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High Capacity Optical Networks and Enabling Technologies (HONET), 2012 9th International Conference on

Date 12-14 Dec. 2012

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Displaying Results 1 - 25 of 55
  • Welcome

    Page(s): 1 - 8
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  • Committees

    Page(s): 9 - 10
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  • [Copyright notice]

    Page(s): 11
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  • Authors index

    Page(s): 12
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  • Table of contents

    Page(s): 13 - 15
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  • Mobile user connectivity performance with coexisting femtocell networks

    Page(s): 016 - 020
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1588 KB) |  | HTML iconHTML  

    In Femto-Macro cellular networks, the femto user (FUE) can be connected to femto access point (FAP) with low communication range rather than higher communication range to macro base station (MBS). Furthermore, in such emerging networks, the spatial reuse of resources is permissible and the transmission range can be decreased, then the probability of connectivity is high. In this work, we propose an analytical model for mobile user connectivity probability in Femto-Macro cellular networks. On the other hand, we study the capability of femtocell networks to serve macro users (MUEs) at the boundary of macrocell i.e., no coverage or poor signal as well as to serve the users fully inside the femtocell i.e., reduce the communication load of macrocell. Numerical results demonstrate the efficiency of computing the connectivity probability in Femto-Macro cellular networks. View full abstract»

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  • Adaptive fair radio interface scheduling for LTE networks

    Page(s): 021 - 026
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (799 KB) |  | HTML iconHTML  

    The goal of advanced radio resource management procedures in 4G Long Term Evolution (LTE) is to increase the spectral efficiency beyond an ever achieved level. This objective, however, should be realized by considering an optimal trade-off between system performance and fairness among the users. This work proposes an adaptive packet scheduling mechanism which provides higher spectral efficiency during the times of high system load and a better fairness when enough radio resources are available. The proposed scheme dynamically switches between the well-known Proportional Fair and Blind Equal Throughput scheduling schemes based on the congestion level at the radio interface. Moreover, this work also provides a sophisticated mechanism to estimate the radio interface congestion level to assist the operations of the proposed Adaptive Fair scheduling scheme. The proof of concept is provided with the help of simulation results where the performance of the proposed scheme is evaluated at different radio interface congestion levels. View full abstract»

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  • Investigation of chromatic dispersion effect on 802.16 WiMax over long haul transmission distances

    Page(s): 027 - 031
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    We present a novel FTTH based access network architecture that integrates the wireless and wired services in a converged provision with dynamic bandwidth allocation. A wide range of interactive multimedia services are available to end-users by using latest-generation, OFDM based wireless technologies. Direct VCSEL modulation with 16QAM and 64QAM OFDM based WiMax signal (3.5 GHz) was modeled by using VPItransmissionMaker for upstream transmission by investigating the error vector magnitudes (EVMs). WiMax over standard single mode fibre (SSMF) is first examined and maximum limit stated in current standard of IEEE 802.16 WiMAX using 16QAM (EVM of -24.43 dB) and 64QAM (EVM of -30.4 dB) are achieved at 110km and 95 km respectively. For the second part of the analysis, dispersion compensating fiber (DCF) is deployed in order to achieve long haul transmission distances. A maximum achievable distance of 600km and 450km was realized with -27.6 dB EVM results after dispersion compensation technique applied to both 16QAM and 64QAM OFDM based WiMax respectively. View full abstract»

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  • Adapting statistical multi-hop wireless broadcast protocol decision thresholds using rate control

    Page(s): 032 - 036
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (765 KB) |  | HTML iconHTML  

    Multi-hop wireless broadcast is an important component of Vehicular Ad-hoc Network (VA NET) data dissemination applications. Protocols that address multi-hop broadcast must perform well across a broad spectrum of network conditions while being resilient to the rapidly changing network topology of moving vehicles. We propose the Rate-Adaptive Broadcast (RAB) protocol to address this problem. RAB is tailored specifically for information dissemination in VANETs. It is based on the simple distance-method scheme, requires no knowledge of network topology, and yet is adaptive to network conditions. By assuming a VA NET dissemination application with fixed periodic updates, RAB is able to use a novel decision threshold control algorithm based on the rate of incoming messages. It tracks both the rate of received new messages and duplicate messages. If the new message rate dips below its long-run average, the decision threshold is adjusted to improve message propagation. While the new message rate is stable, RAB adjusts the decision threshold to keep the duplicate message rate in an efficient range. Thus RAB jointly optimizes the broadcast message delivery rate and the bandwidth consumption. RAB is evaluated in a realistic vehicular networking simulation using JiST/SWANS and unlike similar protocols that require no overhead messaging, is shown to achieve a high reachability level across a wide range of networking scenarios while maintaining efficient bandwidth consumption. View full abstract»

