• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.18-25
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• 2006

In mobile ad-hoc networks(MANETs), nodes are mobile and network topology changes very frequently. The mobility of nodes does affect the system performance. There has been considerable attention on the mobility models, however, most work is confined to the simulation or test-bed. In this paper, we propose an analytical method to evaluate the performances of MANETs such as the average radio range dwell time of mobile nodes, link holding time, and transmission failure probability considering the node's mobility. In the proposed model, MANETs consist of the multi-hop and multicasting routing paths. A simulation is done to validate our proposed analytical model.

• ETRI Journal
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• v.34 no.2
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• pp.264-267
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• 2012

This letter analyzes the performance of a two-hop MIMO multiuser relay network with a fixed gain amplify-and-forward protocol and antenna selection at the transmitter and receiver. A new expression for the cumulative distribution function of the highest instantaneous end-to-end signal-to-noise ratio is derived. Based on the above result, closed-form expressions for outage probability and bit error rate are presented. Also, the diversity order of the system is determined. Finally, computer simulations are compared to the analytical results, and insights and observations are provided.

• ETRI Journal
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• v.33 no.3
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• pp.299-309
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• 2011

Energy consumption is a key issue in body sensor networks (BSNs) since energy-constrained sensors monitor the vital signs of human beings in healthcare applications. In this paper, packet size optimization for BSNs has been analyzed to improve the efficiency of energy consumption. Existing studies on packet size optimization in wireless sensor networks cannot be applied to BSNs because the different operational characteristics of nodes and the channel effects of in-body and on-body propagation cannot be captured. In this paper, automatic repeat request (ARQ), forward error correction (FEC) block codes, and FEC convolutional codes have been analyzed regarding their energy efficiency. The hop-length extension technique has been applied to improve this metric with FEC block codes. The theoretical analysis and the numerical evaluations reveal that exploiting FEC schemes improves the energy efficiency, increases the optimal payload packet size, and extends the hop length for all scenarios for in-body and on-body propagation.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.10
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• pp.1079-1083
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• 2014

In this paper, a new zone radius determination algorithm is proposed for a nature-inspired routing protocol that emulates the foraging behavior of bees based on their ability to find an optimal route from nectar sites. Instead of changing the radius of nodes one-hop by one-hop, the proposed algorithm alters the radius of nodes as gaps of another radius and adapt quickly to network conditions. The simulation results show that the proposed algorithm has higher efficiency compared with existing studies in an aspect of computational complexity and end-to-end delay.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1371-1374
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• 2002

This paper compares four network con-figurations for using as the logical topology in multi- hop wavelength division multiplexing (WDM) networks. The regular network configurations studied in this paper axe ShuffleNet, de Bruijn graph, hypercube, and Man-hattan street network. Instead of using the weight mean hop distance of node placement problem for comparing optimum logical topology, we introduce a new objective function that includes h and the network cost. It can be seen that the network cost strongly depends on the logical topology selected for the implementation of the network. The objective of this paper is to find an optimum logical topology for WDM networks that gives low as well as low network cost.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.109-115
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• 2009

Recently, the relay communication is focused for the power saving and coverage extension of ad-hoc networks. For the high date rate transmission, it is proposed to adapt OFDMA relays. In this paper, we assume the 2 hop cooperative OFDMA relays between the source and the destination. The performance of 3 different relaying methods are derived and compared. We noticed that the selective OFDMA relaying method has the best performance followed by opportunistic OFDMA relaying and repetition-based OFDMA relaying method under the same threshold mutual information rate.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.205-206
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• 2006

In this paper, we have proposed an ad-hoc routing protocol named "RRMR (Reliable and Resilient Multipath Routing)" that is expanded from AODV to acquire multiple path at one time. This protocol needs less overhead to configure data routing paths and the paths are maintained to transmit data stably. To get these advantages, RRMR protocol is constructed by expanding from multipath acquiring and maintaining method based on distance vector method and hop-by-hop routing of AODV.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.53-54
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• 2006

In this paper, we analytically evaluate packet delay and energy consumption of S-MAC protocol with a modified Markov chain model. Although some models, based on IEEE 802.11 MAC protocol, to analyze the S-MAC protocol in wireless sensor network (WSN) have been proposed, they fail to consider the differences in architecture between the S-MAC and the 802.11 MAC. Therefore, by reflecting the significant features in the S-MAC function, we model the operation of S-MAC protocol, and derive its packet delay and energy consumption in single-hop WSN. Numerical results show the delay and the dissipated energy at various duty cycle values according to offered load, where a practical mote is used.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.503-504
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• 2007

The most Important thing in Sensor Network Design is a Energy Efficiency. Limited sources of Sensor Mote tan occur merging of Protocol. In this paper, we proposed Cross Layer Protocol for Energy Efficienty. The proposed protocol can increase the network life time using multi hop transmission. sensor network should use multi hop communication and small radius because radio in wireless communication is the most spendable thing in sensor network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.857-859
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• 2015

In this letter, we consider a directional routing protocol that reduces the duplicated packets for AODV-based flooding in the course of establishing the end-to-end route in the multi-hop maritime ad-hoc networks. We propose an adaptive means of reducing the routing overhead subject to the node density and the target probability of successful routing that is analyzed by the stochastic geometry.