• Title/Summary/Keyword: Wireless Cellular Network

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An Effective Hotspot Cell Management Scheme Using Adaptive Handover Time in 4G Mobile Networks (4G 이동 망에서 적응적 핸드오버 시간을 활용한 효과적인 핫스팟 셀 관리 기법)

  • Kim Dong-Wook;Lee Han-Jin;Jeon Seung-Woo;Sawhney Mrinalini;Yoon Hyun-Soo
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.06d
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    • pp.217-219
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    • 2006
  • 4G mobile networks are expected to support various multimedia services over IP networks and also satisfy high spectral efficiency requirement. In cellular systems including 4G networks, hotspot cells can occur when available wireless resources at some location are not enough to sustain the needs of users. The hotspot cell can potentially lead to blocked and dropped calls, which can deteriorate the service quality for users. In a 4G mobile network, a band of users enjoying multimedia services can move around, which may generate heavy flows of traffic load. This situation can generate the hotspot cell which has a short life span of only a few minutes. In this paper, we propose a handover-based scheme which can effectively manage hotspot cells in 4G mobile networks. With the scheme, the current serving cell can recognize the load status of the target cell in advance before handover execution. Adaptive handover time control according to the amount of traffic load of cells can effectively and flexibly manage the hotspot cell in the network. And, through our hotspot cell management scheme, acceptable service quality can be supported as users continuously maintain connections with the network. In the simulation results, we find that our scheme generates smaller number of hotspot cells and supports higher service quality than the compared schemes.

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Analysis of Mobility Robustness Optimization Technology in LTE Self Organization Networks (LTE 자가구성 네트워크에서 MRO 기술 분석)

  • Yang, Mo-Chan
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.6
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    • pp.1025-1030
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    • 2019
  • This paper describes SON(: Self Organization Network) technology in LTE networks. The SON is a unique feature of LTE compared to previous cellular systems such as UMTS and GSM, and it is a tool that effectively derives the best performance in the time-varying wireless radio environment. Also, the SON has the ability for the operator to automate the setting of the network, allowing for centralized planning and reducing the need for manual work. The SON is largely divided into three categories: Self-Configuration, Self-Optimization, and Self-Healing. Each large categories has a detailed description of technology, and the technologies in each categories are gathered to complete the technology called the SON. In this paper, we focus on MRO which is one of the Self-Optimization technique in each of the three categories.

Analytical Approach of Cross-Layer-Based Handoff Scheme in Heterogeneous Mobile Networks (이종의 모바일 네트워크에서 크로스 레이어 기반 핸드오버 기법의 분석적 접근법)

  • Kim, DongHwi;Jeong, Jongpil
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.6
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    • pp.1-16
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    • 2013
  • Smartphones and tablets including phone, calendar are the necessities of modern man. They are one of the MN(Mobile Node), each with wireless network capabilities. Necessities of modern human MNs are almost included cellular module available in LTE/3G and Wi-Fi module for high-speed Internet. Until now, MN mobility management is handled, but using network-based mobility management in this paper. Then, carriers can manage and maintain the network for low-cost. In addition, it was considered that use a lot of modern people with Wi-Fi and LTE/3G, and using Cross-Layer-Based handoff.

Design and Implementation of Ubiquitous Parking Management System using Sensor Network (센서 네트워크를 이용한 유비쿼터스 주차관리 시스템의 설계 및 구현)

  • Byun, Chang-Hee;Lee, Je-Hye;Joe, Hyun-Woo;Kim, Hyung-Shin
    • Journal of KIISE:Computing Practices and Letters
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    • v.13 no.6
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    • pp.388-396
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    • 2007
  • In this paper, a ubiquitous parking management system(UPMS) using sensor network is proposed. Ubiquitous parking management system provides information on free space in the parking lot through PDA or cellular phone connected to wireless LAN. For the implementation of UPMS, we have developed sensor node, sensor application and web server application. The proposed system periodically updates parking space data and monitors in real-time according to the user's request from the personal internet device. Collected parking data are stored onto the database for further analysis. The implemented UPMS system was installed on campus parking lot using 10 sensor nodes and we successfully demonstrated its feasibility by accessing the web server from out of the campus.

