• Journal of Industrial Technology
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• v.27 no.B
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• pp.43-51
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• 2007

In mobile multi-hop wireless networks, the authentication between a base station and a mobile multi-hop node, between multi-hop nodes, and between user a station and a multi-hop node is needed for the reliable and secure network operation. In this paper, we survey various authentication schemes which can be considered to be adopted in mobile multi-hop wireless networks and propose a concept of novel mutual authentication scheme applicable to mobile multi-hop network architecture. The scheme should resolve the initial trust gain problem of a multi-hop node at its entry to the network, the problem of rogue mobile multi-hop node and the problem of hop-by-hop authentication between multi-hop nodes. Effectively, the scheme is a hybrid scheme of the distributed authentication method and the centralized authentication method which are considered to be deployed in the wireless ad-hoc network and the wireless network connected to wired authentication servers, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.11
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• pp.1550-1553
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• 2020

In this paper, we maximize the lifetime of a multi-hop path through a cooperative wireless energy sharing scheme between constituent nodes in a wireless multi-hop communication. Considering a bidirectional multi-hop communication environment, we present an optimization problem to maximize path lifetime by adjusting the amount of energy each node needs to share with its neighboring nodes. On the basis of solidarity property, i.e., the lifetime of the multi-hop path is maximized when the lifetimes of all nodes are the same, we convert the considered optimization problem into a linear programming problem and solve it easily. Simulation result shows that the proposed two-way wireless energy sharing method maximizes the path lifetime of multi-hop communications and approximately doubles the path lifetime compared with the one-way energy sharing method.

• Journal of Communications and Networks
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• v.15 no.4
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• pp.430-438
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• 2013

This paper addresses the issue of throughput-delay of one-to-many wireless multi-hop flows based on random linear network coding (RLNC). Existing research results have been focusing on the single-hop model which is not suitable for wireless multi-hop networks. In addition, the conditions of related system model are too idealistic. To address these limitations, we herein investigate the performance of a wireless multi-hop network, focusing on the one-to-many flows. Firstly, a system model with multi-hop delay was constructed; secondly, the transmission schemes of system model were gradually improved in terms of practical conditions such as limited queue length and asynchronous forwarding way; thirdly, the mean delay and the mean throughput were quantified in terms of coding window size K and number of destination nodes N for the wireless multi-hop transmission. Our findings show a clear relationship between the multi-hop transmission performance and the network coding parameters. This study results will contribute significantly to the evaluation and the optimization of network coding method.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.1
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• pp.120-130
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• 2009

In recent years, many mobile wireless communication devices and applications have been deployed on the planet. The mobile multi-hop wireless network models appeared to provide means to access to networks where few infrastructure exists. However, the mobile multi-hop wireless networks have weaker points in attacks and intrusions than the wired and one-hop wireless networks. In this paper, the secure routing issues in most mobile multi-hop wireless network models are surveyed in depth. The state-of-the-art technologies and research activities are explained. Finally, the issues and technologies for the secure routing specific to a maritime network model are sufficiently discussed as conclusions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10B
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• pp.872-882
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• 2006

The Wireless Mesh Network uses a wireless communication technology with transmission rates similar to that of a cable, which is used as a backbone network. The topology structure is in a Mesh form which resembles an Ad-hoc network, however a metric is needed in order to set the channel and channel methods since the operation intentions and interior motions are different. This thesis proposes a metric(ETR : Expected Transmission Rate) that sets the channel with physical link performance and multi hop transmission capabilities. This metric will also be based on multi channel creation methods and Hop-by-hop routing techniques for an effective multi hop transmission with no loops.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.1
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• pp.5-25
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• 2009

