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Telecommunications (BIHTEL), 2012 IX International Symposium on

Date 25-27 Oct. 2012

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  • [Front cover]

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  • [Title page]

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  • 2012 IX International Symposium on Telecommunications (BIHTEL) [Copyright notice]

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  • 2012 IX International Symposium on Telecommunications (BIHTEL)

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  • Table of contents

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  • Author index

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  • [Back cover]

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  • A flexible FPGA-based module for wireless communications in astroparticle physics experiments

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3302 KB) |  | HTML iconHTML  

    TDMA-based wireless networks have been successfully operated in cosmic ray experiments over many years. However, the current DSP-based approach cannot be scaled to the demands of novel detection techniques. In this paper we present a design based on FPGAs which realizes a domain-specific TDMA communication protocol. The system is flexible to be adapted to different type of detector arrays and link condition by variable network parameters. The implemented hardware, firmware and the protocol allow a trade-off compromising between bandwidth and robustness on a per-link basis. Results based on four recently installed communication links at the Pierre Auger Observatory experiment site in Argentina are discussed. View full abstract»

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  • A novel subspace-based joint TDOA and FDOA estimation using chirp signals for mobile multipath environment

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (889 KB) |  | HTML iconHTML  

    In this paper, we propose subspace-based joint time difference of arrival (TDOA) and frequency difference of arrival (FDOA) estimation method using chirp signals for mobile multipath environments. The conventional methods for TDOA and FDOA estimation has been developed based on the signal model derived in a single path. However, single path channel model is not preferred in algorithm development for TDOA since it is not a realistic channel. Therefore, the conventional algorithms which have been developed based on the single path channel model cannot be easily extended to multipath channel. Thus, we propose a new TDOA and FDOA estimation technique based on multipath channel model. To achieve high accuracy, the subspace-based parameter estimation technique ESPRIT is used with some modification for a joint estimation of TDOA and FDOA. The proposed technique shows superior performance in multipath decomposition. Using the decomposition capability, the TDOA and FDOA for the direct path (the first arrival path) can be estimated well in spite of the interference caused by the other received paths. The performance of the proposed joint TDOA and FDOA estimation technique is evaluated through computer simulations under mobile multipath channel and compared with those of conventional methods. View full abstract»

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  • Evaluation of the maximum permissible transmission distance for the mixed-HDWDM systems

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (959 KB) |  | HTML iconHTML  

    The authors have evaluated the maximum permissible transmission distance for the purposed configuration of mixed-HDWDM system that is offered as model for the designing of next generation of an optical transport networks. In general, the investigated mixed-WDM FOTS can be represented using the following configuration scheme: [1st, 4th and 7th channels: NRZ-OOK, R= 10 Gbit/s] - [2nd (fc = 193.1 THz), 5th and 8th channels: 2-POLSK, R=40 Gbit/s] - [3rd, 6th and 9th channels: NRZ-DPSK, R=40 Gbit/s]. This is the “pessimistic scenario” since secures the highest in system's channel detected signals bit-error-rate as compared with other possible bitrate distribution among the channels. The maximum distance reach was evaluated using iteration loops consisted of chromatic dispersion compensation module (DCM), optical signal inline amplifier (based on EDFA) and one span of standard single mode fiber (SSMF, ITU-T Rec. G.652 D). One such loop emulates one sector of a fiber-optic transmission line (FOTL) over which the optical signals can be transmitted and then successfully detected on the other fiber end with appropriate error probability below the maximum permissible threshold. It is found out and analysed the correlation between the maximum distance reach and the investigated system's average spectral efficiency and the length of used SSMF span. View full abstract»

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  • Performance improvement of high speed spectrum-sliced dense WDM-PON system

