Giljae Lee

A Cluster-Based Energy-Efficient Routing Protocol without Location Information for Sensor Networks

With the recent advances in Micro Electro Mechanical System (MEMS) technology, low cost and low power consumption wireless micro sensor nodes have become available. However, energy-efficient routing is one of the most important key technologies in wireless sensor networks as sensor nodes are highly energy-constrained. Therefore, many researchers have proposed routing protocols for sensor networks, especially cluster-based routing protocols, which have many advantages such as reduced control messages, bandwidth re-usability, and improved power control. Some protocols use information on the locations of sensor nodes to construct clusters efficiently. However, it is rare that all sensor nodes know their positions. In this article, we propose another cluster-based routing protocol for sensor networks. This protocol does not use information concerning the locations of sensor nodes, but uses the remaining energy of sensor networks and the desirable number of cluster heads according to the circumstances of the sensor networks. From performance simulation, we found that the proposed protocol shows better performance than the low-energy adaptive clustering hierarchy (LEACH).

A base station centralized simple clustering protocol for sensor networks

Sensor nodes in wireless sensor network are severely energy-constrained. This has been a key factor to limit its performance. So far, many energy-efficient routing protocols have been proposed. Cluster-based routing protocols have been paid much attention because of their advantages. However, the cluster-based routing protocols require information on the locations of the sensor nodes in the network to construct clusters. Due to cost, it is not feasible to know the locations of all sensor nodes in the network. In this paper, we propose a base station centralized simple clustering protocol (BCSP) which requires no location information of the sensor nodes. Instead, BCSP utilizes information on the remaining energy of each sensor node and the number of cluster heads which is changed depending on the circumstance of the sensor network. From performance experiments, BCSP shows better performance than low-energy adaptive clustering hierarchy (LEACH)

A simple dynamic clustering approach to achieve energy efficiency for wireless sensor networks

Purpose – Recent wireless communication and electronics technology has enabled the development of low‐cost, low‐power, and multi‐functional sensor nodes. However, the fact that sensor nodes are severely energy‐constrained has been an issue and many energy‐efficient routing protocols have been proposed to resolve it. Cluster‐based routing protocol is one of them. To achieve longer lifetime, some cluster‐based routing protocols use information on GPS‐based location of each sensor node. However, because of high cost, not all sensor nodes can be GPS‐enabled. The purpose of this paper is to propose a simple dynamic clustering approach to achieve energy efficiency for wireless sensor networks (WSN).Design/methodology/approach – Instead of using location information of each sensor node, this approach utilizes information of remaining energy of each sensor node and changes in the number of cluster head nodes dependent on the number of sensor nodes alive. Performance results are presented and compared with some re...

DTPD: Data Transfer Tool Performance Diagnosis System in High Speed Networks

As the need for large data transmission is increased, the speed of network is also increased. Although the performance of the network is improved, the real data transmission over the high performance network is not improved as we expected. This is because most of host systems are optimized for the old low speed network. Indeed, the host system itself acts as the bottleneck. There are many researches to solve this problem. NDT and NPAD are the most famous projects. To achieve a high speed transmission, they provide a method for diagnosing problems in the network and end-systems that are the most common causes of all severe performance degradation over end-to-end paths. In spite of these efforts, the performance of data transmission is still limited if some data transfer tools such as SCP, SFTP, RSYNC are used. The reason is that the data transfer tools have some internal data transmission control mechanisms which can limit the transmission rate. In this case, end users have to use another efficient data transfer tool but it is difficult for them to find out the internal problem of the tools. Thus, experts have to provide a method for testing users tools and guidelines on tool selection to the end users. In this paper, we propose the DTPD which diagnose the data transfer tool by monitoring the window size of the data transmission connection between two end systems. By using the DTPD, end users can easily test their tools through web pages and may choose more efficient data transport tools.

A sophisticated base station centralized simple clustering protocol for sensor networks

In wireless sensor networks, energy efficiency has been a key factor. So far, many energy-efficient routing protocols have been proposed and much attention has been paid to cluster-based routing protocols due to their advantages. However, some cluster-based sensor network routing protocols need location information of the sensor nodes in the network to construct clusters efficiently. Owing to the cost, it is not feasible to know the locations of all sensor nodes in the sensor network. In this paper, we propose a sophisticated base station centralized simple clustering protocol (SBCSP). The proposed protocol utilizes the remaining energy of each sensor node, standard deviation of their energy consumed and the number of cluster heads changed depending on the number of sensor nodes alive in the sensor network. Throughout the performance experiments, we show that SBCSP has better performance than low-energy adaptive clustering hierarchy (LEACH).

Performance Evaluation of Gigabit Ethernet Interfaces

In high performance computational environments, communication stands out as the major limiting factor to performance. However, high speed network infrastructures are constructed and high speed data transfer protocols, such as BIC TCP and UDT, are capable of transferring the data at the speed of 6~7 Gbps. Despite these circumstances, normal PC users, still have difficulties transferring bulk data in 1 Gbps network. In this paper we try to find out performance limiting factor in end systems. First of all, we investigate the performance effect according to types of NIC and we characterize the current capabilities of PCI, PCI-X and PCI-E Gigabit Ethernet Interfaces and identify requisite components for optimal performance.

Hybridtcp for High Speed Data Transfer

There are many emerging eScience applications. More and more scientists want to collaborate on their investigation with international partners without space limitation by using these applications. Since these applications have to analyze the massive raw data, scientists need to send and receive the data in short time. Most of applications use TCP for data transfer. But TCP was designed under low bandwidth network, therefore, general TCP, Reno TCP, cannot utilize the whole bandwidth of high capacity network. There are several TCP variants to solve TCP problems related to high speed networking. They can be classified into two groups: loss based TCP and delay based TCP. In this paper, the two approaches of TCP variants are compared and a hybrid approach for high speed networking is proposed, which is a synergy of delay-based and loss-based approach.

A Base Station Controlled Simple Sensor Network Protocol

In this paper, we propose a <i>base</i> <i>station</i> <i>controlled</i> <i>simple</i> <i>sensor</i> <i>network</i> <i>protocol</i> <i>(BCSP)</i>, which does not use the location information of each sensor node but the information of remaining energy to prolong lifetime of a sensor network.

A Hybrid Transport Protocol for High Speed Data Transferring in Long Fat Network

There are many emerging eScience applications. More and more scientists want to collaborate on their investigation with international partners without space limitation by using these applications. Since these applications have to analyze the massive raw data, scientists need to send and receive the data in short time. Most of applications use TCP for data transfer. But TCP was designed under low bandwidth network, therefore, general TCP, for example Reno TCP, cannot utilize the whole bandwidth of high capacity network. There are several TCP variants to solve TCP problems related to high speed networking. They can be classified into two groups: loss based TCP and delay based TCP. In this paper, I will compare two approaches of TCP variants and propose a hybrid approach for high speed networking