Location based or &#x201D;context aware&#x201D; computing is becoming increasingly recognized as a vital part of a mobile computing environment. As a consequence, the need for location-management middleware is widely recognized and actively researched. Location-management is frequently offered to the application through a &#x201C;location API&#x201D; (e.g. JSR 179) where the mobile unit can find out its own location as coordinates or as &#x201C;building, floor, room&#x201D; values. It is then up to the application to map the coordinates into a set of localized variables, e.g. direction to the nearest bookshop or the local timezone. It is the opinion of the authors that a localization API should be more transparent and more integrated: The localized values should be handed to the application directly, and the API for doing so should be the same as the general storage mechanisms. Our proposed middleware for location and context management is built on top of Mobispace. Mobispace is a distributed tuplespace made for mobile units (J2me) where replication between local replicas takes place with a central server (over GPRS) or with other mobile units (using Bluetooth). Since a Bluetooth connection indicates physical proximity to another node, a set of stationary nodes may distribute locality information over Bluetooth connections, and this information may be retrieved through the ordinary tuplespace API. Besides the integration with the general framework for communication and coordination the middleware offers straightforward answers to questions like: Where is node X located? Which nodes are near me? What is the trace of node Y?

Anders Fongen

Christian Larsen

Gheorghita Ghinea

Simon J. E. Taylor

Tacha Serif

Location Based Mobile Computing&#x2013;A Tuplespace Perspective

Location Based Services can be considered as one of the most rapidly expanding fields of the mobile communications sector, with an impressively large application range. The proliferation of mobile/wireless Internet and mobile computing, and the constantly increasing use of handheld, mobile devices and position tracking technologies prepared the grounds for the introduction of this new type of services. The combination of position fixing mechanisms with location-dependent, geographical information, can offer truly customized personal communication services through the mobile phone or other type of devices. Prompted by the avalanche of technology advances in the aforementioned areas in this paper we present an integrated platform for delivering Location Based Services (LBS). The platform covers the full life cycle of a LBS starting from the specification of the service, covering issues like the deployment and maintenance of services, the service invocation and the final delivery of the produced results to the invoking user. A prototype implementation of the discussed platform was developed and used to perform a series of trial services, with the purpose of demonstrating the pursued functionality.

Ioannis Priggouris

Dimitrios Spanoudakis

Manos Spanoudakis

Stathes Hadjiefthymiades

A Generic Framework for Location-Based Services (LBS) Provisioning

With evolution in computer and mobile networking technologies comes the challenge of offering novel and complex multimedia applications and end-user services in heterogeneous environments for both developers and service providers. This paper describes one novel service, called LiveMail that explores the potential of existing face animation technologies for innovative and attractive services intended for the mobile market. This prototype service allows mobile subscribers to communicate using personalized 3D face models created from images taken by their phone cameras. The user can take a snapshot of someone's face &#x2013; a friend, famous person, themselves, even a pet &#x2013; using the mobile phone's camera. After a quick manipulation on the phone, a 3D model of that face is created and can be animated simply by typing in some text. Speech and appropriate animation of the face are created automatically by speech synthesis. Furthermore, these highly personalized animations can be sent to others as real 3D animated messages or as short videos in MMS. The clients were implemented on different platforms, and different network and face animation techniques, and connected into one complex system. This paper presents the architecture and experience gained in building such a system.

Tomislav Kosutic

Miran Mosmondor

Ivan Andrisek

Mario Weber

Maja Matijasevic

Igor Pandzic

Personalized Avatars for Mobile Entertainment

Wireless sensor network refers to a group of sensors, linked by a wireless medium to perform distributed sensing task. The primary interest is their capability in monitoring the physical environment through the deployment of numerous tiny, intelligent, wireless networked sensor nodes. Our interest consists of a sensor network, which includes a few specialized nodes called processing elements that can perform some limited computational capabilities. In this paper, we propose a model called SPLAI that allows the network to compute a finite element problem where the processing elements are modeled as the nodes in the linear triangular approximation problem. Our model also considers the case of some failures of the sensors. A simulation model to visualize this network has been developed using C++ on the Windows environment.