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1337 KB) |  | HTML iconHTML  

    This paper contains the investigation of reach improvement of dense wavelength-division-multiplexed passive optical network (DWDM-PON) using spectrum-sliced amplified spontaneous emission (ASE) source as a seed light. It is shown that flat-top AWG unit provides excellent channel separation and filtering at the same time passing sufficient high optical power from spectrally sliced ASE broadband light source. The maximum reach of the spectrum-sliced dense wavelength-division-multiplexed passive optical network (SS-DWDM PON) system with data transmission speed 2.5 Gbit/s can be fairly limited by chromatic dispersion (CD) because of large optical bandwidth per channel compared to the bit rate. And therefore, dispersion degrades the performance of a SS-DWDM PON system more than it is observed in conventional laser-based system. This paper contains the investigation of improved high speed 8-channel spectrum-sliced DWDM PON system with efficient CD compensation methods like dispersion compensating fiber (DCF) and fiber Bragg grating (FBG). In this research it is shown that CD compensation has an important role for guaranteed downstream optical link performance and maximum link length of high speed SS-DWDM PON system. Results show that FBG used for CD compensation in high speed spectrum-sliced dense WDM PON systems provides better accumulated CD compensation and increase link length up to 150% while DCF fiber provides up to 130% network reach improvement. View full abstract»

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  • Overview of IMS application layer interaction management

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (251 KB) |  | HTML iconHTML  

    IMS (IP Multimedia Subsystem) network has high demands from perspective of multimedia, flexible and interactive communications. Fulfillment of those demands, with appropriate levels of quality, is not a simple task. As usage of services has great progress lately, there is high demand for their interaction management. Authors suggest way of Next Generation Networks application level organization and way of modeling of application level according to service responses to application requests. Main goal is to shift overload boundaries on the application layer and to show that IMS application layer interaction management is very complex, depending topic. View full abstract»

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  • Basic telephony SIP end - to - end performance metrics

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (462 KB) |  | HTML iconHTML  

    The Internet Protocol Multimedia Subsystem (IMS) has been recognized as a common signaling architecture for providing next generation multimedia services. In order to enhance perceived service quality regardless of access network and device, IMS supports Quality of Service (QoS) negotiation and signaling. The IMS procedures used for that purpose are based on Session Initiation Protocol (SIP). Therefore, signaling performance of SIP plays an important role in affecting the overall Quality of Experience (QoE) in next generation networks. Although many standards to evaluate the performance of telephony signaling protocols have been proposed, none of the metrics address SIP. Recent research in this field has resulted in the definitions of a standard set of metrics for measuring the performance of end-to-end SIP for basic telephony service. This paper aims to provide an insight in the process of measuring and evaluating SIP performance metrics as defined in Internet Engineering Task Force (IETF) Request for Comments (RFC) 6076. The open source IMS platform is used as the test environment for the purpose of examining SIP performance metrics under different conditions. Presented results show the impact of SIP signaling performance on QoE for IMS-based telephony service. View full abstract»

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  • Model and implementation of mobile interactive guide

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (658 KB) |  | HTML iconHTML  

    This paper presents a model and implementation of applications used as an interactive guide which aims to filter the specified locations of interest that are located near the current device position. Locations of interest are defined by geographic coordinates according to Google Maps standard, and it is possible to display them graphically on a map and to administrate them via web services. The effects of the ownership of these applications by telecom operators are also explored in the paper. View full abstract»

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  • Modelling and analysing the TLS protocol using Casper and FDR

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (228 KB) |  | HTML iconHTML  

    This paper analyses the TLS Handshake protocol in a progressive manner, by gradually building the protocol's messages and message fields. Messages constituting the TLS protocol are described by Casper, a compiler for the analysis of security protocols. FDR, a model checking tool is then used to test whether the protocol achieves its goals. It has been shown that TLS achieves its security goals for the systems tested. By using this progressive approach of the TLS Handshake analysis, this paper identifies the importance of each message and message field to the overall achievement of the security goal of the TLS protocol. The study also shows that the TLS protocol contains much redundancy. A few important points that show how TLS has been carefully designed to thwart some attacks that have appeared in many of the previous security protocols are also emphasized. View full abstract»

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  • Macrocell capacity and coverage planning for UMTS in GSM frequency band

