Frank T. Johnsen (Norwegian Defence Research Establishment (FFI), Norway); Trude Hafsøe (Norwegian Defence Research Establishment (FFI), Norway

Web services technology is in widespread use, but employing the technology in highly dynamic environments is a challenge. The current Web services discovery standards are tailored for use in fixed infrastructure networks and single hop ad hoc networks. They are not suitable for use in highly dynamic multi-hop mobile ad hoc networks (MANETs), such as the networks employed in search and rescue operations. In a search and rescue operation we also need to know about not only the available services, but also where the nodes participating in the operation are. In this paper we address these needs by designing an experimental Web services discovery protocol that can be used in such multi-hop MANETs. We combine service and location discovery in our novel Web services discovery protocol called SAM, which we have implemented, tested in a field trial, and released as an open source project. pp. 1731-1735

Sergio Cabrero (University of Oviedo, Spain); Xabiel Garcia Pañeda (University of Oviedo, Spain); David Melendi (University of Oviedo, Spain); Roberto Garcia (University of Oviedo, Spain)

Mobile ad-hoc network research tackles many different environments. In all of them, node mobility is a determining factor, because credibility of the experiments in this subject is strongly related to the realism of the scenario. For that reason, a lot of effort has gone into designing realistic mobility models and gathering real world mobility traces. However, these scenarios are scarce and difficult to examine. With the purpose of building more complete benchmarks, researchers may want to modify them or obtain derived situations. The MASS editor is designed to ease the laborious task of editing MANET scenarios. In this paper, we present the first version, showing its potential. In addition, a markup language MASS-ML is defined with the purpose of standardizing MANET descriptions. pp. 1736-1740

Nearchos Paspallis (University of Cyprus, Cyprus); Achilleas Achilleos (University of Cyprus, Cyprus); Konstantinos Kakousis (University of Cyprus, Cyprus); George Papadopoulos (University of Cyprus, Cyprus)

The constant advent of powerful mobile devices has raised the potential of building novel context-aware applications.These applications let the users enjoy a better experience by sensing their context and automating tasks that would otherwise require signi.cant user attention. This paper presents two context-aware applications, built on top of the MUSIC middleware's context management framework. By describing the development steps, we reveal how development is facilitated via Separation of Concerns and how code reuse is enabled in terms of reusable context plug-ins. It is argued that this approach reduces the required development and maintenance e.ort and thus lowers the associated cost. pp. 1741-1746

Albana Gaba (Vrije Universiteit Amsterdam, The Netherlands); Spyros Voulgaris (Vrije Universiteit, The Netherlands); Maarten van Steen (VU University Amsterdam, The Netherlands)

We discuss protocols for all-to-all dissemination in ad-hoc wireless networks. We identify shortcomings and challenges related to high traffic and explore their causes by observing the performance at the MAC layer. Through simulations we show that a congestion assessment mechanism can re- duce up to 1/3 of the traffic on a good part of the nodes without a ecting dissemination performance. We conclude that MAC-layer congestion awareness is important for im- proving application-level efficiency, and that we should not separate the two when dealing with all-to-all broadcasting. pp. 1747-1752

Using multiple paths to transmit data simultaneously in wireless sensor networks is regarded to reduce end-to-end delay and achieve higher throughput. However, the interference between these multiple paths causes a significant reduction in the overall performance. Previous methods tried to solve this problem either with the aid of special hardware or under unrealistic assumption, such as the interference range is the same as the communication range. In this paper, we propose a novel interference aware multipath routing (IAMR) protocol for wireless sensor networks. Without any special hardware support, IAMR can establish interference minimized paths in a simple and efficient way and is also applied for the realistic situation that the interference range is twice as the communication range. We evaluate IAMR by comparing with AOMDV protocol and extensive simulations show that IAMR achieves good performance in terms of packet delivery ratio, end-to-end delay, throughput and energy usage balancing. pp. 1753-1757

Sang-Seon Byun (Norwegian University of Science and Technology, Norway); Ilangko Balasingham (Norwegian University of Science & Technology, Norway)

