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This paper discusses the requirements and motivations for setting-up and utilizing two different optical fiber test-beds both of a Telecom Operator as well as the UEssex/JANET Aurora field fiber testbed for optical metro networks research within the EU ICT MAINS project. Using both test-beds the MAINS project aims to evaluate its proposed mesh-ring topologies which feature innovative sub-wavelength...
A novel receiver optimization for spatial multiple access scenario is studied in this paper where each user uses single antenna and multiple antenna array is used at the base station. To achieve space division multiple access, the newly introduced minimum probability of error (MPE) beamforming method is used instead of the conventional minimum mean square error (MMSE) beamforming. To increase the...
Spectrally efficient FDM (SEFDM) systems are new and attractive multicarrier systems that can significantly enhance spectral utilization. However, as a multicarrier system SEFDM is prone to high peak to average power ratio (PAPR). In this work we present for the first time a study of the PAPR in SEFDM systems. We explore the performance of standard PAPR reduction techniques and propose a novel PAPR...
Future networks are becoming larger in scale, more dynamic and heterogeneous, imposing new requirements to the design and provision of advanced services. In order to cope with these requirements, new approaches have to be proposed that are able to handle the changes in the network topology in an autonomic manner and relieve application developers from dealing with network topology volatility. In this...
Cognitive Radio (CR) is an essential technique for the future generation green communication paradigm owing to its inherent advantages of adaptability and cognition. The compulsory spectrum sensing is a critical component to facilitate systems co-existence. In this paper, we propose a new Time-Division Energy Efficient (TDEE) sensing scheme in which the sensing period is divided into an optimal number...
The access to communication technologies has become essential for the handicapped people. This study introduces the initial step of an automatic translation system able to translate visual speech used by deaf individuals to text, or auditory speech. A such a system would enable deaf users to communicate with each other and with normal-hearing people through telephone networks or through Internet by...
Over the last decade, translucent WDM networks have appeared as a promising candidate for next generation core networks. Using sparse regeneration techniques, translucent networks may achieve a pretty tradeoff between the low cost of transparent networks and the quality of transmission guaranteed by fully-opaque networks. On one hand, deploying large-scale transparent networks is still a critical...
Early Retransmission (ER) has already been shown to improve TCP-SACK's performance in delivering time sensitive media. In this paper, we integrate the ER scheme into a delay-based TCP variant, namely TCP-PERT, and performs extensive ns2 simulation. Our results show that ER can also improve PERT's performance in delivering real time media by reducing the latency caused by retransmission timeouts. Furthermore,...
This paper investigates and compares the schemes suggested by the ITU and the IETF for MPLS-TP ring protection, and proposes two MPLS-TP ring protections to ensure reliability of MPLS-TP multicast services. The introduced ring protection schemes are named, the SPME-based-Wrapping protection scheme and the SPME-based-ROM-Wrapping protection scheme, both of which aim at retaining the advantages of previous...
In this paper we propose a user dependent scheme for enhancing security of the transmitted content in the future telecommunication systems. In order to achieve a higher level of security we introduce a scheme where the user identity gets involved in the encryption/decryption processes using an additional component for the block cipher which represents the user's behavioural model. Applying such a...
The Radio Interferometric Positioning System (RIPS) was developed by Maroti et al. for the purpose of node localization in wireless sensor networks. They theorized that RIPS would produce ambiguous measurements when distances between nodes exceeded a carrier wavelength. This paper investigates this effect. In this investigation patterns in these invalid measurements are studied and then explained...
In this paper, we propose novel low-complexity adaptive channel estimation techniques for mobile wireless channels in presence of Rayleigh fading, carrier frequency offsets (CFO) and random channel variations. We show that the selective partial update of the estimated channel tap-weight vector offers a better trade-off between the performance and computational complexity, compared to the full update...
A novel spatial diversity scheme is proposed for physical-layer network coding (PNC) aided two-way relay network with a multiple-antenna relay node. Distinct from the traditional virtual-MIMO based MIMO-NC/PNC schemes, a novel PNC-specific maximal-ratio-combining like (MRC-L) scheme is designed to achieve receive diversity in the multiple-access (MA) phase, and the space-time coding (STC) is adopted...
This paper considers iterative detection of bit-interleaved coded continuous phase modulation in the presence of both phase noise (PN) and additive white Gaussian noise (AWGN). The proposed receiver iterates between a detection module and an estimation module. The detection module operates according to the sum-product algorithm and the factor graph framework in order to perform coherent maximum a...
In this paper, we propose a simplified amplify-and-forward (AF) relaying scheme with adaptive modulation to maximize the spectral efficiency. We derive the closed-form expressions of the average spectral efficiency and outage probability of the proposed scheme over Rayleigh fading channels. The analysis results are verified by using Monte Carlo simulation. The numerical results demonstrate that the...
Household appliances are being equipped with embedded micro-controllers and wireless transceivers, offering smart behavior. These augmented appliances form wireless networks and transform residential areas into smart homes. Advancements such as the effective penetration of the Internet in embedded computing and the promising practice of the Web of Things, allow the realization of Web-oriented smart...
In this paper, a novel signal combining and decision scheme is proposed based on Dempster-Shafer (D-S) evidence theory in multiple antenna system. The focal-element-set (FES) is used to describe the uncertainty for the decision statistics, and the corresponding basic-probability-assignment (BPA) of FES is the likelihood measure, which act as the soft-decisions for the receiver signals. The process...
In this paper, we consider the problem of Minimum-Cost Multicast (MCM) sub-graph optimization with network coding subject to uncertainty in link costs. A number of uncertainty sets such as ellipsoids and bounded polyhedral are taken into account. A robust optimization model is developed to obtain the optimal sub-graph by replacing an uncertain model of MCM by its Robust Counterpart (RC). Then, the...
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