• Journal of Digital Contents Society
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• v.8 no.4
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• pp.631-637
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• 2007

In this paper, I propose an adaptive cryptographic protocol which is basic protocol for fair exchange of secrets. For this, I investigate the verifiable oblivious transfer protocol based on discrete logarithm problem proposed by Lein Harn etc. And I propose a new adaptive cryptographic protocol that has the additional funtions on the existing method. This proposed method has the additional functions that enable to authenticate sender and to protect denial of what he/she has sent message to the other. To do this, I make use of bit commitment scheme using pseudo-random sequence generator.

• Journal of Communications and Networks
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• v.7 no.2
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• pp.126-134
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• 2005

Reducing energy consumption in mobile hosts (MHs) is one of the most critical issues in wireles/mobile networks. IP paging protocol at network layer and power saving mechanism (PSM) at link layer are two core technologies to reduce the energy consumption of MHs. First, we investigate the energy efficiency of the current IEEE 802.11 power saving mechanism (PSM) when IP paging protocol is deployed over IEEE 802.11 networks. The result reveal that the current IEEE 802.11 PSM with a fixed wakeup interval (i.e., the static PSM) exhibits a degraded performance when it is integrated with IP paging protocol. Therefore, we propose an adaptive power saving mechanism in IEEE 802.11-based wireless IP networks. Unlike the static PSM, the adaptive PSM adjusts the wake-up interval adaptively depending on the session activity at IP layer. Specifically, the MH estimates the idle periods for incoming sessions based on the exponentially weighted moving average (EWMA) scheme and sets its wake-up interval dynamically by considering the estimated idle period and paging delay bound. For performance evaluation, we have conducted comprehensive simulations and compared the total cost and energy consumption, which are incurred in IP paging protocol in conjunction with various power saving mechanisms: The static PSM, the adaptive PSM, and the optimum PSM. Simulation results show that the adaptive PSM provides a closer performance to the optimum PSM than the static PSM.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.25-33
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• 2021

Energy-harvesting wireless sensor networks(EH-WSNs) can collect energy from the environment and overcome the technical limitations of existing power. Since the transmission distance in a wireless sensor network is limited, the data are delivered to the destination node through multi-hop routing. In EH-WSNs, the routing protocol should consider the power situations of nodes, which is determined by the remaining power and energy-harvesting rate. In addition, in applications such as environmental monitoring, when there are urgent data, the routing protocol should be able to transmit it stably and quickly. This paper proposes an adaptive routing protocol that satisfies different requirements of normal and urgent data. To extend network lifetime, the proposed routing protocol reduces power imbalance for normal data and also minimizes transmission latency by controlling the transmission power for urgent data. Simulation results show that the proposed adaptive routing can improve network lifetime by mitigating the power imbalance and greatly reduce the transmission delay of urgent data.

• Journal of Satellite, Information and Communications
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• v.11 no.3
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• pp.72-79
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• 2016

In this paper, we propose a Service-adaptive Tactical Data Transmission Protocol (STTS) based on Satellite Communications with narrow bandwidth. STTS is designed to provide additional field for scalability and scheduler for reliability of transport stream protocol based on digital broadcasting standard, DVB-S and DVB-S2. It is also verified the effects of lost data packets with narrow bandwidth through the simulator by traffic model and re-transmission of critical data, and checked the design considerations based on STTS system.

• Journal of Communications and Networks
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• v.12 no.5
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• pp.510-517
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• 2010

In this paper, an adaptive MAC protocol (variable load adaptive (VLA)-MAC) is proposed for wireless sensor networks. This protocol can achieve high energy efficiency and provide low latency under variable-traffic-load conditions. In the case of VLA-MAC, traffic load is measured online and used for adaptive adjustment. Sensor nodes transmit packets in bursts under high load conditions to alleviate packet accumulation and reduce latency. This also removes unnecessary listen action and decreases energy consumption in low load conditions. Simulation results show that the energy efficiency, latency, and throughput achieved by VLA-MAC are higher than those achieved by some traditional approaches.

