1,196 research outputs found

    A bluetooth educational content distribution system modelled on a service-oriented architecture

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    In this research, we design and prototype an educational content distribution system modeled on a Service-Oriented Architecture (SOA) paradigm and implemented using Web services, XML and Bluetooth technology. In the prototype, we use an Open Source Learning Management System (LMS) Sakai implemented in Java and branded Vula for the University of Cape Town (UCT). Web services and its specification of SOAP, XML and Bluetooth technology are used to integrate the disparate technologies that form the service architecture. The disparate technologies include among others Bluetooth enabled mobile phones and PDAs, services (modules) which may be running on different operating systems, and deployed over Local Area Networks (LANs) or Internet. The service is meant to leverage the existing infrastructure to provide a new, cheap channel for education content distribution to mobile devices in learning institutions especially Universities in the developing world and Africa in particular. We design, implement and evaluate the prototype for performance and scalability. During the designing and implementation of the architecture, we incorporate SOA principles of service/module re-use, service composition, loose-coupling, standard data exchange within the system or services, and extensibility of the services among others. The aim of the service is to distribute education content uploaded in Learning Management Systems (LMSs) to Bluetooth enabled mobile devices that are increasingly held by students in developing world Universities. The service is intended to supplement existing Web-based and lecture room content distribution channels by opening up the mobile device space. For the prototype, we focus on repackaging structured text content and distributing it to Bluetooth enabled phones and PDAs using Bluetooth technology. We evaluate our prototype for performance using experimental studies

    Network and service monitoring in heterogeneous home networks

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    Home networks are becoming dynamic and technologically heterogeneous. They consist of an increasing number of devices which offer several functionalities and can be used for many different services. In the home, these devices are interconnected using a mixture of networking technologies (for example, Ethernet, Wifi, coaxial cable, or power-line). However, interconnecting these devices is often not easy. The increasing heterogeneity has led to significant device- and service-management complexity. In addition, home networks provide a critical "last meters" access to the public telecom and Internet infrastructure and have a dramatic impact on to the end-to-end reliability and performance of services from these networks. This challenges service providers not only to maintain a satisfactory quality of service level in such heterogeneous home networks, but also to remotely monitor and troubleshoot them. The present thesis work contributes research and several solutions in the field of network and service monitoring in home networks, mainly in three areas: (1) providing automatic device- and service-discovery and configuration, (2) remote management, and (3) providing quality of service (QoS). With regard to the first area, current service discovery technology is designed to relieve the increasing human role in network and service administration. However, the relevant Service Discovery Protocols (SDPs) are lacking crucial features namely: (1) they are not platform- and network-independent, and (2) they do not provide sufficient mechanisms for (device) resource reservation. Consequently, devices implementing different SDPs cannot communicate with each other and share their functionalities and resources in a managed way, especially when they use different network technologies. As a solution to the first problem, we propose a new proxy server architecture that enables IP-based devices and services to be discovered on non-IP based network and vice versa. We implemented the proxy architecture using UPnP respectively Bluetooth SDP as IP- and non-IP-based SDPs. The proxy allows Bluetooth devices and UPnP control points to discover, access, and utilize services located on the other network. Validation experiments with the proxy prototype showed that seamless inter-working can be achieved keeping all proxy functionalities on a single device, thus not requiring modification of currently existing UPnP and Bluetooth end devices. Although the proxy itself taxes the end-to-end performance of the service, it is shown to be still acceptable for an end user. For mitigating resource conflicts in SDPs, we propose a generic resource reservation scheme with properties derived from common SDP operation. Performance studies with a prototype showed that this reservation scheme significantly improves the scalability and sustainability of service access in SDPs, at a minor computational cost. With regard to the second area, it is known that the end-to-end quality of Internet services depends crucially on the performance of the home network. Consequently, service providers require the ability to monitor and configure devices in the home network, behind the home gateway (HG). However, they can only put limited requirements to these off-the-shelf devices, as the consumer electronics market is largely outside their span of control. Therefore they have to make intelligent use of the given device control and management protocols. In this work, we propose an architecture for remote discovery and management of devices in a highly heterogeneous home network. A proof-of-concept is developed for the remote management of UPnP devices in the home with a TR-069/UPnP proxy on the HG. Although this architecture is protocol specific, it can be easily adapted to other web-services based protocols. Service providers are also asking for diagnostic tools with which they can remotely troubleshoot the home networks. One of these tools should be able to gather information about the topology of the home network. Although topology discovery protocols already exist, nothing is known yet about their performance. In this work we propose a set of key performance indicators for home network topology discovery architectures, and how they should be measured. We applied them to the Link-Layer Topology Discovery (LLTD) protocol and the Link-Layer Discovery Protocol (LLDP). Our performance measurement results show that these protocols do not fulfill all the requirements as formulated by the service providers. With regard to the third area, current QoS solutions are mostly based on traffic classification. Because they need to be supported by all devices in the network, they are relatively expensive for home networks. Furthermore, they are not interoperable between different networking technologies. Alternative QoS provision techniques have been proposed in the literature. These techniques require end-user services to pragmatically adapt their properties to the actual condition of the network. For this, the condition of the home network in terms of its available bandwidth, delay, jitter, etc., needs to be known in real time. Appropriate tools for determining the available home network resources do not yet exist. In this work we propose a new method to probe the path capacity and available bandwidth between a server and a client in a home network. The main features of this method are: (a) it does not require adaptation of existing end devices, (b) it does not require pre-knowledge of the link-layer network topology, and (c) it is accurate enough to make reliable QoS predictions for the most relevant home applications. To use these predictions for effective service- or content-adaptation or admission control, one should also know how the state of the home network is expected to change immediately after the current state has been probed. However, not much is known about the stochastic properties of traffic in home networks. Based on a relatively small set of traffic observations in several home networks in the Netherlands, we were able to build a preliminary model for home network traffic dynamics

