• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4531-4535
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• 2011

In this paper, USN(Ubiquitous Sensor Network) is used in the structure of the tree routing was implemented in embedded systems. Tree Routing in the USN to the sink node to transmit sensor data is one of the techniques. When routing, sensor data is transmitted based on pre-defined ID according hop number. In order to have optimal routing path, the current state of the wireless sector and the sensor node informations were used. Also, received sensor data and the results of the tree routing by implementing an embedded system. This embedded system can be applied to a portable sensor information collecting system.

• Journal of Information Technology Applications and Management
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• v.14 no.2
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• pp.1-10
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• 2007

The ubiquitous computing system is expected to be widely utilized in digital home, logistics control, environment/disaster management, medical/health-care services and other applications. The ubiquitous sensor network (USN) is a key infra-structure of this system. Nodes in the USN are exposed to adverse environments and required to perform their missions with very limited power supply only. Also the sensor network is composed of much more nodes. In case some node consumes up its power capacity under a certain required level, the network topology should change and re-routing/ re-transmission of data is necessitated. Resultantly communication protocols studied for conventional wireless networks or ad-hoc networks are not suitable for the sensor network. Schemes should be devised to control the efficient usage of node power in the sensor network. This paper proposes a routing algorithm to enhance the efficiency of power consumption for USN node and analyzes its performance by simulation.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.716-720
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• 2006

In this paper, we designed and proposed new routing algorithm that can support a variety of vital-sign traffic characteristic and could be applicable to USN for telemedicine by using adaptive transmission power level and increase frequency of routing request message. In proposed routing algorithm, when an emergency vital-sign traffic is applied, we use large transmission power to reduce route query response time and make the priority order in route process. On the other hand, for non emergency vital-sign traffic, we use low transmission power and adaptive decrease frequency of routing request message. which is insensitive to delay. The proposed scheme should be better QoS performance in complex USN than conventional method, which is performed based on uniform transmission power level.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.546-549
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• 2005

It is evident that advancement of ubiquitous technologies in the near future guarantees more convenient and plentiful living. With regarding to car life, we dream of an automatic driving without any effort of operation. This paper touches the realization issue, a convergence of wireless sensor network and Telematics specializing on an information routing mechanism between participating components in Telematics sensor communication network. We list up new requirements of wireless sensor network deployed for Telematics services. Then context-aware routing architecture is proposed in order to solve these constraints, in which a network topology for routing can be dynamically configured according to the combination of context models of network components.

• Journal of information and communication convergence engineering
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• v.6 no.4
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• pp.466-469
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• 2008

The existing routing protocols in USN environment, PEGASIS is more efficient than LEACH, which is a hierarchical routing protocol, for network configuration based on power consumption. Despite its merit that it can reduce energy consumption per node, however, the PEGASIS protocol also has a weakness that it is less responsive to frequent changes that occur in the configuration of sensor network due to BS nodes that keep changing, which is a typical characteristic of the sensor network. To address this problem, this paper proposes to select sub-cluster heads and have them serve as intermediate nodes. This paper presents and analyses that this method can resolve the aforementioned problem of the PEGASIS algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5B
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• pp.557-565
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• 2011

In this paper, we assume that sensor nodes organize the multi-hop networks, are fixed, and operate as full function devices(FFD). The wireless sensor network(WSN) only consists of mobile nodes without the assistance from the fixed infrastructure, which increases the flexibility of the network. However, it is difficult to perform routing in the WSN, since sensor nodes freely join in and drop out of the network, and some sensor nodes have very low power. We propose the algorithm combining routing schemes based on the bitmap and cluster methods in this paper. Through computer simulations, we show the validity of the proposed algorithm.

• Convergence Security Journal
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• v.5 no.4
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• pp.49-58
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• 2005

We propose a specific ubiquitous sensor network (USN) architecture as a promising candidate of the future telemedicine model which offers the patient's mobility and more cost-efficient medical care system. This new USN architecture is a kind of cell-based secure sensor network supporting encrypted multi-casting communications and it has a hybrid routing protocol by adapting flat routing to hierarchical routing. For the patient's privacy and the protection of patient's vital information from eavesdropping, we adopt a lightweight PKI-based secure communication protocol with some formal presentation on its core procedure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1647-1652
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• 2008

The PEGASIS protocol is more effective about energy consumption more than LEACH in USN environment. However, PEGASIS is weakness enemy in change of sensor network net composition because It changes BS node frequently. Therefore, we propose new routing protocol that use Sub-Cluster Chaining to solve this problem in this paper. It can reduce overhead that happen in election of middle node doing so and reduce energy consumption. Also, It can supplement limitation that PEGASIS has. This is treatise shows that new protocol that propose than existent PEGASIS through simulation is superior.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.370-376
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• 2009

Recently, Study for routing protocol is gone vigorously in the Ubiquitous Sensor Network. A hierarchical routing protocol is being practical and received interest among them. Therefore we analyze a weak point of HEED. And I suggest the new protocol that solved a weak point of HEED. The new protocol that we propose puts weight in the energy remainder amount than HEED and elect CH. And elected CH is designed to change by new node when quantity of energy leftover becomes less than 50%. Therefore all nodes come to use energy fairly. The protocol that we proposed can prove the cluster survival rate about 30%. And CH is more effective because when elect CH replace, response time selects small node.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.2
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• pp.51-57
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• 2009

Ubiquitous sensor network is the communication environment where sensor nodes move freely and construct network to get the services from the system. So, it does not need fixed infrastructure and can easily be placed in unaccessible regions like war or calamity area. Wireless sensor network protocol has self-organizing capability, need to adapt topology change flexibly and also has technique that sensor nodes work cooperatively, because network disconnection is frequently occurred due to the active mobility of sensor nodes. In this paper, we design a cluster based fault-tolerant routing protocol for the efficient topology construction and to guarantee stable data transmission in USN. The performance of the proposed protocol is evaluated by an analytic model.