Tae-Sub Kim, Seung-Yeon Kim, Seungwan Ryu, Hyong-Woo Lee, Choong-Ho Cho 1 First Author Dept.of Computer and Information Science, Korea University, Korea 2,4 Dept.of Information Systems, Chung-Ang University, Korea 3 Dept.of Electronics and Information Engineering, Korea University, Korea *5 Corresponding Author Dept.of Computer and Information Science, Korea University, Korea {ree31206, kimsy8011, hwlee, chcho}@korea.ac.kr, ryu@cau.ac.kr

In this paper, we propose a resource allocation schemes, called proximity user detection-based resource allocation (PUDRA), or advanced proximity user detection-based resource allocation (APUDRA) in an LTE-Advanced device-to-device (D2D) network. In the proposed schemes, in order to reduce the interference between macro user equipment (mUEs) and D2D links or between D2D links, D2D link shall use a frequency bandwidth that the neighboring mUEs or D2D links do not use. We analyzed and compared the two schemes and the random resource allocation scheme in terms of the system throughput for downlink and outage probability according to the number of D2D receivers (D2DRs). Simulation results show that the APUDRA scheme has better performance than the PUDRA and random resource allocation scheme performance in terms of the system throughput and outage probability for mUEs and D2DRs.

Tae-Sub Kim, Suk-Ho Yoon, Seungwan Ryu, Choong-Ho Cho 1, First Department of Computer and Information Science, Korea University, Korea, ree31206@korea.ac.kr Department of Computer and Information Science, Korea University, Korea, bluepig5@korea.ac.kr Department of Information Systems, Chung-Aug University, Korea, ryu@cau.ac.kr *4,Corresponding Department of Computer and Information Science, Korea University, Korea, chcho@korea.ac.kr

최근 스마트 단말의 보급으로 데이터 트래픽에 대한 수요가 급증하고 있어 한정된 자원을 가진 기지국이 수용하기에는 많은 어려움이 따른다. 이러한 해결책으로 셀 또는 서로 인접한 셀 내의 단말들이 서로간에 기지국을 거치지 않고 디바이스간 직접적인 통신(D2D, Device-to-Device)을 통해 기지국의 과부하를 줄이고 주파수 부족 현상을 완화시킬 수 있는 방안이 제안되고 있다. 하지만 LTE-Advanced 시스템 내에서 셀룰러 링크와 무선 자원을 공유하는 D2D 링크는 자신이 속한 셀룰러 네트워크에 심각한 간섭을 줄 가능성이 높기 때문에 간섭을 제거하거나 완화시킬 필요가 있다. 따라서 본 논문에서는 셀룰러 링크와 D2D 링크가 자신의 간섭을 최소화하는 SFR(Soft Frequency Reuse) 기반 자원할당과 전송전력 조절 방법을 제안한다. 제안된 방법의 성능검증을 위해 시뮬레이션을 수행하였으며, 결과를 통하여 신호대 잡음비(SINR, Signal to Noise Ratio)와 시스템 평균 전송량(Throughput)에서 성능 이득을 가짐을 보였다. Currently, Demand of data traffic has rapidly increased by popular of smart device. It is very difficult to accommodate demand of data traffic by limited resource of base station (BS). To solve this problem, method has proposed that the Device-to-Device (D2D) reduce frequency overload of the BS and all of the user equipment (UE) inside the BS and neighbor BS don't allow communicating directly to BS. However, in LTE-Advance system cellular link and sharing radio resources of D2D link, the strong interference of the cellular network is still high. So we need to eliminate or mitigate the interference. In this paper, we use the transmission power control method and Soft Frequency Reuse (SFR) resource allocation method to mitigate the interference of the cellular link and D2D link. Simulation results show that the proposed scheme has high performance in terms of Signal to Noise Ratio (SINR) and system average throughput.

In this paper, we propose a resource allocation and Tx power control scheme, called resource allocation and power control (RAPC), in LTE Advanced device-to-device (D2D) network. In the proposed scheme, the macro base station (mBS) and D2D senders (D2DSs) service macro user equipments (mUEs) and D2D receivers (D2DRs) use the different frequency bands and Tx power chosen as D2D links' locations in inner and outer zones to reduce interference substantially. Simulations show the proposed scheme outperforms D2D networks with soft frequency reuse (SFR) systems in terms of the signal to interference and noise ratio (SINR) and system throughput for mUEs and D2DRs.

It is expected that many heterogeneous wireless systems, such as 3GPP LTE systems, WiMAX systems and WLAN systems, will coexist in the next generation wireless communication environments. Integrated radio resource management and seamless vertical handoff (VHO) should be supported to provide integrated communication services over multi-radio access networks. A new class of adaptive VHO system that views the handoff problem as a pattern recognition problem is proposed. In this paper, we propose a unified radio resource management (URRM) architecture and Support Vector Machine (SVM) based vertical handoff decision system. Extensive simulation studies show the proposed VHO algorithm outperforms RSS based VHO algorithms in terms of throughput and service cost.

