• The Journal of the Korea Contents Association
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• v.10 no.4
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• pp.55-65
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• 2010

We present a method for increasing network lifetime without link failure due to lack of battery capacity of nodes in wireless ad-hoc networks with low mobility. In general, a node with larger remaining battery capacity represents the one with lesser traffic load. Thus, a modified AODV routing protocol is proposed to determine a possible route by considering a remaining battery capacity of a node. Besides, the total energy consumption of all nodes increase rapidly due to the huge amount of control packets which should be flooded into the network. To reduce such control packets efficiently, a source node can store information about alternative routes to the destination node into its routing table. When a link failure happens, the source node should retrieve the route first with the largest amount of the total remaining battery capacity from its table entries before initiating the route rediscovery process. To do so, the possibility of generating unnecessary AODV control packets should be reduced. The method proposed in this paper increases the network lifetime by 40% at most compared with the legacy AODV and MMBCR.

• The KIPS Transactions:PartC
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• v.11C no.6 s.95
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• pp.829-834
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• 2004

Nodes communicate through wireless channels under peer-to-peer level in ad-hoc mobile networks. The nodes are free to move around in a geographical area and are loose]y bounded by the transmission range of the wireless channels. Also, a node is completely free to move around, there is no fixed final topology. Hence, to manage the inter-node communication and data exchange among them a leader node is required. In this paper we introduce an efficient leader election algorithm for mobile ad hoc networks where inter-node communication is allowed only among the neighboring nodes. Furthermore we present the result of performance evaluation through simulation. The algorithm is efficient and practical since it uses least amount of wireless resources and does not affect the movement of the nodes.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.6
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• pp.25-34
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• 2011

In this paper, In this paper, we propose a Cooperative Routing Protocol (CooRP) for supporting network convergence and transmission services efficiently in mobile ad-hoc wireless sensor networks with Rayleigh fading environments. The main contributions and features of this paper are as follows. First, the routing routes are decided on route stability based on entropy concepts using mobility of nodes within the direction guided line region to increase the operational lifetime of routes as well as reduce control overhead for route construction. Second, a cooperative data transmission strategy based on the constructed stable routing route is used to increase packet delivery ratio with advanced SNR. Third, a theoretical analysis for cooperative data transmission of the proposed CooRP with outage probability is presented. The performance evaluation of the proposed CooRP is performed via simulation using OPNET and analysis. The results of performance evaluation show that the proposed CooRP by using stable routing routes and cooperative transmission can increase packet delivery ratio efficiently.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.2
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• pp.36-43
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• 2009

In this paper, we propose a Cooperative Routing using ARQ-based Transmission (CRARQ) in Mobile Ad-hoc Wireless Sensor Networks (MAWSN). The goals of the CRARQ are to improve both the efficiency of transmission and the reliability of transmission together. The main features and contributions of the proposed CRARQ for supporting these goals are as follows. First, CRARQ uses a reactive concept to construct a route from a source to a destination. Second, CRARQ chooses the most stable relay at each hop along the route by mobility-based strategy. Third, cooperative transmission using the ARQ technique which can improve reliability is used at each hop to send data packets from source to destination. Finally, we present a theoretical analysis model for the proposed CRARQ. The performance evaluation of our protocol is implemented via simulation using Optimized Network Engineering Tool (OPNET) and analysis. The results of both simulation and analysis show that CRARQ achieves the improved packet delivery ratio (PDR) and outage probability.

• Journal of Korea Society of Industrial Information Systems
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• v.22 no.1
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• pp.1-9
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• 2017

With the Development of Wireless Network Technology and Wireless Link Technology, Wireless Mesh Network (WMN) is Attracting Attention as a Key Technology to Construct the Wireless Transit Network. The WMN has been Studied for a Long Time in Various Fields, however there are still many Problems that have not been solved yet. One of them is the Routing Problem to find an Optimal path in a Multi-hop Network Composed of Wireless Links. In the Hybrid-WMN, which is one of the Three Types of WMN, Optimal Path Selection Requires Research on Path Search Protocols that Effectively use the Infrastructure Mesh as a Transit Network, Together with Research for a Routing Metric with Excellent Performance. Therefore, this Paper Proposes a Dual Mode-AODV(Ad hoc On-demand Distance Vector) for Hybrid-WMN. Simulation result shows that the Path Selection Delay was Reduced by 52% than AODV when the Proposed Dual Mode-AODV was applied.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.8
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• pp.1444-1451
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• 2016

