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Software, Telecommunications and Computer Networks, 2007. SoftCOM 2007. 15th International Conference on

Date 27-29 Sept. 2007

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Displaying Results 1 - 25 of 93
  • Technology evolution: Fuzzier boundaries-broader opportunities

    Publication Year: 2007 , Page(s): 1 - 9
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1299 KB) |  | HTML iconHTML  

    Technology evolution in storage, processing, communications, sensors and terminals is making boundaries among IT and telecommunications fuzzier than ever, and at the same time it creates overlap across the industries. Telcos want to become media companies, Computer companies drop the word "computer" from their name, SecondLife mashes onto Google.. These changing boundaries are opening up new opportunities. Can the established companies reposition themselves or are they too busy to compete against each other to perceive that the market is going somewhere else. The presentation aims to stimulate new thinking on what may happen and what role each of us can play. In this talk I would like to share with you some ideas on some classes of technology roadmaps discussing the likely impact on the biz of Telecommunications. View full abstract»

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  • Why we need a reference model for intrusion handling systems for Wireless LANs?

    Publication Year: 2007 , Page(s): 1 - 6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1890 KB) |  | HTML iconHTML  

    WLANs are different from the traditional wired LANs in terms of their exposure to potential threats, vulnerability and security techniques. Intrusions to WLANs are facts of the everyday life and handling them becomes more and more difficult. Currently there is no standardised reference model which may help to design, compare and evaluate the existing or future Intrusion Handling Systems (IHSs1) for WLANs. Analysis of the commercial IHSs shows that they all are built as a proprietary systems which are neither taking into consideration existence of other IHSs nor they are trying to find the ways to establish inter-IHS collaboration which may help to achieve better security for the end-users. Hence this paper starts by an analysis of the features of existing IHSs for WLANs, followed by proposing the new ways to enhance their design, and then discussion of development of such a novel reference model for a scalable distributed IHS architecture. View full abstract»

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  • Performance of multisink geographic routing with different distance metrics

    Publication Year: 2007 , Page(s): 1 - 5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (305 KB) |  | HTML iconHTML  

    In this work we propose a data dissemination protocol for multisink wireless sensor networks, based on a colored area concept related to the nodes coverage area and on geographic multiple sinks locations. We investigate how the inter-nodes distance definition could affect the protocol performance; in particular we introduce two distance metrics (the classic Euclidean and a metric that takes into account the nodes radio signal coverage) and we show how these ones can foresee different number of transmissions required to perform a task; this could results in different routing path selections and different energy consumption expectations. We show how to obtain an energy gain around the 7% thanks to the radio coverage based metric with respect to the classic Euclidean one. View full abstract»

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  • Ethernet: The future network access technology

    Publication Year: 2007 , Page(s): 1 - 5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (188 KB) |  | HTML iconHTML  

    The telecommunication industry has been through disruptive times, but data networking service revenue has continued to rise. Services such as frame relay (FR), asynchronous transfer mode (ATM) and IP virtual private networks (IP VPN) are growing in terms of use and revenues and the signs are that the legacy layer 2 services are growing, and part of the reason for this is the emergence of a strong Ethernet alternative. This paper will focus on the standards of 10 gigabit Ethernet (10GbE) along with its advantages, applications, potential cost savings as well as the uses and benefits of 10GbE in extending the range and capabilities of local area networks (LANs), Metropolitan area networks (MANs) and wide area networks (WANs). It will also take a brief look at Ethernet's past, and it will look to the future of Ethernet with a brief overview of 40 Gigabit Ethernet and the reasons why it will be the next logical step in Ethernet's life cycle. View full abstract»

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  • Transparent TCP improvement over satellite links

    Publication Year: 2007 , Page(s): 1 - 5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (834 KB) |  | HTML iconHTML  

    Since satellite channel can be used as a part of an heterogeneous network, researchers attention is focused on the optimization of the use of that resource. Unfortunately, protocols studied for wired traditional network, and widely used for Internet services, performs very poorly on this transmission medium, in particular the TCP. In the last years a lot of works have been published about this topic, but up to now there is not a standardized solution able to solve all the problems created to heterogeneous networks by satellite links. In this paper we present a possible solution to the problem of TCP data transmission over satellite links that have as characteristics easy implementation and compatibility to existent standard and protocols. We implemented our solution and tested it on a emulated heterogeneous network scenario and on a real satellite link, and we demonstrate how, adding a very simple mechanism of selective repeat combined to an additional congestion control, the TCP performances over a satellite channel are improved. View full abstract»

