WICON 2010
UBSN 2010

    WICON

    5th International ICST Conference on Wireless Internet

    The Wireless Internet Conference (WICON) will continue to serve as a premier international forum to discuss novel research results related to the emerging Wireless Internet. WICON 2010 is soliciting both academic research and industry practice papers. Today, same Internet services are already ac…

    The Wireless Internet Conference (WICON) will continue to serve as a premier international forum to discuss novel research results related to the emerging Wireless Internet. WICON 2010 is soliciting both academic research and industry practice papers. Today, same Internet services are already accessed using different terminals over various types of networks. Through digital convergence, we are able to integrate the separate worlds of audio, video, data and voice services. Specifically, the borders between fixed-line and wireless mobile networks are disappearing.

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    Editor(s): Hsiao-Hwa Chen, Mahmoud Daneshmand and Stanley Liu
    Publisher
    IEEE
    ISBN
    978-963-9799-86-8
    Conference dates
    1st–3rd Mar 2010
    Location
    Singapore, China
    Appeared in EUDL
    29th Nov 2011
    Appears in
    IEEEXplore

    Copyright © 2011–2013 ICST

    • Joint spectrum allocation and relay selection in cellular cognitive radio networks

      Research Article in 5th International ICST Conference on Wireless Internet

      Ke Lang, Yuan Wu, Danny H.K. Tsang

      Abstract
      Cognitive radio network (CRN) has been proposed in recent years to solve the spectrum scarcity problem by exploiting the existence of spectrum holes. One of the important issues in a cellular CRN is …Cognitive radio network (CRN) has been proposed in recent years to solve the spectrum scarcity problem by exploiting the existence of spectrum holes. One of the important issues in a cellular CRN is how to efficiently allocate primary user (PU) spectrums without causing harmful interference to PUs. In this paper, we present a cross-layer framework which jointly considers spectrum allocation and relay selection with the objective of maximizing the minimum traffic demand of secondary users (SUs) in a cellular CRN. Specifically, we consider (1) CRN tries to utilize PU spectrums even when the CRN cell is not outside the protection region of the PU cell, and (2) cooperative relay is used in cellular CRNs to improve the utilization of PU spectrums. We formulate this cross-layer design problem as a mixed integer linear programming (MILP), and use LINGO to obtain the optimal solution. Compared with a simple channel allocation scheme, the numerical results show a significant improvement by using our method.
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    • Energy minimization approach for optimal cooperative spectrum sensing in sensor-aided cognitive radio networks

      Research Article in 5th International ICST Conference on Wireless Internet

      Hai Ngoc Pham, Yan Zhang, Paal E. Engelstad, Tor Skeie, Frank Eliassen

      Abstract
      In a sensor-aided cognitive radio network, collaborating battery-powered sensors are deployed to aid the network in cooperative spectrum sensing. These sensors consume energy for spectrum sensing and…In a sensor-aided cognitive radio network, collaborating battery-powered sensors are deployed to aid the network in cooperative spectrum sensing. These sensors consume energy for spectrum sensing and therefore deplete their life-time, thus we study the key issue in minimizing the sensing energy consumed by such group of collaborating sensors. The IEEE P802.22 standard specifies spectrum sensing accuracy by the detection and false alarm probabilities, hence we address the energy minimization problem under this detection accuracy constraint. Firstly, we derive the bounds for the number of sensors to simultaneously guarantee the thresholds for high detection probability and low false alarm probability. With these bounds, we then formulate the optimization problem to find the optimal sensing interval and the optimal number of sensor that minimize the energy consumption. Thirdly, the approximated analytical solutions are derived to solve the optimization accurately and efficiently in polynomial time. Finally, numerical results show that the minimized energy is significantly lower than the energy consumed by a group of randomly selected sensors. The mean absolute error of the approximated optimal sensing interval compared with the exact value is less than 4% and 8% under good and bad SNR conditions, respectively. The approximated optimal number of sensors is shown to be very close to the exact number.
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    • On the impact of primary user localization on rate performance of CR systems

      Research Article in 5th International ICST Conference on Wireless Internet

      Nurul H. Mahmood, Geir E. Øien, Maïté Brandt-Pearce

      Abstract
      This paper investigates how localization knowledge of primary users impacts the sum-rate performance of a secondary system in an underlay cognitive radio setting. Two different probabilistic models f…This paper investigates how localization knowledge of primary users impacts the sum-rate performance of a secondary system in an underlay cognitive radio setting. Two different probabilistic models for the primary users' location information are assumed, one uniform distribution and the other with Gaussian distribution. The interplay between the achievable rate of the secondary system and the primary users' location information under the AWGN and a fading channel model are presented and analyzed. Investigations are carried out for different propagation environments, localization models and primary-secondary user settings. Results show that the relationship between the secondary system sum-rate and the primary users' location information depends on the number of primary and secondary users, as well as the propagation environment. Empirical expressions for the sum-rate are proposed for different localization probability distributions.
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    • A concept for context-aware multihoming with heterogeneous radio access technologies

      Research Article in 5th International ICST Conference on Wireless Internet

      Stefano Carrella, Christian Mannweiler , Andreas Klein , Joerg Schneider , Hans D. Schotten

      Abstract
      There are several radio access technologies providing connectivity for mobile devices. In the future, more and more mobile devices will be capable of supporting more than one access technology. For b…There are several radio access technologies providing connectivity for mobile devices. In the future, more and more mobile devices will be capable of supporting more than one access technology. For being able to use these technologies simultaneously, there is a need for multihoming capabilities. Due to the variety of access technologies and the ability to use them simultaneously, new concepts for managing multihoming are needed. Higher requirements on efficiency and user satisfaction put new challenges on decision processes for multihoming. These higher requirements can be met by incorporating context information in the decision process. To enable context-based decisions, there is the need for determining, acquiring, and managing the required context information as well as the need for a decision scheme facilitating this information.
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    • Dilution of precision for mobile location in Non-Line-of-Sight environments

      Research Article in 5th International ICST Conference on Wireless Internet

      J.Y. Huang, P. Wang , Q. Wan, L. P. Chiang , F. H. Choo

      Abstract
      We present an analysis of the time of arrival (TOA) and time difference of arrival (TDOA) based positioning methods in Non-Line-of-Sight (NLOS) environments. Single path propagation is assumed. The p…We present an analysis of the time of arrival (TOA) and time difference of arrival (TDOA) based positioning methods in Non-Line-of-Sight (NLOS) environments. Single path propagation is assumed. The positioning accuracy is investigated in terms of Dilution of precisions (DOPs) depending on different NLOS cases. We then show that the weighted DOP (WDOP) is equal to the Cramer-Rao Lower Bound (CRLB) when the number of Line-of-Sight (LOS) base stations (BSs) is sufficient (three or more). Some characteristics of the DOP in the Global positioning system (GPS) are introduced to investigate the performance of positioning accuracy. In addition, some new characteristics of the DOP and the relationship of the DOP between the TOA and TDOA based methods are derived. According to these characteristics, the system can improve positioning accuracy through proper choice of optimum BSs and location techniques.
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