Kwihoon Kim

Energy Efficient Cooperative Multicast Scheme Based on Selective Relay

Multicast communication has been researched for many years in efforts to simultaneously achieve high throughput and good fairness, which have a trade-off relationship. Recently, a cooperative multicast scheduling scheme was proposed. It is considered a promising solution owing to its trade-off characteristics realized by promoting user cooperation among group members. However, it requires significant relay power consumption for user cooperation, since all group members in a good channel condition should relay without checking whether there is at least one user requesting a relay in the transmission boundary. Therefore, in order to resolve this inefficiency, we proposed an energy efficient cooperative multicast scheme (EECM) based on selective relay. We can achieve reduced unnecessary relay power expenditure by selecting relay users with consideration of the condition of nearby users. The performance results derived from a numerical analysis reveal that the proposed scheme requires less energy consumption than the existing solution with almost the same throughput performance.

Research of Social TV service technology based on smart TV platform in next generation infrastructure

This paper is to provide implementation supporting Social TV service technology based on SDP (Service Delivery Platform). This technology is for adaptor to provide the method for converging web portal API (Application Program Interface)s using SDP.

Cooperative jamming polar codes for multiple-access wiretap channels

The authors study cooperative security in the physical layer of wireless systems based on the recently developed polar codes for multiple access channel (MAC). Specifically, the authors first consider the case of a m-user MAC with external eavesdropper. Using polar alignment, the authors formulate a discrete optimisation problem where security and reliability criteria can be handled separately over the bases of a set of deterministic binary matrices. A discrete algorithm with incrementally polynomial complexity is used to maximise the uniform sum secrecy rate of users. Moreover, the proposed coding scheme is shown to achieve strong security for any subset of users. The authors next examine the case of minimum number of cooperative helpers to fulfil a feasible secrecy rate requirement at the legitimate user. Here, a low-complexity suboptimal algorithm is presented with at most one helper more than the optimal solution. Using Tal–Sharov–Vardy implementation of MAC polar codes, secure polar coding is implemented for a 2-user Gaussian wiretap MAC channel. The upper and lower bound of block error probability are compared, respectively, at the legitimate receiver and the eavesdropper. The results demonstrate clearly that with sufficiently long block length, strong secrecy with respect to the eavesdropper is achieved, while block error probability approaches 0.5.

Design of Unified Authentication for Multi-mode Terminal between Service and Access network in NGN

Presently, while the various accesses come out, it is necessary to have the separate authentication process if it wants to connect to each access. The various accesses are accommodated in the future NGN leading in ITU-T and TISPAN. Service providers become to provide a service based on them. The important access network is the XDSL, WLAN, WiMax and WCDMA. The ongoing wireless LAN standardization and R&D activities worldwide, which target bit rates higher than 100 Mb/s, combined with the recent successful deployment of WLANs in numerous hotspots justify the fact that WLAN technology will play a key role in wireless data transmission. Cellular network operators have recognized this fact, and strive to exploit WLAN technology and integrate this technology into their cellular data networks. In order that the service continuity is guaranteed while crossing the access network, the mobility management technology and integrated authentication and authorization technology are needed. In order that the seamless handover is provided, the various modes which are the same as those of the fast handover are considered. However, it has an effect that it is moreover many with authentication process. In this paper, we suppose that the various accesses are passed through. We propose for a single-sign-on for crossing from various accesses to the service level about the efficient integrated authentication technology. We focus on these interworking mechanisms, which effectively combine the various data access networks into integrated fixed, wireless and mobile data environments capable of ubiquitous data services and very high data rates in hotspot locations..

