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The goal of the SMART4ALL EU funded project is to build capacity amongst European stakeholders via the development of self-sustained, cross-border experiments that transfer knowledge and technology between academia and industry. It... more
The goal of the SMART4ALL EU funded project is to build capacity amongst European stakeholders via the development of self-sustained, cross-border experiments that transfer knowledge and technology between academia and industry. It targets Customized Low Energy Computing (CLEC) in the Cyber-Physical (CPS) and the Internet of Things (IoT) domains. The vision of the project will be mainly realized through funded (via open calls) Pathfinder Application Experiments (PAEs) that will enable the transformation of academic knowledge into products.It is important to mention that SMART4ALL sets forward the concept of marketplace which is offered as a service (Marketplace-as-a-Servtce or MaaS) that acts as one-stopsmart-stop by offering tools, HPC services, and platforms to the PAE grantees. The purpose of this paper is to present the SMART4ALL High-Performance Computing (HPC) infrastructure and services realized according to the Hardware-as-a-Service paradigm. The SMART4A11 HPC infrastructure includes CPU, Memory, GPU, storage as well as FPGA resources connected with high-speed links.
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Smart home ecosystems aim to adapt to users' needs and preferences and provide comfort and improved quality of life. Users need access to efficient and effective applications in order to interact with such environments. The target of... more
Smart home ecosystems aim to adapt to users' needs and preferences and provide comfort and improved quality of life. Users need access to efficient and effective applications in order to interact with such environments. The target of this paper is to present a mobile application designed and created to support end user interaction with smart home ecosystems; this application is capable of adapting to any smart home, regardless of this architecture and the devices used. We followed a user first design thinking approach to design the user experience of this application and we deployed it on the infrastructure of the Ambient Assisted Living Laboratory, AAL House. Users via our application can monitor sensors and devices, define their routine preferences and view data on energy consumption. In order to study the acceptance and performance of our application, a survey was conducted using a questionnaire.
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Utilization of emerging WSN technologies in the field of demanding medical applications comprise one of the most critical and challenging objectives of the ARMOR project. However, contemporary WSN node implementations are notorious for... more
Utilization of emerging WSN technologies in the field of demanding medical applications comprise one of the most critical and challenging objectives of the ARMOR project. However, contemporary WSN node implementations are notorious for the resource limitations e.g. in terms of processing and memory capabilities. Therefore, significant effort is devoted in hardware based implementations of critical components with respect to the project objectives that can alleviate respective re-source limitations drawback.
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ABSTRACT In recent years, several network services regarding multimedia, sensor, control and many other applications are becoming more and more popular. It is envisaged that every mobile electronic device will have a wireless network... more
ABSTRACT In recent years, several network services regarding multimedia, sensor, control and many other applications are becoming more and more popular. It is envisaged that every mobile electronic device will have a wireless network interface that allows it to join in general, heterogeneous networks and exchange information among its devices. From the user perspective, these devices must work transparently and any communication must be performed efficiently with respect to QoS and heterogeneity. In this paper, a framework architecture is presented to support interoperability for heterogeneous networked systems. The proposed framework design is accompanied by a generalized set of device characteristics that provides the adequate mechanisms for exposing the different devices particularities in a unified way to the application.
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ABSTRACT Demographic and epidemiologic transitions in Europe have brought a new health care paradigm where life expectancy is increasing as well as the need for long-term care. To meet the resulting challenge, European healthcare systems... more
ABSTRACT Demographic and epidemiologic transitions in Europe have brought a new health care paradigm where life expectancy is increasing as well as the need for long-term care. To meet the resulting challenge, European healthcare systems need to take full advantage of new opportunities offered by technical advancements in ICT. The RADIO project explores a novel approach to user acceptance and unobtrusiveness: an integrated smart home/assistant robot system where health monitoring equipment is an obvious and accepted part of the user’s daily life. By using the smart home/assistant robot as sensing equipment for health monitoring, we mask the functionality of the sensors rather than the sensors themselves. In this manner, sensors do not need to be discrete and distant or masked and cumbersome to install; they do however need to be perceived as a natural component of the smart home/assistant robot functionalities.
