• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.772-776
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• 2004

This paper proposes an interference avoidance approach for Constraint-Based Routing (CBR) algorithm in the Multi-Protocol Label Switching (MPLS) network. The MPLS network itself has a capability of integrating among any layer-3 protocols and any layer-2 protocols of the OSI model. It is based on the label switching technology, which is fast and flexible switching technique using pre-defined Label Switching Paths (LSPs). The MPLS network is a solution for the Traffic Engineering(TE), Quality of Service (QoS), Virtual Private Network (VPN), and Constraint-Based Routing (CBR) issues. According to the MPLS CBR, routing performance requirements are capability for on-line routing, high network throughput, high network utilization, high network scalability, fast rerouting performance, low percentage of call-setup request blocking, and low calculation complexity. There are many previously proposed algorithms such as minimum hop (MH) algorithm, widest shortest path (WSP) algorithm, and minimum interference routing algorithm (MIRA). The MIRA algorithm is currently seemed to be the best solution for the MPLS routing problem in case of selecting a path with minimum interference level. It achieves lower call-setup request blocking, lower interference level, higher network utilization and higher network throughput. However, it suffers from routing calculation complexity which makes it difficult to real task implementation. In this paper, there are three objectives for routing algorithm design, which are minimizing interference levels with other source-destination node pairs, minimizing resource usage by selecting a minimum hop path first, and reducing calculation complexity. The proposed CBR algorithm is based on power factor calculation of total amount of possible path per link and the residual bandwidth in the network. A path with high power factor should be considered as minimum interference path and should be selected for path setup. With the proposed algorithm, all of the three objectives are attained and the approach of selection of a high power factor path could minimize interference level among all source-destination node pairs. The approach of selection of a shortest path from many equal power factor paths approach could minimize the usage of network resource. Then the network has higher resource reservation for future call-setup request. Moreover, the calculation of possible path per link (or interference level indicator) is run only whenever the network topology has been changed. Hence, this approach could reduce routing calculation complexity. The simulation results show that the proposed algorithm has good performance over high network utilization, low call-setup blocking percentage and low routing computation complexity.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1846-1850
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• 2005

This paper presents a constrained-based routing (CBR) algorithm called, Dynamic Possible Path per Link (D-PPL) routing algorithm, for MultiProtocol Label Switching (MPLS) networks. In MPLS on-line routing, future traffics are unknown and network resource is limited. Therefore many routing algorithms such as Minimum Hop Algorithm (MHA), Widest Shortest Path (WSP), Dynamic Link Weight (DLW), Minimum Interference Routing Algorithm (MIRA), Profiled-Based Routing (PBR), Possible Path per Link (PPL) and Residual bandwidth integrated - Possible Path per Link (R-PPL) are proposed in order to improve network throughput and reduce rejection probability. MIRA is the first algorithm that introduces interference level avoidance between source-destination node pairs by integrating topology information or address of source-destination node pairs into the routing calculation. From its results, MIRA improves lower rejection probability performance. Nevertheless, MIRA suffer from its high routing complexity which could be considered as NP-Complete problem. In PBR, complexity of on-line routing is reduced comparing to those of MIRA, because link weights are off-line calculated by statistical profile of history traffics. However, because of dynamic of traffic nature, PBR maybe unsuitable for MPLS on-line routing. Also, both PPL and R-PPL routing algorithm we formerly proposed, are algorithms that achieve reduction of interference level among source-destination node pairs, rejection probability and routing complexity. Again, those previously proposed algorithms do not take into account the dynamic nature of traffic load. In fact, future traffics are unknown, but, amount of previous traffic over link can be measured. Therefore, this is the motivation of our proposed algorithm, the D-PPL. The D-PPL algorithm is improved based on the R-PPL routing algorithm by integrating traffic-per-link parameters. The parameters are periodically updated and are dynamically changed depended on current incoming traffic. The D-PPL tries to reserve residual bandwidth to service future request by avoid routing through those high traffic-per-link parameters. We have developed extensive MATLAB simulator to evaluate performance of the D-PPL. From simulation results, the D-PPL improves performance of MPLS on-line routing in terms of rejection probability and total throughput.