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  • Analysis of beaconing message rate in VANET multi-hop broadcast protocols

    Page(s): 037 - 041
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1297 KB) |  | HTML iconHTML  

    Multi-hop wireless broadcast is a critical component in Vehicular Ad-hoc Networks (VANET). Many VA NET applications, such as traffic data dissemination, utilize broadcast as a primary mode of communication. Thus creating efficient broadcast schemes is important for supporting practical VANETs. Multi-hop broadcast protocols are generally composed of two components: a rebroadcast algorithm and a beaconing scheme. Beaconing allows nodes to discover topology and exchange neighborhood information with nearby nodes. Rebroadcast algorithms often depend on this information to make retransmit decisions that determine the performance of the protocol. Thus the beaconing scheme plays a key role in the performance of the overall broadcast system. In this paper, we evaluate different types of broadcast protocols to determine beaconing rates required to support them. We test a statistical protocol, DAD, a self-pruning topological protocol, SBA, and a dominant-pruning topological protocol, MPR. Simulation results from JiST/SWANS are shown using simulated traffic mobility models for a range of overhead messaging rates. Results show that overhead-messaging requirements can vary widely between broadcast algorithms in VANET, thus highlighting the need to design efficient broadcast methods that are insensitive to rapidly changing topologies for VANET applications. View full abstract»

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  • Biologically-inspired systems: A new direction for large-scale wireless networks

    Page(s): 042 - 046
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (236 KB) |  | HTML iconHTML  

    The current approaches to wireless communication protocols and networking design cannot cope with the scalability and other challenges of future pervasive wireless applications. This fact holds true for protocols currently implemented in networking solutions as well as for protocols proposed in the literature. New solutions are needed to address the scalability, security, fault-tolerance and evolutionary requirements of future and envisioned pervasive wireless applications. Many biological systems in nature are observed to have successfully dealt with the host of challenges mentioned above. Biologically-inspired algorithms are new direction to networking designs that hold ample promises for pervasive applications. In this paper, we present some of these solutions and discuss their application to pervasive networking protocols design. View full abstract»

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  • Fault tolerant aviation data tracker design

    Page(s): 047 - 051
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (480 KB) |  | HTML iconHTML  

    When a plane crash occurs, the black box is lost and teams are dispatched at a considerable cost to find it. In the flight-tracker project, the feasibility of transmitting data to ground servers in real time is investigated. There is a great need for tracking flight data in real-time. There are obvious advantages in finding the data instantly after a plane crash instead of waiting for several days until the black box is found. Earlier, this idea has been highlighted in the literature but no software scheme has been presented for its implementation. The flight tracker project includes a distributed handshaking and data transmission protocol and header formats for communication between plane and ground servers. A set of algorithms is developed to packetize the flight data, transmit it to the ground to an array of servers and integrate the transmitted data to recover the flight information. We hope this work will contribute towards saving human lives and improving the safety and reliability of aircrafts. View full abstract»

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  • Fast decoding of low density parity check codes

    Page(s): 052 - 056
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1425 KB) |  | HTML iconHTML  

    The Layered Belief Propagation L-BP algorithm is is a modified Belief Propagation BP algorithm, where the check nodes are divided in subgroups called layers and each iteration is broken into multiple sub-iterations. In this paper, we consider layered belief propagation decoding and propose an efficient variable node layering for decoding LDPC codes that performs well. We compare the performance of the first introduced LDPC decoding algorithm BP and Layered BP using check node layering with Layered BP using variable node layering in terms of bit error rate (BER). We show that the convergence for decoding LDPC codes is increasing by using a simple and efficient layering strategy. View full abstract»

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  • Covert channel detection: A survey based analysis

    Page(s): 057 - 065
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    Secret communication via network has always been an area of interest for many. It has not only attracted the trusted parties to communicate with each other secretly but has also attracted the hackers/attackers to find ways to discover and leak the information and use the network in a manner that violate security policies. Steganography and covert channels are most widely used approaches for secret communication. Number of detecting techniques has been proposed for steganography and covert channel detection. This paper covers detecting techniques of covert channel only as the covert channel is a modern way of leaking information and it is difficult to detect such channels. Covert channel falls into two categories: storage covert channel and timing covert channel. Storage covert channel is created by manipulating the header fields of packets whereas timing covert channel is created by timing of event i.e. arrival pattern of packets. In this paper different techniques for detecting storage and timing covert has been surveyed and analysis of these techniques is done. View full abstract»

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  • VANET-based privacy preserving scheme for detecting traffic congestion

    Page(s): 066 - 071
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1693 KB) |  | HTML iconHTML  