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Wireless sensor networks (WSNs) comprise a cornerstone to state-of-the-art and future CyberPhysical systems. Respective networking domain is characterized by a drastically different communication paradigm compared to typical wireless... more
Wireless sensor networks (WSNs) comprise a cornerstone to state-of-the-art and future CyberPhysical systems. Respective networking domain is characterized by a drastically different communication paradigm compared to typical wireless networks offering flexible, dynamically adaptive, low power yet reliable and robust data exchange capabilities. In that context accurate, reliable, and time constrained event detection represents one of the important tasks of a WSN so as to be actually useful and reliable. Therefore in this chapter a comprehensive taxonomy and analysis is attempted of adequate event detection techniques ranging from simple threshold-based to highly sophisticated AI-based approaches specifically targeting WSN networks and CPS applications.
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Research Interests: Computer Science, Distributed Computing, Multimedia, Congestion Control, Traffic control, and 15 moreMobile Ad Hoc Network, Computer Network, Wireless Network, Ad Hoc Networks, Low Power, Network Performance, Ad hoc network, Vehicular ad hoc network, Cross layer, Mobile Network, Cross Layer Design, Network Simulator, Electrical And Electronic Engineering, Wireless Ad Hoc Network, and network congestion
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The growing global epidemic of coronavirus, as well as the shortage in health care professionals, impose protection measures to be taken by citizens themselves. One of these measures is social distancing. In an autonomous and assisted... more
The growing global epidemic of coronavirus, as well as the shortage in health care professionals, impose protection measures to be taken by citizens themselves. One of these measures is social distancing. In an autonomous and assisted living environment a set of technologies can offer protection to the tenants by monitoring the individuals’ distance between them. This paper proposes to leverage the social distancing application in Ambient assisted living environments, following the precautions proposed by the experts against Covid-19. The evaluation results were quite impressive and a high accuracy was achieved as the difference between application’s and real world measurements was up to 5%.
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In this work, an IoT system with edge computing capability is proposed facilitating postoperative surveillance of patients who have undergone knee surgery. The main objective is to reliably identify whether a set of orthopedic... more
In this work, an IoT system with edge computing capability is proposed facilitating postoperative surveillance of patients who have undergone knee surgery. The main objective is to reliably identify whether a set of orthopedic rehabilitation exercises are executed correctly, which is critical since, it is often necessary to supervise patients during the rehabilitation period so as to avoid injuries or long recovery periods. The proposed system leverages Internet of Things (IoT) paradigm, in combination with Deep Learning and Edge Computing to classify the extend-flex movement of one’s knee via embedded Machine Learning (ML) classification algorithms. The contribution of the proposed work is multilayered. Furthermore as an outcome of this work a dataset of labeled knee movements is freely available on https://www.kaggle.com/datasets/billskarm/knee-range-of-motion to the research community. It also provides real time movement detection with an accuracy reaching 100%, which is achieved...
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A morphological feature estimation method is presented, that can be used to monitor fish from low contrast underwater images and videos. The fish orientation is classified in order to apply a shape alignment technique that is based on the... more
A morphological feature estimation method is presented, that can be used to monitor fish from low contrast underwater images and videos. The fish orientation is classified in order to apply a shape alignment technique that is based on the Ensemble of Regression Trees machine learning method. Shape alignment allows the estimation of fish dimensions (length, height, mass) and the location of fish body parts of particular interest such as the eyes and gills. The developed system can be exploited both for fish monitoring in open sea as well as aquacultures where non-invasive, low cost morphological feature extraction is essential. Fish health can be assessed from malformations in body shape, the color of the eyes or the gills as well as the fish behavior. The proposed method can estimate the position of 18 landmarks with an accuracy of about 95% from low resolution and low contrast underwater images where the fish can be hardly distinguished from its background. Hardware acceleration ca...
