• 제목/요약/키워드: Cellular Network Design

검색결과 112건 처리시간 0.024초

유전자 알고리즘을 이용한 다중계층 채널할당 셀룰러 네트워크 설계 (Hierarchical Cellular Network Design with Channel Allocation Using Genetic Algorithm)

  • 이상헌;박현수
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2005년도 추계학술대회 및 정기총회
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    • pp.321-333
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    • 2005
  • With the limited frequency spectrum and an increasing demand for cellular communication services, the problem of channel assignment becomes increasingly important. However, finding a conflict free channel assignment with the minimum channel span is NP hard. As demand for services has expanded in the cellular segment, sever innovations have been made in order to increase the utilization of bandwidth. The innovations are cellular concept, dynamic channel assignment and hierarchical network design. Hierarchical network design holds the public eye because of increasing demand and quality of service to mobile users. We consider the frequency assignment problem and the base station placement simultaneously. Our model takes the candidate locations emanating from this process and the cost of assigning a frequency, operating and maintaining equipment as an input. In addition, we know the avenue and demand as an assumption. We propose the network about the profit maximization. This study can apply to GSM(Global System for Mobile Communication) which has 70% portion in the world. Hierarchical network design using GA(Genetic Algorithm) is the first three-tier (Macro, Micro, Pico) model, We increase the reality through applying to EMC (Electromagnetic Compatibility Constraints). Computational experiments on 72 problem instances which have 15${\sim}$40 candidate locations demonstrate the computational viability of our procedure. The result of experiments increases the reality and covers more than 90% of the demand.

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셀룰러 토폴로지를 이용한 솔리드 모델 스트리밍 (Streaming of Solid Models Using Cellular Topology)

  • 이재열;김현
    • 산업공학
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    • 제16권spc호
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    • pp.87-92
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    • 2003
  • Progressive mesh representation and generation have become one of the most important issues in network-based computer graphics. However, current researches are mostly focused on triangular mesh models. On the other hand, solid models are widely used in industry and are applied to advanced applications such as product design and virtual assembly. Moreover, as the demand to share and transmit these solid models over the network is emerging, the generation and the transmission of progressive solid models depending on specific engineering needs and purpose are essential. In this paper, we present a Cellular Topology-based approach to generating and transmitting progressive solid models from a feature-based solid model for internet-based design and collaboration. The proposed approach introduces a new scheme for storing and transmitting solid models over the network. The Cellular Topology (CT) approach makes it possible to effectively generate progressive solid models and to efficiently transmit the models over the network with compact model size.

셀룰러 망에서 SIP 재전송 간격조절에 의한 성능 개선과 이를 이용한 홈 네트워크 구현 (Improving the Performance of Cellular Network by Controlling SIP Retransmission Time Interval and Implementing Home Network)

  • 권경희;김진희;고윤미
    • 한국콘텐츠학회논문지
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    • 제8권2호
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    • pp.67-73
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    • 2008
  • 최근 이동통신의 급격한 발전으로 인해 IP를 기반으로 한 네트워크에서 제공되던 멀티미디어 서비스가 이동단말기에서도 가능케 되고 있다. 셀룰러 망에서는 다양한 멀티미디어 서비스를 제공하기 위해 SIP(Session initiation Protocol)를 호 설정 프로토콜로 사용하는 추세이다. 그러나 높은 비트 에러율, 좁은 대역폭을 사용하는 셀룰러 망에서 기존 SIP RTI(Retransmission Time Interval : 재전송 타임 간격) 값은 오히려 네트워크 성능을 저하시키고 호 설정 시간을 지연시킨다. 본 논문에서는 시뮬레이터 NS-2를 이용하여 셀룰러 망에서의 호 설정 시간을 최소화하는 적합한 SIP RTI 값을 찾아 성능을 향상하였고 그 값을 적용하여 SIP를 이용한 홈 네트워크를 설계, 구현하였다.

셀룰러 토폴로지를 이용한 프로그레시브 솔리드 모델 생성 및 전송 (Generation and Transmission of Progressive Solid Models U sing Cellular Topology)

  • 이재열;이주행;김현;김형선
    • 한국CDE학회논문집
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    • 제9권2호
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    • pp.122-132
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    • 2004
  • Progressive mesh representation and generation have become one of the most important issues in network-based computer graphics. However, current researches are mostly focused on triangular mesh models. On the other hand, solid models are widely used in industry and are applied to advanced applications such as product design and virtual assembly. Moreover, as the demand to share and transmit these solid models over the network is emerging, the generation and the transmission of progressive solid models depending on specific engineering needs and purpose are essential. In this paper, we present a Cellular Topology-based approach to generating and transmitting progressive solid models from a feature-based solid model for internet-based design and collaboration. The proposed approach introduces a new scheme for storing and transmitting solid models over the network. The Cellular Topology (CT) approach makes it possible to effectively generate progressive solid models and to efficiently transmit the models over the network with compact model size. Thus, an arbitrary solid model SM designed by a set of design features is stored as a much coarser solid model SM/sup 0/ together with a sequence of n detail records that indicate how to incrementally refine SM/sup 0/ exactly back into the original solid model SM = SM/sup 0/.

진화하는 셀룰라 오토마타 신경망의 하드웨어 구현에 관한 연구 (A Study on Implementation of Evolving Cellular Automata Neural System)

  • 반창봉;곽상영;이동욱;심귀보
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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    • pp.255-258
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    • 2001
  • This paper is implementation of cellular automata neural network system which is a living creatures' brain using evolving hardware concept. Cellular automata neural network system is based on the development and the evolution, in other words, it is modeled on the ontogeny and phylogeny of natural living things. The proposed system developes each cell's state in neural network by CA. And it regards code of CA rule as individual of genetic algorithm, and evolved by genetic algorithm. In this paper we implement this system using evolving hardware concept Evolving hardware is reconfigurable hardware whose configuration is under the control of an evolutionary algorithm. We design genetic algorithm process for evolutionary algorithm and cells in cellular automata neural network for the construction of reconfigurable system. The effectiveness of the proposed system is verified by applying it to time-series prediction.