• Journal of Communications and Networks
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• v.8 no.4
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• pp.422-431
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• 2006

This paper proposes an adaptive routing protocol called ARCA for converged ad-hoc and cellular network (CACN). Due to the limitation of both bandwidth and transmission range in a cell, a mobile host (MH) may not be able to make a call during busy time. CACN offers a flexible traffic diversion mechanism that allows a MH to use the bandwidth in another cell to ease the congestion problem and increase the throughput in a cellular network. Based on the presentation of CACN's physical characteristics, the paper details the design issues and operation of the adaptive routing protocol for CACN (ARCA). Detailed numerical analysis is presented in terms of both route request rejection rate and routing overhead, which, along with the simulation results, have indicated the effectiveness and efficiency of the ARCA protocol.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.4
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• pp.1437-1459
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• 2020

Wireless Sensor Networks (WSN) is a distributed Sensor network whose terminals are sensors that can sense and check the environment. Sensors are typically battery-powered and deployed in where the batteries are difficult to replace. Therefore, maximize the consumption of node energy and extend the network's life cycle are the problems that must to face. Low-energy adaptive clustering hierarchy (LEACH) protocol is an adaptive clustering topology algorithm, which can make the nodes in the network consume energy in a relatively balanced way and prolong the network lifetime. In this paper, the novel multi-objective LEACH protocol is proposed, in order to solve the proposed protocol, we design a multi-objective coupling algorithm based on bat algorithm (BA), glowworm swarm optimization algorithm (GSO) and bacterial foraging optimization algorithm (BFO). The advantages of BA, GSO and BFO are inherited in the multi-objective coupling algorithm (MBGF), which is tested on ZDT and SCH benchmarks, the results are shown the MBGF is superior. Then the multi-objective coupling algorithm is applied in the multi-objective LEACH protocol, experimental results show that the multi-objective LEACH protocol can greatly reduce the energy consumption of the node and prolong the network life cycle.

• ETRI Journal
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• v.28 no.5
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• pp.660-663
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• 2006

In this letter, we propose a frame-size adaptive MAC protocol for high rate wireless personal area networks (WPANs). In the proposed scheme, during communication, frame error rate is periodically reported to a transmitting device and the frame size is changed according to the measured results. Thus, the channel can be more effectively utilized by adapting to variable radio conditions. Analytical results show that this scheme achieves a much higher throughput than a non-frame-size adaptive media access control protocol in high-rate WPANs.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.2
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• pp.11-18
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• 1995

Error detection in ARQ(Automatic Repeat Request) protocols is very important in wireless data communication systems. The throughput efficiency of ARQ protocols can be improved by dynamically adapting the protocol packet length so that it approaches the optimum value for throuhput efficiency. In this paper, a simple and novel adaptive packet length allocation method is proposed which transmits the packets with variable length by dyanmically estimating the channel codition. The simulation results show that the average of throughput is improved by 315.4% in the stop-and-wait protocol, 41.4% in the go-back-N protocol and 155.9% in the selective repeat protocol respectively. And the throughput performances of adaptive packet length allocation method approximately approach the theoritically optimal throughput performances.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10A
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• pp.1004-1014
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• 2007

In sensor networks, it is crucial to reliably and energy-efficiently deliver sensed information from each source to a sink node. Specifically, in mobile sink (user) applications, due to the sink mobility, a stationary dissemination path may no longer be effective. The path will have to be continuously reconfigured according to the current location of the sink. Moreover, the dynamic optimal path from each source to the sink is required in order to reduce end-to-end delay and additional energy wastage. In this paper, an Adaptive Reversal Optimal path Tree (AROT) protocol is proposed. Information delivery from each source to a mobile sink can be easily achieved along the AROT without additional control overhead, because the AROT proactively performs adaptive sink mobility management. In addition, the dynamic path is optimal in terms of hop counts and the AROT can maintain a robust tree structure by quickly recovering the partitioned tree with minimum packet transmission. Finally, the simulation results demonstrate that the AROT is a considerably energy-efficient and robust protocol.