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  • Energy-aware, delay-constrained routing in wireless sensor networks through genetic algorithm

    Publication Year: 2007 , Page(s): 1 - 5
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1017 KB) |  | HTML iconHTML  

    In this paper, we propose an energy-aware QoS routing protocol for wireless sensor networks. The protocol finds energy-efficient paths for delay-constrained data in realtime traffic. The described QoS routing problem is very similar to typical path constrained path optimization (PCPO) problems, which are proved to be NP-complete. Hence we present a heuristic solution for the aforesaid problem. We use a genetic algorithm (GA) to create energy efficient QoS routing. Our algorithm generates a sequence of routing paths that maximizes the system lifetime.Network lifetime can be defined as the time it takes for the first node or a fraction of all the nodes in the network to be depleted of their energies, we want to maximize network lifetime, instead of the average time over all scenarios. Simulation results have demonstrated the effectiveness of our approach for different metrics. View full abstract»

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  • Adaptive parallel interference cancellation for uplink MC-CDMA in Rayleigh fading channels

    Publication Year: 2007 , Page(s): 1 - 5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (201 KB) |  | HTML iconHTML  

    In this paper, an adaptive parallel interference cancellation (PIC) receiver is introduced for asynchronous multicarrier code division multiple access based (MC-CDMA) communications systems. The multiple access interference (MAI) estimates are obtained using the bit estimates from the previous stage and the adaptive weights for the bit estimates. The adaptive weights are updated by minimizing the mean squared error between the received signal and its estimate based on the adaptation of the normalized least mean square (LMS) algorithm. The results from the simulations show that the performance of conventional PIC (CPIC) and adaptive PIC (APIC) can be different depending on the combining schemes used. View full abstract»

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  • Technical method for service quality measurement and user’s service usage collection in wireless broadband data service

    Publication Year: 2007 , Page(s): 1 - 5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (383 KB) |  | HTML iconHTML  

    In this study, the relationship between network access quality and RF quality parameter in the wireless networks which have different characteristics from wired networks when the dedicated terminals being connected to the high speed wireless data networks (in other words, broadband wireless access service networks) such as CDMA IX EV-DO, WCDMA (HSDPA), or Mobile WiMax (WiBro) is analyzed. Also, this study proves that the analysis in connection with the users' service usage patterns is available. This was possible by constructing and operating the broadband wireless access service Monitoring System (BWA Monitoring System) that collects user data in connection with the CM (Connection Manager) program of the respective terminal. And, analysis regarding the users' network usage patterns was possible which could be utilized as reference in creating new business models; furthermore, the study shows that the SLA (Service Level Agreement) in the wireless network sector can be proved. View full abstract»

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  • Quantifying the quality of service of streaming media in differentiated services networks

    Publication Year: 2007 , Page(s): 1 - 5
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (148 KB) |  | HTML iconHTML  

    Quality of service (QoS) support in the current Internet is indispensable because of QoS-sensitive real-time applications such as voice-over-IP, IP-TV, video conferencing, online gaining etc. Since the introduction of the differentiated services (Diff-Serv) architecture there has been considerable work reported in literature on its performance evaluation. However, none of them have addressed the basic issue of quantification of QoS for supporting streaming media. The main contribution in this paper is the quantification of the QoS of streaming media in terms of mean opinion score (MOS) values. A test bed has been implemented using off-the-shelf components. The experimental results and MOS values are used to show that in a DiffServ assured forwarding network architecture, with class based weighted fair queue scheduling discipline, the QoS of streaming media is not compromised when the load exceeds the reserved capacity, even in case of congestion. View full abstract»

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  • From ‘Quality-of-Service’ and ‘Quality-of-Design’ to ‘Quality-of-Experience’: A holistic view on future interactive telecommunication services

