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The Ethernet passive optical network (EPON) is one of the most promising broadband access networks. We propose a new dynamic scheduling algorithm, referred to as cyclic-polling-based dynamic bandwidth allocation with service level agreements (CPBA-SLA), for service differentiation that meets the service level agreements between the OLT and ONUs. The(More)
In recent years, along with the rapid development of LED technology, indoor positioning systems based on visible light communication (VLC) have been researched. In this paper, we propose an accurate indoor positioning method using white-light LEDs and a dual image sensor. Indoor LED lights are located at the ceiling in a room and broadcast information on(More)
Ethernet passive optical networks (EPONs) are an emerging access network technology that provides a low-cost method of deploying optical access lines between a carrier's central office and customer sites. Dynamic bandwidth allocation (DBA) provides statistical multiplexing between the optical network units for efficient upstream channel utilization. To(More)
Emerging white-light LEDs allow the combination of illumination and optical wireless communication in one optical source. Visible light communication (VLC) uses solid-state LEDs to broadcast information and is an attractive technology for indoor positioning system. In this paper, we propose a higher accuracy indoor positioning algorithm using a stereo image(More)
  • Su-il Choi
  • 2012 Fourth International Conference on…
  • 2012
Visible light communications (VLC) uses modern solid-state LEDs to broadcast information. Emerging white-light LEDs allows the combination of lighting and optical wireless communication in one optical source. In this paper, a new shape of LED lighting is proposed for illuminance and data communication. Performance of LED lightings is analyzed under the(More)
As distributed denial-of-service (DDoS) attacks have caused serious economic and social problems, there have been numerous researches to defend against them. The current DDoS defense system relies on a dedicated security device, which is located in front of the server it is required to protect. To detect DDoS attacks, this security device compares incoming(More)
In order that multicast routing characteristics are reflected under wireless environments, multicast routing metric is required for qualifying the multicast tree cost in wireless multi-hop mesh networks. We design a new multicast routing metric called the multicast-tree transmission ratio which quantifies the multicast tree cost, considering the link(More)