in order to minimize an overlapped area due to omnidirectional flooding. To analyze its performance, BDF has been compared with omnidirectional flooding and NEDF schemes. [ABSTRACT FROM AUTHOR]

Wireless sensor network consists of sensor nodes having limited resources. Energy saving is very important to increase the life time of these networks. In this paper, we propose Minimum Energy and Latency MAC (MELM) protocol for wireless sensor networks. MELM uses dual frequency radio setup inspired by STEM and LEEM to minimize the energy consumption and the latency in a multi-hop environment. Both LEEM and STEM protocols squander energy and increase latency because of overhearing, over-transmission and packet collisions. MELM eliminates these problems by maintaining a scheduling table in all nodes having logical 2-hop distance from the receiver node and by using advance channel reservation mechanism. MELM eradicates the hidden terminal and the exposed terminal problems, which is a key advantage, by maintaining a 2-hop receiver centric scheduling table. [ABSTRACT FROM AUTHOR]

Many routing protocols have been proposed for wireless sensor networks. However, few of the existing routing protocols have considered the link quality, such as the different communication rate, different Packet Loss Ratio (PLR). As a result, the routes tend to have the shortest hop count may contain weak links, which may lead to low performance and are susceptible to breaks in the presence of mobility. In this paper, we analyze the impact of link quality in data transmission and propose a Link Quality-Aware Optimization Mechanism for routing protocols. Specifically, the link quality is measured by PLR and each sensor node upon the routes will maintain a Link Quality Table (LQ-Table) which records link quality information of its neighboring nodes. By computing to select alternative sensor nodes for data transmission, the mechanism can assist the routing protocol to avoid transmitting data through bad link and efficiently prevent intolerable delay or unnecessary energy consumption due to the bad link's packet loss. Simulation and experiment results show that our design can efficiently improve the performance of routing protocols in energy efficiency and transmission latency. [ABSTRACT FROM AUTHOR]