Browsing by Author "Lim, Wansu"

Now showing items 1-17 of 17

    • Analytical time-domain model for radio over free space optical (RoFSO) systems considering the scintillation effect 

      Lim, Wansu; Cho, Tae-Sik; Yun, Changho; Kourtessis, Pandelis; Kim, Kiseon; Yang, Yeon-Mo (2012)
      An analytical time-domain model is presented to analyze a radio over free space optical (RoFSO) system considering the scintillation effect with a log-normal distribution. This analytical model uses a dual-drive Mach-Zehnder ...

    • Average BER analysis of SCM-based free-space optical systems by considering the effect of IM3 with OSSB signals under turbulence channels 

      Lim, Wansu; Cho, Teasik; Yun, Changho; Kim, Kiseon (2009-11)
      In this paper, we derive the average bit error rate (BER) of subcarrier multiplexing (SCM)-based free space optics (FSO) systems using a dual-drive Mach-Zehnder modulator (DD-MZM) for optical single-sideband (OSSB) signals ...

    • BER performance analysis of radio over free-space optical systems considering laser phase noise under Gamma-Gamma turbulence channels 

      Lim, Wansu; Yun, Changho; Kim, Kiseon (2009-03)
      This paper analytically investigates a bit error rate (BER) performance of radio over free space optical (FSO) systems considering laser phase noise under Gamma-Gamma turbulence channels. An external modulation using a ...

    • Burst-polling based dynamic bandwidth allocation using adaptive minimum guaranteed bandwidth for EPONs 

      Lim, Wansu; Yun, Changho; Yang, Yeon-Mo; Lee, Hyunju; Kim, Kiseon (2009-12)
      The enhanced burst-polling dynamic bandwidth allocation (EBDBA) method is proposed to support broadband access networks based on quality of service for Ethernet passive optical networks (EPONs). EBDBA adaptively increases ...

    • Dynamic Bandwidth Allocation in Heterogeneous OFDMA-PONs Featuring Intelligent LTE-A Traffic Queuing 

      Lim, Wansu; Kourtessis, Pandelis; Kanonakis, Konstantinos; Milosavljevic, Milos; Tomkos, Ioannis; Senior, J.M. (2014-05-15)
      A heterogeneous, optical/wireless dynamic bandwidth allocation framework is presented, exhibiting intelligent traffic queuing for practically controlling the quality-of-service (QoS) of mobile traffic, backhauled via ...

    • Dynamic Subcarrier Allocation for 100 Gbps, 40 km OFDMA-PONs with SLA and CoS 

      Lim, Wansu; Kourtessis, Pandelis; Milosavljevic, Milos; Senior, J.M. (2013-04-01)
      The quality of service of 100Gbps orthogonal frequency division multiple access passive optical networks (OFDMA-PONs) performing dynamic bandwidth allocation is evaluated. New medium access control protocols and frame ...

    • Dynamic Subcarrier Allocation for OFDMA-PONs with Monitoring Mechanism 

      Lim, Wansu; Kourtessis, Pandelis; Milosavljevic, Milos; Senior, J.M. (Optical Society of America (OSA), 2011-06)
      A new protocol design for 10G OFDMA-PONs is reported, demonstrating dynamic subcarrier allocation based on monitoring of each ONU's queuing status. 0.7 ms packet delay and 540 Mbps throughput were achieved for SLA0 ONUs.

    • Efficient T-CONT-agnostic Bandwidth and Wavelength Allocation for NG-PON2 

      Kourtessis, Pandelis; Lim, Wansu; Merayo, Noemi; Yang, Yeon-Mo; Senior, John (2019-07-01)
      Dynamic bandwidth and wavelength allocation are used to demonstrate high quality of service (QoS) in time wavelength-division multiplexed–passive optical networks (TWDM-PONs). Both bandwidth and wavelength assignment are ...