Radio Resource Management of CoMP System in HetNet under Power and Backhaul Constraints

  • Yu, Jia;Wu, Shaohua;Lin, Xiaodong;Zhang, Qinyu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.11
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    • pp.3876-3895
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    • 2014
  • Recently, Heterogeneous Network (HetNet) with Coordinated Multi-Point (CoMP) scheme is introduced into Long Term Evolution-Advanced (LTE-A) systems to improve digital services for User Equipments (UEs), especially for cell-edge UEs. However, Radio Resource Management (RRM), including Resource Block (RB) scheduling and Power Allocation (PA), in this scenario becomes challenging, due to the intercell cooperation. In this paper, we investigate the RRM problem for downlink transmission of HetNet system with Joint Processing (JP) CoMP (both joint transmission and dynamic cell selection schemes), aiming at maximizing weighted sum data rate under the constraints of both transmission power and backhaul capacity. First, joint RB scheduling and PA problem is formulated as a constrained Mixed Integer Programming (MIP) which is NP-hard. To simplify the formulation problem, we decompose it into two problems of RB scheduling and PA. For RB scheduling, we propose an algorithm with less computational complexity to achieve a suboptimal solution. Then, according to the obtained scheduling results, we present an iterative Karush-Kuhn-Tucker (KKT) method to solve the PA problem. Extensive simulations are conducted to verify the effectiveness and efficiency of the proposed algorithms. Two kinds of JP CoMP schemes are compared with a non-CoMP greedy scheme (max capacity scheme). Simulation results prove that the CoMP schemes with the proposed RRM algorithms dramatically enhance data rate of cell-edge UEs, thereby improving UEs' fairness of data rate. Also, it is shown that the proposed PA algorithms can decrease power consumption of transmission antennas without loss of transmission performance.

A Mesh Router Placement Scheme for Minimizing Interference in Indoor Wireless Mesh Networks (실내 무선 메쉬 네트워크에서의 간섭 최소화를 위한 메쉬 라우터 배치 기법)

  • Lee, Sang-Hwan
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.4
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    • pp.421-426
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    • 2010
  • Due to the ease of deployment and the extended coverage, wireless mesh networks (WMNs) are gaining popularity and research focus. For example, the routing protocols that enhance the throughput on the WMNs and the link quality measurement schemes are among the popular research topics. However, most of these works assume that the locations of the mesh routers are predetermined. Since the operators in an Indoor mesh network can determine the locations of the mesh routers by themselves, it is essential to the WMN performance for the mesh routers to be initially placed by considering the performance issues. In this paper, we propose a mesh router placement scheme based on genetic algorithms by considering the characteristics of WMNs such as interference and topology. There have been many related works that solve similar problems such as base station placement in cellular networks and gateway node selection in WMNs. However, none of them actually considers the interference to the mesh clients from non-associated mesh routers in determining the locations of the mesh routers. By simulations, we show that the proposed scheme improves the performance by 30-40% compared to the random selection scheme.

Considerations of Automatic Passenger Counting System using Infrared Sensors at doorway in Overseas Railway Transit (적외선 센서를 이용한 자동 승객 계수 시스템에 대한 고찰)

  • Kim, Jin-Seok;Gwak, Ho-Seung
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.418-423
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    • 2009
  • Unlike domestic railway transportation system in which majority of station are equipped with gate access controller and ticket office, it has been a very common practice in overseas railway transit or railway station that they use a pressure door mat, infrared-sensors or CCTV cameras so as to automatically determine the number of passenger onboard and alight and to reflect the information to their business (i.e., deployment of vehicles and human resources). The data collected by the automatic passenger counting (APC) system provides methods how to obtain the information about the number of passenger using the vehicles on the basis of date, time and stop(station) which enables large-scaled transit company to create profits through effective vehicle deployment and management of their employees. This paper addresses the basic features of the automatic passenger counting system using infrared sensor and describes those of the extended APC system in conjunction with wireless technologies such as GPS, WLAN or Cellular network.

