Bhum-Cheol Lee

Bio: Bhum-Cheol Lee is an academic researcher from Electronics and Telecommunications Research Institute. The author has contributed to research in topics: Cloud computing & Network packet. The author has an hindex of 12, co-authored 54 publications receiving 394 citations.

System and method for time synchronization on network

Abstract: A system and method for time synchronization on a network is provided. According to the system and method for time synchronization, a slave clock device does not continuously receive a time synchronization message periodically transferred from a master clock device and thus does not correct its time upon all such occasions. Rather, the slave clock device requests time information from the master clock device only when the slave clock device needs to correct its time, and receives a time synchronization message transferred from the master clock device and compensates for its time deviation only while the slave clock device is activated, thereby reducing its power consumption and amount of computation.

Hierarchical packet process apparatus and method

Abstract: Provided is a hierarchical packet processing apparatus and method. In one general aspect, a packet is analyzed, divided into an upper layer and a lower layer. It is determined whether a property of the packet to be analyzed has been already analyzed or has to be re-analyzed with respect to each of the upper and lower layers of the packet. Therefore, deep packet inspection is performed only when it is required, and thus assurance of quality of service (QoS) during packet processing can be achieved, as well as reduced waste of resources.

Network flow-based scalable video coding adaptation device and method

Abstract: Provided is a network flow-based scalable video coding (SVC) adaptation device. Without permitting a network transmitting end to divide image data into image data having various levels of quality and send the image data having the various levels of quality to all networks, since an adaptation device is installed in a network device of an ingress of a lower network of a subscriber and the adaptation device and the network transmitting end share network information about attributes of a terminal and the lower network of the subscriber so as to provide an image service having image quality corresponding to the terminal to the terminal, network efficiency can be maximized.

A Time-to-Digital Converter Based on a Multiphase Reference Clock and a Binary Counter With a Novel Sampling Error Corrector

Abstract: A new type of sampling error corrector for a time- to-digital converter (TDC) having a multiphase reference clock and a binary counter is demonstrated. With this corrector, sampling errors caused by asynchronous TDC inputs are corrected without requiring additional counters or reclocking circuits. A TDC having the corrector is implemented in 90-nm CMOS logic technology. It has 13.6-ps/least significant bit resolution and 13-bit input dynamic range. It consumes 18 mW from a 1.2-V supply and occupies a 100 × 210 μm2 chip area.

Switch and method for guaranteeing quality of service of multi-tenant cloud service and system having the same switch

Abstract: Provided are a method, apparatus, and system for providing a multi-tenant cloud service, which can guarantee quality of service (QOS) in units of flows and virtual machines (VMs). A dynamic virtual flow switch includes a switch flow agent configured to receive and store virtual machine QOS information about each of a plurality of virtual machines operating in a plurality of computer servers and flow QOS information about a flow generated by the virtual machine from a virtual flow controller and a flow processing unit configured to receive the flow generated by the virtual machine and determine a QOS priority of the flow based on the stored virtual machine QOS information of the virtual machine and flow QOS information of the flow.

Resource Allocation in NFV: A Comprehensive Survey

Abstract: Network functions virtualization (NFV) is a new network architecture framework where network function that traditionally used dedicated hardware (middleboxes or network appliances) are now implemented in software that runs on top of general purpose hardware such as high volume server. NFV emerges as an initiative from the industry (network operators, carriers, and manufacturers) in order to increase the deployment flexibility and integration of new network services with increased agility within operator’s networks and to obtain significant reductions in operating expenditures and capital expenditures. NFV promotes virtualizing network functions such as transcoders, firewalls, and load balancers, among others, which were carried out by specialized hardware devices and migrating them to software-based appliances. One of the main challenges for the deployment of NFV is the resource allocation of demanded network services in NFV-based network infrastructures. This challenge has been called the NFV resource allocation (NFV-RA) problem. This paper presents a comprehensive state of the art of NFV-RA by introducing a novel classification of the main approaches that pose solutions to solve it. This paper also presents the research challenges that are still subject of future investigation in the NFV-RA realm.

Conductor pattern structure of capacitive touch panel

Abstract: Disclosed is a conductor pattern structure of a capacitive touch panel. First-axis conductor assemblies and second-axis conductor assemblies are formed on a surface of a substrate. Each first-axis conductor assembly includes a plurality of first-axis conductor cells that are interconnected by first-axis conduction lines. An insulation layer is formed on a surface of each first-axis conduction line. Each second-axis conductor assembly includes a plurality of second-axis conductor cells that are interconnected by second-axis conduction lines. Each second-axis conduction line extends across the insulation layer of the associated first-axis conduction line.

A Survey on the Placement of Virtual Resources and Virtual Network Functions

Abstract: Cloud computing and network slicing are essential concepts of forthcoming 5G mobile systems. Network slices are essentially chunks of virtual computing and connectivity resources, configured and provisioned for particular services according to their characteristics and requirements. The success of cloud computing and network slicing hinges on the efficient allocation of virtual resources (e.g., VCPU and VMDISK) and the optimal placement of virtualized network functions (VNFs) composing the network slices. In this context, this paper elaborates issues that may disrupt the placement of VNFs and virtual machines (VMs). This paper classifies the existing solutions for VM placement based on their nature, whether the placement is dynamic or static, their objectives, and their metrics. This paper then proposes a classification of VNF placement approaches, first, regarding the general placement and management issues of VNFs, and second, based on the target VNF type.

Two-stage intrusion detection system for high-speed packet processing using network processor and method thereof

Abstract: A system and method for detecting network intrusion by using a network processor are provided. The intrusion detection system includes: a first intrusion detector, configured to use a first network processor to perform intrusion detection on layer 3 and layer 4 of a protocol field among information included in a packet header of a packet transmitted to the intrusion detection system, and when no intrusion is detected, classify the packets according to stream and transmit the classified packets to a second intrusion detector; and a second intrusion detector, configured to use a second network processor to perform intrusion detection through deep packet inspection (DPI) for the packet payload of the packets transmitted from the first intrusion detector. Thereby, intrusion detection for high-speed packets can be performed in a network environment.

Virtual Network Function Placement Considering Resource Optimization and SFC Requests in Cloud Datacenter

Abstract: Network function virtualization (NFV) brings great conveniences and benefits for the enterprises to outsource their network functions to the cloud datacenter. In this paper, we address the virtual network function (VNF) placement problem in cloud datacenter considering users’ service function chain requests (SFCRs). To optimize the resource utilization, we take two less-considered factors into consideration, which are the time-varying workloads, and the basic resource consumptions (BRCs) when instantiating VNFs in physical machines (PMs). Then the VNF placement problem is formulated as an integer linear programming (ILP) model with the aim of minimizing the number of used PMs. Afterwards, a Two-StAge heurisTic solution (T-SAT) is designed to solve the ILP. T-SAT consists of a correlation-based greedy algorithm for SFCR mapping (first stage) and a further adjustment algorithm for virtual network function requests (VNFRs) in each SFCR (second stage). Finally, we evaluate T-SAT with the artificial data we compose with Gaussian function and trace data derived from Google's datacenters. The simulation results demonstrate that the number of used PMs derived by T-SAT is near to the optimal results and much smaller than the benchmarks. Besides, it improves the network resource utilization significantly.