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Network 분석과 신경망을 이용한 Cellular 생산시스템 설계 (Network Analysis and Neural Network Approach for the Cellular Manufacturing System Design)

  • 이홍철
    • 대한산업공학회지
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    • 제24권1호
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    • pp.23-35
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    • 1998
  • This article presents a network flow analysis to form flexible machine cells with minimum intercellular part moves and a neural network model to form part families. The operational sequences and production quantity of the part, and the number of cells and the cell size are taken into considerations for a 0-1 quadratic programming formulation and a network flow based solution procedure is developed. After designing the machine cells, a neural network approach for the integration of part families and the automatic assignment of new parts to the existing cells is proposed. A multi-layer backpropagation network with one hidden layer is used. Experimental results with varying number of neurons in hidden layer to evaluate the role of hidden neurons in the network learning performance are also presented. The comprehensive methodology developed in this article is appropriate for solving large-scale industrial applications without building the knowledge-based expert rule for the cellular manufacturing environment.

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이동통신망과 WiBro망과의 연동을 위한 네트워크 아키텍처와 구현방안 (Design and Implementation of Interworking Architecture between 3G Cellular Network and Wireless Broadband Network)

  • 우대식;박성수;이동학;유재황;임종태
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2006년도 하계학술대회
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    • pp.47-52
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    • 2006
  • In this paper, we suggested new network architecture to provide seamless service between the cellular system and new wireless broadband network such as IEEE 802.16e, called WiBro. The interworking technologies are very important issue because mobile operator should provide service connectivity between various wireless networks based on different access technologies. Moreover a change and modification on legacy network should be minimized for providing interworking with new wireless broad-band network. We implemented proposed interworking architecture between 3G cellular network and 802.16e network to provide seamless service including interworking unit in real test environment. Also, we performed performance evaluation in hybrid network environments.

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라그랑지안 기반의 휴리스틱 기법을 이용한 셀룰러 모바일 네트워크의 설계 (Designing Cellular Mobile Network Using Lagrangian Based Heuristic)

  • 홍정만;이종협
    • 대한산업공학회지
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    • 제37권1호
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    • pp.19-29
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    • 2011
  • Cellular network is comprised of several base stations which serve cellular shaped service area and each base station (BS) is connected to the mobile switching center (MSC). In this paper, the configuration modeling and algorithm of a cellular mobile network with the aim of minimizing the overall cost of operation (handover) and network installation cost (cabling cost and installing cost of mobile switching center) are considered. Handover and cabling cost is one of the key considerations in designing cellular telecommunication networks. For real-world applications, this configuration study covers in an integrated framework for two major decisions: locating MSC and assigning BS to MSC. The problem is expressed in an integer programming model and a heuristic algorithm based on Lagrangian relaxation is proposed to resolve the problem. Searching for the optimum solution through exact algorithm to this problem appears to be unrealistic considering the large scale nature and NP-Completeness of the problem. The suggested algorithm computes both the bound for the objective value of the problem and the feasible solution for the problem. A Lagrangian heuristics is developed to find the feasible solution. Numerical tests are performed for the effectiveness and efficiency of the proposed heuristic algorithm. Computational experiments show that the performance of the proposed heuristics is satisfactory in the quality of the generated solution.

셀형유연조립시스템에서의 네트웍형 셀배치 (Network-type Cell Layout in Cellular Flexible Assembly Systems)

  • 노인규;최형호
    • 산업경영시스템학회지
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    • 제19권39호
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    • pp.63-73
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    • 1996
  • With the success of flexible manufacturing systems (FMSs), flexible assembly systems (FASs) have been developed to automate factories further. As in a cellular FMS, a cellular FAS is considered as the most flexible and feasible assembly system configuration Because of the differences between manufacturing and assembly operation, the logic of cell formation and cell layout between a FMS and a FAS is not the same. Since the time for assembly operation is usually relatively short, the transfer time is thus very crucial for the performance of assembly systems. Therefore in assembly systems it is important to reduce the transfer time by sequencing operations efficiently and arranging machines like the sequences. The network-type layout is not only feasible for the machine arrangement based on operation sequences, but it has also layout flexibility. Therefore it is a reasonable layout configuration for cellular FASs. This paper presents a method for the cell layout based on the network-type layout in a cellular FAS design.

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ARCA-An Adaptive Routing Protocol for Converged Ad-Hoc and Cellular Networks

  • Wu, Yumin;Yang, Kun;Chen, Hsiao-Hwa
    • Journal of Communications and Networks
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    • 제8권4호
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    • pp.422-431
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    • 2006
  • This paper proposes an adaptive routing protocol called ARCA for converged ad-hoc and cellular network (CACN). Due to the limitation of both bandwidth and transmission range in a cell, a mobile host (MH) may not be able to make a call during busy time. CACN offers a flexible traffic diversion mechanism that allows a MH to use the bandwidth in another cell to ease the congestion problem and increase the throughput in a cellular network. Based on the presentation of CACN's physical characteristics, the paper details the design issues and operation of the adaptive routing protocol for CACN (ARCA). Detailed numerical analysis is presented in terms of both route request rejection rate and routing overhead, which, along with the simulation results, have indicated the effectiveness and efficiency of the ARCA protocol.