Earticle

Background/Objectives: Network traffic forms a lot in many modern server communication worlds. Methods/Statistical analysis: As a result, the network can exchange data with each other, and the sudden increase in trapping results in malfunction and communication error due to server overload. Findings: Traffic spikes can be attributed to scheduled backups within the LAN, remote backup programs, mail servers, software (SW) upgrades, malware generation and hacking attempts. In general, a small increase in traffic that is easily seen by everyone is likely to recover after a while. However, when traffic attacks coming from too much traffic and hacking intentions, fast network traffic detection, and responses are needed. Improvements/Applications: Therefore, the proposed proposal is proposed to maintain the causes of network traffic surges and countermeasures.

무선통신 시스템에서는 부족한 주파수를 가지고 채널 용량을 늘이는 분야는 활발하게 연구되고 있다. 주파수 파워를 높이고 밴드폭을 늘리면 채널 용량은 좋아지지만 노이즈 간섭을 일으킴으로 통신이 안 될 수도 있다. 무선주파수 할당은 한 무선통신 시스템으로 말미암아 타 무선통신시스템에 간섭이 없게 하기위해 법적인 효력을 갖는 표준을 통해 정부차원에서 관리하고 있다. 본고에서는 항공기에서 간섭없이 무선 랜을 구축시 여러 파라메터를 만족해야하는 지를 분석을 통해 제시하고자 한다. 이를 위해 시나리오를 바탕으로 전파 분석을 시뮬레이션해서 항공기 내부와 외부건물이 있는 경우의 이격거리를 얼마로 해야 간섭없는 송신기 설치가 가능한지에 대한 연구이다.

In a wireless communication system, increasing the channel capacity with a limited frequency is a problem in all frequency bands. Increasing the frequency bandwidth and increasing the output can increase the channel capacity, but sometimes the communication is not possible due to interference noise. If the radio frequency allocation is set to world standardization such as WRC or ITU-R, each country has strict control over regulations. This is because one wireless communication system should not affect other systems. We present the results of a study on scenarios and analysis of radio waves to be installed inside and outside the aircraft without interfering with the wireless LAN.

This paper having a purpose of research of multimedia service frequency allocation effectively by telecommunication and broadcasting. It analyze frequency usage status by operators to allocate multimedia service frequency and define parameter to allocate frequency by telecommunication and broadcasting, set up maximum transmission rate by operator service, finally, make optimize frequency bandwidth by calculated frequency value. Also assume that data transmission rate(9.6K,10K,14.4K,144K,700K,2Mbps), simultaneous access rate(10%,15%,20%), line usage rate(20%,25%,30%), threshold frequency rate (0.7) and population density(subscriber) to optimize multimedia service. population density will define number of subscriber, rate of uplink and downlink will simulate based on Matlab by HSDPA. Consequently, throguh this research will show and allocate not 100 MHz but 50MHz bandwidth of each operator's usage frequency .

By considering the limited energy of Internet of Things (IoT) devices. We take the resource allocation to guarantee the stringent Quality of Service (QoS) depending on the joint optimization of power control and finite blocklength of channel. To achieve large volumes of arrival rates, we propose Adversarial Training based Generative Adversarial Networks (AT-GANs), which utilize a significant number of extreme events to provide high reliability and adjust real data in real-time. Simulation results show that Deep-Reinforcement Learning (Deep-RL) for AT-GAN could eliminate the transient training time. As a result, the AT-GAN keeps the reliability higher than 99.9999%.

In this letter, we propose an optimal joint bandwidth and power allocation method for heterogeneous wireless networks (HetNets) by maximizing the users’ quality of experience (QoE), which is a widely used subjective metric reflecting the users’ satisfaction of the multimedia service. By taking two factors into consideration simultaneously: Rate Factor (RF) and Energy Factor (EF), we can measure the QoE of end-users effectively. An optimal QoE-driven allocation algorithm is further developed for maximizing the end-users’ QoE utility subject to the constraints of transmit bandwidth, power and data rate. The simulation results demonstrate the theoretical analysis.

With the rise of bandwidth-intensive applications, such as video streaming and cloud services, efficient routing decision networks have become increasingly important. Bandwidth allocation issues arise from various causes. This paper examines the Bandwidth Starvation Problem (BSP), where routing decisions that insufficiently account for low-demand flows hinder high-demand flows. Current Reinforcement Learning (RL)-based hop-by-hop routing methods overlook bandwidth demand factors, worsening the BSP. We propose a bandwidth demand-oriented reward function and a Deep Reinforcement Learning (DRL) framework to address this challenge. Experiments on Topology Zoo topologies demonstrate proposed approach enhances throughput, utilization, and maximum service capacity over existing methods.