• 한국지능시스템학회논문지
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• 제22권2호
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• pp.148-153
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• 2012

본 논문에서는 무선 센서 네트워크에서 실시간 대용량 데이터를 전송하고자 할 때 QoS 요구조건과 에너지 효율성 요구를 만족시킬 수 있는 간섭 인지 기반의 결함 허용 QoS 라우팅 기법을 제안한다. 제안된 기법에서는 처리량을 최대화하고 지연시간을 최소화하기 위해 간섭비율과 예측전송시간을 기반으로 하는 새로운 누적 경로 메트릭을 사용하여 전송 경로에 결함이 발생하더라도 최적의 전송경로를 결정하도록 한다. 마지막으로, 시뮬레이션을 통하여 제안된 라우팅 기법을 사용하면 네트워크 처리량 및 지연시간 측면에서 성능이 향상됨을 보인다.

• Advances in Computational Design
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• 제3권2호
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• pp.191-200
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• 2018

Establishment of an efficient routing technique in multiple-input-multiple-output (MIMO) based mobile ad hoc network (MANET) is a new challenge in wireless communication system to communicate in a complex terrain where permanent infrastructure network implementation is not possible. Due to limited power of mobile nodes, a minimum power consumed routing (MPCR) algorithm is developed which is an integration of cooperative transmission process. This algorithm select relay node and support short distance communication. The performance analysis of proposed routing algorithm increased signal to noise interference ratio (SNIR) resulting effect of cooperative transmission. Finally performance analysis of the proposed algorithm is verified with simulated result.

• 한국정보과학회논문지:정보통신
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• 제36권4호
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• pp.286-296
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• 2009

고밀도 파장 분할 다중화 방식(DWDM: Dense-Wavelength Division Multiplexing) 기반 차세대 광 인터넷 백본망(NGOI: Next Generation Optical Internet)의 주요 연구주제 중 하나는 다양한 멀티미디어 응용 서비스들의 서비스 품질(QoS: Quality-of-Service)을 고려한 멀티캐스트 서비스용 효율적인 라우팅 및 파장할당(RWA: Routing and Wavelength Assignment) 문제이다. 특히, 차세대 광 인터넷 백본망에서 망 대역폭의 효율적인 사용 측면의 RWA 문제는 매우 중요한 요소이다. 그러나 기존의 RWA 알고리즘들은 멀티캐스트 트리 형성 시 발생하는 혼잡상황과 경로에 대한 우선순위를 고려하지 않아 성능이 매우 제한적이다. 따라서 본 논문에서는 이러한 문제를 해결하기 위한 방안으로 멀티캐스트 트리 형성시 발생하는 혼잡경로를 피하고 노드의 우선순위를 고려하는 효율적인 우선순위기반 최소간섭 경로 멀티캐스트 라우팅(PMIPMR - Priority-based Minimum Interference Path Multicast Routing) 알고리즘을 제안한다. 제안된 알고리즘은 시뮬레이션 결과를 통해 파장 사용률과, 파장 채널 사용률 측면에서 기존의 알고리즘과 비교, 제안된 알고리즘의 효율성을 검증한다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (3)
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• pp.538-540
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• 2004

차세대 인터넷 어플리케이션으로서 각광받고 있는 다양한 실시간 멀티미디어 서비스들이 기존 인터넷망에서 유니케스트 라우팅 방식으로 제공되면서 사용자수의 한계와 서버의 부하 문제에 따른 여러 문제점을 안고 있다. 이로 인해 한번에 여러 사용자들에게 동일한 데이터를 보내야 하는 멀티미디어 서비스의 경우에는, 각 사용자들에게 데이터를 여러 번 전송하는 유니캐스트 라우팅(Unicaast Routing)방식에 비해 멀티캐스팅(Multicast Routing)방식으로 전송하는 것이 대역폭 활용면에서 더 효율적이다. 그러나 Multicast Routing 을 DWDM 기반의 차세대 광인터넷망에 적용하기에는 optical signal splitter의 사용으로 인한 cost의 증가와 Power Penalty 의 보상 문제 등 해결해야 할 여러가지 문제가 남아있다. 따라서 본 논문은 이러한 제한 사항을 극복하기 위해서 제한된 노드에 대해서만 optical signal splitter 를 사용하는 Virtual Source 기반의 Multicast Routing 알고리즘을 제안한다.