    • Flexible QoS Differentiation in Converged OFDMA-PON and LTE Networks 

      Lim, Wansu; Kanonakis, Konstantinos; Kourtessis, Pandelis; Milosavljevic, Milos; Tomkos, Ioannis; Senior, J.M. (Optical Society of America (OSA), 2013)
      We propose a Weighted-DSA scheduling algorithm which allows efficient mapping of LTE QCIs over the optical queues of an OFDMA-PON. A 63ms end-end wireless packet delay has been demonstrated for QCI5 at highest network loads

    • MAC Protocol Design for the Support of DBA in OFDMA-PON Networks 

      Lim, Wansu; Gliwan, Ali; Kourtessis, Pandelis; Kanonakis, Konstantinos; Tomkos, Ioannis; Senior, J.M. (2011-06)
      Original MAC frame formats have been developed to provide recommendations for new protocol designs in OFDMA-PONs. The portrayed scalability of the Dynamic Subcarrier Allocation (DScA) protocol is complemented by the ...

    • MAC protocol requirements for OFDMA-PONs 

      Lim, Wansu; Milosavljevic, Milos; Gliwan, Ali; Kourtessis, Pandelis; Senior, J.M. (Institute of Electrical and Electronics Engineers (IEEE), 2012)
      This paper provides specifications of the parameters defining the design of medium access control (MAC) protocols for orthogonal frequency division multiple access (OFDMA) passive optical networks (PONs). A dynamic bandwidth ...

    • Modeling of LTE back-hauling through OFDMA-PONs 

      Lim, Wansu; Kourtessis, Pandelis; Kanonakis, Konstantinos; Milosavljevic, Milos; Tomkos, Ioannis; Senior, J.M. (Institute of Electrical and Electronics Engineers (IEEE), 2013)
      This paper evaluates a novel mapping and scheduling scheme which allows efficient control over the quality-of-service (QoS) experienced by long term evolution (LTE) users when backhauled over an orthogonal frequency division ...

    • Multicast polling for 10G-EPON 

      Lim, Wansu; Yang, Yeon-Mo; Milosavljevic, Milos (2012-04)
      A multicast polling scheme is proposed for 10G Ethernet passive optical networks (10G-EPONs). In the multicast polling scheme, the GATE message is broadcast to all ONUs with a new op-code of 0007. Comparing the proposed ...

    • Optical and Wireless Convergence : Paper AW2A.5 

      Lim, Wansu; Milosavljevic, Milos; Kourtessis, Pandelis; Senior, J.M. (Optical Society of America (OSA), 2012)
      This paper presents the requirements and possible solutions for wireless convergence in next generation PONs. System level simulation of LTE was performed to evaluate two different approaches for connecting eNBs to ONUs

    • Optimisation of Transmission Bandwidth for Cellular Indoor Optical Wireless Communications System Using a Dynamic Handover Decision-Making Algorithm 

      Wu, D; Ghassemlooy, Z; Minh, H. Le; Rajbhandari, S; Lim, Wansu (2012-07)
      In this paper, we propose a novel cellular optical wireless communications (COWC) system with four diffused cells. A dynamic handover scheme is proposed to make the link more flexible by the way of adaptive channel allocation ...

    • Parallel dynamic subcarrier and time allocation protocol for long-reach OFDMA-PONs 

      Lim, Wansu; Kourtessis, Pandelis; Milosavljevic, Milos; Senior, J.M.; Choi, H. (Institute of Electrical and Electronics Engineers (IEEE), 2015)
      A new advanced medium access control protocol is described to support 100 km reach access networks, exhibiting the required quality-of-service for next generation passive optical networks based on orthogonal frequency ...

    • QoS mapping for LTE backhauling over OFDMA-PONs 

      Lim, Wansu; Milosavljevic, Milos; Kourtessis, Pandelis; Senior, J.M. (Institute of Electrical and Electronics Engineers (IEEE), 2012)
      This paper reports on the quality of service (QoS) mapping mechanisms for converged OFDMA-PON and LTE networks to satisfy the stringent QoS requirements. Various options for exhibiting QoS mapping between the LTE bearers ...