Earticle

통신 네트워크상에서 많은 장비가 일관적으로 통신하기 위해서는 일정한 규칙이 필요하 다. 이러한 규칙이 존재함으로써 네트워크에서 장치끼리 서로 통신하는 방식을 공통화 할 수 있으며, 데이터를 정확하고 효율적으로 전송할 수 있다. 이런 규칙들을 네트워크 프로토 콜 이라고 한다. 최초 1966년에 등장한 RTSP, 그 이후 현재 라이브 방송에서 사용되고 있는 RTMP 등 다양한 영상전송 프로토콜이 각 상황에 맞게 적용되면서 그 기술이 발전되 어 왔다. 그러나 기술의 발전에도 불구하고 아직까지는 이용자 요구사항에 맞는 높은 신 뢰성과 우수성 그리고 보안 이슈 영역에 분명한 한계가 있다. 이러한 한계를 극복하기 위 하여 등장한 프로토콜이 SRT(Secure Reliable Transport) 프로토콜이다. SRT 프로토콜은 높 은 신뢰성과 우수성은 물론, 최적의 코덱 지원에서 보안 이슈까지 모두 커버가 가능한 것 으로 실시간으로 유,무선 영상을 전송하는 데에 매우 적합하다고 할 수 있다. 이 논문에서는 현재 다양한 분야에서 사용하는 대표적인 프로토콜 방식에 대한 비교를 통해 장 단점을 이해하고 각각의 프로토콜의 단점을 개선·보완한 차세대 독보적 전송 프로 토콜인 SRT 기술을 정보기관 및 군사 분야에 적용함으로써 영상전송 문제의 해결 방안을 제시함과 동시에 뛰어난 화질과 저지연 전송의 강점을 토대로 점차 활용성이 증가하는 무 인 무기 체계의 고도화 방안을 제시하고자 한다.

Certain rules are required for many equipment to communicate consistently on the communication network. The existence of these rules can commonize the way devices communicate with each other in the network and transmit data accurately and efficiently. These rules are called network protocols. Since then, various image transmission protocols such as RTSP, which first appeared in 1966, and RTMP, which is currently used in live broadcasting, have been applied to each situation, and the technology has been developed. However, despite the advancement of technology, there are still clear limitations in the areas of high reliability, excellence, and security issues that meet user requirements. The protocol that has emerged to overcome these limitations is the Secure Reliable Transport (SRT) protocol. The SRT protocol can cover not only high reliability and superiority, but also all security issues from optimal codec support, and it can be said to be very suitable for transmitting wired and wireless images in real time.By comparing representative protocol methods currently used in various fields, this paper aims to solve the video transmission problem by applying SRT technology, a next-generation unique transmission protocol that understands strengths and weaknesses and improves and supplements the shortcomings of each protocol, to intelligence agencies and military fields.

The performance of cellular networks depends heavily on accurate traffic prediction, as it is essential for smooth service delivery and effective resource management. However, the unpredictable and constantly changing patterns of network activity make this task highly challenging. Traditional forecasting approaches often fall short in representing these complex dependencies, leading to reduced prediction accuracy and inefficiency. To address this issue, the objective of this work is to design a prediction model that is both accurate and computationally efficient. In this paper, we have proposed a lightweight hybrid prediction model integrated with an Advanced Temporal model with Attention Mechanism (ATAM). The temporal attention mechanism enhances the model’s ability to focus on relevant sequential patterns, while the hybrid architecture ensures computational efficiency and scalability for real-time deployment. The model’s performance is evaluated through Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and paired t-test demonstrating significant improvements over traditional forecasting approaches. These findings highlight that combining temporal attention with lightweight architecture enhances predictive performance while maintaining efficiency. In conclusion, the ATAM-based framework offers a reliable solution for traffic prediction in 5G and beyond cellular networks. Further our proposed model can be extended to support adaptive resource allocation strategies, thereby enabling operators to optimize network quality of service while reducing computational overhead.