    Publication Year: 2007 , Page(s): 1 - 6
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (540 KB) |  | HTML iconHTML  

    Telecommunications research can no longer be considered to be pure communications engineering. The convergence of fixed-line and mobile telephony with the Internet together with the rise of novel technologies for rapid service creation has made economic efficiency and user acceptance/usability to crucial factors for the success of the telecommunication business as such. In the emerging new paradigm, a holistic view onto the entire value chain from basic architectural concepts over the efficient design and implementation of new services and applications up to the end customer is becoming indispensable. Within this broad interdisciplinary field, the present paper focuses on the evolution of corresponding concepts for service quality. Whereas the traditional notion of 'QoS' (Quality-of-Service) is already well-established and has led to a plethora of research work mainly in the area of network architectures and protocols, the quality of service design ('QoD') has by far not received comparable attention in the research community. Nevertheless, we argue that both concepts are equally important for achieving a sufficient quality of user experience ('QoE') which eventually leads to both economic viability and user satisfaction. To illustrate our claim, we discuss recent developments in the area of QoS-enabled next generation network architectures as well as novel user-centric service design paradigms, examples for the resulting QoE evaluations and a novel HCI lab approach which allows flexible user tests of mobile applications "in the wild". View full abstract»

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  • Wireless pre-paid Phone cards distributing system based on SMS

    Publication Year: 2007 , Page(s): 1 - 4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (172 KB) |  | HTML iconHTML  

    There are so many kinds of pre-paid phone cards from several telecom service providers. But how to distribute them in a safe, prompt, and cheap manner seems to be a challenge. This paper proposes a wireless distributing system based on SMS (short message service) which consists of a database centered Server and several mobile hand-held terminals. The Server's structural scheme and the data consistency problems confronted and their solutions are discussed. The terminal which is manipulated by an embedded system provides a convenient User Interface to the agents and it communicates with the Server through SMS in an interlocked protocol. To reduce the data redundancy in the transmission, an encoding algorithm is presented, and 8 pre-paid phone cards could be sent in one Short Message. View full abstract»

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  • Modeling of energy efficient wireless communication

    Publication Year: 2007 , Page(s): 1 - 5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (96 KB) |  | HTML iconHTML  

    Energy efficiency of wireless communication technologies is a crucial aspect in order to ensure a widespread use. To increase the efficiency, intelligent protocols (on different layers w.r.t. the OSI architecture) determine when, where and how data has to be transmitted, i.e. they set such parameters like packet size or field strength of the sending antenna. We defined a ubiquitous energy model and conducted simulations to facilitate the development of smart sending strategies and thus enhance the practicability of wireless solutions in surroundings where energy is scarce. View full abstract»

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  • Efficiency of the gossip algorithm for wireless sensor networks

    Publication Year: 2007 , Page(s): 1 - 5
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (201 KB) |  | HTML iconHTML  

    Gossip is a well-known technique for distributed computing in an arbitrarily connected network of nodes. The gossip algorithm, which is very simple to implement, takes into account strong limitations in computational, communication and energy resources that usually characterize nodes in sensor networks. In gossip, the computational burden is distributed among the nodes, and computation and communication are managed in a very quick and efficient way: in essence, each node acquires its own measure and, starting from it, exchanges information with its neighbors, according with a connection probability distribution. In this paper, we study the performance of gossip algorithms, aiming to test the agreement between analytical results on the averaging time and the actual convergence time for specific scenarios, estimated through numerical simulations. Furthermore, we apply an optimization technique, recently appeared in the literature, that theoretically allow to accelerate convergence. Numerical simulations permit to assess the effects of optimization in real cases, thus evaluating the actual improvement in performance it achieves. View full abstract»

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  • An integrated Ambient Networks prototype

    Publication Year: 2007 , Page(s): 1 - 5
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (269 KB) |  | HTML iconHTML  

    Ambient networks (AN) project focuses on the convergence of heterogeneous networks over different domains. The aim (among others) is to facilitate co-operation, mobility support and multi-access between networks and terminals. One of the most important goals is to integrate the different AN-concepts together for validation. This paper presents an integrated prototype as proof-of-concepts, which can be used for demonstration purposes. In particular the prototype has integrated host identity protocol (HlP)-based mobility, HIP network mobility, simultaneous multi-access (SIMA) policies, generic link layer (GLL), mobility triggering (TRG) and basic composition concepts within the Ambient Control Space framework. View full abstract»