Ruzana Ishak

Shaharuddin Salleh

Stephan Olariu

Mohd.Ismail Abdul Aziz

SPLAI: Computational Finite Element Model for Sensor Networks

In emergency scenarios we can obtain a more effective coordination among team members, each of them equipped with hand-held devices, through the use of workflow management software. Team members constitute a Mobile Ad-hoc NETwork (MANET), whose topology both influences and is influenced by the workflow. In this paper we propose an algebraic approach for modeling workflow progress as well as its modifications as required by topology transformations. The approach is based on Algebraic Higher-Order Nets and sees both workflows and topologies as tokens, allowing their concurrent modification.

Paolo Bottoni

Fabio De Rosa

Kathrin Hoffmann

Massimo Mecella

Applying Algebraic Approaches for Modeling Workflows and their Transformations in Mobile Networks

This paper discusses the improvements and parameter optimization issues of LTRACK, a recently proposed mobility management algorithm. Mathematical modelling of the algorithm and the behavior of the Mobile Node (MN) are used to optimize the parameters of LTRACK. A numerical method is given to determine the optimal values of the parameters. Markov chains are used to model both the base algorithm and the so-called loop removal effect. An extended qualitative and quantitative analysis is carried out to compare LTRACK to existing handover mechanisms such as MIP, Hierarchical Mobile IP (HMIP), Dynamic Hierarchical Mobility Management Strategy (DHMIP), Telecommunication Enhanced Mobile IP (TeleMIP), Cellular IP (CIP) and HAWAII. LTRACK is sensitive to network topology and MN behavior so MN movement modelling is also introduced and discussed with different topologies. The techniques presented here can not only be used to model the LTRACK algorithm, but other algorithms too. There are many discussions and calculations to support our mathematical model to prove that it is adequate in many cases. The model is valid on various network levels, scalable vertically in the ISO-OSI layers and also scales well with the number of network elements.

Benedek Kov&#xe1;cs

M. Szalay

S. Imre

Modelling and Quantitative Analysis of LTRACK&#x2013;A Novel Mobility Management Algorithm

Mobile computing has enabled users to seamlessly access databases even when they are on the move. Mobile computing environments require data management approaches that are able to provide complete and highly available access to shared data at any time from any where. In this paper, we propose a novel replicated data protocol for achieving such goal. The proposed scheme replicates data synchronously over stationary sites based on three dimensional grid structure while objects in mobile sites are asynchronously replicated based on commonly visited sites for each user. This combination allows the proposed protocol to operate with less than full connectivity, to easily adapt to changes in group membership and not require all sites to agree to update data objects at any given time, thus giving the technique flexibility in mobile environments. The proposed replication technique is compared with a baseline replication technique and shown to exhibit high availability, fault tolerance and minimal access times of the data and services, which are very important in an environment with low-quality communication links.

J. H. Abawajy

M. Mat Deris

M. Omar

A Novel Data Replication and Management Protocol for Mobile Computing Systems

The problem of congestion control in wireless sensor networks is very important, especially in very dense networks. In this work, we use a simple packet repetition scheme as congestion and event-reliability control. In contrast to other works on the performance study of such a scheme, we use a random radio pathloss model. We are motivated by this choice, because the radio model usually used in most of studies on wireless sensor networks is deterministic. However, this is not the case encountered in real hardware. Here, we show that the analysis of such a scheme by simulation is not trivial when more realistic radio models are used. We emphasise this problem by comparing the differences of simulation results with respect to the non random pathloss case, also known as isotropic model. As expected, simulations confirm that radio irregularities can not be neglected and the efficiency of event-reliability based congestion control should be properly revised. This aspect calls for new mechanisms of coordination among sensor nodes.

