• Title/Summary/Keyword: and Route Optimization

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A Study on Mobile IP-over-MPLS Framework to Provide Mobile IP service with Guarantied QoS (QoS 보장형 이동성 IP 서비스 제공을 위한 Mobile IP-over-MPLS 구조 연구)

  • 김호철;김영탁
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.9B
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    • pp.834-844
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    • 2003
  • Mobile IP has some performance degrade factors such as triangle routing and packet loss by the hand-off because the original IP was designed for the fixed network. The design goal for the next generation Internet service is to guarantee QoS. So, Mobile IP also should be able to provide the guaranteed QoS with performance enhancement because it is an IP-based mobile Internet service. In this paper, we propose route optimization, smooth hand-off scheme and MIP-LDP(Mobile IP-Label Distribution Protocol) on Mobile IP-over-MPLS framework to enhance the performance of the previously researched Mobile IP-over-MPLS schemes. The proposed framework enhanced long routing path problem and packet loss problem by the hand-off.

On NeMRI-Based Multicasting for Network Mobility (네트워크 이동성을 고려한 NeMRI 기반의 멀티캐스트 라우팅 프로토콜)

  • Kim, Moon-Seong;Park, Jeong-Hoon;Choo, Hyun-Seung
    • Journal of Internet Computing and Services
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    • v.9 no.2
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    • pp.35-42
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    • 2008
  • Mobile IP is a solution to support mobile nodes, however, it does not handle NEtwork MObility (NEMO). The NEMO Basic Support (NBS) protocol ensures session continuity for all the nodes in the mobile network. Since the protocol is based on Mobile IP, it inherits the same fundamental problem such as tunnel convergence, when supporting the multicast for NEMO. In this paper, we propose the multicast route optimization scheme for NEMO environment. We assume that the Mobile Router (MR) has a multicast function and the Nested Mobile Router Information (NeMRI) table. The NeMRI is used to record o list of the CoAs of all the MRs located below it. And it covers whether MRs desire multicast services. Any Route Optimization (RO) scheme can be employed here for pinball routing. Therefore, we achieve optimal routes for multicasting based on the given architecture. We also propose cost analytic models to evaluate the performance of our scheme. We observe significantly better multicast cost in NEMO compared with other techniques such as Bi-directional Tunneling, Remote Subscription, and Mobile Multicast based on the NBS protocol.

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Intelligent Optimal Route Planning Based on Context Awareness (상황인식 기반 지능형 최적 경로계획)

  • Lee, Hyun-Jung;Chang, Yong-Sik
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.117-137
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    • 2009
  • Recently, intelligent traffic information systems have enabled people to forecast traffic conditions before hitting the road. These convenient systems operate on the basis of data reflecting current road and traffic conditions as well as distance-based data between locations. Thanks to the rapid development of ubiquitous computing, tremendous context data have become readily available making vehicle route planning easier than ever. Previous research in relation to optimization of vehicle route planning merely focused on finding the optimal distance between locations. Contexts reflecting the road and traffic conditions were then not seriously treated as a way to resolve the optimal routing problems based on distance-based route planning, because this kind of information does not have much significant impact on traffic routing until a a complex traffic situation arises. Further, it was also not easy to take into full account the traffic contexts for resolving optimal routing problems because predicting the dynamic traffic situations was regarded a daunting task. However, with rapid increase in traffic complexity the importance of developing contexts reflecting data related to moving costs has emerged. Hence, this research proposes a framework designed to resolve an optimal route planning problem by taking full account of additional moving cost such as road traffic cost and weather cost, among others. Recent technological development particularly in the ubiquitous computing environment has facilitated the collection of such data. This framework is based on the contexts of time, traffic, and environment, which addresses the following issues. First, we clarify and classify the diverse contexts that affect a vehicle's velocity and estimates the optimization of moving cost based on dynamic programming that accounts for the context cost according to the variance of contexts. Second, the velocity reduction rate is applied to find the optimal route (shortest path) using the context data on the current traffic condition. The velocity reduction rate infers to the degree of possible velocity including moving vehicles' considerable road and traffic contexts, indicating the statistical or experimental data. Knowledge generated in this papercan be referenced by several organizations which deal with road and traffic data. Third, in experimentation, we evaluate the effectiveness of the proposed context-based optimal route (shortest path) between locations by comparing it to the previously used distance-based shortest path. A vehicles' optimal route might change due to its diverse velocity caused by unexpected but potential dynamic situations depending on the road condition. This study includes such context variables as 'road congestion', 'work', 'accident', and 'weather' which can alter the traffic condition. The contexts can affect moving vehicle's velocity on the road. Since these context variables except for 'weather' are related to road conditions, relevant data were provided by the Korea Expressway Corporation. The 'weather'-related data were attained from the Korea Meteorological Administration. The aware contexts are classified contexts causing reduction of vehicles' velocity which determines the velocity reduction rate. To find the optimal route (shortest path), we introduced the velocity reduction rate in the context for calculating a vehicle's velocity reflecting composite contexts when one event synchronizes with another. We then proposed a context-based optimal route (shortest path) algorithm based on the dynamic programming. The algorithm is composed of three steps. In the first initialization step, departure and destination locations are given, and the path step is initialized as 0. In the second step, moving costs including composite contexts into account between locations on path are estimated using the velocity reduction rate by context as increasing path steps. In the third step, the optimal route (shortest path) is retrieved through back-tracking. In the provided research model, we designed a framework to account for context awareness, moving cost estimation (taking both composite and single contexts into account), and optimal route (shortest path) algorithm (based on dynamic programming). Through illustrative experimentation using the Wilcoxon signed rank test, we proved that context-based route planning is much more effective than distance-based route planning., In addition, we found that the optimal solution (shortest paths) through the distance-based route planning might not be optimized in real situation because road condition is very dynamic and unpredictable while affecting most vehicles' moving costs. For further study, while more information is needed for a more accurate estimation of moving vehicles' costs, this study still stands viable in the applications to reduce moving costs by effective route planning. For instance, it could be applied to deliverers' decision making to enhance their decision satisfaction when they meet unpredictable dynamic situations in moving vehicles on the road. Overall, we conclude that taking into account the contexts as a part of costs is a meaningful and sensible approach to in resolving the optimal route problem.

