• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1046-1048
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• 2009

Cooperative transmission is an effective technique to combat multi-path fading and reduce transmitted power. Relay selection and power allocation are important technical issues to determine the performance of cooperative transmission. In this paper, we proposed a new multi-relay selection and power allocation algorithm to increase network lifetime. The proposed relay selection scheme minimizes the transmitted power and increase the network lifetime by considering residual power as well as channel conditions. Simulation results show that proposed algorithm obtains much longer network lifetime than the conventional algorithm.

• The KIPS Transactions:PartC
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• v.17C no.5
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• pp.433-440
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• 2010

Energy efficiency, low latency and scalability for wireless sensor networks are important requirements, especially, the wireless sensor network consist of a large number of sensor nodes should be minimized energy consumption of each node to extend network lifetime with limited battery power. An efficient algorithm and energy management technology for minimizing the energy consumption at each sensor node is also required to improve transfer rate. Thus, this paper propose no-overlap multi-pass protocol provides for sensor data transmission in the wireless sensor network environment. The proposed scheme should minimize network overhead through reduced a sensor data translation use to searched multi-path and added the multi-path in routing table. Proposed routing protocol may minimize the energy consumption at each node, thus prolong the lifetime of the sensor network regardless of where the sink node is located outside or inside the received signal strength range. To verify propriety proposed scheme constructs sensor networks adapt to current model using the real data and evaluate consumption of total energy.

• Journal of Multimedia Information System
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• v.1 no.2
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• pp.101-110
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• 2014

The purpose of this research is to extend Ad-hoc network system lifetime with the proposed routing protocol which has considered hop lifetimes of the nodes while guaranteeing QoS in the establishment process of Ad-hoc network communication paths. Based on another power aware routing system that proposed in the advanced research [1], we are proposing an alternative power aware routing system in which nodes' hop lifetimes are compared in order to extend the lifetime of an Ad-hoc network system and delay factors have been considered for the assurance of QoS. The research of the routing protocol in this paper, which aims to maximize the system survival time considering power consumption status during the path searching in MANET and pursues the mechanism that controls hop delays for the same reason, can be applied to the study of WSN. The study concerning such phenomena is essential so that the proposed protocol has been simulated and verified with NS-2 in Linux system focusing on the lifetimes of the hops of the nodes. Commercialization of smart devices and arrival of the ubiquitous age has brought about the world where all the people and things are connected with networks. Since the proposed power aware method and the hop delay control mechanism used to find the adequate communication paths in MANET which mainly uses batteries or in WSN, they can largely contribute to the lifetime extension of the network system by reducing power consumptions when utilized for the communications attempts among soldiers during military operation, disaster areas, temporary events or exhibitions, mobile phone shadow areas, home networks, in-between vehicle communications and sense networks, etc. This paper presents the definitions and some advantages regarding the proposed outing protocol that sustain and extend the lifetime of the networks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2826-2834
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• 2013

In mobile ad hoc networks (MANET), power-saving technology of mobile nodes is divided into transmit power control (TPC), power-saving mode (PSM), and routing. TPC and PSM are operated in physical layer but the routing is managed in network layer, so the design of a joint algorithm is needed to provide better performance. Therefore, in this paper, we propose a joint power-saving and routing algorithm for maximizing the network lifetime while satisfying the end-to-end data rate in ad hoc networks. The proposed algorithm first applies the TPC or PSM to reduce the power consumption of mobile nodes and then performs the routing by considering the decided node lifetime in order to maximize the path lifetime. Simulation results show that the proposed algorithm maximize the lifetime while satisfying the required rate according to the number of mobile nodes and the level of interference.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8B
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• pp.624-629
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• 2008

Many routing protocols have been proposed for sensor networks where energy awareness and reliability are essential design issues. This paper proposes an Energy-aware Tree Routing Protocol (ETRP) for Wireless Sensor Networks. The proposed scheme relates to reliable and energy efficient data routing by selecting a data transmission path in consideration of residual energy at each node to disperse energy consumption across the networks and reliably transmit the data through a detour path when there is link or node failure. Simulation results show that the proposed method outperformed traditional Tree Routing (TR) by 23.5% in network lifetime.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.3
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• pp.534-539
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• 2005

The key in wireless sensor networks, which consist of a number of sensor nodes, is an energy efficiency. Many routing protocols have been proposed for prolonging network lifetime and reducing traffic in wireless sensor networks. Wireless sensor networks usually use wireless ad-hoc network protocols for routing, but these protocols are not well-suited for wireless sensor networks due to many reasons. In this paper, RM-flooding protocol is proposed for reducing routing overhead occurred when packet flooding. The nodes using this routing protocol can consume the limited energy effectively, and exchange information with remote nodes usulg information receiving from multipath. So, RM-flooding prolongs the network's lifetime.