    We propose a VA NET-based (Vehicular Ad hoc NETwork), privacy-preserving, distributed, collaborative traffic congestion detection and dissemination system that conserves bandwidth and provides drivers with real-time information on traffic congestions over long distances. The system uses vehicles equipped with simple inexpensive devices, as gatherers and distributors of information without the need for costly road infrastructure such as sensors, cameras or external communication equipment. Each vehicle is assumed to be equipped with a Global Positioning System (GPS) device that provides with vehicle's current location, a real-time clock and a wireless communication device such as a two-way radio that allows it to communicate with vehicles nearby. The vehicles broadcast their current location, speed and direction at fixed time intervals. Our simulation results show that our solution addresses location privacy concerns and uses aggregation in the form of congestion sections to reduce bandwidth consumption. View full abstract»

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  • On the use of failure detection and recovery mechanism for network failure

    Page(s): 072 - 076
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (652 KB) |  | HTML iconHTML  

    Future of internet is predicted to be multi-interfaced. Site Multi-homing by IPv6 Intermediation-Shim6 is a proposal presented in IETF to provide multi-homing support in IPv6 based networks. Although initially it was intended for static networks but recently it has been tested to provide end host mobility. Failure detection and recovery in Shim6 is performed through REAchability (REAP) Protocol. This protocol shows significant improvements over MIPv6. Recently, due to inherited flaws in MIPv6, more protocols and combination of protocols are implemented and also been tested. In this contribution we implemented LinShim6 test bed and observed the behavior of switching locators under the use of REAP. This work is done by keeping in view that how the QoS factors are affected when REAP is used for network failure and recovery in home environment. REAP is activated when the communication path is failed. Sometimes host has access to multiple ISPs through its multiple locators. If one locator fails, communication is shifted to another locator. In Shim6 context it is called locator change. We experimentally validated the working of LinShim6 and condition of network considering packet loss, jitter, throughput and data transferred. In addition we propose that if an intelligent approach is used, switching delay can be reduced. We called this Shim6 Assisted Mobility Scheme (SAMS). Some initial experimental results are also presented in this work. View full abstract»

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  • Impact of cavity size on optical injection locking in semiconductor ring lasers

    Page(s): 077 - 079
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    Effects of the size of semiconductor ring laser on the strength of optical injection locking are discussed. Theoretical model has been developed to study the influence of for frequency response of locked semiconductor ring laser in the master slave configuration using phase modulation of master laser is discussed. In the unidirectional regime the locking range of semiconductor ring laser becomes wider when semiconductor ring laser with smaller size is used. View full abstract»

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  • The charge transport and photoconduction mechanisms of TiO2-based dye sensitized solar cell

    Page(s): 080 - 082
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (694 KB) |  | HTML iconHTML  

    The charge transport and photoconduction mechanisms of the TiO2-based DSSC were analyzed under dark and illumination conditions. The effects of high and low electric fields on charge transport mechanism of the solar cell were investigated by current-voltage characteristics. It was found that the charge transport mechanism of the solar cell was controlled by the thermionic emission (TEC) at lower voltage and followed by space charge limited current (SCLC) at the higher voltages. The photovoltaic parameters of the solar cell were determined. It is evaluated that the charge transport mechanism is controlled by TEC and SCLC mechanisms, while photoconduction is controlled by supralinear recombination mechanism. View full abstract»

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  • Thin film coatings for solar and thermal radiation control prepared by physical vapour deposition

    Page(s): 083 - 086
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (737 KB) |  | HTML iconHTML  

    Growth of multilayer thin film structures containing dielectric and metal layers using physical vapor deposition is investigated for use in applications requiring the control of thermal and solar radiation propagating through glass windows. In particular, metal-dielectric multilayer structures reflecting UV, near-infrared and thermal radiations whilst maintaining a maximum transmission in the visible range are prepared using both an E-Beam and Thermal evaporator and a RF Magnetron sputtering system. Measured transmittance spectra for the developed structures are in agreement with simulation results and demonstrate that with the use of optimum metal-dielectric layer combination it is possible to realize a coated glass transmitting most of the visible light through and reflecting most of the UV, solar and thermal infrared radiations. View full abstract»

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  • Thermal modeling of specialty heat-sinks for low-cost COP packaging of high-power LEDs

    Page(s): 087 - 091
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    We report on the 3D modeling and simulation of specialty heat sink designs for Chip on Plate (COP) packaging of high power UV LEDs. Steady state thermal analyses for COP packaged devices were carried out by using finite element code (FEM). Two different sets of heat-sinks such as plate fins, pin fins and fin/pin type varying in numbers and dimensions were modeled to calculate the junction temperature (Tj) of each heat sink respectively. Comparative study showed that the selected geometries and dimensions of these heat-sinks have significant effect on the device junction temperatures. Furthermore, thermal circuit model (TRC) was also used to calculate the junction temperatures for these -heat sinks. For this, both conductive and convective thermal resistances were also taken into consideration. We found that the TRC results were in good agreement with the FEM modeled data. For best plate fin heat-sink, the junction temperature was around 37°C whereas it was ~41°C for less efficient plate heat-sinks. Finally, the junction temperature for the high density pins heat-sink and the low-density fins heat sink was estimated as 33°C and 46°C respectively. View full abstract»

