• The KIPS Transactions:PartC
• /
• v.13C no.4 s.107
• /
• pp.447-454
• /
• 2006

An ad-hoc network routing protocol, AODV(Ad-hoc On-demand Distance Vector) initially uses ERS(Expanding Ring Search) algorithm to control the RREQ(Route Request) retransmission in the route discovery process. Because ERS uses the fixed NTT(Node Travesal Time), it does not reflect accurately ad-hoc network environment. In this paper, we propose an improved ERS algorithm which lowers the retransmission rate. It uses RREP(Route Reply) and gives different weights in NTT of each node in accordance with the adjacency to an originating node. To show the effectiveness of the proposed algorithm, we perform a simulation using ns2. The simulation results showed that the proposed algorithm has better performance than existing algorithms.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.10c
• /
• pp.375-377
• /
• 2000

유선 네트워크 환경을 위해 디자인된 경로설정 프로토콜들은 대역폭의 제한성과 예측할 수 없는 토폴로지의 변화로 인해 ad-hoc 네트워크 환경에 적용하기에는 부적합하다. 최근 들어 ad-hoc 네트워크 환경에 적합한 경로설정 프로토콜들이 많이 개발되었다. 본 논문에서는 기존의 ad-hoc 경로설정 프로토콜을 토폴로지 변화에 대한 적응력을 향상시키기 위해서 GPS(Global Positioning System) 기술을 활용하여 가상 지역(virtual zone) 개념을 제안하고 있다. 본 논문에서 제안하는 프로토콜은 AODV(Ad-hoc On-demand Distance Vector) 경로설정 프로토콜을 기본으로 하고 있다. AODV의 경로설립(route discovery) 과정 시 이러한 가상 지역 개념을 도입함으로써 이동 단말의 이동성에 의한 토폴로지의 변화에도 불구하고 잘 적응할 수 있는 안정된 경로의 설립을 목표로 하고 있다. 본 논문에서는 시뮬레이션을 통하여 다양한 트래픽 상태와 단말들의 이동성 형태에 따른 중요 변수들을 설명하였으며 이에 따라 제안된 경로설정 프로토콜(AODV-GPS)의 효율성을 검증하고 있다.

• Journal of Korea Multimedia Society
• /
• v.13 no.6
• /
• pp.849-864
• /
• 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.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.2
• /
• pp.308-316
• /
• 2015

In this paper, we carried out performance comparison of four routing protocols that had been proposed for mobile ad hoc networks using the NS-3 network simulator. Those four routing protocols consist of two proactive routing protocols, DSDV(destination-sequenced distance vector) and OLSR(optimized link state routing), and two reactive routing protocols, AODV(ad-hoc on-demand distance vector) and DSR(dynamic source routing). Two performance metrics, system throughput and packet delivery ratio, are adopted and performance evaluation was carried out in a square communication area where each communicating mobile node moves independently. Numerical results show that the AODV routing protocol provides the best performance among those four routing protocols.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.3
• /
• pp.593-600
• /
• 2007

In this paper, we composed several road network and evaluated the network for the performance of the network with protocols. The protocols we applied were the MANET routing protocols such as AODV(Ad-hoc On-Demand Distance Vector) and DSR(Dynamic Source Routing) protocols. Generally, the AODV performs better than the DSR. However, in my ad-hoc vehicular network, the performance of the DSR is the better than the AODV when there are more vehicles in the road environment than there are the less vehicles. For the simulation, we composed 4-lane road with vehicles and simulated in the OPNET.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.6
• /
• pp.1092-1099
• /
• 2017

In this paper, we propose a novel geographical on-demand routing protocol for a mobile ad-hoc network (MANET) that resolves the broadcast storm problem of ad-hoc on-demand distance vector (AODV) routing protocol. The candidates relaying route request (RREQ) packet are geographically restricted by the locations of the destination and a (RREQ sender. Then, the duplicate RREQs, which are generally discarded in the protocols that follow the principle of the AODV, are parsed to avoid redundant RREQ rebroadcasts and to perform passive acknowledgement with respect to a RREQ rebroadcast. The proposed routing protocol is implemented by modifying the source code of the AODV in QualNet. It is shown through QualNet simulations that the proposed routing protocol significantly improves the packet delivery ratio and the latency of the AODV in high-density and heavy traffic network scenarios.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.4 no.1
• /
• pp.14-19
• /
• 2009