Purpose: The demand for advanced practice nurses (APNs) has increased globally due to a shortage of physicians and an increased demand for high-quality healthcare. Research is needed on the enhancement of advanced practice nurses' organization commitment. Organization commitment (OC) directly impacts the retention of APNs. This study aims to identify the key factors affecting the OC of advanced practice nurses. Method: A cross-sectional survey was conducted at the largest hospital in South Korea. A total of 189 APNs answered survey questions. A partial least squares-structural equation modeling method was employed to analyze the survey responses. Results: A pay scale of APNs is positively associated with person-organization fit (POF). However, the effect of job location and computer self-efficacy on POF is not significant. Job satisfaction plays a salient direct role in supervision and POF. Job satisfaction is also a significant moderator in the relationship between supervision and POF. POF is significantly associated with both OC and supervision. Supervision has a positive effect on organization commitment. Conclusions: Pay scale, job satisfaction, supervision, and POF are significant factors affecting organization commitment. Establishing an intra-organization entity, such as APN steering committee, to ensure mutual consensus and transparent communication between administrators and APNs would enhance POF, the rating of supervision, and organization commitment.

Methane, one of the important greenhouse gas, has a higher global warming potential than that of carbon dioxide. Agriculture, especially livestock, is considered as the biggest sector in producing anthropogenic methane. Among livestock, ruminants are the highest emitters of enteric methane. Methanogenesis, a continuous process in the rumen, carried out by archaea either with a hydrogenotrophic pathway that converts hydrogen and carbon dioxide to methane or with methylotrophic pathway, which the substrate for methanogenesis is methyl groups. For accurate estimation of methane from ruminants, three methods have been successfully used in various experiments under different environmental conditions such as respiration chamber, sulfur hexafluoride tracer technique, and the automated head-chamber or GreenFeed system. Methane production and emission from ruminants are increasing day by day with an increase of ruminants which help to meet up the nutrient demands of the increasing human population throughout the world. Several mitigation strategies have been taken separately for methane abatement from ruminant productions such as animal intervention, diet selection, dietary feed additives, probiotics, defaunation, supplementation of fats, oils, organic acids, plant secondary metabolites, etc. However, sustainable mitigation strategies are not established yet. A cumulative approach of accurate enteric methane measurement and existing mitigation strategies with more focusing on the biological reduction of methane emission by direct-fed microbials could be the sustainable methane mitigation approaches.

In 2016, Google proposed Bottleneck Bandwidth and Round-trip-time (BBR), a new TCP congestion control algorithm to avoid bottleneck queue formation and utilize underlying bandwidth in full. However, recent reports have found significant flaws in BBR, especially a high packet retransmissions problem, and throughput unfairness issue. We propose BBR Advanced (BBR-A) that resolves these issues by halving the congestion window and slowing down the pacing gain for actual congestion events, which it decides based on packet losses and RTT. Mininet emulation experiments confirm that BBR-A reduces retransmissions up to 60% and increases fairness index up to 10% in comparison with BBR.

The metaverse promises to revolutionize the internet by introducing a new era of three-dimensional objects. The advancements in artificial intelligence and immersive technologies have made the metaverse a trending topic in various industries, including manufacturing. This study aims to provide a comprehensive understanding of the metaverse, its underlying technologies, and the current trends shaping its development. By delving into the concept and potential applications of the metaverse in manufacturing, we seek to uncover its transformative benefits for the industry. Through an exploration of existing use cases, we aim to highlight the practical implications of the metaverse. Recognizing the need for further research, this study also addresses the limitations, privacy concerns, and security implications associated with the metaverse. By examining these aspects, we hope to motivate further investigation and contribute to the ongoing discourse surrounding this emerging paradigm.

Objective To evaluate the compliance and satisfaction of rehabilitation recommendations for advanced cancer patients hospitalized in the palliative care unit. Methods Advanced cancer patients admitted to a hospice palliative care unit were recruited. Patients with advanced cancer and a life expectancy of less than 6 months, as assumed by the oncologist were included. Patients who were expected to die within 3 days were excluded. ECOG and Karnofsky performance scales, function ambulatory category, level of ambulation, and survival days were evaluated under the perspective of comprehensive rehabilitation. Problem-based rehabilitations were provided categorized as physical therapy at the gym, bedside physical therapy, physical modalities, medications and pain intervention. Investigation of compliance for each category was completed. Patient satisfaction was surveyed using a questionnaire. Results Forty-five patients were recruited and received evaluations for rehabilitation perspective. The subjects were reported to have gait-related difficulties (71.1%), pain (68.9%), poor medical conditions (68.9%), bladder or bowel problems (44.4%), dysphagias (11.1%), mental status issues (11.1%), edemas (11.1%), spasticity (2.2%), and pressure sores (2.2%). In the t-test, patients with good compliance for GymPT showed higher survival days (p<0.05). In the satisfaction survey, patients with performance scales showed a greater satisfaction in Spearman’s correlation analysis (p<0.05). Conclusion Advanced cancer patients admitted to the hospice palliative care unit have many rehabilitation needs. Patients with a longer survival time showed better compliance for GymPT. Patients with a better performance scale showed a higher satisfaction. Comprehensive rehabilitation may be needed to advanced cancer patients in the hospice palliative care unit.