With respect to the rapidly growing Fourth Generation (4G) wireless communication system, an outstanding feature is the heterogeneous wireless access. Despite the fact that this amazing feature allows users to connect to several wireless access networks simultaneously, various challenges with respect to bandwidth allocation (BA) among various heterogeneous networks also arise. A feasible and effective solution to tackle this problem has been proposed in this paper, which concerns a bandwidth allocation using game (BAG) algorithm with respect to heterogeneous wireless networks. This paper proposes modeling a Resource allocation RA or Bandwidth Allocation problem as a game, and then formulating it to increase the total utility to a maximum of the dissimilar networks. The game model that has been proposed in this paper also establishes the existence of the Experimental Economic Method (EEM). In order to divert assigning too much Resource or bandwidth to a single user, utility functions have also been designed. Moreover, simulation results reveal that the scheme proposed in this paper not only achieves a high utility, but also reduces blocking probability within a few iterations.

A primary latest video coding standard H.265/SHVC (Scalable High Efficiency Video Coding), an extension of High Efficiency Video Coding (HEVC) is dealt in this paper. To transfer high quality video over any network that usually occupies large bandwidth, suffers bandwidth limitation. It can be controlled by trading-off between the quality and the coding efficiency. The trade-off between these two parameters is considered in this paper to keep the difference at the minimum level. A novel Neural Network based Adaptive De-blocking Filter (NNADF) technique is proposed to maintain good PSNR with minimum bit rate in SHVC encoder. The adaptive de-blocking filter (ADF) performs block matching for nonlinear predictions to all frames in the video. Moreover, the ADF performs frame de-noising hence good quality of the video is achieved and trains a neural network (NN) model. The NN model restrains their outputs to achieve bit rate reduction, thereby coding efficiency is achieved. The simulation results show that the proposed NNADF technique delivers an average increment of 0.62 dB in BD-PSNR and an average decrement of 24 % in BD-BR for combined quality and spatial ratios respectively compared with the previously proposed algorithm.

Ultra-wideband (UWB) technology is a good candidate for low-latency high-resolution localization. This paper proposes the -law operation (XLO) to boost the positioning accuracy of UWB localization systems. The proposed scheme significantly reduces the contribution of low-SNR samples and increases the time resolution of the pulse. Thus, the XLO achieves a time-of-arrival (ToA) positioning accuracy that existing methods require more energy and bandwidth to attain. The significant performance gain of the XLO for localization makes the XLO a good candidate for simultaneous positioning and communication with low complexity, high performance, and low power consumption suited for Internet of Things (IoT) devices.

Software Defined Network (SDN) is a new network architecture for designing, building, and managing networks that separates the networks control plane and forwarding plane to better support the scalability and innovation in a network infrastructure. The overall network performance of an application is mostly affected by the two major factors, bandwidth, and latency. Between each pair of network elements in network infrastructure, there may exist multiple paths connecting them with different properties. A traditional network does not take this knowledge into consideration and may result in sub-optimal performance of applications and underutilization of a network resource. This research proposes a concept of Application aware routing which could improve the overall performance of a network by categorizing the application in bandwidth oriented and latency oriented and allocate the separate route for each type of traffic based on the application preferences using Software defined network architecture and OpenFlow protocol. The research also proposes a design of an application aware network topology by using software defined network architecture which uses open flow protocol and open flow protocol based controller. Routes for the application packets are chosen based on the application type. To verify the feasibility and practical implementation of the proposed concept SDN topology is implemented in emulated environment using mininet.

A microstrip dual-band bandpass filter (DBPF) with controllable bandwith is designed and simulated at 3.08 GHz and 7.05 GHz. A step impedance resonator (SIR) with open stubs and the shunt open stub is employed that consists in a pair has advantage of having a compact and excellent transmission characteristics. The 3 dB bandwidth of a first band is 950 MHz with the insertion loss (S21) of -0.2dB and the second bandwidth is 1400 MHz with the insertion loss (S21) of -0.7dB. This bandpass filter can be applied to the domestic and international fixed and mobile satellite telecommunications, fixed meteorological satellite, ultra-wideband(UWB), and broadcast relay, The overall size of bandpass filter is 15 mm × 20 mm.

Stereo vision is actively researched as a solution for distance measurement in autonomous driving. This technique involves triangulation-based distance calculation using left and right images acquired from two image sensors. A kernel window is employed to determine the disparity between these left and right images. To achieve optimal disparity in various environments, it is essential to support different kernel sizes. Moreover, there is a need for research to integrate high-throughput memory, such as high bandwidth memory (HBM), for processing real-time highresolution stereo vision images from sensors. In this paper, we propose a stereo vision accelerator structure utilizing HBM, which supports various kernel sizes.