In this paper, we consider the measurement allocation problem in a spatially correlated sensor field. Our goal is to determine the probability of each sensor's being measured based on its contribution to the estimation reliability; it is desirable that a sensor improving the estimation reliability is measured more frequently. We consider a correlation model reflecting transmission power limit, noise in measurement process and channel, and channel attenuation. Then the estimation reliability is defined as the distortion error between the event source in the sensor field and its estimation at the sink. Motivated by the correlation nature, we model the measurement allocation problem into a cooperative game, and then express each sensor's contribution using Shapley value - a formal quantification of individual player's average marginal contribution. Against the intractability in the computation of exact Shapley value, we deploy randomized method that enables to compute approximate Shapley value within reasonable time. In numerical experiments, we evaluate approximate Shapley value by comparing it to the exact one, and illustrate that measurement allocation according to Shapley value turns to the balance between the estimation reliability and network lifetime. pp. 1758-1763

Amr G M Al Asaad (The University of British Columbia, Canada); Sathish Gopalakrishnan (University of British Columbia, Canada); Victor CM Leung (The University of British Columbia, Canada)

Wireless Mesh Networks (WMNs) have emerged as an important technology in building next generation fixed wireless broadband networks that provide low cost Internet access for fixed and mobile users. An orthogonal evolution in computer networking has been the rise of Peer-to-Peer (P2P) applications such as P2P file sharing. It is of interest to enable effective P2P file sharing in this type of networks. Our main contribution in this paper is innovative schemes for content caching and replication at mesh routers that enhance the performance of P2P file sharing in WMNs. We first motivate our proposed schemes by showing the impact of caching P2P contents at mesh routers on the performance of P2P file sharing in WMNs. We then describe the design and operation of our content caching and replication schemes. Finally, we compare the performance of our proposed schemes against other existing schemes using simulations. We focus on P2P file sharing but other applications can also be supported by the proposed schemes. pp. 1764-1768

Anna Lina Ruscelli (Scuola Superiore Sant'Anna, Italy); Gabriele Cecchetti (Scuola Superiore S. Anna, Pisa, Italy); Sathish Gopalakrishnan (University of British Columbia, Canada); Giuseppe Lipari (Scuola Superiore S.Anna, Italy)

The design of a Wireless Sensor Network suitable to meet the applications requirements is particularly relevant in environments where it is not possible to operate after the deployment, modifying the network to respect the desired behavior. This paper proposes a model to allow performance evaluation of the network before its deployment, helping its design and the choice of the right value of the network parameters. In particular our model is tailored for wireless sensor networks using the geographic routing. The model has been both numerically analyzed and simulated showing its ability to set such parameters to meet the requirements expressed in terms of established service levels. pp. 1769-1774

The research and industrial community started to think of more complex application scenarios for wireless sensor networks, where the use of mobile sensor nodes is essential. The support of mobile sensor nodes in such applications requires the existence of a suitable mobility management protocol. However, existing mobility protocols, like MIPv6, can not be directly applied on mobile sensor nodes, since they are inefficient in terms of energy, communication, and computation cost, and fail to meet the stringent operational requirements of a mobile sensor node. In this paper we propose a new mobility management protocol for 6LoWPAN which uses the technology of Proxy Agents and aims to enhance the handoff time by predicting or rapidly responding to a handover event. The proposed protocol lessens the involvement of the mobile node in mobility-related message exchange. pp. 1775-1780

Alexander Garcia Davalos (Universidad Autonoma de Occidente, Colombia); Andres Navarro (Universidad Icesi, Colombia); Fabio Guerrero (Universidad del Valle, Colombia)

A myriad of Vertical Handoff Algorithms (VHA) have been proposed by researchers and networks practitioners. These algorithms allow mobile terminals (MT) to maintain the network connection when they switch from one wireless network to another one. Given the amount of proposed VHA and the need for an objective assessment of these solutions different evaluation methodologies have been proposed, becoming the problem of evaluation of VHA in an interesting challenge. However, there is no consensus on how to evaluate performance of VHA. In this paper, we address this issue by proposing a new approach for evaluating the VHA, which is based on multi-criteria evaluation and criticality analysis - a specific concept taken from the operational reliability. The new approach allows evaluating VHA using measured values of some defined parameters, which can be obtained from simulating VHA on a network simulation tool (e.g. NCTUns) or special software simulation tools (e.g. MATLAB). We present an evaluation of two VHA as a test of the new model. pp. 1781-1785