Online video services are responsible for a large amount of global data traffic, which is why wireless video caching has become a major focus in order to deal with the increasing amount of data. While conventional caching methods have been successful in reducing file transmission latency and data traffic on the core network, there is still a lot of potential to improve wireless caching for streaming users’ satisfaction, especially as video streaming technology continues to improve. To improve caching, it is important to consider the distinct characteristics of a video file, video encoding, dynamic video streaming, and even 3D video services such as virtual reality (VR) and augmented reality (AR). This paper investigates the distinct video features that can be used to design video caching policies. Additionally, recent studies on wireless video caching and delivery are surveyed, with a focus on four key characteristics: (1) partitioning a video file, (2) encoding a video file into multiple quality versions, (3) recognizing that video file popularity is dynamic and heterogeneous, and (4) understanding that video recommendation affects a series of user requests.

Objective To analyze patient characteristics of cancer rehabilitation and outcomes at our hospital.Methods This retrospective study analyzed 580 patients, who underwent cancer rehabilitation at our hospital and rehabilitation outcome after therapy were investigated. The relationship between the initial Barthel index and discharge outcomes was investigated, with a special focus on cancer patients with bone metastasis. The Barthel index and performance status (Eastern Cooperative Oncology Group) before and after rehabilitation were analyzed, and threshold value of home discharge was calculated from a receiver operating characteristic curve (ROC). General criteria for home discharge from our hospital included independence in performing basic activities of daily living such as bathing, feeding, and toileting or availability of home support from a family member/caregiver.Results The outcomes after rehabilitation among all the patients were as follows: discharge home 59%, death 13%, and others 27%. Statistical differences were observed between the initial and final values of the Barthel index in patients with bone metastasis, who could be discharged home (p=0.012). ROC analysis of the initial Barthel index for predicting home discharge revealed a threshold value of 60, sensitivity of 0.76, and specificity of 0.72.Conclusion The patients with bone metastasis had a lower rate of home discharge and a higher rate of mortality than all the study patients who underwent cancer rehabilitation at our hospital. It is proposed that at the time of initiation of rehabilitation for patients with bone metastasis, an initial Barthel index lower than 60 might predict a worse outcome than home discharge.

The dilated cardiomyopathy is the common type of cardiomyopathy, and its distinctive characteristic is the systolic dysfunction. Not many reports were issued about the efficacy of cardiac rehabilitation in patients with an advanced dilated cardiomyopathy until yet. A 50-year-old man who was diagnosed with dilated cardiomyopathy with congestive heart failure was admitted to the emergency room after a sudden collapse and a ventricular fibrillation was presented in the actual electrocardiogram. After three months, the patient participated in an 8-week cardiac rehabilitation program with electrocardiogram monitoring for 50 minutes per session at five times per week. The maximal oxygen consumption improved from 13.5 to 19.4 mL/kg/min during this time. At 3.9 metabolic equivalents, the myocardial oxygen demand decreased from 21,710 to 12,669 mmHg.bpm and the Borg’s scale of perceived exertion decreased from 15 to 9. The left ventricular ejection fraction improved from 14% to 19%. So in this case report will be presented a patient after a successful cardiac rehabilitation program. Before this the patient suffered from a much more advanced dilated cardiomyopathy and was resuscitated from cardiac arrest.

Objective: To investigate the effects of a home-based rehabilitation program on physical capacity, lung function, and health-related quality of life (QOL) in patients with advanced lung cancer undergoing platinum-based chemotherapy.Methods: Between December 2021 and December 2023, participants were randomly assigned to exercise and control groups. The exercise group engaged in a home-based exercise program, including respiratory, aerobic, and resistance training, for 60 minutes per session, three times per week, before the first tumor response evaluation. Outcome evaluations included the 6-minute walk test, spirometry to measure lung function (specifically assessing forced expiratory volume in 1 second [FEV1] and forced vital capacity, hand grip strength, and QOL assessments using the Short Form 36-Item Health Survey and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Lung Cancer Module 29. Participants were assessed at baseline, post-intervention, and followed up for 1 year.Results: Twenty-one of the 26 participants completed the study. The control group showed a significant decrease in FEV1 (p=0.011). Delays in chemotherapy occurred in 40.0% of participants in the control group but none in the exercise group (p=0.019). Mental health showed improvement in the exercise group (p=0.041), whereas adverse effects were more common in the control group (p=0.007), according to QOL questionnaire results.Conclusion: Home-based rehabilitation during chemotherapy may help maintain lung function, improve mental health, and reduce side effects in patients with lung cancer, warranting further research.

