• Journal of Internet Computing and Services
• /
• v.4 no.4
• /
• pp.15-25
• /
• 2003

Wireless ad-hoc networks are only composed with mobile devices. Unlike the traditional wired networks, those devices are mostly operated with battery power. Since the battery-operated power is limited, the efficient energy resource managements becomes an important issue in wireless ad-hoc networks and various studies that considered these characteristics are progressed. One of those studies is an energy efficient routing using coordinators. In this method. only devices elected as coordinator participate in data transmissions in ad-hoc networks, while other devices remain in sleep node. The overall energy consumption of a system can be reduced. In order to minimize energy consumption of a total network, previous results try to maximize the number of nodes in sleep mode. However, minimizing the number of coordinators does not ensure to increase the system lifetime. In this thesis, we propose an algorithm that can elect coordinators with considering the amount of necessary energy to transmit assigned data and a connectivity of nodes in the networks. The result of proposed coordinator election algorithm can increase the system lifetime of an Ad-hoc network from the results of existing coordinator election algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.1
• /
• pp.87-94
• /
• 2009

The intrusion detection system is one of the active fields of research in wireless networks. Intrusion detection in wireless mobile Ad hoc network is challenging because the network topologies are dynamic, lack centralization and are vulnerable to attacks. Detection of malicious nodes in an open ad-hoc network in which participating nodes do not have previous security association has to face number of challenges which is described in this paper. This paper is about determining the malicious nodes under critical conditions in the mobile ad-hoc network and deals with security and vulnerabilities issues which results in the better performance and detection of the intrusion.

• Journal of KIISE:Information Networking
• /
• v.29 no.5
• /
• pp.459-465
• /
• 2002

Ad-hoc networks have the dynamic topology characteristics and most of the applications on ad-hoc networks require the group communication capability. Previously proposed multicast mechanisms on mobile ad-hoc networks build multicast-infrastructures like the tree or mesh for the group communication and these infrastructures nay cause significant overhead especially in a highly dynamic mobile ad-hoc network environment. Therefore, in this paper, we propose a new multicast mechanism supporting multicast services based on only the underlying unicast routing tables, hence any multicast-related infrastructures like trees and meshes are not required to be constructed.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.8A
• /
• pp.639-648
• /
• 2005

A wireless ad-hoc network is a temporal network formed by a collection of wireless mobile nodes without the aid of any existing network infrastructure or centralized ad-ministration. Numerous routing protocols have been developed for changing messages among the nodes in a wireless ad-hoc network. Some multi-path routing protocols have also been proposed to support load balancing and QoS for wireless ad-hoc networks. In this paper, we propose not only an efficient routing algorithm for wireless ad-hoc net-worts but also a protocol that can improve data transmission rate and reduce end-to-end delay. In our protocol, each mobile node need not broadcast routing messages periodically and the mobile node that wants to send data packets initiates route request and route establishment procedure. By simulation, we showed that faster route recovery is possible by maintaining multiple routing paths in each node, and the route maintenance overhead can be reduced by limiting the number of multiple routing paths.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2004.05a
• /
• pp.1609-1612
• /
• 2004

Ad hoc network is a kind of new wireless network paradigm for mobile hosts. Ad Hoc wireless networks consist of wireless mobile hosts forming a temporary network without the aid of any established infrastructure or centralized administration. Mobile hosts rely on each other to keep the network connected. Each host is not only mobile hosts but also router. So how to design a routing protocol is the most important problem. Dynamic source routing is a kind of routing protocol. In this paper we suggest a new automatic route shortening method and an energy-aware routing mechanism based on DSR.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.3
• /
• pp.188-190
• /
• 2014

In mobile ad hoc networks(MANETs), each node rebroadcast received route request packets for route discovery. Flooding from large number of nodes induces the broadcast storm problem which causes severe degradation in network performance due to redundant retransmission, collision and contention. This paper presents a node status algorithm based on probabilistic scheme to alleviate the broadcast storm problem for wireless ad hoc networks.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.13 no.4
• /
• pp.17-22
• /
• 2013

In this paper, we propose a multi-hop cooperative transmission protocol over Rayleigh fading channels. In the proposed protocol, the multi-hop cooperative transmission is used to improve the system performance. Due to broadcast nature, we do not limit the receiving node to be only the next node, but the destination and all the nodes between the transmitting node and the destination. The proposed protocol can hence save the average transmit power, compared with multi-hop direct transmission protocol due to the skipped transmissions from some intermediate nodes or chosen relays. The proposed scheme is implemented and evaluated in mobile ad-hoc wireless networks.

• Journal of information and communication convergence engineering
• /
• v.5 no.3
• /
• pp.209-214
• /
• 2007

In this paper, we proposed a new MANET (Mobile Ad hoc Networks) technology of routing protocol. The MANET has a mobility formation of mobile nodes in the wireless networks. Wireless network have two types architecture: the Tree based multicast and shared tree based. The two kind's architecture of general wireless networks have difficult to solve the problems existing in the network, such as connectivity, safety, and reliability. For this purpose, as using that ADDMRP (Ad hoc network Doppler effect-based for Dynamic Multicast Routing Protocol), this study gives the following suggestion for new topology through network durability and Omni-directional information. The proposed architectures have considered the mobility location, mobility time, density, velocity and simultaneous using node by Doppler effects and improved the performance.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.4
• /
• pp.87-93
• /
• 2016

In this paper, we propose a RF energy harvesting based routing protocol in mobile ad-hoc wireless sensor networks. The main features and contributions of the proposed routing protocol are as follows. First, establishment of routing route based on both remaining energy of mobile sensor nodes and RF energy harvesting. Second, establishment of routing route by considering availability and stability of route based on energy of mobile sensor nodes to increase lifetime of networks and route. The performance evaluation of the proposed routing protocol using OPNET shows that the routing method considering both route availability and route stability based on RF energy harvesting can increase efficiently route lifetime.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.8 no.5
• /
• pp.121-127
• /
• 2009

Wireless devices can communicate between each other without existing infrastructure in mobile Ad-hod network. Ad hoc networks can be used under difficult conditions, where it is difficult to construct infrastructures, such as shadowing areas, disaster areas, war area, and so on. In order to support to considerable and various wireless services, more spectrum resources are needed. However, efficient utilization of the frequency resource is difficult because of spectrum scarcity and the conventional frequency regulation. Ad-hoc networks employing cognitive radio (CR) system that guarantee high spectrum utilization provide effective way to increase the network capacity. In this paper, we simulate and compare the performance of conventional single and cooperative spectrum sensing with CR system using ad-hoc networks. And we demonstrate performance improvement by analyzing the system performance.