물리검층-탄성파 자료의 대비는 탄성파 자료 해석의 층서 및 퇴적시스템 해석에 큰 영향을 미친다. 따라서물리검층 자료에 비해 탄성파 자료의 낮은 분해능을 향상시킬 필요가 있다. 탄성파 자료의 해상도를 높일 스펙트럼향상 기법은 띠 통과 필터를 이용해 전체 주파수 범위를 여러 개의 좁은 주파수 띠로 분리하며, 나누어진 주파수 띠의중심 주파수에 가중치를 주어 스펙트럼의 모양을 변화시킨 후 모든 주파수 띠를 다시 합치는 과정으로 구성된다. 스펙트럼 향상 기법이 적용된 탄성파 자료는 평균 주파수와 띠폭이 변화되며 수직 분해능이 향상된다. 물리검층자료와의대비 결과 합성 탄성파 기록과 스펙트럼 향상 자료와의 상관도가 원본 자료에 비해 높게 나타났다. 이 연구에서 적용된 스펙트럼 향상기법은 결과적으로 탄성파 반사법 자료의 지질학적 해석 기능을 높일 것으로 기대된다.

Well to seismic tie is a very critical part of seismic interpretation of stratigraphy and depositional system. Improving the vertical resolution of seismic reflection data is essential to correlation of seismic profile to well logging data. Such a work can be achieved through spectral enhancement. Spectral enhancement technique employed in this study includes decomposing the seismic signal into a number of narrow frequency bands through bandpass filtering, spectral shaping through central frequency modulation with weighting factors, and adding back into the original data. Vertical resolution of seismic data is dramatically improved as a result of extended bandwidth and changed mean frequency by spectral enhancement technique. Synthetic trace computed from logging data is well tied to the reflection events improved by this spectral enhancement technique. This method employed in this study will increase the geological interpretability of the seismic reflection data.

최근 기간망의 전송속도는 괄목할 만한 성장을 이루고 있으나 가입자 전송망의 전송속도는 이전 수준에 비교해서 진정이 없는 상태이다. 그래서 가입자 접속 구간은 다수의 LAN과 백본망 사이에 병목지점으로 지적되고 있다. 현재 가입자 구간은 VOD, 양방향게임, 양방향 영상회의와 같은 새로운 대용량 멀티미디어 서비스를 수용하기에 충분한 대역폭을 제공하지 못하고 있다. 그런 가운데 저가의 이더넷 장비와 광선로 인프라를 융합한 EPON(Ethernet Passive Optical Network)이 차세대 가입자 접속망에 가장 적합하다. 하지만 이러한 우수성을 가진 EPON도 안정적인 대용량 멀티미디어 서비스를 제공하기에는 부족함을 가지고 있다. EPON에서 ONU가 수신할 수 있는 대역폭은 1GBPS이지만 송신하기 위한 대역폭은 모든 ONU가 공유해야 하므로 부족하다. 따라서 양방향 초고속 가입자 접속망을 위해 FTTx를 지원하는 EPON의 부족한 상향 전송 대역폭을 충족시키는 상향 대역폭 할당 방법이 필요하다. 본 논문에서는 EPON의 상향 트래픽에 대한 QoS를 보장하기 위한 우선순위 큐를 고려한 가중치 기반의 차등대역폭 할당 방식을 제안한다.

The subscriber access network is cause of the bottleneck phenomenon because equipment and infrastructure were not originally designed for busty high-bandwidth traffic between MAN(Metro Area Network) and LAN(Local Area Network). Whether riding on shorter copper drops or optical fiber, Ethernet is emerging as the future broadband protocol of choice, offering plug and play simplicity, and low cost. EPON(Ethernet Passive Optical Network) combines point-to-multipoint optical infrastructure with low-cost high-bandwidth Ethernet. The future broadband access network will be a combination of point-to-point and point-to-multipoint Ethernet, optimized for transporting IP data, as well as time critical voice and video. EPON is being considered as a novel communications infrastructure for next-generation broadband access network for the convergence of low-cost Ethernet equipment and low-cost fiber infrastructure. But, EPON has a problem with duplex multimedia services. It is the insufficiency of bandwidth for upstream. Because all ONUs use a shared transmission media for upstream. In this paper, we addressed the problem of upstream bandwidth in EPONs. We presented a wavelength division EPON supporting QoS in the differentiated services framework.

본 논문에서는 GEO 기반 위성 네트워크에서의 호 수락 제어 성능을 개선할 수 있는 대역폭 빌림 방법을 제안하였다. 일반적으로 통신이나 스트리밍 서비스의 경우는 고정된 목표 데이터 속도가 있지만, 데이터 서비스의 경우에는 고정된 목표 데이터 속도가 존재하지 않는다. 따라서 데이터 서비스의 경우에는 시스템 부하 상태에 따라서 데이터 속도를 유동적으로 변화시킬 수 있다. 데이터서비스의 이런 특성을 이용하면 시스템에서 이용할 수 있는 대역폭이 충분하지 않는 경우에 데이터 서비스의 데이터 속도를 감소시켜서 실시간 서비스의 호 수락 요청을 받아들일 수 있다. 본 논문에서는 이러한 대역폭 빌림 방법에 대한 큐잉 모델을 만들고 시뮬레이션을 통해 결과를 검증하였다. 시뮬레이션 결과에 따르면 대역폭 빌림 방법을 통해서 전체 블로킹 확률의 8.7-35.2 dB의 이득을 얻을 수 있다.