CrossRef is an association of scholarly publishers that develops shared infrastructure to support more effective scholarly communications. This infrastructure is centred around the Digital Object Identifier (DOI), and the associated bibliographic metadata that publishers deposit with CrossRef. To deposit this metadata, publishers need to provide the relevant information to CrossRef in extensible markup language (XML). Some publishers have a high level of XML expertise, and some are less familiar with formatting XML and need more assistance in order to register DOIs with CrossRef. There are some basics of depositing which can be picked up quickly, with the help of CrossRef tools, but there is a lot of information that publishers can provide via their XML to supplement the basic deposit information. This article will cover some of the more advanced information that publishers can deposit with CrossRef when they register DOIs, to help them participate in additional CrossRef services and provide additional value for the scholarly research community.

Purpose: The purpose of the present study was to assess factors associated with quality of life (QOL) and to determine whether anxiety and depression are predictive of QOL in patients with advanced gastrointestinal cancer at initial diagnosis and during the treatment process. Methods: One hundred and twenty patients with gastrointestinal cancer requiring palliative chemotherapy were enrolled. Results: At baseline, depression, performance status, and anxiety accounted for 55.0% (p<.001) of the variance in global health status score, depression accounted for 22.0% (p<.001) of the variance in functional scales score, and anxiety accounted for 19.0% (p<.001) of the variance in symptom scales score. At 3 months, depression, pain, and performance status accounted for 72.0% (p<.001) of the variance in global health status score, 76.0% (p<.001) of the variance in functional scales score, and 74.0% (p<.001) of the variance in symptom scales score. Conclusion: Anxiety and depression were significant predictive factors of QOL in patients with advanced gastrointestinal cancer. Depression and performance status were significant predictive factors of QOL at both baseline and 3 months, and anxiety and pain were significant predictive factors of QOL at baseline and 3 months, respectively.

Purpose The current study aimed to examine the casual relationships among belongingness during clinical practice, stress, satisfaction with clinical practice, and self-esteem, which are factors affecting the selfdirected learning that results from the clinical practice of advanced practice nurse (APN) students. Methods Data were collected between April 5 and May 19, 2010, from 202 students in 11 APN training institutions located in and outside of Seoul, who were selected using convenience sampling. For hypothesis testing, the collected data were analyzed using AMOS 8.0. Results Analysis of the path coefficients in this study showed that 37% of the variation in self-directed learning could be explained by variations in the model. Self-esteem and belongingness during clinical practice directly affected the self-directed learning of APN students, and belongingness also had an indirect effect via self-esteem. However, stress and satisfaction with clinical practice had no significant mediating effect on self-directed learning. At the same time, belongingness during clinical practice was found to be a good predictive factor to explain stress and satisfaction with clinical practice. Conclusions This study demonstrated the hierarchical relationship among belongingness, self-esteem,and self-directed learning based on the conceptual framework developed by Levett-Jones and Lathlean,thus proving the usefulness of this framework for application in the field. Therefore, this study found that there are needs of high self-esteem and belongingness in order to improve self-directed learning for APN students in clinical practice. [Asian Nursing Research 2011;5(1):48?59]