    A Component-Based Approach for Securing Indoor Home Care Applications

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    eHealth systems have adopted recent advances on sensing technologies together with advances in information and communication technologies (ICT) in order to provide people-centered services that improve the quality of life of an increasingly elderly population. As these eHealth services are founded on the acquisition and processing of sensitive data (e.g., personal details, diagnosis, treatments and medical history), any security threat would damage the public's confidence in them. This paper proposes a solution for the design and runtime management of indoor eHealth applications with security requirements. The proposal allows applications definition customized to patient particularities, including the early detection of health deterioration and suitable reaction (events) as well as security needs. At runtime, security support is twofold. A secured component-based platform supervises applications execution and provides events management, whilst the security of the communications among application components is also guaranteed. Additionally, the proposed event management scheme adopts the fog computing paradigm to enable local event related data storage and processing, thus saving communication bandwidth when communicating with the cloud. As a proof of concept, this proposal has been validated through the monitoring of the health status in diabetic patients at a nursing home.This work was financed under project DPI2015-68602-R (MINECO/FEDER, UE), UPV/EHU under project PPG17/56 and GV/EJ under recognized research group IT914-16

    Discovery and Push Notification Mechanisms for Mobile Cloud Services

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    Viimase viie aasta jooksul on mobiilsed seadmed nagu sĂŒlearvutid, pihuarvutid, nutitelefonid jmt. tunginud peaaegu kĂ”igisse inimeste igapĂ€evaelu tegevustesse. Samuti on pĂ”hjalik teadus- ja arendustegevus mobiilsete tehnoloogiate vallas viinud mĂ€rkimisvÀÀrsete tĂ€iustusteni riistvara, tarkvara ja andmeedastuse alal. TĂ€napĂ€eval on mobiilsed seadmed varustatud sisseehitatud sensorite, kaamera, puutetundliku ekraani, suurema hulga mĂ€luga, kuid ka tĂ”husamate energiatarbemehhanismidega. Lisaks on iOS ja Android operatsioonisĂŒsteemide vĂ€ljalaske tĂ”ttu suurenenud nii mobiilirakenduste arv kui keerukus, pakkudes arvukamalt kĂ”rgetasemelisi rakendusi. Sarnaselt on toimunud olulised arengud ja standardiseerimisele suunatud jĂ”upingutused veebiteenusete valdkonnas ja elementaarsetele veebiteenuste ligipÀÀsu kasutatakse laialdaselt nutitelefonidest. See on viinud loogilise jĂ€rgmise sammuna veebiteenuste pakkumiseni nutitelefonidest. Telefonidest veebiteenuste pakkumise kontseptsioon ei ole uus ning seda on pĂ”hjalikult uurinud Srirama, kes pakkus vĂ€lja Mobile Host (Mobiilne Veebiteenuse Pakkuja) kontseptsiooni. Algne realisatsioon kasutas aga aegunud tehnoloogiaid nagu JMEE, PersonalJava, SOAP arhitektuur jne. See töö uuendab Mobile Host'i kasutades uusimaid tehnoloogiad, nagu Android OS ja REST arhitektuur, ning pakub vĂ€lja teenusemootori, mis pĂ”hineb Apache Felix'il - OSGi platvormi realisatsioonil piiratud ressurssidega seadmetele. HĂ€mmastava kiirusega toimunud arengud mobiilsete arvutuste vallas vĂ”imaldavad uue pĂ”lvkonna veebirakenduste loomist valdkondades nagu keskkonnateadlikkus, sotsiaalvĂ”rgustikud, koostöövahendid, asukohapĂ”hised teenused jne. Sellised rakendused saavad Ă€ra kasutada Mobile Host'i vĂ”imalusi. Selle tulemusena on klientidel ligipÀÀs vĂ€ga suurele hulgale teenustele, mistĂ”ttu tekib vajadus efektiivse teenuste avastamise mehhanismi jĂ€rele. See töö pakub vĂ€lja kataloogipĂ”hise avastusmehhanismi vĂ”rgu ĂŒlekatte toega suurtele, kĂ”rge liikuvusega vĂ”rgustikele. See mehhanism toetub OWL-S'le, mis on ontoloogia veebiteenuseid pakkuvate ressursside avastamiseks, vĂ€ljakutseks, koostamiseks ja jĂ€lgimiseks. Töö kirjeldab ka Srirama vĂ€lja pakutud algupĂ€rast teenuste avastamise mehhanismi, mis toetub peer-to-peer vĂ”rkudele ja Apache Lucene vĂ”tmesĂ”na otsingumootorile. Uurimuse kĂ€igus uuendatakse teenuseotsing kasutama Apache Solr'i, Apache Lucene'i viimast versiooni. Teenuste avastust testiti pĂ”hjalikult ja tulemused on