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This paper introduces a Quaternion-based rotational representation of low power, low resource, commercial-of-the-shelf (COTS) IMU sensors, offering high accuracy, reliability and real time performance. A critical aspect of this work is... more
This paper introduces a Quaternion-based rotational representation of low power, low resource, commercial-of-the-shelf (COTS) IMU sensors, offering high accuracy, reliability and real time performance. A critical aspect of this work is the distributed implementation of the proposed solution that facilitates its integration with IoT platforms utilizing the MQTT communication protocol while efficiently applying a modified Madgwick’s filter implementation to extract the sensor’s orientation and rotation. Based on the proposed solution, sensor orientation outperforms conventional implementations based on previously widely applied methods like Euler Angles and effectively tackles important shortcomings such as a sluggish response and issues like Gimbal Lock. Comprehensive, experimental evaluation reveals that the proposed solution yields state-of-the-art accuracy, while being deployed on a typical, low-cost COTS sensor while delay measurements indicate a highly reliable and time constrained performance adequate for a wide range of real life scenarios.
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The shortage in health care professionals is expected to create demands for Ambient Assisted Living (AAL) technology that helps to prolong independent living of individuals facing various challenges (e.g., the elderly, people with various... more
The shortage in health care professionals is expected to create demands for Ambient Assisted Living (AAL) technology that helps to prolong independent living of individuals facing various challenges (e.g., the elderly, people with various disabilities, etc.). It will allow health care professionals to remotely monitor and support these individuals more efficiently. Our proposal is to leverage Ambient Intelligence in AAL environments, by exploiting all the recent advances in AI/ML.
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The main goal of this paper is to develop an integrated general-purpose simulator for the Profibus MAC layer protocol in order to evaluate the steady-state behavior of this protocol, under a variety of possible operational conditions in a... more
The main goal of this paper is to develop an integrated general-purpose simulator for the Profibus MAC layer protocol in order to evaluate the steady-state behavior of this protocol, under a variety of possible operational conditions in a faulty communication channel. This protocol is part of the Profibus-DP system used widely as a standard and popular industrial communication system. This work examines deeply the performance of the protocol taking into account all critical system parameters and focusing on the main control (token/polling) and data communication (request/response) transactions. Using this simulator it can be shown how the data packet transfers, as well as the control packet transactions are strongly affected by the channel faults, especially for complex and expanded network topologies. However, under certain operational conditions the network performance can be acceptable.
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A personal assistance, is a software component offering advanced Human Machine Interface (HMI) features by initiating and making a "conversations" between humans and machines. Its main objective is to identify the sentences and... more
A personal assistance, is a software component offering advanced Human Machine Interface (HMI) features by initiating and making a "conversations" between humans and machines. Its main objective is to identify the sentences and the context from human’s question and respectively give an adequate response to the question posed. The proper response is given after analyzing the words of the question with those registered in its database. This type of application is called a personal assistant - chatbot. In this work, such an application is presented where it can be installed in any smart home as well as assisted living environment. Through the application, all automations, as well as the home robot also, are controlled by human voice in Greek language. Also, a number of auxiliary applications can be performed in the direction of better human service.
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This paper aims to provide comparative performance evaluation of various available TCP algorithms over a hybrid local area network comprising by, both wired and wireless sections. Although TCP originally was designed aiming to control... more
This paper aims to provide comparative performance evaluation of various available TCP algorithms over a hybrid local area network comprising by, both wired and wireless sections. Although TCP originally was designed aiming to control internet traffic, LAN networks increasingly depend on new TCP protocol versions to provide congestion control, fairness and optimum resource utilization. Additionally wireless LANs' popularity increase exponentially. Based on the aforementioned observations, the objective of this paper is two-fold. Firstly, to present an adequate test-bed enabling, through a significant number of experiments, an accurate performance evaluation of five different TCP versions available by a typical Linux distribution. Secondly based on the conclusions extracted, propose efficient, yet low complexity modifications, able to improve network performance of the considered scenarios.