In recent years the popularity of multi-hop wireless networks has been growing. Its flexible topology and abundant routing path enables many types of applications. However, the lack of a centralized controller often makes it difficult to design a reliable service in multi-hop wireless networks. While packet routing has been the center of attention for decades, recent research focuses on data discovery such as file sharing in multi-hop wireless networks. Although there are many peer-to-peer lookup (P2P-lookup) schemes for wired networks, they have inherent limitations for multi-hop wireless networks. First, a wired P2P-lookup builds a search structure on the overlay network and disregards the underlying topology. Second, the performance guarantee often relies on specific topology models such as random graphs, which do not apply to multi-hop wireless networks. Past studies on wireless P2P-lookup either combined existing solutions with known routing algorithms or proposed tree-based routing, which is prone to traffic congestion. In this paper, we present two wireless P2P-lookup schemes that strictly build a topology-dependent structure. We first propose the Ring Interval Graph Search (RIGS) that constructs a DHT only through direct connections between the nodes. We then propose the ValleyWalk, a loosely-structured scheme that requires simple local hints for query routing. Packet-level simulations showed that RIGS can find the target with near-shortest search length and ValleyWalk can find the target with near-shortest search length when there is at least 5% object replication. We also provide an analytic bound on the search length of ValleyWalk.

• Journal of Information Processing Systems
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• v.13 no.6
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• pp.1544-1553
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• 2017

The network coding mechanism has attracted much attention because of its advantage of enhanced network throughput which is a desirable characteristic especially in a multi-hop wireless network with limited link capacity such as the device-to-device (D2D) communication network of 5G. COPE proposes to use the XOR-based network coding in the two-hop wireless network topology. For multi-hop wireless networks, the Distributed Coding-Aware Routing (DCAR) mechanism was proposed, in which the coding conditions for two flows intersecting at an intermediate node are defined and the routing metric to improve the coding opportunity by preferring those routes with longer queues is designed. Because the routes with longer queues may increase the delay, DCAR is inefficient in delivering real-time multimedia traffic flows. In this paper, we propose a network coding-aware routing protocol for multi-hop wireless networks that enhances DCAR by considering traffic load distribution and link quality. From this, we can achieve higher network throughput and lower end-to-end delay at the same time for the proper delivery of time-sensitive data flow. The Qualnet-based simulation results show that our proposed scheme outperforms DCAR in terms of throughput and delay.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.231-234
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• 2003

In this paper, we propose the enhanced CSMA/CA MAC protocol fir mobile multi-hop wireless Ad-hoc networks. In the conventional wireless Ad-hoc network such as WLAN using CSMA/CA MAC protocol, communications between terminals that fn connected within multi-hop node may degrade the transmission efficiencies as increasing the multi-hop nodes because of RTS-CTS-DATA-ACK message exchange between terminals. In this raper, we apply the ACK/RTS control message into multi-hop transmission between terminals for wireless ad-hoc networks and improve the data traffic transmission efficiencies compared with conventional CSMA/CA MAC protocol used in WLAN.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.4
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• pp.800-818
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• 2013

Supporting video streaming over multi-hop wireless networks is particularly challenging due to the time-varying and error-prone characteristics of the wireless channel. In this paper, we propose a joint optimization scheme for video streaming over multi-hop wireless networks. Our coding scheme, called Joint Source/Network Coding (JSNC), combines source coding and network coding to maximize the video quality under the limited wireless resources and coding constraints. JSNC segments the streaming data into generations at the source node and exploits the intra-session coding on both the source and the intermediate nodes. The size of the generation and the level of redundancy influence the streaming performance significantly and need to be determined carefully. We formulate the problem as an optimization problem with the objective of minimizing the end-to-end distortion by jointly considering the generation size and the coding redundancy. The simulation results demonstrate that, with the appropriate generation size and coding redundancy, the JSNC scheme can achieve an optimal performance for video streaming over multi-hop wireless networks.

• Journal of Communications and Networks
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• v.14 no.1
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• pp.63-74
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• 2012

Multicast data communication is an efficient communication scheme, especially inmulti-hop ad hoc networks where the media access control (MAC) layer is based on one-hop broadcast from one source to multiple receivers. Compared to unicast, multicast over a wireless channel should be able to deal with varying channel conditions of multiple users and user mobility to provide good quality to all users. IEEE 802.11 does not support reliable multicast owing to its inability to exchange request-to-send/clear-to-send and acknowledgement packets with multiple recipients. Thus, several MAC layer protocols have been proposed to provide reliable multicast. However, additional overhead is introduced, as a result, which degrades the system performance. In this paper, we propose an efficient wireless multicast MAC protocol with small control overhead required for reliable multicast in multi-hop wireless ad hoc networks. We present analytical formulations of the system throughput and delay associated with the overhead.