töös kokkuvĂ”tvalt vĂ€lja toodud. Mobiilsete tehnoloogiate vallas uuritakse ka vĂ”imalust kasutada pilvetehnolologiat laiendamaks mobiilseadmete salvestusmahtu ja töökoormust edastades pilve andme- ja arvutusmahukad ĂŒlesanded. See soodustab keerulisemate ja vĂ”imalusrohkemate mobiilirakenduste arendust. Pilve delegeeritavate toimingute aeganĂ”udva iseloomu tĂ”ttu aga on vajalik asĂŒnkroonne mehhanism teavitamaks kasutajat, millal töömahukad tegevused on lĂ”petatud. Mobiilsete pilveteenuste pakkujad ja vahevara lahendused vĂ”ivad kasu saada Mobile Host'ist ja selle asĂŒnkroonsete teavituste vĂ”imekusest. Uurimus esitleb nelja teavitusmehhanismi: AC2DM, APNS, IBM MQTT ja Mobile Host'i pĂ”hine teavitus. Töö vĂ”tab kokku kvantitatiivse analĂŒĂŒsi tulemused ja toob vĂ€lja nelja teavitamise lĂ€henemise tugevused ja nĂ”rkused. Lisaks kirjeldatakse CroudSTag rakenduse realisatsiooni - CroudSTag on mobiilirakendus, mille eesmĂ€rgiks on sotsiaalsete gruppide moodustamine kasutades nĂ€otuvastustehnoloogiat. CroudSTag-i realisatsioon kasutab mobiilseid pilveteenuseid ja Mobile Host'i, et pakkuda oma funktsionaalsust kasutajale.In the last lustrum the mobile devices such as laptops, PDAs, smart phones, tablets, etc. have pervaded almost all the environments where people perform their day-to-day activities. Further, the extensive Research and Development in mobile technologies has led to significant improvements in hardware, software and transmission. Similarly, there are significant developments and standardization efforts in web services domain and basic web services have been widely accessed from smart phones. This has lead to the logical next step of providing web services from the smart phones. The concept of the web service provisioning from smart phones is not new and has been extensively explored by Srirama who proposed the concept of Mobile Host. However, the original implementation considered aged technologies such as JMEE, PersonalJava, SOAP architecture among others. This work updates the Mobile Host to the latest technologies like Android OS and REST architecture and proposes a service engine based on Apache Felix, and OSGI implementation for resource constraint devices. Moreover, the astonishing speed in developments in mobile computing enable the new generation of applications from domains such as context-awareness, social network, collaborative tools, location based services, etc., which benefit from the Mobile Host service provisioning capabilities. As a result the clients have access to a huge number of services available; therefore, an efficient and effective service discovery mechanism is required. The thesis proposes a directory-based with network overlay support discovery mechanism for large networks with high mobility. The proposed discovery mechanism relies in OWL-S, an ontology for service discovery, invocation, composition, and monitoring of web resources. The work also considers the original service discovery mechanism proposed by Srirama relying in peer-to-peer networks and Apache Lucene, a keyword search engine. The study updates the service search to Apache Solr, the latest development for Apache Lucene. The service discovery was extensively tested and the results are summarized in this work. Mobile technologies are looking into the clouds for extending their capabilities in storage and processing by offloading data and process intensive tasks. This fosters the development of more complex and rich mobile applications. However, due to the time-consuming nature of the tasks delegated to the clouds, an asynchronous mechanism is necessary for notifying the user when the intensive tasks are completed. Mobile cloud service providers and Middleware solutions might benefit from Mobile Host and its asynchronous notification capabilities. The study presents four push notification mechanisms being AC2DM, APNS, IBM MQTT and Mobile Host based push notification. The work summarizes the results of a quantitative analysis and highlights the strengths and weakness of the four notifications approaches. In addition, it explains CroudSTag realization, a mobile application that aims the social group formation by means of facial recognition that relies in mobile cloud services and Mobile Host to provide its functionality to the user