Flush message based Route Optimization Mechanism to Prevent Packet Out-of Sequence Problem in Proxy MIPv6 (Proxy MIPv6에서 패킷의 순서 어긋남을 해결할 수 있는 Flush 메시지 기반의 경로 최적화 메커니즘)

  • Lee, Chang-Min;Lee, Beom-Jae;Lee, Jae-Hwoon;Park, Hyun-Seo;Shin, Gyung-Chul
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.3
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    • pp.61-67
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    • 2008
  • Proxy MIPv6 (PMIPv6) is that network-based mobility management protocol that network supports mobile node's mobility on behalf of the MN. In PMIPv6, when two MNs located within the same PMIPv6 domain want to communicate each other, sub-optimal path is established between the two MN. Route optimization method for PMIPv6 is proposed to resolve the problem. However, the method still suffer from the performance degradation due to out-of-sequence packet problem. In this paper, we propose the route optimization mechanism in PMIPv6 based on Flush message to resolve the out-of-sequence packet problem. The proposed mechanism is evaluated by performing simulations, and the simulation results show that the proposed one gives better performance.

Route Optimization Scheme using Routing Protocol in Nested Mobile Networks (중첩된 이동 네트워크환경에서 동적 라우팅 프로토콜을 이용한 경로 최적화 기법)

  • Kim, Eui-Kook;Lee, Jong-Hyup
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.11
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    • pp.1966-1975
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    • 2008
  • NEMO Basic Support Protocol standardized in IETF provides the seamless communication environment to all nodes within the mobile network regardless of the network movement while the network is moving. According to the standard, when the mobile network moves outside of its home network the network can make use of the binding update message or dynamic routing protocol in order to register the mobility information into the Home Agent(HA). But because these two methods don't consider the route optimization, all packets destined to Mobile Network Nodes(MNNs) attached into the Mobile Router(MR) have to go through HAs of MRs so that they bring on the transmission delay and the waste of the bandwidth. This situation is to be worse and causes the packet fragmentation problem if MRs within the mobile network are nested. Even though there have been some researches about the route optimization to recover the problems, they have problems in the packet transmission performance side. In this paper, we propose a new scheme to improve the network performance by using a dynamic routing protocol and minimizing the number of HAs on the end-to-end path. Various performance evaluations show that the proposed mechanism gives better performance in view of the packet transmission compared to the existing schemes.

A Secure Route Optimization Mechanism for Mobile VPN users in Foreign Networks (모바일 VPN 사용자를 위한 보안 강화 경로 최적화 방안)

  • Kim, Kyoung-Min;Byun, Hae-Sun;Lee, Mee-Jeong
    • Journal of KIISE:Information Networking
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    • v.34 no.5
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    • pp.348-359
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    • 2007
  • The conventional mobile VPN services assumed the mobile communications occur between the MN in foreign networks and the CN in the home network. However, if a MN wants to communicate with another MN in a foreign network, it could degrade the performance of the mobile VPN service because of the triangular routing problem. In this paper, we propose a route optimization mechanism based on the mobile VPN using an x-HA allocated by diameter MIP in order to support the efficient communication between the mobile VPN users in foreign networks. The i-HA maintains the VPN-TIA as well as the x-HoA as the CoAs to solve the security problem and to provide an efficient route optimization simultaneously. Moreover, we proposed revised IPSec tunnel configuration to reduce the IPSec tunnel overheads at a MN when the MN communicates with several MNs in the foreign networks at the same time. The VPN server, a security management entity in the home network, notifies an additional IPSec tunnel establishment between the x-HAs where the communication peers are registered. The simulation result showed that the proposed scheme decreases the end-to-end packet delay time and improves the throughput after the handoff compared to the existing mechanism.