• ETRI Journal
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• 제27권6호
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• pp.733-746
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• 2005

In the context of multi-protocol label switching (MPLS) traffic engineering, this paper proposes a scalable constraintbased shortest path first (CSPF) routing algorithm with multiple QoS metrics. This algorithm, called the multiple constraint-based shortest path first (M_CSPF) algorithm, provides an optimal route for setting up a label switched path (LSP) that meets bandwidth and end-to-end delay constraints. In order to maximize the LSP accommodation probability, we propose a link weight computation algorithm to assign the link weight while taking into account the future traffic load and link interference and adopting the concept of a critical link from the minimum interference routing algorithm. In addition, we propose a bounded order assignment algorithm (BOAA) that assigns the appropriate order to the node and link, taking into account the delay constraint and hop count. In particular, BOAA is designed to achieve fast LSP route computation by pruning any portion of the network topology that exceeds the end-to-end delay constraint in the process of traversing the network topology. To clarify the M_CSPF and the existing CSPF routing algorithms, this paper evaluates them from the perspectives of network resource utilization efficiency, end-to-end quality, LSP rejection probability, and LSP route computation performance under various network topologies and conditions.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.11-12
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• 2007

OVPN(Optical Virtual Private Network) based on DWDM(Dense Wavelength Division Multiplexing) backbone framework is considered as a promising approach for the future VPN. This paper proposes a new routing algorithm, called PMIPMR (Priority-based Minium Interference Path Multicast Routing) algorithm which finds an alternate route considering node priorities when the congestion is occurred in a network. The PMIPMR algorithm tries to improve blocking probability and wavelength utilization by avoiding congested path for potential future connection requests.

• 한국멀티미디어학회논문지
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• 제14권5호
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• pp.658-668
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• 2011

지난 수 십 년간 통신 기술의 발전과 웹 서비스의 팽창은 인터넷 사용자 수의 폭발적인 증가와 화상회의, 가상 증감 현실, 인터넷 게임 등 실시간 멀티미디어 멀티캐스트 서비스의 급격한 증가를 초래했다. 고밀도 파장분할다중화기술에 기반한 DWDM(Dense-Wavelength Division Multiplexing) 기술은 인터넷 사용자의 증가와 그에 따른 대역폭 요구를 수용하기 위한 방안으로 국가나 글로벌 영역 범위의 차세대 인터넷망 구현을 위한 백본망 기술로 여겨지며, 이러한 DWDM 전달망에서는 멀티캐스트 연결 요구에 대해 최적의 경로를 선택하고 선택된 경로에 효율적으로 파장을 할당하는 멀티캐스트 RWA(Routing and Wavelength Assignment) 문제가 파장 대역폭의 효율적인 활용 측면에서 매우 중요하게 다루어지고 있다. 주어진 파장 수 환경에서 최대한 많은 수의 멀티캐스트 연결을 달성하는 문제는 일반적으로 Non -deterministic Polynomial-time-complete 문제로 여겨지는 데, 본 논문에서는 가상소스를 기반으로 노드의 능력에 따른 차등화로 우선 순위를 적용하여 휴리스틱하게 멀티캐스트 라우팅 경로를 효율적으로 선정하는 DVS-PMIPMR (Differentiated Virtual Source-based Priority Minimum Interference Path Multicast Routing) 알고리즘을 제안한다. 마지막으로 같은 조건에서 더 많은 수의 멀티캐스트 라우팅 패스의 연결이 가능함을 시뮬레이션 및 성능분석 증명한다.

• 한국멀티미디어학회논문지
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• 제13권6호
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• pp.849-864
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• 2010

This paper proposes a multipath routing protocol called cross-layer multipath AODV (CM-AODV) for wireless ad hoc networks, which selects multiple routes on demand based on the signal-to-interference plus noise ratio (SINR) measured at the physical layer. Note that AODV (Ad hoc On-demand Distance Vector) is one of the most popular routing protocols for mobile ad hoc networks. Each time a route request (RREQ) message is forwarded hop by hop, each forwarding node updates the route quality which is defined as the minimum SINR of serialized links in a route and is contained in the RREQ header. While achieving robust packet delivery, the proposed CM-AODV is amenable to immediate implementation using existing technology by neither defining additional packet types nor increasing packet length. Compared to the conventional multipath version of AODV (which is called AOMDV), CM-AODV assigns the construction of multiple paths to the destination node and makes it algorithmically simple, resulting in the improved performance of packet delivery and the less overhead incurred at intermediate nodes. Our performance study shows that CM-AODV significantly outperforms AOMDV in terms of packet delivery ratio and average end-to-end delay, and results in less routing overhead.