Purpose: Advanced schistosomiasis, the most severe stage of Schistosoma japonicum infection, profoundlyimpairs patients’ quality of life (QoL) and increases vulnerability to anxiety and depression. Since 2004, China has launched a medical assistance program for the patients with access to medicaland/or surgical treatment, in which health workers have incorporated nursing interventions to addressthese challenges. This meta-analysis evaluated the effects of nursing interventions on QoL, anxiety,depression, and complications in advanced schistosomiasis patients. Methods: Seven databases [PubMed, Web of Science, the Cochrane Library, China Biology Medicine, ChinaNational Knowledge Infrastructure, China Science and Technology Journal Database, and Wanfang] weresystematically searched for randomized controlled trials up to August 1, 2024. Data were analyzed usingReview Manager 5.4 (Cochrane Collaboration) and R 4.2.3 (R Project, a free, open-source language andenvironment primarily used for statistical computing and graphics). Outcomes included QoL (WorldHealth Organization Quality of Life Brief scale and Karnofsky performance status), anxiety (Self-ratingAnxiety Scale), depression (Self-rating Depression Scale), and complications. The protocol was previouslyregistered with the International Prospective Register of Systematic Reviews (CRD42023406707). Results: A total of 23 studies with 2232 patients were included. Nursing interventions improved QoL withgreater benefits observed in longer intervention periods. Anxiety (standardized mean difference: -1.52,95% confidence interval (CI): -2.10 to ?? 0.94) and depression (standardized mean difference: -1.13, 95% CI:-1.43 to ?? 0.84) scores were markedly reduced. The risk of complications decreased by 64% (relative risk:0.36, 95% CI: 0.27 to 0.48). Subgroup analyses highlighted age as a key modifier of intervention efficacy. Conclusion: Nursing interventions effectively enhance QoL, alleviate psychological distress, and reducecomplications in advanced schistosomiasis patients. These findings advocate for integrating structurednursing protocols into China’s national healthcare programs and global schistosomiasis managementstrategies.

Fractal arrays are repetitive-geometry-based smart arrays having impressive array factor properties. However, the performance of these arrays degrades owing to their large number of antenna elements at higher expansion levels. This research work presents the thinning of Sierpinski fractal arrays while keeping an applicable balance between all array factor properties by using two types of bounded binary-fractal-tapering techniques known as Sierpinski and Haferman carpet anti-diagonal tapering techniques. Approximately 22% to 50% of antenna elements are thinned in each successive iteration of the Sierpinski fractal array with the proposed tapering techniques.

Purpose The purposes of this study were to develop a taxonomy for detection of errors related to hypertension management and to apply the taxonomy to retrospectively analyze the documentation of nurses in Advanced Practice Nurse (APN) training. Method We developed the Hypertension Diagnosis and Management Error Taxonomy and applied it in a sample of adult patient encounters (N= 15,862) that were documented in a personal digital assistantbased clinical log by registered nurses in APN training. We used Standard Query Language queries to retrieve hypertension-related data from the central database. The data were summarized using descriptive statistics. Result Blood pressure was documented in 77.5% (n = 12,297) of encounters; 21% had high blood pressure values. Missed diagnosis, incomplete diagnosis and misdiagnosis rates were 63.7%, 6.8% and 7.5% respectively. In terms of treatment, the omission rates were 17.9% for essential medications and 69.9% for essential patient teaching. Contraindicated anti-hypertensive medications were documented in 12% of encounters with co-occurring diagnoses of hypertension and asthma. Conclusion The Hypertension Diagnosis and Management Error Taxonomy was useful for identifying errors based on documentation in a clinical log. The results provide an initial understanding of the nature of errors associated with hypertension diagnosis and management of nurses in APN training. The information gained from this study can contribute to educational interventions that promote APN competencies in identification and management of hypertension as well as overall patient safety and informatics competencies. [Asian Nursing Research 2010;4(1):19?31]

본 논문에서는 4세대 이동통신 기술표준인 LTE/LTE-A 시스템에서 기존 실외 기지국인 eNB 에 집중되는 이동통신 트래픽 부하를 경감시키고 실내 사용자에게 만족스런 통신품질을 제공하여 더 많은 가입자를 수용하기 위해 적용되고 있는 초소형 실내 기지국인 펨토셀(FemtoCell)에서 발생할 수 있는 다양한 유형의 핸드오버 문제의 최적화 방법을 제시하였다. LTE/LTE-A에서는 펨토셀의 최적 설치와 운용을 위해 자가구성네트워크(SON) 기술이 제안되고 있으며, 특히 실내 사용자의 펨토셀간 이동시 발생할 수 있는 링크절체(RLF)에 의한 핸드오버 문제의 최소화를 위해 핸드오버 파라미터를 최적화하는 MRO 기능이 적용된다. 펨토셀간의 핸드오버에서는 너무 이른 핸드오버, 너무 늦은 핸드 오버 그리고 잘못된 셀로의 핸드오버의 세 가지 유형의 핸드오버 문제가 발생한다. 본 논문에서는 이 러한 세 가지 유형의 핸드오버에서 발생하는 RLF에 의한 핸드오버 문제를 해결하기 위한 효과적인 핸드오버 파라미터 최적화 방안을 제시하고 분석하였다. 본 논문에서 제안하는 MRO 기법은 단말기 에서 측정된 펨토셀들의 수신신호 강도를 기반으로 서빙셀과 타겟셀의 CIO 값을 적응적으로 조정할 수 있는 최적화 기법이다. 다섯 개의 펨토셀로 구성된 모의실험환경에 대한 성능분석 연구결과 본 논 문에서 제안한 MRO 기법은 이 알고리즘을 적용하지 않은 환경에 비해 약 80% 정도의 성능개선 효 과를 제공한다. 따라서 본 논문에서 제안한 펨토셀의 핸드오버 문제 해결과 최적화를 위한 MRO 기 법은 실내 사용자를 위한 LTE-A시스템의 펨토셀 환경에서 효과적인 RLF 방지와 개선을 위해 적용 될 수 있을 것으로 기대된다.