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (423 KB) |  | HTML iconHTML  

    Implementing UMTS system in the GSM frequency band has gained a lot of attention in Europe in the last few years. There are several reasons for this. Those include better radio propagation in the lower frequency band, resulting in much lower price per bit for operators. In remote, sparsely populated areas, operators face cost-efficiency difficulties in providing UMTS at 2GHz range. However, by implementing UMTS at 900 MHz range, significant site number reduction can be achieved when comparing to 2GHz band for the same coverage. Following trends, operators in B&H have chosen to introduce UMTS900 technology in their mobile networks as well, providing global UMTS coverage very efficient. When it comes to UMTS network planning, coverage and capacity must be planned simultaneously, because traffic distribution, used services, and capacity requirements does have an impact to cell sizes. In this paper, influence of user demands and expected rate of broadband adoption (Broadband intensity) to UMTS900 greenfield overall planning is considered. Load factor and calculation method for a planned service mix has been proposed. Even simplified, dedicated to the first phase of planning, there is a need for method of planned broadband intensity in advance, integrated into the load factor equation. Broadband intensity parameter a has been introduced, and effect of changing of this parameter to actual network planning is presented. View full abstract»

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  • SIP server security with TLS: Relative performance evaluation

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1619 KB) |  | HTML iconHTML  

    VoIP (Voice over Internet) provides delivery of voice information over unsecured IP-based networks like the Internet. VoIP data, signaling and voice, needs to be secured in such an environment. Security mechanisms take their toll on VoIP system performance. SIP is dominant signaling protocol for VoIP. This paper measures relative decrease in VoIP performance of system with secured SIP signaling over one without it. It compares SIP with authentication enabled over three transport protocols: UDP, TCP and TLS. Peak throughput of concurrent calls, registration request delay, session request delay, SIP server CPU and RAM usage are measured. Testbed environment consists of Asterisk IP private branch exchange (PBX) as a part of Elastix server, several SIP user agents and SIPp traffic generator. Test results show that performance of SIP over TLS based signaling is four times lower than the SIP signaling over UDP in most metrics. View full abstract»

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  • Method for processing and classification of laser beam images using PLD

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (410 KB) |  | HTML iconHTML  

    This article discusses a problem of the laser beam dynamic image processing as applied to the systems of data communication by a laser beam. A method for calculation of the coordinates of this image is proposed for solution of this problem. The practical implementation of the method is presented on the basis of PLD (programmable logic device). View full abstract»

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  • Modelling optical network components: A network simulator-based approach

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (143 KB) |  | HTML iconHTML  

    The paper describes the design goals and methodology in creating a new model of optical telecommunication network. The model is implemented by discrete-event network simulator ns-3. The advantages of using the existing simulator core infrastructure provided by ns-3 are analyzed and compared to building own simulator from scratch, or selecting a tool among other existing simulators such as ns-2, OMNeT++, and OPNET. The requirements for feature functionality are outlined and high-level overview of the model architecture and its components are provided. Finally, the possibilities for extending the model in future research and development work are described. View full abstract»

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  • Distributed spectrum management for DSL networks

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (245 KB) |  | HTML iconHTML  

    Crosstalk is one of the main limiting factors in the data rates achievable by digital subscriber line (DSL) systems. The presence of crosstalk transforms DSL systems in a multi-user multi-carrier interference environment, where different users can significantly impact each other's data transmission. In previous years, many algorithms have been proposed to mitigate this impairment. Some of them are centralized and others are distributed. Unbundling of local loop will force telecom operators to use distributed systems because it's difficult to manage a spectrum of different operators from one center. In this work, a new DSM method for DSL systems is derived from the well-known Iterative Water-Filling (IWF) algorithm. This algorithm gives a good performance in many realistic scenarios. We present here some of them. View full abstract»

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  • IPv4/IPv6 transition using DNS64/NAT64: Deployment issues