Research Interests: Computer Science, Congestion Control, Topology, Performance Evaluation, Computer Network, and 13 moreProtocols, Throughput, Network Performance, Wireless Lan, Network Topology, Transport Layer, Local Area Network, Bandwidth, Resource Utilization, Admission Control, Test Bed, Internet traffic, and Low Complexity
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Mobile applications that can be used for the training and classification of plant diseases are described in this paper. Professional agronomists can select the species and their diseases that are supported by the developed tool and follow... more
Mobile applications that can be used for the training and classification of plant diseases are described in this paper. Professional agronomists can select the species and their diseases that are supported by the developed tool and follow an automatic training procedure using a small number of indicative photographs. The employed classification method is based on features that represent distinct aspects of the sick plant such as, for example, the color level distribution in the regions of interest. These features are extracted from photographs that display a plant part such as a leaf or a fruit. Multiple reference ranges are determined for each feature during training. When a new photograph is analyzed, its feature values are compared with the reference ranges, and different grades are assigned depending on whether a feature value falls within a range or not. The new photograph is classified as the disease with the highest grade. Ten tomato diseases are used as a case study, and the...
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Accurate and reliable door detection comprise a critical cornerstone for nowadays robots aiming to offer advanced features and services. At the same time, the range of robotic platforms for indoor scenarios is continuously expanding,... more
Accurate and reliable door detection comprise a critical cornerstone for nowadays robots aiming to offer advanced features and services. At the same time, the range of robotic platforms for indoor scenarios is continuously expanding, emphasizing on the use of low cost, versatile components able to boost widespread use of such solutions. However, respective door detection algorithms have to address specific challenges such as, not relying on specialized expensive sensors, being able to offer robust and accurate operation based on commodity cameras as well as efficient execution on low resource embedded systems. Driven by aforementioned observations in this paper the design and development of a practical and reliable door detection methodology is presented based solely on typical off the shelf web-camera, while posing minimum requirements on the height or angle it is mounted. Furthermore, a critical contribution of this paper is the experimental evaluation of the developed algorithm o...
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Home Automation Systems comprises a rapidly evolving research domain as well as a commercial filed. This is due to, on one hand, the increasing demands for Ambient Assisted Living environment, 24/7 monitoring and security, comfort... more
Home Automation Systems comprises a rapidly evolving research domain as well as a commercial filed. This is due to, on one hand, the increasing demands for Ambient Assisted Living environment, 24/7 monitoring and security, comfort control, power management and many application scenarios. On the other hand, respective solutions are required to address present and pressing real life problems so the industrial domain is actively pushing towards efficient and reliable solutions in real deployments. The two cornerstone technologies adopted in proposed future Home Automation designs are Internet of Things reliable communication infrastructure and Robotic technologies, which enhance drastically the capabilities of the overall platform. In that respect this paper presents a complete design effort efficiently combining the two aforementioned pillars. Additionally, relative development activities will be presented highlighting the offered advantages, capabilities and features.
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Complete end-to-end security support in the context of a complex CPS system in context of sensitive medical applications goes beyond pure technical countermeasures, hardware and techniques. Especially since highly sensitive medical data... more
Complete end-to-end security support in the context of a complex CPS system in context of sensitive medical applications goes beyond pure technical countermeasures, hardware and techniques. Especially since highly sensitive medical data will be created, accesses, stored, processes and transferred it is of paramount importance to define accurate and comprehensive data management processes. Critical objectives achieved from accurate and comprehensive data management processes definition include:
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Efficient residential load power management represents, on one hand, a cornerstone towards Smart City Grids while, on the other hand a multifaceted challenge. The identified interplay between multiple parameters concerning both power... more
Efficient residential load power management represents, on one hand, a cornerstone towards Smart City Grids while, on the other hand a multifaceted challenge. The identified interplay between multiple parameters concerning both power consumption as well as generation, call for novel design approaches such as Fuzzy Logic, machine learning and AI regarding respective algorithms. Furthermore, aiming to propose highly reliable and practical solutions, respective implementations much be undertaken and evaluated in the context of real-world prominent communication and power control infrastructures. Driven, by such observations this paper presents a complete, efficient and feasible proposal able to tackle respective requirements. Specifically, a comprehensive multimodal Fuzzy Logic Inference (FIS) design is proposed able to incorporate heterogeneous factors pertaining both to residential power consumption and generation. Additionally, proposed designed is implemented in the context of a fully functional KNX based infrastructure monitoring and controlling power consumption of a real residence. Respective performance evaluation, firstly, serve as FIS implementation validation indicating convergence between Matlab based and KNX based performance. Secondly, it highlights the benefits the end-user can anticipate using such a system. Finally, an estimated projection is attempted based on actual performance results and Europe wide statistics concerning residential power consumption as well as CO2 omissions.