T. Yang

G. De Marco

M. Ikeda

L. Barolli

Impact of Radio Randomness on Performances of Lattice Wireless Sensors Networks Based on Event-Reliability Concept

A mobile ad hoc network (MANET) is a collection of wireless mobile nodes that forms a temporary network without the aid of a fixed communication infrastructure. Since every node can be mobile and network topology changes can occur frequently, node disconnection is a common mode of operation in MANETs. Providing reliable data access and message delivery is a challenge in this dynamic network environment. Caching and replica allocation within the network can improve data accessibility by storing the data and accessing them locally. However, maintaining data consistency among replicas becomes a challenging problem. Hence, balancing data accessibility and consistency is an important step toward data management in MANETs. In this paper, we propose a replica-based data-storage mechanism and undelivered-message queue schemes to provide reliable data storage and dissemination. We also propose replica update strategies to maintain data consistency while improving data accessibility. These solutions are based on a clustered MANET where nodes in the network are divided into small groups that are suitable for localized data management. The goal is to reduce communication overhead, support localized computation, and enhance scalability. A simulation environment was built using an NS-2 network simulator to evaluate the performance of the proposed schemes. The results show that our schemes distribute replicas effectively, provide high data accessibility rates and maintain consistency.

Mieso K. Denko

Hua Lu

Replica Dissemination and Update Strategies in Cluster-Based Mobile Ad Hoc Networks

Intrusion detection has over the last few years, assumed paramount importance within the broad realm of network security, more so in case of wireless mobile ad hoc networks. The inherently vulnerable characteristics of wireless mobile ad hoc networks make them susceptible to attacks in-spite of some security measures, and it may be too late before any counter action can take effect. As such, there is a need to complement traditional security mechanisms with efficient intrusion detection and response systems. This paper proposes an agent-based model to address the aspect of intrusion detection in cluster based mobile wireless ad hoc network environment. The model comprises of a set of static and mobile agents, which are used to detect intrusions, respond to intrusions, and distribute selected and aggregated intrusion information to all other nodes in the network in an intelligent manner. The model is simulated to test its operation effectiveness by considering the performance parameters such as, detection rate, false positives, agent overheads, and intrusion information distribution time. Agent based approach facilitates flexible and adaptable security services. Also, it supports component based software engineering components such as maintainability, reachability, reusability, adaptability, flexibility, and customization.

B. M. Reshmi

S. S. Manvi

Bhagyavati

An Agent Based Intrusion Detection Model for Mobile Ad Hoc Networks

Over the last few years, there has been a blossoming of developing mobile healthcare programs. Bluetooth technology, which has the advantages of being low-power and inexpensive, whilst being able to transfer moderate amounts of data over a versatile, robust and secure radio link, has been widely applied in mobile healthcare as a replacement for cables. This paper discussed the applications of Bluetooth technology in healthcare. It started with the brief description of the history of Bluetooth technology, its technical characteristics, and the latest developments. Then the applications of Bluetooth technology in healthcare sector were reviewed. The applications are based on two basic types of links of Bluetooth technology: point-to-point link and point-to-multipoint link. The special requirements from healthcare and the challenges of successful application of Bluetooth in healthcare will be discussed. At last the future development of Bluetooth technology and its impacts on healthcare were envisioned.

X. H. Wang

M. Iqbal

Bluetooth: Opening a Blue Sky for Healthcare

About this journal

Mobile Information Systems publishes original research articles as well as review articles that report the theory and/or application of new ideas and concepts in the field of mobile information systems.

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Chief Editor&nbsp;Dr Alessandro Bazzi&nbsp;is based at the University of Bologna, Italy. His current research is focused on wireless technologies applied to automated and connected vehicles.

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Mobile Information Systems - Table of contents 2006

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Mobile Information Systems publishes original research articles as well as review articles that report the theory and/or application of new ideas and concepts in the field of mobile information systems.

Mobile Information Systems