• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.43 no.1
• /
• pp.1-6
• /
• 2020

Fast service access involves keeping track of the location of mobile users, while they are moving around the mobile network for a satisfactory level of QoS (Quality of Service) in a cost-effective manner. The location databases are used to keep track of Mobile Terminals (MT) so that incoming calls can be directed to requested mobile terminals at all times. MT reporting cell system used in location management is to designate each cell in the network as a reporting cell or a non-reporting cell. Determination of an optimal number of reporting cells (or reporting cell configuration) for a given network is reporting cell planning (RCP) problem. This is a difficult combinatorial optimization problem which has an exponential complexity. We can see that a cell in a network is either a reporting cell or a non-reporting cell. Hence, for a given network with N cells, the number of possible solutions is 2^N. We propose a biogeography based optimization (BBO) for design of mobile station location management system in wireless communication network. The number and locations of reporting cells should be determined to balance the registration for location update and paging operations for search the mobile stations to minimize the cost of system. Experimental results show that our proposed BBO is a fairly effective and competitive approach with respect to solution quality for optimally designing location management system because BBO is suitable for combinatorial optimization and multi-functional problems.

• Journal of the Korea Society for Simulation
• /
• v.17 no.4
• /
• pp.41-50
• /
• 2008

In this study, an improved scheme for distance-based registration (DBR) is proposed and its performance is analyzed. In the DBR, when a mobile station (MS) enters a new cell, it calculates the distance between last registered cell and current cell and registers its location if the distance reaches reference distance D. In this study, two-location DBR (TDBR) is proposed to improve the performance of the DBR. In the TDBR, an MS stores not only last registered location area (LA) but also previously registered LA, and then no registration is needed when the MS crosses two LAs stored already. However, since the TDBR may increase paging cost, trade-off is necessary between decreased registration cost and increased paging cost. In this study, the performances of two schemes are analyzed and compared using 2-dimensional random walk mobility model in hexagonal cell configuration. We show that our mathematical analysis is accurate by comparing with simulation. From the numerical results for various circumstances, it is shown that our proposed TDBR outperforms current DBR in most cases.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.4
• /
• pp.1032-1044
• /
• 1999

In the mobile communication systems such as PCS(Personal Communication Service), several strategies have been proposed to optimize the signalling traffic load by using the characteristics of traffic and mobile patterns for effective mobility management. According to IS-41 standard, LA(Location Area) consists of static and arbitrarily-defined set of cells, which do not take into account mobility patterns of mobile stations. In this paper, we propose an improved location management mechanism which contains the neighbor cells of the LA selectively using the mobility history of a mobile station and accommodates the LA size adaptively according to the speed of the mobile station. Also, we use the paging priorities for cells in LA to improve the paging efficiency. We compare the performance of conventional mechanism with that of the proposed mechanism using numerical analysis. The analysis results show that the proposed location management mechanism is better than conventional mechanism significantly.

• The Korean Journal of Emergency Medical Services
• /
• v.11 no.2
• /
• pp.87-101
• /
• 2007

Health and disease related characteristics of 226 selected by systematic sampling from 452 personal emergency response system(PERS) beneficiaries and actual conditions of using PERS by them are as follows. Over 86% of PERS beneficiaries have not good health conditions and 70.7% of them have chronic diseases. On social supports family was highest as 52.2% and cases having social workers' assistance were 15.2%, but 53 as 23.7% had not visit or call from anyone and showed very low social supports. 86.2% was given PERS within 3years and 79.1% had it by the recommendation from related agencies and 4.0% was by their demand. On wearing it, 78.3% didn't bring it with them and 92% of them answered they were not sick and then it was found that they didn't use it because they had not special emergency. On satisfaction with paging system's operation, 81.3% answered they were satisfied with it, 48.8% used it for 'acute and emergency diseases' and 29.3% called ambulance for 'appointed medical treatment'. Time required for ambulance to arrive at the field was within 10 min. in 87.8% and after 10 min. in 12.2% and emergency service for beneficiaries by fire service was very good. On satisfaction with use of PERS, 85.4% were satisfied with it, 81.9% who requested repair or replacement of radio paging got it back after one or two days of their request and they answered they were satisfied with A/S. 45.5% answered they powered off it because 'they didn't use it' and 12.1% had 'economical reason of phone charge'.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.38 no.1
• /
• pp.69-78
• /
• 2001

This paper presents the design and FPGA implementation of a FLEX PSP(Protocol Signal Processor) for the portable high speed paging system. In this approach, two algorithms are newly proposed for implementing the PSP which provides capabilities of the maximum 6,400bps at speed, high-channel throughput, real time error correction and an effective frame search function. One is an accurate symbol synchronization algorithm which is applied for synchronizing the interleaved 4-level bit symbols which are received at input stage of A/D converter, and the other is a modified fast decoding algorithm which is provided for realizing double error correction of (31,21)BCH signal. The PSP is composed of six functional modules, and each module is modelled in VHDL(VHSIC Hardware Description Language). Both functional simulation and logic synthesis have performed for the proposed PSP through the use of Synopsys$^{TM}$ tools on a Axil-320 Workstation, and where Altera 10K libraries are used for logic synthesis. From logic synthesis, we can see that the number of gates is about 2,631. For FPGA implementation, timing simulation is performed by using Altera MAX+ PLUS II, and its results will be also given. The PSP which is implemented in 6 FPGA devices on a PCB has been verified by means of Logic Analyzer.r.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.4
• /
• pp.131-140
• /
• 2011