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  • Synthesis and electrical characterization of dyesensitized solar cell with Fluorescein Sodium Salt

    Page(s): 092 - 096
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1018 KB) |  | HTML iconHTML  

    Fluorescein Sodium Salt dye sensitized solar cell based on nanostructure TiO2 was synthesized. Photovoltaic and impedance spectroscopy properties of the solar cell with fluorescein sodium were investigated. The solar cell gives a short circuit current density of 72μA/cm2 and an open circuit voltage of 0.56 V under AM 1.5. The capacitance-voltage, the conductance-voltage, the series resistance-voltage characteristics of the solar cell were carried out in a wide range of frequency for the development of the dye sensitized solar cells. The present investigation is useful for the improvement of the photovoltaic performance of the solar cell and can be further improved using combination of different dyes. View full abstract»

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  • Wavelength exchanging technologies modeling, comparison, and validation

    Page(s): 097 - 101
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1379 KB) |  | HTML iconHTML  

    Simultaneous power exchange between two input signals, has been theoretically and experimentally demonstrated based on two phenomena: Four Wave Mixing (FWM) in High-Linear Dispersion Shifted Fiber (HNL-DSF) and Three Wave Mixing (TWM) in NonLinear Photonic Crystals (NL-PC). These phenomena have been used in many applications in WDM optical networks such as, wavelength conversion, wavelength sampling, optical 3R, optical interconnects and optical add-drop multiplexing. In this work, numerical simulation of the exchanging process is presented to compare the performance of using these components in WDM optical networks using MatIab-Simulink. View full abstract»

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  • Metallization of crystalline silicon solar cells: A review

    Page(s): 102 - 109
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2661 KB) |  | HTML iconHTML  

    Metallization plays both optical and electrical roles in the performance of a solar cell. Optically, the gridline width contributes to shading, which impacts the short circuit current. And electrically in the series resistance through contact and grid line resistances, which influences the fill factor. In the manufacturing of solar cell, metallization is the second most expensive step in the fabrication of a solar cell. In this paper contact formation to crystalline silicon solar cell is reviewed It starts with the photolithography contacts, which is precise and common to other semiconductor devices but expensive and non-manufacturable, to screen-printed and the alternatives that are less expensive. The importance of less expensive contacting technologies through use of less metal is stressed with the view to decreasing the cost of photovoltaic electricity. View full abstract»

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  • Solar electricity: Realizing the dream through digital inkjet metallization of multi-crystalline Si solar cell

    Page(s): 110 - 114
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    Solar electricity is an attractive resource that can be tapped without exhaustion. However, solar cell, the device which converts sunlight into electricity must be cost effective to encourage widespread use of solar electricity. Cost-effective solar cell can be achieved through material usage, efficiency and economy of scale. The economy of scale has been employed since 2004 with production capacities in the 1 GW range for several companies, but the efficiency is not high enough because of the limitations in the current metallization technology. The alternative technologies, such as laser opening and plate, extrusion, laser transfer process, inkjet and aerosol seed and plate investigated by several researchers are still far away from production ready. The inkjet metallization is an alternative that is very promising because of the associated precision in material usage in creating fine and uniform gridlines for reduced shading. Efficiencies of >19% and 17.4%, respectively, on mono and multi-crystalline cells, have been demonstrated using the same process as with the screen-printing technology. In this paper the results of digital inkjet metallization of multi-crystalline silicon solar cell is presented, for the first time, with efficiency of 17.4%. The technology road map to achieve lower-cost and higher efficiency multi-crystalline solar cells is also presented. View full abstract»

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  • Design strategies of unmanned aerial vehicle-aided communication for disaster recovery

    Page(s): 115 - 119
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    This paper presents a novel approach of using unmanned aerial vehicles (UA Vs) to establish a communication infrastructure in case of disasters. Due to the collapse of buildings, power systems, and antennas, the collapse of communication infrastructure is the usual effect of disasters. In this study, we propose an emergency communications system established by unmanned aerial vehicles (UA Vs). The system is a post-disaster solution; hence, it can be used anywhere required. In this study, first we briefly explain the details of the system in three aspects: end-to-end communication, localization and navigation, and coordination Then, we evaluate the efficiency of the localization and navigation subsystem. Our simulation studies with Air Robot quadrotor helicopters in Unified System for Automation and Robot Simulation (USARSim) simulation environment show that UAV-aided communications system can be used in case of disasters to establish an emergency communications infrastructure in terms of localization and navigation. View full abstract»

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