Security mechanisms such as authentication, message integrity, and non-repudiation are extremely important features for both vehicle-to-vehicle and vehicle-to-infrastructure communications in vehicular ad hoc networks. This paper proposes an Efficient and Scalable Authentication Protocol (ESAP) that provides anonymity and conditional privacy for vehicular ad hoc networks based on the self-generated certificates. The proposed ESAP provides all required security services such as authentication, message integrity, non-repudiation and revoking malicious vehicles in an efficient and scalable manner while supporting user anonymity, location privacy and conditional privacy. Moreover, accuracy of this protocol does not depend on the availability of Road Side Units. pp. 1786-1791

Omer Boyaci (Columbia University, USA); Victoria Beltran (Technical University of Catalonia (UPC), Spain); Henning Schulzrinne (Columbia University, USA)

The SECE (Sense Everything, Control Everything) system allows users to create services that combine communication, calendaring, location and devices in the physical world. SECE is an event-driven system that uses a natural-English-like language to trigger action scripts. Presence updates, incoming calls, email, calendar and time events, sensor inputs and location updates can trigger rules. SECE retrieves all this information from multiple sources to personalize services and to adapt them to changes in the user's context and preferences. Actions can control the delivery of email, change the handling of phone calls, update social network status and set the state of actuators such as lights, thermostats and electrical appliances. We give an overview of the SECE language and system architecture. pp. 1792-1797

María Teresa González Aparicio (University of Oviedo, Spain); Roberto Garcia (University of Oviedo, Spain); Xabiel Garcia Pañeda (University of Oviedo, Spain); David Melendi (University of Oviedo, Spain); Sergio Cabrero (University of Oviedo, Spain)

The popularity evolution of multimedia videos, which were emitted in three different Spanish local on-line newspapers, has been researched in this paper. The statistic distribution from which the popularity came from is unknown. In fact, throughout the literature, many papers have modeled popularity with different distributions, such as Mandelbrot, Stretched, Zipf-like and so on. In this paper, the Box-Cox transformation has been proposed as a unified approach that would cover all the former distributions. The main advantage is its non-parametric nature and in consequence the model selection might be avoided. pp. 1798-1802

Daisuke Ishii (Keio University, Japan); Kenta Nakahara (Keio University, Japan); Satoru Okamoto (Keio University, Japan); Naoaki Yamanaka (Keio University, Japan)

With the advance of ubiquitous society including IPv6, it is expected that everything will be connected to the network. Then, a ubiquitous grid networking environment (uGrid) has been proposed. In uGrid, everything from devices to programs is defined as "Service-part", and several Service-Parts are combined to provide new service for users. IP Routing/Signaling based grid service provisioning is proposed as a new concept for uGrid. The feature of this concept is to assign IP addresses to Service-Parts and to execute grid service provisioning in the network layer. By using IP protocol which is scalable and has sophisticated technologies accumulated for years, the construction of scalable and intelligent ubiquitous grid networking environment is expected. As key techniques, Service Routing and Service Signaling have been introduced, and the issues of each technique are listed. By experiment, it was confirmed that Service Signaling could make the provisioning of a simple video grid service. pp. 1808-1812

Yutaka Arakawa (Kyushu University, Japan); Shigeaki Tagashira (Kyushu University, Japan); Akira Fukuda (Kyushu University, Japan)

The objective of this paper is to clear out the relation ship between user's contexts and really used words in order to realize the context-aware IME that we have proposed as one of context-aware service. We focus on public tweets of Twitter, because it includes various users' real sentences with geocode (latitude and longitude). We analyze 471274 tweets that have been collected from 15 December 2009 to 10 June 2010 for specifying the relationship to landmark information and TV program. As a result, we show that 5.1% of tweets include landmark words, and 9% of tweets include TV program words. Additionally, we bring out that there are location dependent words and time dependent words. pp. 1813-1817

A session for demonstrating working on ubiquitous computing and networks: 1) Navigating the Web of Things Mathieu Boussard, Alcatel-Lucent, France 2) Bridging communications and the physical world: Sense Everything, Control Everything Omer Boyaci, Columbia University, USA 2) MASS: editor for mobile ad-hoc networks scenarios Xabiel Garcia Pañeda, University of Oviedo, Spain

This panel will focus on a discussion about the new innitiatives to address the research challenges on Ubiquitous computing and networks. The researchers will have the opportunity to share their ideas and also to find partners to collaborate on research issues related to ubiquitous computing and networks