• Industrial Engineering and Management Systems
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• 제15권3호
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• pp.259-267
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• 2016

In Wireless Sensor Network, various routing protocols were employed by our Research and Development community to improve the energy efficiency of a network as well as to control the traffic by considering the terms, i.e. Packet delivery rate, the average end-to-end delay, network routing load, average throughput, and total energy consumption. While maintaining network connectivity for a long-term duration, it's necessary that routing protocol must perform in an efficient way. As we discussed Optimized Link State Routing protocol between all of them, we find out that this protocol performs well in the large and dense networks, but with the decrease in network size then scalability of the network decreases. Whenever a link breakage is encountered, OLSR is not able to periodically update its routing table which may create a redundancy problem. To resolve this issue in the OLSR problem of redundancy and predict link breakage, an enhanced protocol, i.e. S-OLSR (More Scalable OLSR) protocol has been proposed. At the end, a comparison among different existing protocols, i.e. DSR, AODV, OLSR with the proposed protocol, i.e. S-OLSR is drawn by using the NS-2 simulator.

• 대한임베디드공학회논문지
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• 제13권2호
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• pp.83-91
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• 2018

With the development of IT (Information Technology) technology, embedded system and network technology are combined and used in various environments such as military environment as well as everyday life. In this paper, we propose a new airdropped distributed mobility model (ADMM) modeling the dispersion falling of the direct shot of a cluster bomb, and we compare and analyze some representative MANET routing protocols in ADMM in ns-3 simulator. As a result of the analysis, we show OLSR routing protocol is promising in ADMM environment in the view points of packet delivery ratio (PDR), end to end delay, and jitter. In addition, we propose a new adaptation scheme for OLSR, AND-OLSR (Average Node Distance based adaptive-OLSR) to improve the original OLSR in ADMM environment. The new protocol calculates the average node distance, adapts the period of the control message based on the average node distance increasing rate. Through the simulation study, we show that the proposed AND-OLSR outperforms the original OLSR in PDR and control message overhead.

• 한국멀티미디어학회논문지
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• 제19권11호
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• pp.1829-1836
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• 2016

Today, the application area and scope of FANET(Flying Ad Hoc Network) has been extended. As a result, FANET related research are actively conducted, but there is no decision yet as the routing protocol for FANET. In this paper, we propose the OLSR-Pds (Prediction with direction and speed) which is added a method to predict status of link for OLSR protocol. The mobility of nodes are modeled using Gauss-Markov algorithm, and relative speed between nodes were calculated by derive equation of movement, and thereby we can predict link status. An experiment for comparing AODV, OLSR and, OLSR-Pds was conducted by three factors such as packet delivery ratio, end to end delay, and routing overhead. In experiment result, we were confirm that OLSR-Pds performance are superior in these three factors. OLSR-Pds has the disadvantage that requires time-consuming calculations for link state and required for computing resources, but we were confirm that OLSR-Pds is suitable for routing to the FANET environment because it has all the characteristics of proactive protocol and reactive protocol.

• 전기학회논문지P
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• 제60권4호
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• pp.257-261
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• 2011

In this paper, we research the OLSR(Optimized Link State Routing Protocol) of the mobile ad-hoc network protocols, and design the system implementation based on the Embedded Linux for the Ubiquitous Space construction. We prove the performance of proposed system in the various experiment environments through several scenarios which is about transmitting the image data on the mobile ad-hoc network environment.

• 한국통신학회논문지
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• 제36권7A호
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• pp.662-668
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• 2011

본 논문에서는 MANET (Mobile Ad hoc Network)를 위한 가장 대표적인 라우팅 프로토콜인 AODV (Ad hoc On-demand Distance Vector)와 OLSR (Optimized Link State Routing)의 성능을 노드 이동성 모델에 따라 분석한다. 노드의 이동성은 망 토폴로지의 변화를 일으키므로 라우팅 프로토콜의 성능에 많은 영향을 미친다. 따라서, MANET 라우팅 프로토콜의 성능을 정확하게 평가하기 위해서는 노드의 이동 패턴에 가장 적합한 이동성 모델을 사용하는 것이 무엇보다 중요하다. 본 논문에서는 기존 MANET 라우팅 프로토콜 성능분석에 가장 많이 사용되고 있는 random way point 모델과 최근에 실제 인간의 이동 패턴과 가창 유사하다고 발표된 Levy walk 모델을 기반으로 AODV와 OLSR의 성능을 ns-2 시뮬레이션을 통해 비교 분석한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권1호
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• pp.270-286
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• 2012

In this paper, we propose a novel routing protocol called the Cartography Enhanced OLSR (CE-OLSR) for multi hop mobile ad hoc networks (multi hop MANETs). CE-OLSR is based on an efficient cartography gathering scheme and a stability routing approach. The cartography gathering scheme is non intrusive and uses the exact OLSR reduced signaling traffic, but in a more elegant and efficient way to improve responsiveness to the network dynamics. This cartography is a much richer and accurate view than the mere network topology gathered and used by OLSR. The stability routing approach uses a reduced view of the collected cartography that only includes links not exceeding a certain distance threshold and do not cross obstacles. In urban environments, IEEE 802.11 radio signals undergo severe radio shadowing and fading effects and may be completely obstructed by obstacles such as buildings. Extensive simulations are conducted to study the performances of CE-OLSR and compare them with those of OLSR. We show that CE-OLSR greatly outperforms OLSR in delivering a high percentage of route validity, a much higher throughput and a much lower average delay. In particular the extremely low average delay exacerbated by CE-OLSR makes it a viable candidate for the transport of real time data traffic in multi hop MANETs.