It is expected that many heterogeneous wireless networking systems such as 3GPP Long-term Evolution (LTE) system, WiMAX/WiBro system and WLAN system will exist in the next generation wireless communication environment. Under such environment, various communication services will be introduced by integrating heterogeneous wireless networking technologies, especially at radio access networks. In order to provide such integrated communication services, integrated radio resource management and seamless vertical handover across such heterogeneous access networks should be supported. In this paper, to tackle these problems, we propose a Generic Link Layer (GLL) based Common Radio Resource Management (CRRM) architecture and three vertical handover decision algorithms. We propose a vertical handover decision (VHD) algorithm that is a combination of a policy and a multi-criteria decision making (MCDM) approaches designed for achieving effective and seamless handover between heterogeneous radio access networks, especially between the LTE and the WLAN systems. We also propose the Data Mining(C4.5) based VHO decision making algorithm not only to consider various VHO decision factors but also to decide the handover trigger point adaptively to the network traffic situation. In order to verify effectiveness of the proposed CRRM architecture and the three proposed VHO decision making algorithms, extensive simulation studies are performed under various traffic situations. Simulation study shows that the proposed two VHO algorithms outperform the conventional received signal strength (RSS) based VHO algorithm in terms of the data throughput, the handover success rate, and the system service cost.

차세대 이동통신 시스템에서는 3세대 진화망인 LTE(long-Term Evolution), WiMAX/WiBro, 차세대 WLAN등 다양한 무선 접속 기술이 All-IP 기반의 핵심망을 중심으로 통합되는 형태로 발전하고 있다. 이러한 발전에 따라 중첩된 다양한 무선 이종망 환경에서 최적의 조건을 제공하는 망으로의 접속을 제공하는 수직적 핸드오버가 필요하다. 그러나 현재까지는 각각의 네트워크가 독자적 서비스 제공을 위해 독립적인 무선자원관리 기능을 제공하여 왔으므로, 이종망 환경에서의 다양한 네트워크를 끊김없이 서비스를 제공하기 위해서는 개별 네트워크의 무선자원들을 통합적으로 관리하여 최적의 서비스를 제공할 수 있어야 할 것이다. 최근 이러한 무선 이종망 환경에서의 문제점을 해결하기 위해 적응적이동성을 위한 범용링크계층(GLL)과 통합무선자원관리(CRRM) 방식의 개념이 도입되고 있다. 본 논문에서는 LTE와 WLAN 사이에서의 효율적인 수직적 핸드오버를 위한 범용링크계층을 기반으로 정책기반과 다기준 의사결정법(MCDM)을 혼합한 수직적 핸드오버 알고리즘을 제안하고, 퍼지 로직 제어기(FLC)를 이용하여 핸드오버 시점을 적응적으로 결정하는 방안을 제안한다. 시뮬레이션 연구 결과 본 논문에서 제안하는 수직적 핸드오버 기법은 수신신호의 세기를 기반으로하는 방법과 MCDM 만을 사용하는 방법에 비해 데이터 처리량, 핸드오버 성공확률, 서비스 사용비용 그리고 핸드오버 시도 횟수 측면에서 우수한 성능을 보였다. For the next generation mobile communication system, diverse wireless network techniques such as beyond 3G LTE, WiMAX/WiBro, and next generation WLAN etc. are proceeding to the form integrated into the All-IP core network. According to this development, Beyond 3G integrated into heterogeneous wireless access technologies must support the vertical handover and network to be used of several radio networks. However, unified management of each network is demanded since it is individually serviced. Therefore, in order to solve this problem this study is introducing the theory of Common Radio Resource Management (CRRM) based on Generic Link Layer (GLL). This study designs the structure and functions to support the vertical handover and propose the vertical handover algorithm of which policy-based and MCDM are composed between LTE and WLAN systems using GLL. Finally, simulation results are presented to show the improved performance over the data throughput, handover success rate, the system service cost and handover attempt number.

It is expected that many heterogeneous wireless networking systems such as 3GPP Long-term Evolution (LTE) systems, WiMAX/WiBro systems and WLAN systems will be exist in next generation wireless communication environment. Under such environment, various communication services will be introduced by integrating heterogeneous wireless networking technologies, especially at the radio access networks. In order to provide such integrated communication services, integrated radio resource management and seamless vertical handover across such heterogeneous access networks should be supported. In this paper, to tackle these problems, we propose a Generic Link Layer (GLL) based common radio resource management (CRRM). In particular, we propose the network architecture and functions of each network element for integrated radio resource management among heterogeneous access networks. Then, we propose policy-based and multi criteria decision making (MCDM) based seamless vertical handover schemes between LTE and next generation WLAN systems. Performance of the proposed vertical handover schemes are evaluated via extensive simulation studies. Simulation results show that the proposed VHO schemes outperform other VHO schemes such as received signal strength (RSS) based VHO scheme in terms of throughput, handover success rate and the service cost.

