• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.3
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• pp.25-33
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• 2008

In this paper, the transmit power minimization for Poisson distributed wireless ad-hoc relay networks in Rayleigh fading channels is considered. We investigate two power allocation methods one is a minimum power allocation (MPA) strategy and the other is an equal outage power allocation (EOPA) strategy. We analyze the total transmit power of two allocation methods under the given end-to-end outage probability constraint. Our results show that the MPA achieves more power saving than EOPA, and the power saving is more significant as the number of relay nodes increases.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1067-1070
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• 2005

In this paper, we propose the address allocation algorithm in hybrid Mobile ad-hoc network (MANET). Most of proposed address autoconfiguration algorithms are node based. Node based address autoconfiguration algorithms are inefficient. Because the node based algorithms waste bandwidth and consume much battery in mobile ad-hoc networks. we present the address allocation algorithm using internet gateway based address autoconfiguration by modifing the IPv6 stateless address autoconfiguration protocol. We use the network simulator NS-2 in our experiments. The simulation result shows reducing network traffic and saving battery.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.1976-1996
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• 2011

Cognitive radio (CR) MAC protocol provides access control of unused spectrum resources without causing interference to primary users. To achieve this goal, in this paper a TDMA based cooperative multi-channel cognitive radio MAC (MCR-MAC) protocol is proposed for wireless ad hoc networks to provide reliable protection for primary users by achieving cooperative detection of incumbent system signals around the communication pair. Each CR node maintains transmission opportunity schedules and a list of available channels that is employed in the neighbor discovery period. To avoid possible signal collision between incumbent systems and cognitive radio ad hoc users, we propose a simple but efficient emergency notification message exchanging mechanism between neighbor CR nodes with little overhead. Our simulation results show that the proposed MCR-MAC can greatly reduce interference with primary users and remarkably improve the network throughput.

• Journal of the Korea Society of Computer and Information
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• v.21 no.3
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• pp.25-32
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• 2016

Mobile Ad Hoc Networks(MANETs) consists of mobile nodes which communicate with each other without any centralized infrastructure. Message broadcasting by flooding for route discovery in MANET can result in high redundant retransmission, contention and collision of broadcasting packet, known as the broadcast storm problem collectively. The cross-layer design is adopted in this paper, which lets routing layer share the received signal strength information at MAC layer. Also this paper proposes a new probabilistic approach that dynamically adjusts the rebroadcasting probability of a node for routing request packets (RREQs) according to the received signal strength. The simulation results show that the proposed approach demonstrates better performance than blind flooding, fixed probabilistic broadcasting approaches.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.293-295
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• 2009

In an Intelligent Transport System(ITS), data dissemination based on inter-vehicle communication is effective for acquiring real-time traffic-jam information. In this paper, we propose a novel method for traffic jam information dissemination in vehicular ad-hoc networks. In our proposed method, vehicles already trapped in a Traffic-Jam elect leaders according to their locations from upstream and downstream respectively. Then each leader generates traffic data which contains their position, velocity and leader counter respectively, and disseminate the information. {{br}}The implementation of our proposed method is evaluated by means of simulation, and we also present simulation result

• Proceedings of the Safety Management and Science Conference
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• 2002.05a
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• pp.121-127
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• 2002

In this paper, we propose traffic management support and evaluate the performance through simulation. We suggest traffic management routing protocol that can guarantee reliance according to not only reduction of the Network traffic congestion but also distribution of the network load that prevents data transmission. For performance evaluation, we analyzed the average data reception rate and network load, considering the node mobility. We found that in the mobile Ad Hoc networks, the traffic management service increased the average data reception rate and reduced the network traffic congestion and network load in Mobile Ad Hoc Networks.

• Proceedings of the Korea Society for Simulation Conference
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• 2000.11a
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• pp.97-101
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• 2000

Energy consumption is considered as a principal ingredient in mobile wireless ad-hoc networks. In such a network, most of mobile nodes takes a role in forwarding messages received from neighbor nodes. Energy of these nodes is consumed in different rates depending on message traffic routes. This paper proposes a scheme to balance routing energy consumption by transferring routing function from node with small residual energy to node with enough residual energy. This scheme requires additional local message transfer, increasing the energy consumption of nodes to transfer routing function, and increasing total energy consumption of ad-hoc network. But balancing of energy consumption make the system lifetime the longer and increase the average node lifetime.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.2
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• pp.119-127
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• 2011

The paper surveys various analytical models for IEEE 802.11 medium access control protocols and critically discusses recent issues developing in wireless mobile ad hoc networks and their MACs. The surveyed MAC protocols include the standard IEEE 802.11 MAC suites such as IEEE 802.11 DCF, IEEE 802.11 PCF, IEEE 802.11e EDCA, and IEEE 802.11 ad hoc mode; and also the newer, de facto MAC protocols. We study the analytic models of the standard MAC suites followed by the newer analytic models that have been published in recent years. Also, the paper tries to include most of current literatures discussing analytic modeling of MAC in conjunction to some critical issues such as contention among ad hoc nodes, hidden terminal problems, and real-time service support.

• Journal of Communications and Networks
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• v.6 no.4
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• pp.295-306
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• 2004

In this paper, a novel air-interface is presented for Fleet-Net1, a self-organizing network for inter-vehicle and vehicle-toroadsidecommunication. The air-interface is based upon the lowchip-rate version of UMTS/TDD. To adapt the cellular UMTS standard to an air-interface for ad hoc networks, changes of the physical layer, medium access control sub-layer and radio resource management are required. An overview of the required modifications is given here. Particularly, a decentralized synchronization mechanism is presented and analyzed by means of simulations. Furthermore, changes for the medium access control are explained in detail, which allow for an efficient operation in partly meshed networks and prioritization. Performance results of the overall system considering throughput and delay are derived by means of analytical evaluations and event-driven simulations. Based on realistic mobility models, it is shown that the presented solution provides a robust communication platform even in vehicular environments. The proposed air-interface is a cost-effective solution not only for inter-vehicle communication, but also for ad hoc networking in general, benefiting from the mass-market of UMTS.

• IEMEK Journal of Embedded Systems and Applications
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• v.1 no.1
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• pp.8-13
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• 2006

In mobile ad hoc networks, most of on demand routing protocols such as DSR and AODV do not deal with traffic load during the route discovery procedure. To achieve load balancing in networks, many protocols have been proposed. However, existing load balancing schemes do not consider the remaining available buffer size of the interface queue, which still results in buffer overflows by congestion in a certain node which has the least available buffer size in the route. To solve this problem, we propose a load balancing protocol called Dynamic Congestion Aware Routing Protocol (DCAR) which monitors the remaining buffer length of all nodes in routes and excludes a certain congested node during the route discovery procedure. We also propose two buffer threshold values to select an optimal route selection metric between the traffic load and the minimum hop count. Through simulation study, we compare DCAR with other on demand routing protocols and show that the proposed protocol is more efficient when a network is heavily loaded.