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The EU funded project RADIO brings forward a new health care paradigm according to which a mobile robot platform can act as assistant to an elderly person in his/her domestic environment. Under this context, unobtrusiveness is of... more
The EU funded project RADIO brings forward a new health care paradigm according to which a mobile robot platform can act as assistant to an elderly person in his/her domestic environment. Under this context, unobtrusiveness is of paramount importance since the robot should be a natural participant of patients' daily life. However, robot assistance in everyday living still suffers from limited autonomy dictaded by the robot battery. This paper presents the approach taken in the project in order to reduce, to the extent possible, the usage of the power-hungry processing components. This minimizes the need for revisiting the robot charging station during the day, by using hardware accelerated ultra-low-power monitoring during the periods of inactivity.
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Without Gateways comprise critical cornerstones for a wide range of Cyber Physical Systems (CPS) and IoT application scenarios. In this context, the main objective of this paper is to present a novel Gateway able to effectively address... more
Without Gateways comprise critical cornerstones for a wide range of Cyber Physical Systems (CPS) and IoT application scenarios. In this context, the main objective of this paper is to present a novel Gateway able to effectively address all heterogeneity aspects. Additionally, a critical objective of the proposed Gateway is offering advanced features facilitating the dynamic, run time service management. Aiming to offer a comprehensive solution all important aspects are presented in detail while a real-world evaluation is provided. The latter, is achieved by integrating the implemented solution with a real CPS infrastructure enabling (i) hands on proof of concept concerning heterogeneity support and offered features and (ii) realistic performance evaluation.
In the context of RADIO project, seamless integration of Robotic platform, heterogenous home automation technologies and diverse back infrastructures comprised an integral challenge to the success of the overall endeavor. This observation... more
In the context of RADIO project, seamless integration of Robotic platform, heterogenous home automation technologies and diverse back infrastructures comprised an integral challenge to the success of the overall endeavor. This observation gave the involved partners the chance to explore difference technological and design approaches in order to yield the optimum implementation. At the same time, it highlighted the need to follow a structured, multifaceted approach in order to tackle efficiently all requirements. Based on this process, the main objective of this chapter is to present the most important lessons learned as well as emphasize on the key aspects where enhancements and novel contributions were achieved in RADIO. Therefore, in the first section, after the conceptual communication architecture defined in RADIO is presented, critical communication requirements of the RADIO platform are identified focusing on local area ultra-low power communication technologies deployed in the home premises as well as efficient cloud infrastructure utilized. Then the second section highlights the actual state-of-the-art communication technologies explored, deployed, and integrated in the context of RADIO platform emphasizing on bridging and coexistence critical challenges encountered and addressed. Focusing on the integration problem the RADIO Gateway entity represented one of the most important cornerstones for the overall RADIO platform performance effectively comprising a highly complex compound entity, adequately analyzed in Sect. 5.3. Then in Sect. 5.4 important research activities based on BLE communication technology are presented, enabling, on one hand, accurate indoor localization and, on the other hand, extended coverage area capabilities through multi-hop communication. Finally, Sect. 5.5 presents all development and integration effort devoted by RADIO partners to the backend infrastructure. Although, many times, not highlighted adequately, backend infrastructure is a critical part of the overall architecture since it effectively comprises the bases for key services such as, data storage, data processing, data representation, network management, network configuration, etc.