In Mobile Ad-hoc Network, link failure and packet loss may occur frequently due to its nature of mobility and limited battery life. In this paper, an enhanced robust routing protocol based on AODV(Ad hoc On-demand Distance Vector routing) by monitoring variation of receiving signal strength is proposed. New metric function that consists of node mobility and hops of path is used for routing decision. For preventing route failure by node movement during data transmission, a new route maintenance is presented. If the node movement is detected, the routing agent switches local path to its neighbor node. Simulation results show that the performance of the proposed routing scheme is superior to previous AODV protocol.

• The KIPS Transactions:PartC
• /
• v.14C no.2
• /
• pp.191-198
• /
• 2007

A mobile ad-hoc network (MANET) is an autonomous, infrastructure-less system that consists of mobile nodes. In MANET, on demand routing protocols are usually used because network topology changes frequently. AODV, which is a representative on demand routing protocol, operates using the routing table of each node that includes next hop of a route for forwarding packets. It maintains the established route if there is not an expiration of route or any link break. In the paper, we propose a partially adaptive route maintenance scheme (AODV-PA) based on AODV, which provides dynamic route modification of initial route for selecting the effective route using not only next hop but also next-hop of next-hop (i.e. 2-hop next node) acquired through route discovery process. In addition, the proposed scheme additionally manages the routing table for preventing exceptional link breaks by route modification using HELLO messages. We use NS 2 for the computer simulation and validate that the proposed scheme is better than general AODV in terms of packet delivery ratio, latency, routing overhead.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.10c
• /
• pp.265-267
• /
• 2003

이동성을 가진 다수의 노드들로 구성된 Ad­Hoc 무선 네트워크는 유선망이나 기지국이 존재하지 않는 환경에서 통신망을 구성하기 위한 목적으로 연구되어 왔다. Ad­Hoc 무선 네트워크에서 라우팅 프로토콜은 이동 노드들간의 연결을 위한 경로를 제공하며, 본 논문에서는 무선 Ad­Hoc 라우팅 프로토콜 중 AODV(Ad­Hoc On­Demand Distance Vector routing)의 개선된 알고리즘을 제안하고자 한다. AODV는 경로획득, 경로유지. 경로복구의 크게 3단계로 나누어져 있고, AODV에서의 경로복구는 전체 경로를 재설정하는 것으로 많은 오버헤드를 가지고 있다. 제안한 방법에서는 링크손실로 인한 경로복구의 과정을 링크 손실이 발생한 인접 지역내에서 행하게 함으로써 전체적인 성능 향상을 가져왔다.

• The KIPS Transactions:PartC
• /
• v.12C no.3 s.99
• /
• pp.429-436
• /
• 2005

A mobile ad hoc network (MANET) is a collection of mobile nodes without any fixed infrastructure or my form of centralized administration such as access points and base stations. The ad hoc on-demand distance vector routing (AODV) protocol is an on-demand routing protocol for MANETs, which is one of the Internet-Drafts submitted to the Internet engineering task force (IETF) MANET working group. This paper proposes a new multipath routing protocol called maximally disjoint multipath AODV (MDAODV), which exploits maximally node- and link-disjoint paths and outperforms the conventional multipath protocol based on AODV as well as the basic AODV protocol. The key idea is to extend only route request (RREQ) message by adding source routing information and to make the destination node select two paths from multiple RREQs received for a predetermined time period. Compared to the conventional multipath routing protocol, the proposed MDAODV provides more reliable and robust routing paths and higher performance. It also makes the destination node determine the maximally node- and link-disjoint paths, reducing the overhead incurred at intermediate nodes. Our extensive simulation study shows that the proposed MDAODV outperforms the conventional multipath routing protocol based on AODV in terms of packet delivery ratio and average end-to-end delay, and reduces routing overhead.