This paper proposes a Tabu search algorithm to minimize the required energy to send data between a source and a destination using the cooperative communication in wireless ad hoc networks. As the number of nodes in wireless ad hoc networks increases, the amount of calculation for establishing the path between nodes would be too much increased. To obtain the optimal cooperative path within a reasonable computation time, we propose a new Tabu search algorithm for a high-density wireless network. In order to make a search more efficient, we propose some efficient neighborhoods generating operations of the Tabu search algorithm. We evaluate those performances through some experiments in terms of the minimum energy required to send data between a source and a destination as well as the execution time of the proposed algorithm. The comparison results show that the proposed algorithm outperforms other existing algorithms.

• The KIPS Transactions:PartC
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• v.14C no.7
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• pp.583-588
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• 2007

It is easy to implement a temporary network with a mobile ad-hoc network in which mobile nodes have without using a infrastructure network. They depend on their limited power. Recently, it is a hot issue to save the energy in a mobile ad-hoc network because a mobile nodes have a limited energy. Research of IEEE 802.11 PSM was proposed in a single hop ad-hoc assumption. If IEEE 802.11 PSM is applied to multi hop ad-hoc network, non-optimal paths will be generated by the mobile nodes which didn't receive a message of routing request. Non-optimal paths increase not only a network latency but also energy consumption of mobile nodes. Reconfiguring algorithm of non-optimal paths caused by the mobile nodes which didn't receive a message of routing request is proposed in this paper. A mobile node can overhear the data in his range. A wireless medium is shared by all mobile nodes using the same bandwidth. All mobile nodes lookout the non-optimal paths with these properties of a medium, if non-optimal path is generated, optimal reconfiguring will be accomplished by modifying routing table of itself or sending a request message of routing update to nearby nodes. By reconfiguring the non-optimal paths to optimized ones, network latency and energy consumption was decreased. It is confirmed to ignore the overhead caused by a algorithm presented in this paper through the result of the simulation.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.5
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• pp.155-162
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• 2014

We proposed a 2 level tree based cluster based routing protocol for mobile ad hoc networks. it is our crucial goal to establish improved clustering's structure in order to extend average node life-time and elevate the average packet delivery ratio. Because of insufficient wireless resources and energy, the method to form and manage clusters is useful for increasing network stability. but cluster-head fulfills roles as a host and a router in clustering protocol of Ad hoc networks environment. Therefore energy exhaustion of cluster-head causes communication interruption phenomenon. Effective management of cluster-head is key-point which determines the entire network performance. The scheme focuses on improving the performance the life time of the network and throughput through the management of cluster-heads and its neighbor nodes. In simulation, we demonstrated that it would obtain averagely better 17% performance than LS2RP.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10B
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• pp.865-875
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• 2008

In this paper, we propose a reliable multicast scheme for the tactical wireless ad hoc network where the members share the situation and operation data. Our scheme consists of two phases to guarantee the reliability. During the dissemination phase, we utilizes an epidemic approach similar to gossip-based ad hoc routing. Then the group members interchange the message reception state information periodically so that they are able to recover missing packets from the other members. We evaluate the performance of our scheme through extensive simulations using the network simulator in comparison with other existing reliable multicast schemes in mobile ad hoc network. Our scheme shows higher packet delivery ratio regardless of the mobility and imposes much lower control overhead to the non-group members compared with the existing schemes.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.3
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• pp.75-85
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• 2016

MANET is a network composed only mobile network having limited resources and has dynamic topology characteristics. Therefore, every mobile node acts as a route and delivers data by using multi-hop method. In particular, group communication such as multicast is desperately needed because of characteristics such as battery life of limited wireless bandwidth and mobile nodes. However, the multicast technique can have different efficient of data transmission according to configuring method of a virtual topology by the movement of the nodes and the performance of a multicast can be significantly degraded. In this paper, the region based security multicast technique is proposed in order to increase the efficiency of data transmission by maintaining an optimal path and enhance the security features in data transmission. The group management node that manages the state information of the member nodes after the whole network is separated to area for efficient management of multicast member nodes is used. Member node encrypts using member key for secure data transmission and the security features are strengthened by sending the data after encrypted using group key in group management node. The superiority of the proposed technique in this paper was confirmed through experiments.