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Research Interests: Computer Science and IEEE
Cyber-Physical Systems (CPS) comprise a rapidly expanding research domain incorporating various diverse ICT aspects. Consequently, such systems are characterized by high degree of heterogeneity regarding communication, hardware and... more
Cyber-Physical Systems (CPS) comprise a rapidly expanding research domain incorporating various diverse ICT aspects. Consequently, such systems are characterized by high degree of heterogeneity regarding communication, hardware and software technologies. Additionally, a high number of challenges must be tackled before such horizontal architectures can yield useful services, that can be exploited by todays and future consumer electronics and respective vertical domains. Aiming to address such objectives, this paper proposes a holistic end-to-end CPS architecture based on message passing communication technologies able to support the inherent complexity of respective deployments spanning several areas of applied industrial research and development. In this context, this paper aims to serve as a roadmap on how existing, prominent technologies from different domains can be effectively integrated and address all changes while be applied in diverse application demands. This is achieved by analytically presenting the proposed ATLAS infrastructure emphasizing on integration of prominent consumer electronics technologies. Finally, the deployment of the proposed solution in different verticals is presented, highlighting i) the applicability of the system and ii) a resource conservative behavior advocating the integration with nowadays COTS embedded systems.
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Wireless Sensor Networks (WSN) networks are increasingly utilized in highly demanding scenarios such as medical applications. In such cases hardware designs emerge as a prominent approach to address processing demanding tasks offering... more
Wireless Sensor Networks (WSN) networks are increasingly utilized in highly demanding scenarios such as medical applications. In such cases hardware designs emerge as a prominent approach to address processing demanding tasks offering significant advantages over respective software based solutions. In such cases reconfiguration capabilities enable the achievement of critical trade-off between adequate performance and resource conservation. In this context the main contribution of this paper is the proposal and performance evaluation of a reconfigurable encryption module with respect to the encryption key size aiming towards WSN utilization. Performance will be presented with respect to encryption process delay, reconfiguration delay and power consumption projecting to energy expenditure.
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Connectivity is crucial feature of every network and assuring it, is fundamental for the network operation and efficiency. This work presents a connectivity evaluation algorithm based on graph theory methods, which can be used for... more
Connectivity is crucial feature of every network and assuring it, is fundamental for the network operation and efficiency. This work presents a connectivity evaluation algorithm based on graph theory methods, which can be used for simulation and analysis of the network regarding its connectivity in pre-deployment phase. For each network topology the following metrics can be computed: the number of the network parts, the number of the single critical node and the number of the double critical nodes, i.e., any node or combination of two nodes, which failure partitions the network. In case that the network is partitioned, the number of the isolated nodes, the number of the sub-network parts and the number of nodes belonging to each part are also calculated and enumerated.
Communication comprises the most power consuming operation that a sensor node performs. In this work we present a topology reduction algorithm and perform pre-deployment simulations of a senor network and analyze the initial topology for... more
Communication comprises the most power consuming operation that a sensor node performs. In this work we present a topology reduction algorithm and perform pre-deployment simulations of a senor network and analyze the initial topology for possibility of links reduction. The alternative link-reduced topologies are analyzed and compared against the initial topology regarding the overall number of links in the network, the number of neighbors and the possibility for transmission power reduction. Furthermore, a calculative estimation of the power consumption and respective node lifetime, from a communication perspective, is provided.
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As networks become more and more complicated and applications more and more demanding, a very common network topology for state-of-the-art multimedia applications is a hybrid wired/wireless architecture. The impact of this... more
As networks become more and more complicated and applications more and more demanding, a very common network topology for state-of-the-art multimedia applications is a hybrid wired/wireless architecture. The impact of this topology's particularities, like different throughput and bandwidth or packet format, on the Quality of Service (QoS) demanding nature of multimedia applications, is a growing research field. This paper presents