Chimoon Han

Power-Efficient Load Distribution for Multihomed Services With Sleep Mode Over Heterogeneous Wireless Access Networks

The use of multi-interfaced devices has been steadily increasing due to the popularity of multihomed streaming services in heterogeneous wireless access networks. However, running multiple interfaces simultaneously in a mobile terminal (MT) may cause serious battery drain even when interfaces employ sleep modes. In addition, sleep modes may result in significant degradation of the quality of service (QoS) in terms of packet delay or jitter. This paper examines multihomed MTs and the use of data stripping load distribution across the multiple wireless interfaces of the MTs to minimize their power consumption. This paper then develops a theoretical framework for a power-efficient multipath load distribution that encompasses a dynamic load distribution to each interface employed with sleep mode. For this purpose, the paper first presents analytical models for power consumption and the delay of each interface by considering a medium access control (MAC) operation. Using these models, two simple greedy distribution algorithms are proposed to optimize the load distribution. Extensive simulations in an ns-2 simulator under various practical configurations demonstrate that the proposed algorithms significantly reduce power consumption while satisfying QoS constraints.

A harmful content protection in peer-to-peer networks

A variety of activities like commerce, education, voting is taking place in cyber-space these days. As the use of the Internet gradually increases, many side effects have appeared. Therefore, it is time to address the many troubling side effects associated with the Internet. In this paper, we propose a method of prevention of adult video and text in Peer-to-Peer networks and we evaluate text categorization algorithms for Peer-to-Peer networks. We also suggest a new image categorization algorithm for detecting adult images and compare its performance with existing commercial software.

UNA: Provision of accessibility from the IPv4 Internet to other networks

The address space shortage problem in the IPv4 Internet was forecasted a long time ago, and many earlier attempts to resolve the problem were combined to form a promising solution, IPv6. However, the deployment of IPv6 has been delayed. As a result, new mechanisms and architecture to expand the IPv4 Internet or to replace it have been presented, with no prominent success. A main reason of slow deployment of IPv6 and new proposals is lack of reasonable accessibility from the IPv4 Internet to new networks. We present UNA (universal network adaptation), which provides scalable accessibility from the IPv4 Internet (including private IPv4 networks) to any other non-public-IPv4 networks. In UNA, LASes (local autonomous systems) are built in IPv4 subscriber networks to provide communication channels from IPv4 hosts in LASes to non-public-IPv4 networks, and no host needs to be modified.

A OSPF Routing Scheme based on Energy Profiles and Its Characteristics for QoS-Aware Energy Saving(QAES) in IP Core Networks

Nowadays various methods for energy saving have been studied in IP networks. This paper suggests a 2-phase OSPF routing method for energy saving on IP networks having various energy profiles and analyzes its characteristics. The phase-1 of the routing is an OSPF routing method considering the energy cost of devices besides existing metrics to minimize energy consumption. In the phase-2 of the routing, it makes core nodes go into sleep sate for energy saving and reroutes the paths affected by sleeping core nodes. At this time, we confirm that the characteristics of mean delay and energy efficiency can be satisfied by limiting an allowable hop number in the reroute paths, and utilization rate of nodes and links for assuring energy saving and network-level QoS. Since the efficiency of energy saving and delay characteristics differ according to selection methods of core nodes to go into sleep state, it is that the a method of core node selection based on MP(minimum_path) is more excellent than others in terms of network-level QoS and energy saving in IP networks.

On the Security Effect of Abnormal Traffic Controller Deployed in Internet Access Point

ATC (Abnormal traffic controller) is presented as next generation security technology to securely support reliable Internet service in traffic-intended unknown attack. The key concept of the ATC is abnormal traffic monitoring and traffic control technology. When fault factors exist continuously and/or are repeated, abnormal traffic control guarantees service completeness as much as possible. The ATC with control policy on abnormal traffic is superior to the ATC with blocking policy as well as conventional network node, when the ratio of effective traffic to abnormal traffic is higher than 30%. As the proposed ATC can be applied to the edge point of backbone network as well as Internet access point, it guarantees network survivability and provides reliable Internet service.

An Automatic Security Evaluation System for IPv6 Network

IP version 6 is a new version of the Internet Protocol, designed as the successor to IP version 4(IPv4). IPv6 is now a deployment phase. For Security of IPv6 network, IPsec(IP Security) is designed by IPsec Working Group of IETF. IPsec(IP Security) offers not only Internet security service such as Internet secure communication and authentication but also the safe key exchange and anti-replay attack mechanism. Recently, Several Project implement IPv6 IPsec on the various Operating Systems. But there is no existing tool that checks the servers, which provide IPsec services, work properly and provide their network security services well. In this paper, we design and implement an automatic security evaluation system for IPv6 network. This system is operated on Windows and UNIX platform and operated on IPv6 network. We developed the system using Java and C language.

Design and Analysis of Hierarchical VPN Based on SCG

Most of VPN (Virtual Private Network) protect the information only through the public network. There is need to develop the various forms of VPN. Therefore, various types of VPN are going to be studied in the view of SCG (Secure Communication Group). In this paper, the problems of path-definition method and the area-definition method to construct SCG are analyzed, then possible models among VPNs based on SCG technology are reviewed. This paper proposed the hierarchical VPN based on SCG number that apply the area-definition method to the internet, and analyzed the characteristics of the proposed VPN model on the point of the authentication frequency and the number of management keys.