• International Journal of Computer Science & Network Security
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• 제22권10호
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• pp.137-144
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• 2022

Wireless community networks (WCNs) are considered another form of ownership of internet protocol (IP) networks, where community members manage and own every piece of equipment in a decentralized way, and routing for traffic is done in a cooperative manner. However, the current routing protocols for WCNs suffer from stability and scalability issues. In this paper, an enhanced routing protocol is proposed based on the optimized link state routing (OLSR) protocol to meet the standards of efficiency in terms of stability and scalability. The proposed routing protocol is enhanced through two phases: multicasting expansion and multipoint relay (MPR) selection based on an analytical hierarchical process (AHP). The experimental results demonstrate that the proposed routing protocol outperforms the OLSR protocol in terms of network control overhead and packet delivery ratio by 18% and 1% respectively.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제14권4호
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• pp.352-362
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• 2008

MANET(Mobile Ad-hoc Network) 내에서는 노드는 자유롭게 이동하나 에너지 제약을 가지며 이러한 특징이 네트워크 회선 단절을 유발한다. 따라서 MANET을 적용하여 유비쿼터스 서비스를 수행할 경우에는 노드의 이동성에 따른 토폴로지 변경에 유연하게 적응하면서 동시에 연속적인 패킷 전송이 가능하도록 패킷의 전송률을 향상시키는 기법이 요구된다. 본 논문에서는 이러한 문제점의 해결을 위해 PAOMDV(Possibility based AOMDV)와 OLSR-ME(OLSR with Modify Energy Efficiency)를 동시에 적용한 혼합형 프로토콜을 제안한다. 특히 모바일 에드 혹 네트워크를 클러스터로 구분함으로써 PAOMDV는 클러스터 간 통신을 담당하고 OLSR-ME는 클러스터 내부 통신을 담당하도록 구현하였다. 또한 홉 수가 증가하는 경우에도 기존 프로토콜보다 더 효율적인 프로토콜을 설계하기 위해 패킷 전달을 책임질 포워딩 노드 선택 알고리즘도 제안한다. 제안한 프로토콜을 기존의 프로토콜인 AODV, AOMDV, ZRP와 비교 실험하고 그 성능을 검증하였다. 실험 결과, 제안 프로토콜이 패킷 전송률, 전송 지연, 라우팅 오버헤드에서 기존 프로토콜 보다 우수함을 확인하였다.

• Journal of Communications and Networks
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• 제15권1호
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• pp.31-37
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• 2013

Mobile ad hoc networks (MANET) refers to a network designed for special applications for which it is difficult to use a backbone network. In MANETs, applications are mostly involved with sensitive and secret information. Since MANET assumes a trusted environment for routing, security is a major issue. In this paper we analyze the vulnerabilities of a pro-active routing protocol called optimized link state routing (OLSR) against a specific type of denial-of-service (DOS) attack called node isolation attack. Analyzing the attack, we propose a mechanism called enhanced OLSR (EOLSR) protocol which is a trust based technique to secure the OLSR nodes against the attack. Our technique is capable of finding whether a node is advertising correct topology information or not by verifying its Hello packets, thus detecting node isolation attacks. The experiment results show that our protocol is able to achieve routing security with 45% increase in packet delivery ratio and 44% reduction in packet loss rate when compared to standard OLSR under node isolation attack. Our technique is light weight because it doesn't involve high computational complexity for securing the network.

• 한국인터넷방송통신학회논문지
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• 제9권3호
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• pp.9-17
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• 2009

A Mobile Ad hoc network(MANET) is a network consisting of a set of wireless mobile nodes, which communicate with each other without centralized control or established infrastructure. In this paper, to obtain a better understanding of AODV(Ad hoc On-Demand Distance Vector Routing Protocol)and OLSR(Optimized Link State Routing Protocol) routing protocols, different performances are simulated and analyzed using OPNET modeler 14.5 with the various performance metrics, such as packet delivery ratio, end-to-end delay and routing overhead. As a conclusion, in static analysis, the routing overhead of OLSR is affected by the number of nodes, but not data traffic. In AODV case, it is affected by both data traffic and number of nodes. In mobility analysis, routing overhead is not greatly affected by mobility speed in AODV and OLSR, and the PDR(Packet Delivery Ration) of OLSR is decreased as the node speed increased, while AODV is not changed. AS to delay, AODV is always higher than OLSR in both static and nobility cases.