• Journal of Internet Technology
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• v.21 no.4
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• pp.977-988
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• 2020

A guard-band is used to prevent collision between paths in multipath routing protocols. However, problems such as traffic congestion, reduced lifetime, and void occurrence arise because existing protocols do not exploit the guard-band during packet transmission, but only transfer packets on the same path. To solve these problems, we propose radio-disjoint multipath routing that consists of guard-band shifting and balanced node selection. The proposed scheme transfers a packet on the constructed path and alternatively, into the guard-band area. In addition, the intermediate node is selected according to link quality and remaining energy, so all of the nodes involving packet transmission can be exploited equally. Through a performance evaluation, we demonstrate that the proposed scheme achieves a higher packet delivery ratio and prolongs the average network lifetime by at least 31% and up to approximately 99% compared with existing routing protocols, under the condition of a 90% link success ratio.

• The KIPS Transactions:PartC
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• v.15C no.4
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• pp.303-310
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• 2008

To increase the lifetime of ad-hoc networks, a ratio of energy consumption for each node should be kept constant by equally distributing network traffic loads into all of the nodes. In this paper, we propose a modified AODV routing protocol to determine a possible route by considering a remaining battery capacity of a node and the degree of its usage. In addition, to reduce the amount of energy consumption during the path rediscovery process due to the huge amount of the AODV control messages the limited number of possible routes are stored into a routing table of a source node. When some links of a route fail, another possible path can be looked up in the table before the route discovery process should be initiated. We have tested our proposed method with a conventional AODV and a MMBCR method which is one of the power-efficient energy routing protocols based on the three performance metrics, i.e., the total remaining battery capacity, network lifetime and the ratio of data packets received by the destination node to compare their performance.

• Korean Journal of Social Welfare
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• v.61 no.1
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• pp.323-357
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• 2009

This study illuminates the mechanism of life course on labor status of old age complementing the limits of labor status hypothesis of old age and model of statues attainment and combining them. The main results from this analysis are summarized in four points. Firstly, older men mostly engaged in agriculture, forestry and fishing industry or low-class occupations. A very small portion held high level or professional occupations. Regular full-time employees or employers were only 4.4% while, about 70% of older employees were temporal employees or self-employed. This shows that the elderly affluence hypothesis which alleges that most older men maintain high level occupations, applies to only a few. The second finding is that wealth differentials are sizable: about 20% of older workers own less than 50 million won, while 9.3% possess more than 600 million won. Therefore, it is not safe to claim that most people have accumulated enough wealth for old age according to the elderly affluence hypothesis. This gap being mainly reflected by education level, suggests that the model of status attainment is appropriate as wealth accumulation hypothesis. Thirdly, educational level determined not only lifetime careers, but also labor status of old age. Fourthly, using path analysis, the last finding is that education had effect on labor status of old age through lifetime career and wealth. That is, old men who have low education level had unstable lifetime career and own less wealth. They work in low income job, low social occupations and unstable occupation type in old age. This shows that life inequality continues until old age. Therefore, the inequality of education opportunity, spread of part-time work and small scale self employees should be discouraged. Furthermore, related policy should be provided in order to prevent being caught in unstable work.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.469-472
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• 2008

Hierarchical routing in Wireless Sensor Network lowers the amount of a memory used and energy consumption so that the network lifetime longer. But, When Node Failure is occurred, Hierarchical routing do not look for another route. This is the problem of Hierarchical routing. To solve the problem, we would study other hierarchical routings. There are typically hierarchical routing protocols which can be used in WSN, such as the hierarchical routing of Zigbee and HiLow protocol which is submitted as draft to IETF 6LoWPAN WG. Also, there is SCRO algorithm which be able to assign short-cut routing path. This paper explains how to solve the Node Failure in each Zigbee hierarchical routing and HiLow protocol. And we suggest how to solve the Node Failure in SCRO protocol. SCRO protocol is able to assign new routing path rapidly when Node Failure is occurred. Because the strong of SCRO protocol is to assign Short-cut routing path.