Performance of an Efficient Performing Authentication to obtain access to Public Wireless LAN with a Cache table

Currently, Wireless LAN(WLAN) service is widely deployed to provide high speed wireless Internet access through the mobile stations such as notebook and PDA. To provide enhanced security and user access control in the public WLAN area, WLAN access points should have the capability of IEEE 802.1x-based user authentication and authorization functionality. In this paper, we provide a brief understanding of IEEE 802.1x standards and related protocols like EAPOL(Extended Authentication Protocol Over LAN), EAP, RADIUS and describe how the IEEE 802.1x is designed and implemented in our embedded linux-based WLAN AP which is named i-WiNG.(Intelligent Wireless Internet Gateway). And we present an efficient authentication proxy for IEEE 802.1x systems based on the port-based access control mechanism. The proxy function of the AP is allowed to cache the supplicants user ID and password during his first transaction with the server. For the next authentication procedure of the same supplicant, the proxy function of the AP handles the authentication transactions using its cache on behalf of the authentication server. Since the main authentication server handles only the first authentication transaction of each supplicant, the processing load of the server can be reduced. Also, the authentication transaction delay experienced by a supplicant can be decreased compared with the conventional IEEE 802.1x systems. Therefore, the data traffic related to the authentication that has occurred in the backbone network can be considerably reduced to improve the speed of data transmission to the user of the high speed wireless Internet service.

A medium access control for the infraless peer aware communication networks

In this paper, the peer aware communication (PAC) network is introduced as an infraless area network which supports peer group communication for the low power wireless devices. For providing efficient synchronized group communication, the PAC MAC superframe is suggested. To avoid interference among neighboring peer groups implicitly and to support the variety of required quality of peer group services, the cyclic-superframe structure is proposed. The PAC devices can communicate with less power consumption by configuring a cyclic-superframe structure aligned with the service traffic, and can avoid interference to neighbor peer groups by selecting the start time of peer group communication.

Augmented ontology by handshaking with machine learning

Artificial intelligence products are already around us and will be emerging dramatically a lot in near future. Artificial intelligence is all about data analysis. When it comes to data analysis, there are two representative techniques: machine learning and semantic technology. They stand on the other side from where to begin analysis. Simply speaking, machine learning is based on the data while semantic technology relies on human domain knowledge (human learning). What if collected data are insufficient to reflect whole phenomenon? This is a limitation of machine learning. What if circumstance changes a lot as time goes by? Manual rule updating by experts is not a good solution in that circumstance. Based on these observations, we investigate two approaches and find a good solution which maximizes the advantages of both techniques and mitigates the limitations of them. This paper suggests a novel integration idea to compensate each technology with the other: that is semantic filtering. This paper includes a toy semantic modelling and a machine learning algorithm implementation to realize the proposed concept, semantic filtering.

Implementation of Open Web Portal Service Enabler Based on Service Delivery Platform

This paper is to provide implementation supporting open web portal service enabler based on Service Delivery Platform(SDP). This technology is for adapter to provide the method for converging web portal Application Program Interface(API) using SDP. It united the specification of protocols and parameters per web site in order to support “Open Method”. Also for adding the new web site and modifying the existed web site with ease, it utilized database dynamically.

Method for transmitting SMS for VoIP service supporting Multi-protocol

In this paper, we propose the method for transmitting the SMS (Short Message Service) message for the VoIP (Voice over IP) service supporting multi-protocol. The multi-protocol VoIP under consideration are generally composed of H. 323, SIP and MGCP and Most ITSPs (Internet Telephony Service Provider) provide VoIP service with H.323 and SIP now. SMS is killer application in mobile telecom service and many people of various fields use that service. For example, user can send many SMS messages and substitute e-mail. Also SMS can be provided with various internet applications. Ahn, the value added service legacy phone of KT (Korea Telecommunication), can use SMS. Therefore VoIP phone also can be required with the same requirement. With the multi-protocol VoIP we will propose several methods sending efficiently SMS. To show the validity of the proposed method some examples are given in which the results can be expected by intuitive observation

Design and development of the intelligent SSW and SIP application server system

The previous circuit-based telephone service is evolving into the IP-based one with requirement integrating new data service. And session initiation protocol is being widely adopted as a signaling protocol for IP telephony. The IP telephone service is basically provided with the data-based service of video phone, VOD (voice on demand), game and etc. To fit this requirement, we can provide to subscriber of any device the basic telephone service with SSW(softswitch) and the various application service with AS (application server) system. In this paper, we present the design and implementation of a effective SSW and AS. Current AS is not simple and needs many messages to implement service. Design goals of our system are simple AS and intelligent SSW. SSW is multiparty call-leg interaction support, using service sets predefined. Therefore we can propose simple AS system making service with ease