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3GPP LTE-Assisted Wi-Fi-Direct: Trial Implementation of Live D2D Technology

  • Pyattaev, Alexander;Hosek, Jiri;Johnsson, Kerstin;Krkos, Radko;Gerasimenko, Mikhail;Masek, Pavel;Ometov, Aleksandr;Andreev, Sergey;Sedy, Jakub;Novotny, Vit;Koucheryavy, Yevgeni
    • ETRI Journal
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    • v.37 no.5
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    • pp.877-887
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    • 2015
  • This paper is a first-hand summary on our comprehensive live trial of cellular-assisted device-to-device (D2D) communications currently being ratified by the standards community for next-generation mobile broadband networks. In our test implementation, we employ a full-featured 3GPP LTE network deployment and augment it with all necessary support to provide realtime D2D connectivity over emerging Wi-Fi-Direct (WFD) technology. As a result, our LTE-assisted WFD D2D system enjoys the required flexibility while meeting the existing standards in every feasible detail. Further, this paper provides an account on the extensive measurement campaign conducted with our implementation. The resulting real-world measurements from this campaign quantify the numerical effects of D2D functionality on the resultant system performance. Consequently, they shed light on the general applicability of LTE-assisted WFD solutions and associated operational ranges.

Design and Evaluation of a Rough Set Based Anomaly Detection Scheme Considering Weighted Feature Values (가중 특징 값을 고려한 러프 집합 기반 비정상 행위 탐지방법의 설계 및 평가)

  • Bae, Ihn-Han;Lee, Hwa-Ju;Lee, Kyung-Sook
    • Journal of Korea Multimedia Society
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    • v.9 no.8
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    • pp.1030-1036
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    • 2006
  • The rapid proliferation of wireless networks and mobile computing applications has changed the landscape of network security. Anomaly detection is a pattern recognition task whose goal is to report the occurrence of abnormal or unknown behavior in a given system being monitored. This paper presents an efficient rough set based anomaly detection method that can effectively identify a group of especially harmful internal masqueraders in cellular mobile networks. Our scheme uses the trace data of wireless application layer by a user as feature value. Based on the feature values, the use pattern of a mobile's user can be captured by rough sets, and the abnormal behavior of the mobile can be also detected effectively by applying a roughness membership function considering weighted feature values. The performance of our scheme is evaluated by a simulation. Simulation results demonstrate that the anomalies are well detected by the method that assigns different weighted values to feature attributes depending on importance.

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QoS-Oriented User Association in HetNet with a Backhaul Constraint (백홀 용량이 제한된 이기종 네트워크에서 QoS를 고려한 셀 선택 기법)

  • Yang, Chan S.;Kang, Chung G.
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.10
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    • pp.654-663
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    • 2014
  • Heterogeneous network (HetNet) with the various types of cells, e.g., with the different cell size and transmit power, has been introduced to improve the cell coverage and areal capacity in cellular mobile communication system. In this paper, we consider a practical situation in which all cells share the same wireless resource while some of them have a limited backhaul capacity. More specifically, we formularize a cell association problem that utilizes the minimum wireless resource while satisfying the quality of service (QoS) of all users in terms of their transmission time constraint, and propose a distributed algorithm to find the optimal solution. In the event of bottleneck at the backhaul link in some small cells, the proposed algorithm off-loads some users to the adjacent cell with the less congested backhaul capacity. Finally, we verify that the proposed algorithm supports the more numbers of users to satisfy the specified level of QoS than the conventional user association scheme under the limited access and backhaul capacities.