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  • Securing the Madeira network management system

    Publication Year: 2007 , Page(s): 1 - 5
    Cited by:  Papers (1)  |  Patents (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (308 KB) |  | HTML iconHTML  

    In the research project Madeira a meshed network management system based on P2P technologies was developed. Event though, up to date, security has always been neglected in this field of research despite the sensitivity of such systems and the high number of security threats that affect them, Madeira incorporates a security solution aimed at minimizing the identified highest-priority risks on all levels. This solution introduces a distributed certification authority based on threshold cryptography, certificate revocation list distribution points and a collaborative accusation protocol aimed at uncovering hosts that exhibit illegal or unwanted behaviour while avoiding false accusations from a malicious node. View full abstract»

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  • Performance Analysis of Adaptive Decision Feedback Turbo Equalization (ADFTE) using Recursive Least Square (RLS) algorithm

    Publication Year: 2007 , Page(s): 1 - 5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (302 KB) |  | HTML iconHTML  

    Iterative equalization using optimal Multi-User Detector (MUD) & trellis-based channel decoder in coded Code Division Multiple Access (CDMA) systems improves Bit Error Rate (BER) performance. When large number of users is employed in the system over multipath channels, causing significant Multiple-Access Interference (MAI) & Inter Symbol Interference (ISI), the optimal MUD is thus complex. Therefore, the sub-optimal detectors such as low-complexity linear & nonlinear equalizers have to be considered. In this paper, Recursive Least Square (RLS) adaptation algorithm for Adaptive Decision Feedback Equalizer (ADFE) is proposed. Along with the application of the adaptive method to the DFE-RLS equalizer, Turbo-principle can easily be applied. Based on the conventional DFE, a new method is developed by computing the reliable extrinsic Log-Likelihood Ratio (LLR). At each iteration, the estimated symbol by the equalizer is then saved as a priori information for next iteration. Simulation results demonstrate that proposed DFE-RLS algorithm & turbo decoding, offers performance gain improvement of 0.7dB over DFE-LMS. View full abstract»

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  • Accuracy of random walk and Markovian mobility models in location prediction methods

    Publication Year: 2007 , Page(s): 1 - 5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (513 KB) |  | HTML iconHTML  

    Recent wireless networks offer more bandwidth than ever. High quality services are developed and provided by the operators, the number of users is constantly increasing. As the transferred data and the number of terminals are growing, the network providers have to face the increasing complexity of the network management and operation tasks. In this paper we observe the estimation and prediction of users' distribution in a cellular network. We compare the accuracy of mobility models serving for location prediction with our enhanced user motion prediction algorithm. View full abstract»

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  • MAP selection algorithms based on future movement prediction capability

    Publication Year: 2007 , Page(s): 1 - 5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (168 KB) |  | HTML iconHTML  

    Efficient mobility management involves micro-mobility principles. The performance of a representative micro-mobility approach, hierarchical mobile IPv6 (HMIPv6) protocol, is affected by the manner of mobility anchor point (MAP) selection. In this paper, we propose a new method, based on prediction of the future movement of mobile nodes (MNs). Exploiting the information about the future availability of MAPs, the proposed algorithms choose those MAPs that assure a better service. By means of simulations, we compare the proposed solution to other algorithms. The results show promising improvement in terms of average distance from chosen MAPs and average number of MAP changes. Moreover, we showed that, for perceivable improvement of MAP selection, absolute accuracy of movement prediction is not required. View full abstract»

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  • Cross-layer analysis of TCP performance in a 4G system

    Publication Year: 2007 , Page(s): 1 - 6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (103 KB) |  | HTML iconHTML  