    Enabling Multi-Hop Remote Method Invocation in Device-To-Device Networks

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    To avoid shrinking down the performance and preserve energy, low-end mobile devices can collaborate with the nearby ones by offloading computation intensive code. However, despite the long research history, code offloading is dilatory and unfit for applications that require rapidly consecutive requests per short period. Even though Remote Procedure Call (RPC) is apparently one possible approach that can address this problem, the RPC-based or message queue-based techniques are obsolete or unwieldy for mobile platforms. Moreover, the need of accessibility beyond the limit reach of the device-to-device (D2D) networks originates another problem. This article introduces a new software framework to overcome these shortcomings by enabling routing RPC architecture on multiple group device-to-device networks. Our framework provides annotations for declaring distribution decision and out-of-box components that enable peer-to-peer offloading, even when a client app and the service provider do not have a direct network link or Internet connectivity. This article also discusses the two typical mobile applications that built on top of the framework for chatting and remote browsing services, as well as the empirical experiments with actual test-bed devices to unveil the low overhead conduct and similar performance as RPC in reality

    Recent advances in industrial wireless sensor networks towards efficient management in IoT

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    With the accelerated development of Internet-of- Things (IoT), wireless sensor networks (WSN) are gaining importance in the continued advancement of information and communication technologies, and have been connected and integrated with Internet in vast industrial applications. However, given the fact that most wireless sensor devices are resource constrained and operate on batteries, the communication overhead and power consumption are therefore important issues for wireless sensor networks design. In order to efficiently manage these wireless sensor devices in a unified manner, the industrial authorities should be able to provide a network infrastructure supporting various WSN applications and services that facilitate the management of sensor-equipped real-world entities. This paper presents an overview of industrial ecosystem, technical architecture, industrial device management standards and our latest research activity in developing a WSN management system. The key approach to enable efficient and reliable management of WSN within such an infrastructure is a cross layer design of lightweight and cloud-based RESTful web service
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