In this paper, we propose the bandwidth borrowing scheme which improves the performance of the cal admission control of the integrated GEO satellite networks. In general, target transmission rates of communications and streaming services are fixed, but data services do not have the target transmission rates. Therefore, we can control the transmission rates for data services flexibly according to the system loading situation. When the available bandwidth of the system is insufficient, the bandwidth borrowing scheme gives the bandwidth to request real time services by the transmission rates control of data services through packet scheduler. We make the queueing model for our system model and demonstrate the results through simulations. The simulation results show that there is a 8.7-35.2 dB gain at the total blocking probability according to the use of bandwidth borrowing scheme.

윌킨슨 전력분배기 및 90도 하이브리드 회로를 각각 GPS용 마이크로스트립 패치안테나에 적용하여 넓혀진 대역특성 을 비교한다. 패치는 정사각형 패치로 설계하고, 회로를 적용하기 위하여 패치안테나에 2포트 프로브 급전한다. 윌킨슨 전력분배기와 90도 하이브리드 회로를 설계하고 90도 위상차가 나는 출력 포트를 패치안테나에 공급한다. 설계된 패치 와 2가지 회로를 FR4 기판에 구현하고 이들을 각각 결합한다. 구현된 안테나에 대한 정재파비 측정결과 2: 1 기준으로 윌킨슨 전력분배기 적용 때 36.5% 대역폭(1,200~1,775 MHz), 90도 하이브리드 적용 때 29.84% 대역폭(1,230~1,700 MHz) 을 얻었다. 3dB 축비 대역폭은 17.14% 대역폭(1,360~1,630 MHz) 및 15.87% 대역폭(1,400~1,650 MHz)을 얻음으로써 광대 역임이 입증되었고, 윌킨스 전력분배기 적용이 90도 하이브리드 적용보다 좀 더 넓은 대역폭이 나타났다. 무반사실에서 측정한 안테나의 최대이득은 GPS 중심주파수에서 각각 2.84 dBi 및 2.75 dBi를 얻었다.

Enhanced bandwidths of the GPS microstrip patch antennas applied by a Wilkinson power divider and a quadrature hybrid were compared. The square patch was designed, and fed by the two port probes for the circuit application. The Wilkinson power divider and quadrature hybrid circuit were designed, and applied to the patch antenna. The designed patch and two circuits were implemented on the FR4 board, and combined together. The measurement of the bandwidth within a voltage standing wave ratio (VSWR) of 2: 1 were 36.5% (1,200~1,775 MHz) in the case of the Wilkinson power divider and 29.84% (1,230~1,700 MHz) in the case of the quadrature hybrid. Axial ratios (AR) in 3dB were 17.14% bandwidth (1,360~1,630 MHz) and 15.87% bandwidth (1,400~1,650 MHz), respectively. The application of the Wilkinson power divider is wider than that of the quadrature hybrid. The peak gains in the anechoic chamber at the GPS center frequency were measured as 2.84 dBi and 2.75 dBi, respectively.

본 논문에서는 IEEE 802.16e 네트워크 환경에서 기지국이 받은 트래픽을 예측하여 백본 네트워크에서의 대역폭 프로비저닝 방법을 제안한다. 트래픽은 4개의 클래스로 정의하고 각 클래스 별 트래픽을 박스-젠킨스의 시계열 분석법을 사용하여 예측하였다. 이를 바탕으로 프로비저닝을 진행하고 링크의 최대 대역폭을 초과하는 트래픽에 대해서 각 클래스의 우선순위를 최적으로 만족시키는 프로비저닝 방법을 제시하고 우선순위를 고려하지 않은 경우와 비교하였다. 또한 클래스 별 대역폭을 고정적으로 프로비저닝한 경우와 비교하여 패킷의 손실 및 QoS 보장률의 성능이 향상됨을 증명하였다.

In this paper, we propose a dynamic bandwidth provisioning method based on traffic forecasting in IEEE 802.16e packet core network. The traffic is categorized as 4-different classes and the traffic amount of each class is forecasted by the Box-Jenkins method. To increase the service provider’s revenue we provision the bandwidth of 4-different classes dynamically using greedy algorithm. The simulation results show that the number of packet drops is reduced and the level of QoS is improved compared with two different the methods - no priority considering and static provisioning.