    This paper presents results from an experimental study of TCP in a wireless 4G evaluation system. Test-bed results on transport layer performance are presented and analyzed in relation to several link layer aspects. The aspects investigated are the impact of channel prediction errors, channel scheduling, delay, and adaptive modulation switch level, on TCP performance. The paper contributes a cross-layer analysis of the interaction between symbol modulation levels, different scheduling strategies, channel prediction errors and the resulting frame retransmissions effect on TCP. The paper also shows that highly persistent ARQ with fast link retransmissions do not interact negatively with the TCP retransmission timer even for short round trip delays. View full abstract»

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  • Routing intrusions on mobile ad hoc networks: Test bed and vulnerability analysis

    Publication Year: 2007 , Page(s): 1 - 5
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1270 KB) |  | HTML iconHTML  

    This paper reports the experimental results of the analysis of routing intrusions and vulnerabilities in wireless ad hoc networks. A mobile ad hoc network test bed has been implemented, and a set of routing intrusions has been launched on the test bed. For each intrusion, its description, identification of the vulnerabilities that enable an adversary to launch this intrusion, and experimental analysis of the tests performed for this intrusion and observations thereof are given. View full abstract»

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  • Technical capability of the radio access technology 1xEV-DO

    Publication Year: 2007 , Page(s): 1 - 4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (226 KB) |  | HTML iconHTML  

    The performance of a mobile network is essentially based on the capability of its radio access technology. This paper presents technical capabilities of the emerging radio access technology 1xEV-DO. Such capabilities are expressed in terms of throughputs, and are based on realistic radio and geographical parameters, as well as realistic traffic models. Simulation results enable to evaluate how environment conditions affect the throughput offered by 1xEV-DO. View full abstract»

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  • Continuous wavelet transform application in electromagnetic compatibility - algorithms and software realization

    Publication Year: 2007 , Page(s): 1 - 4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (467 KB) |  | HTML iconHTML  

    In this paper, a novel approach to detect electromagnetic interference from electronic equipment by means of continuous wavelet transform is presented. The algorithms of the proposed approach are given together with the software solutions. A case study is made to verify the effectiveness and correctness of this proposed approach and a "Workspace" concept is presented to interface analyzed data with the equipment under test, making the proposed solutions more feasible. View full abstract»

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  • Solving the frequency assignment problem with differential evolution

    Publication Year: 2007 , Page(s): 1 - 5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (246 KB) |  | HTML iconHTML  

    In this paper it is presented and researched the possibility of using the differential evolution (DE) algorithm to solve the frequency assignment problem (FAP). This problem involves a free assignment of a number of available frequencies to a set of requesters, subject to a set of specified constraints given by an interference matrix. Hence, it is a very important problem in the telecommunications area (especially in GSM networks -global system for mobile). In this work, by the first time, the performance of DE is evaluated using for the results seven well-known benchmark problems on the MS-FAP (minimum span frequency assignment problem). Furthermore, we also compare the influence of each configuration parameter of the DE, presenting the most important conclusions. View full abstract»

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  • SAR simulation of a mobile phone in a hand-held position

    Publication Year: 2007 , Page(s): 1 - 5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (913 KB) |  | HTML iconHTML  

    SEMCAD is an electromagnetic simulation platform based on the finite difference time domain method, FDTD, with an especial feature of calculating specific absorption rate, SAR. SAR is a value corresponding to the power absorbed by the human tissue while exposed to microwave radiation. For antenna designers and cellular phone companies, this value is limited and consequently it is an important parameter in the antenna design process. View full abstract»

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  • High frequency electromagnetic analysis of horizontal grounding conductor and near-by passive parallel conductor within two-layer soil

    Publication Year: 2007 , Page(s): 1 - 5
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (385 KB) |  | HTML iconHTML  

    This paper presents the ongoing research results of the high frequency grounding system analysis in two-layer soil structure. On the basis of rigorous electromagnetic field theory, which involves Sommerfeld's integrals, the mathematical model is formulated by the mixed potential integral equation (MPIE). Detailed analysis of a high frequency performance of a typical horizontal grounding conductor placed in the upper or in the bottom layer is given. It is shown that because of the presence of two distinct layers the current distribution and the impedance to ground are highly affected by the parameters of both soil layers. Also, the current distribution in near-by passive horizontal conductor is analyzed. At the end of the paper some observations about the effects of two-layer soil structure at high frequencies are given. View full abstract»

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