The search functionality is under construction.

Author Search Result

[Author] Woongsoo NA(3hit)

1-3hit
  • Log-Based Admission Control Scheme for Dynamic Spectrum Access Networks

    Woongsoo NA  Sungrae CHO  

     
    LETTER-Terrestrial Wireless Communication/Broadcasting Technologies

      Vol:
    E94-B No:10
      Page(s):
    2933-2936

    Dynamic spectrum access (DSA) has drawn immediate attention recently since it can opportunistically exploit any spectrum holes and thus improve bandwidth utilization. From the perspective of medium access control (MAC) design, the QoS requirement of SU is one of the design issues in DSA network. In this paper, we propose a new admission control scheme referred to as log-based dynamic spectrum access admission control (DSAC) aiming at (1) protection of the primary users and (2) QoS prioritization for the existing secondary users. The DSAC algorithm protects the PU by limiting SUs' access using PU's arrival log or statistics. Furthermore, the DSAC reserves a channel for previously admitted SU to reduce frequent service disruption of the SU. Reservation of channels is carried out without assuming any specific arrival process, and thus the DSAC would be practical for general user arrival patterns unlike the existing admission control techniques. Performance evaluation has shown that the proposed DSAC outperforms existing admission control schemes with respect to the PU blocking rate, SU communication stability, and SU aggregate throughput by about 13%, 26%, and 20%, respectively.

  • Design and Implementation of Personalized Integrated Broadcast — Broadband Service in Terrestrial Networks

    Nayeon KIM  Woongsoo NA  Byungjun BAE  

     
    LETTER-Systems and Control

      Vol:
    E103-A No:12
      Page(s):
    1621-1623

    This article proposes a dynamic linkage service which is a specific service model of integrated broadcast — broadband services based ATSC 3.0. The dynamic linkage service is useful to the viewer who wants to continue watching programs using TV or their personal devices, even after the terrestrial broadcast ends due to the start of the next regular programming. In addition, we verify the feasibility of the proposed extended dynamic linkage service through developed emulation system based on ATSC 3.0. In consideration of the personal network capabilities of the viewer environment, the service was tested with 4K/2K Ultra HD and receiving the service was finished within 4 second over intranet.

  • Reliable Broadcast Scheme for IEEE 802.15.5 Low-Rate WPAN Mesh Networks

    Woongsoo NA  Gunwoo LEE  Hyungchul BAE  Jungsuk YU  Sungrae CHO  

     
    PAPER

      Vol:
    E95-B No:9
      Page(s):
    2700-2707

    The IEEE has recently released IEEE 802.15.5 standard [3] to provide multi-hop mesh functions for low-rate wireless personal area networks (WPANs). In this paper, we extensively describe a link-layer reliable broadcast protocol referred to as timer-based reliable broadcast (TRB) [3] in the IEEE 802.15.5 standard. The TRB scheme exploits (1) bitmap based implicit ACK to effectively reduce the unnecessary error control messages and (2) randomized timer for ACK transmission to substantially reduce the possibility of contentions. Performance evaluation shows that the TRB scheme achieves 100% reliability compared with other schemes with expense of slightly increased energy consumption.