The Self-Organizing Network(SON) technology has been developed in 3GPP Release 10 and 11 standard, so called the LTE-Advanced system, for automatic configuration, operation and maintenance of indoor and outdoor base-stations. In particular, the Femtocell, also called a HeNB(Home eNB), is tending to be deployed not only to accommodate indoor mobile communication users, but also to diverge heavy traffic load concentrated to the outdoor base-station(eNB). The Femtocell is connected to the indoor wired communication networks such as Internet. In such LTE/LTE-A Femtocell systems, three types of handover problems such as too late handover, too early handover and to wrong cell handover problems may occur due to inappropriate handover parameters configuration and its resulting radio link failure(RLF). In this paper, a Mobility Robustness Optimization(MRO) algorithm is proposed to tackle the three handover problems in the LTE-A Femtocell systems. Simulation results show that the proposed MRO algorithm is capable to improve such handover problems up to 80% by optimizing handover parameters automatically. The proposed MRO algorithm will play an important role in providing better communication services to the users in the LTE-A indoor environment where many Femtocells are deployed.

본 논문에서는 3GPP release 10과 11 기술표준인 LTE-A 시스템에서 사용되는 초소형 실내 기지국인 HeNB 적용 시 발생할 수 있는 핸드오버 실패 문제의 방법을 제시하였다. LTE-A에서 기지 국의 최적 설치, 운용을 위해 새롭게 개발된 기술인 자가구성네트워크(SON) 기술에는 기지국 설치를 위한 자가설정기술, 기지국 최적 운용을 위한 자가최적화 기술, 그리고 문제 발생 시에 적용하는 자가 치유기술이 있다. 핸드오버 문제는 기지국 운용 시에 발생하는 문제로서 자가최적화기술 중 핸드오버 시 RLF를 최소화하기 위해 핸드오버 파라미터를 최적화하는 MRO 기능이 적용된다. LTE-A의 HeNB 간 핸드오버 시에는 너무 이른 핸드오버, 너무 늦은 핸드오버 그리고 잘못된 셀로의 핸드오버의 세 가 지 문제가 발생한다. 본 논문에서는 너무 늦은 핸드오버 발생과 이로 따른 RLF 발생으로 인한 성능 저하 문제를 제시하고 이의 해결방안을 제시하였다. 제안된 MRO 기법은 UE에서 측정된 수신신호강 도를 기반으로 서빙셀과 타겟셀의 CIO 값을 적응적으로 적용할 수 있는 최적화 기법이다. 모의실험 을 통한 성능분석 연구결과 본 논문에서 제안한 MRO 기법은 이 알고리즘을 적용하지 않은 환경에 비해 약 80% 정도의 성능개선 효과를 제공한다. 따라서, 본 논문에서 제안한 너무 늦은 핸드오버 방 지를 위한 MRO 기법은 LTE-A시스템의 HeNB 적용 환경에서 RLF 의 효과적인 방지와 개선을 위 해 적용될 수 있을 것으로 기대된다.

The Self-Organizing Network(SON) technology has been developed in 3GPP Release 10 and 11 standard, so called the LTE-Advanced system, for automatic configuration, operation and maintenance of eNBs and HeNBs. A HeNB is deployed to cover few users, typically in a home or small indoor environments, using a transport technology such as Internet connection. In such LTE-A HeNB systems, three types of handover problems, too late, too early and to wrong cell handover problems, occur due to inappropriate handover parameters configuration. In this paper, a Mobility robustness optimization(MRO) algorithm is proposed to address the too late handover problem in the LTE-A HeNB systems. Simulation results show that the proposed MRO algorithm is able to improve key performance index(KPI) of too late handover up to 80% by adjusting handover parameters automatically. The proposed MRO algorithm can be applied to the LTE-A indoor environment where many HeNBs are deployed.