Copper is an alternative material to aluminum that has been used as an interconnection material in metallization for large-scale integrated circuits because of its favorable electrical conductivity (1.67 mu Omega-cm) and superior resistance to electro-migration. Cu metallization by ECD (electro-chemical deposition) requires a seed layer of Cu, which should have a continuous and smooth film surface, in order to achieve Cu super-filling. High-quality Cu thin films were deposited on TiN/Si substrates by using a radio-frequency plasma-enhanced atomic layer deposition (RF-PEALD) technique and a hexafluoroacetylacetonate copper vinyltrimethoxysilane [(hfac)Cu(VTMOS)] precursor. The variation in the film's growth mode with the substrate temperature was investigated at temperatures between 150 - 350 degrees C. As the vertical growth rate increase at the temperatures above 200 degrees C, forming a continuous thin film is difficult and the resistivity increases due to voids between grains and due to surface scattering.

– Wireless LAN (WLAN) refers to the wireless network environment constructed indoors or outdoors, by using either radio or light wave technology instead of wire signals from the hub to such clients as PCs (Personal Computers), notebook PCs and PDAs. TGf (Task Group F), among IEEE 802.11 WGs (Working Groups) has proposed IAPP (the Inter Access Point Protocol) designed to secure the interoperability between AP sets produced by different vendors. This is a protocol for securing mobility among APs within sub-networks. It offers seamless connectivity between stations (STAs) by sharing security context or Layer 2 forwarding data between APs without reauthentication when STAs move around among them. In this paper, we propose a mechanism to enhance the wireless LAN secureuser authentication protocol considering the mobility based on IPv6 in a wireless LAN environment. Furthermore, we propose a mechanism to enhance wireless LAN securityprotection related information, that can occur during message transmissions between APs by replacing the movement paths for IAPP-move requests or response messages with the existing movement path utilizing the public key for transmission between the APs above, we conform that the proposed protocol can be made secure from various attacks and provide convenient and real-time user authentication.

Lanthanum hafnium oxide (LHO) thin films were grown using an electron cyclotron resonance atomic layer deposition technique. Tetrakis(ethylmethylamino)hafnium (TEMAHf) and tris(ethylcyclopentadienyl) lanthanum (III) [La(EtCp)3] were utilized as the hafnium and lanthanum precursors, respectively. O2 plasma was used as a reactant gas. Transmission electron microscopy analyses revealed that the as-deposited LHO film had a crystalline structure at a deposition temperature of 400°C. Rapid thermal annealing of the LHO films induced dramatic changes in the electrical properties. The VFB for the films shifted toward the ideal VFB and the amount of positive fixed charge disappeared in the LHO films. The leakage current density of the film deposited at 400°C was estimated to be 4.6×10−7A∕cm2 at −1V. The leakage characteristic of the LHO films was improved with annealing at temperatures above 900°C.

IEEE 802.11i standard supports a secure access control for wireless LAN and IEEE 802.1x standard includes various authentication method protocols. It is expected that next generation wireless LAN security techniques will be based on IEEE 802.1x and IEEE 802.11i standards. However, at present users who are not familiar with a computer and an authentication details have difficulty to setup the network security based on IEEE 802.11i. Accordingly, this paper proposes authentication scenarios to minimize the process needed by users, a password method which is changed randomly and periodically, and authentication protocols. The proposed protocols provide convenience for nonprofessional computer users as well as secure the home network environment against the unwanted attacks such as a dictionary attack or a replay attack and it uses SNMP and the system to be able to detect an intrusion it supposes will occur.

Plasma enhanced atomic layer deposition (PEALD) of titanium dioxide thin films was conducted using Tetrakis dimethylamino titanium (TDMATi) and an oxygen plasma on a polyethersulfon (PES) substrate at a deposition temperature of 90 degrees C. The effects of the induced plasma power on passivation properties were investigated according to film thickness. The growth rate of the titanium dioxide film was 0.8 A/cycle, and the water vapor transmission rate (WTVR) for a 80 nm titanium dioxide film was 0.023 g/m2 day. The passivation performance of the titanium dioxide film was investigated using an organic light-emitting diode (OLED). The coated OLED lifetime was 90 h, 15 times longer than that of an uncoated sample.

Lanthanum oxide (La2O3), hafnium oxide (HfO2) and lanthanum hafnium oxide (LHO) films were deposited by using an electron cyclotron resonance plasma-enhanced atomic layer deposition method. Tris(isopropyl-cyclopentadienyl)lanthanum (La(iPrCP)(3)) and tetrakis(ethylmethylamino)hafnium (TEMAHf) were utilized as the lanthanum and the hafnium precursors, respectively. A self-limiting growth behavior was observed after 2-s injections of each precursor at the temperatures above the 300 degrees C deposition temperature. The growth rates of the La2O3, HfO2 and LHO film were 0.6, 0.6 and 0.5 angstrom/cycle. The dielectric constants of the La2O3, HfO2 and LHO films were 10.8, 12.2 and 16.3, respectively. The leakage current density of the LHO film was 4.33 x 10(-9) A/cm(2) at -1 V for a film with an equivalent oxide thickness of 2.2 nm. The highest dielectric constant and the lowest leakage current obtained for the LHO film were 16.3 and 3.8 x 10(-8) A/cm(2), respectively. Thus, the LHO film is a promising material for a gate oxide.