Routing of ALVs under Uncertainty in Automated Container Terminals (컨테이너 터미널의 불확실한 환경 하에서의 ALV 주행 계획 수립방안)

  • Kim, Jeongmin;Lee, Donggyun;Ryu, Kwang Ryel
    • Journal of Navigation and Port Research
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    • v.38 no.5
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    • pp.493-501
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    • 2014
  • An automated lifting vehicle(ALV) used in an automated container terminal is a type of unmanned vehicle that can self-lift a container as well as self-transport it to a destination. To operate a fleet of ALVs efficiently, one needs to be able to determine a minimum-time route to a given destination whenever an ALV is to start its transport job. To find a route free from any collision or deadlock, the occupation time of the ALV on each segment of the route should be carefully scheduled to avoid any such hazard. However, it is not easy because not only the travel times of ALVs are uncertain due to traffic condition but also the operation times of cranes en route are not predicted precisely. In this paper, we propose a routing method based on an ant colony optimization algorithm that takes into account these uncertainties. The result of simulation experiment shows that the proposed method can effectively find good routes under uncertainty.

An Ant Colony Optimization Heuristic to solve the VRP with Time Window (차량 경로 스케줄링 문제 해결을 위한 개미 군집 최적화 휴리스틱)

  • Hong, Myung-Duk;Yu, Young-Hoon;Jo, Geun-Sik
    • The KIPS Transactions:PartB
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    • v.17B no.5
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    • pp.389-398
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    • 2010
  • The Vehicle Routing and Scheduling Problem with Time Windows(VRSPTW) is to establish a delivery route of minimum cost satisfying the time constraints and capacity demands of many customers. The VRSPTW takes a long time to generate a solution because this is a NP-hard problem. To generate the nearest optimal solution within a reasonable time, we propose the heuristic by using an ACO(Ant Colony Optimization) with multi-cost functions. The multi-cost functions can generate a feasible initial-route by applying various weight values, such as distance, demand, angle and time window, to the cost factors when each ant evaluates the cost to move to the next customer node. Our experimental results show that our heuristic can generate the nearest optimal solution more efficiently than Solomon I1 heuristic or Hybrid heuristic applied by the opportunity time.

A study on material analysis and the usage for efficiency of the Autonomus Station Control System (자율분산 역제어시스템의 효율성을 위한 자료분석 및 자료 활용방법에 관한 연구)

  • Ha, Seung-Tae;Ahn, Jin;Yong, Sung-Wan
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.636-641
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    • 2008
  • In this paper, the analysis methods of available information are reviewed and it is elicited to the method of which the analysis results are applied to the Autonomous Decentralized Train Management System for the optimization at the point of the route control time and for making the efficiency shunting plan in the Autonomous Centralized Station Operation Control System. As the statistics and estimated information which are got through the utilizable information analysis are applied for the automatic route control function and the shunting plan management of the station operation control system, it is possible to use efficiently the station information by the autonomous route control system. And as the exact forecast information needed for the shunting plan establishment and the operation is provided to the operator, it is established to the efficient train operation plan.

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Characteristics of SiC Whisker-Reinforced LAS Matrix Composites Fabricated by the Mixed Colloidal Route and the Sol-Gel Process (콜로이드 혼합법 및 Sol-Gel 법에 의해 제조한 SiC 휘스커 강화 LAS 기지 복합체의 특성)

  • 김광수;장현명;정창주;백용기
    • Journal of the Korean Ceramic Society
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    • v.28 no.12
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    • pp.1012-1018
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    • 1991
  • SiC whisker-reinforced LAS matrix composites were developed by a mixed colloidal processing route. An optimization of processing conditions was made using the zeta potential data of silica, boehmite, and SiC whisker dispersions. Similarly, the SiC whisker-reinforced composites were also fabricated by the conventional sol-gel process using the hydrolysis-condensation reaction of relevant metal alkoxides. The composites fabricated by the mixed colloidal processing route were characterized by a uniform spatial distribution of SiC whisker throughout the matrix. The fracture toughness increased from 1.3 MPa.m1/2 for the LAS specimen to 5.0 Mpa.m1/2 for the hot-pressed composite (95$0^{\circ}C$ and 20 MPa for 20 min) containing 20 wt% SiC whisker. The increase in fracture toughness appears to result mainly from the crack deflection and the crack bridging by whiskers with some additional toughenings from the whisker pullout and the matrix prestressing mechanisms.

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