Proxy Mobile IPv6 (PMIPv6) is designed to provide a network-based localized mobility management protocol, but it does not handle the global mobility of hosts. In this paper, we propose a location management scheme based on Domain Name System (DNS) for PMIPv6. In this proposed scheme, DNS as a location manager provides PMIPv6 for global mobility. In addition, a paging extension scheme is introduced to PMIPv6 in order to support large numbers of mobile terminals and enhance network scalability. To evaluate the proposed location management scheme, we establish an analytical model, formulate the location update and the paging cost, and analyse the influence of the different factors on the total signalling cost. The performance results show how the total signal cost changes under various parameters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2006.05a
• /
• pp.495-500
• /
• 2006

본 논문에서는 셀 환경에서 QoS를 보장하기 위해 통합된 페이징과 루프 정보 관리 캐시를 사용하는 Cellular IP 특성을 가진 Cellular-IP/PRC 네트워크를 제안한다. 제안한 호 수락 방식은, 이동 노드의 홈 기지국 용량이 충분하고, 인접 셀 이동 노드가 흠 기지국에서 호가 수락되었다고 가정할 경우 받을 간섭의 증가량을 고려해 통화 품질이 보장될 때, 홈 기지국은 새로운 호를 이동 노드의 송신 전력 예측에 기반을 둔 호 수락 방식이다. 무선인터넷 네트워크 내의 페이징과 라우터를 관리하기 위해 사용되었던 PC(Paging Cache)와 RC(Routing Cache)를 하나의 PRC(Paging Router Cache)로 통합 관리하고, 모든 노드 내에 구성하여 운용토록 하고, 이동 노드의 핸드 오프 및 로밍 상태를 효율적으로 관리 할 수 있도록 이동 노드에 핸드오프 상태 머신을 추가하고, 노드에서 관련 기능을 수행하도록 하였다. 시스템 환경에서 통화량에 영향을 주는 인자를 각 링크 통화권 및 불균형 정도를 예측, 하향링크에 의해 통화권이 제한을 판단하여 송수신 전력을 기반으로 한 알고리즘과 제안한 알고리즘을 비교하여 QoS가 호 차단 확률과 호 탈락 확률, GoS, 셀 용량의 효율을 예측할 수 있는 QoS로 성능 개선을 연구한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2006.05a
• /
• pp.1069-1072
• /
• 2006

무선 망에서 한정된 무선 자원의 효율을 높이기 위한 페이징 기법들이 많이 제안 되었다. 지금까지 제안된 페이징 기법들은 미리 정의된 규칙에 따라 페이징 영역을 설정한다. 따라서 이동 노드가 네트워크에 접속한 이후에 발생할 수 있는 네트워크의 혼잡이나 라우터의 정지와 같은 갑작스런 상황에 민첩하게 대응할 수 없다. 또한 이동 노드들은 프로세싱 능력이 고정 노드보다 떨어지고 전원도 약하므로 이동 노드가 생성하는 메시지를 줄이기 위한 노력이 필요하다. 이러한 문제점을 해결하기 위해 본 논문에서는 특별한 페이징 영역 설정 없이 페이징을 적용할 수 있는 기법을 제안한다. 제안하는 페이징 기법을 통해 56%의 성능향상을 거두었고 네트워크의 부하도 줄이게 되었다. 또한 이동 노드들은 생성하던 메시지가 줄어들게 되므로 전력 소모가 줄어드는 부가적인 효과를 얻는다.

• Proceedings of the KIEE Conference
• /
• 2004.11c
• /
• pp.553-555
• /
• 2004

In this paper, high performance radio buoy system used for inshore and deep sea fishery is developed and experimented. Location of radio buoy can be accurately monitored and traced by the mother ship using GPS technology, and optimum access protocol is adopted to minimize the power consumption of radio buoy system. Developed system can cover over 80Km coastal range with 8 W transmitting power and -115 dBm receiver sensitivity and can ensure high security from burglary and loss using digital coding technology.

• Korean Management Science Review
• /
• v.28 no.2
• /
• pp.53-62
• /
• 2011

The objective of this paper is to propose a Binary Particle Swarm Optimization(BPSO) for design of reporting cell management system. The assignment of cells to reporting or non-reporting cells is an NP-complete problem having an exponential complexity in the Reporting Cell Location Management(RCLM) system. The number of reporting cells and which cell must be reporting cell should be determined to balance the registration(location update) and search(paging) operations to minimize the cost of RCLM system. Experimental results demonstrate that BPSO is an effective and competitive approach in fairly satisfactory results with respect to solution quality and execution time for the optimal design of location management system.