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (472 KB) |  | HTML iconHTML  

    IPv4 address space is almost exhausted. Usage of IPv6 address by client end hosts is limited due to small percentage of domain names that have IPv6 address. This paper presents practical testing in ISP that gives its users IPv6 addresses and provides them transparent access to both IPv4 and IPv6 Internet locations. DNS64/NAT64 translation mechanism is used for this purpose. Tests measure resource requirements on ISP side and effects on client experience. Results show that additional DNS64 processing causes no visible impact on DNS server CPU load. There is requirement for NAT64 device at ISP on path between IPv6 users and IPv4 Internet. Test results show that memory requirements for this device are small and achievable with standard hardware devices used by ISPs. Measured increase in RTT from IPv6 clients to IPv4 Internet is less than 2%. Conclusion is that DNS64/NAT64 translation system is viable solution for ISP. View full abstract»

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  • System-level gains introduced to 3G UMTS mobile networks by multi-antenna techniques

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2023 KB) |  | HTML iconHTML  

    In order to satisfy constantly increasing user demands, in process of transition towards LTE (Long Term Evolution) mobile networks of 4th generation, for 3G UMTS networks potential solution is exploitation of multi-antenna MIMO (Multiple Input Multiple Output) systems, which provide increase in both capacity and reliability. This paper puts an effort to provide a link between link-level and system-level gains introduced by multi-antenna techniques in UMTS systems. Coverage, capacity and achievable data rates are evaluated and presented for Alamouti scheme, TxAA and D-TxAA. Radio mobile planning tool is used for illustration of coverage improvement achieved by implementation of several multi-antenna techniques. Considering system-level gains, it is seen that implementation of MIMO techniques yields larger service area and/or increase in capacity and available data rates maintaining the same bandwidth. Results presented in this paper help making a clear picture of achievable gains, employment costs and answering the question: Should mobile operators invest in upgrading their 3G networks with MIMO techniques and is that investment justified, considering achievable improvements. View full abstract»

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  • Survey and analysis of 0.18 urn CMOS integrated antennas on 5.8 GHz for RFD

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1063 KB) |  | HTML iconHTML  

    The issue of major interest during RFID systems development is reducing the size and price of RFID tag. This article is dedicated to design and implementation of 0.18 um CMOS integrated antenna for RFID system to include price of antenna implementation in price of RFID IC. Decreasing techniques of influence of layout configuration and methods of decreasing of metal stress states inside chip on antenna parameters are discussed. Functional synchronization was used in the generator to provide 5725 ÷ 5875 MHz differential output signal with 1.8 V supply voltage. Test antenna was implemented within test die, size 5×5 mm2, 0.18 um CMOS technology. A possibility of further decreasing of antenna size up to 1 mm2 was analyzed. Implemented antenna has gain of -25 dB@5.8 GHz and could be used up to 9 GHz without significant loss in efficiency. View full abstract»

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  • Inter-Carrier Interference mitigation by means of precoding

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (176 KB) |  | HTML iconHTML  

    In this work, we discuss the possibility of using precoding as means to mitigate Inter Carrier Interference (ICI) caused by temporal channel variations in Orthogonal Frequency Division Multiplexing (OFDM) systems. Many different precoding schemes have been introduced in the past. However, the promised gains of these techniques are not achievable nor realistic. In this paper, we introduce a practical low-cost precoding technique to mitigate ICI caused by Doppler spread. The gain in terms of Signal to Interference and Noise Ratio (SINR) is 0.5 dB at a velocity of 500 km/h. View full abstract»

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  • FPGA-based wireless sensor network for safety-related cognitive systems

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (583 KB) |  | HTML iconHTML  

    Wireless sensor networks for monitoring and steering industrial systems have emerged as an important new application area for wireless embedded technology in safety-related systems. Therefore several hardware platforms can be targeted. Due to their flexibility and reconfigurability along with high performance and power efficiency, modern Field Programmable Gate Arrays (FPGAs) are an excellent platform to realize such intelligent sensor networks. On one hand, FPGAs can integrate embedded processors and on-chip memory into a single die and can be easily configured to interface with a wide variety of popular communications protocols like SPI, UART and I2C, which are used for sensor communication. On the other hand, the reconfigurability of FPGAs supports the design of self-organizing computing systems, which are increasingly used in sensor applications. In this paper an FPGA-based wireless smart sensor network that integrates acceleration sensors for increasing safety aspects in cognitive systems used for industrial communication is presented. View full abstract»

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