Haosong Gou

An Energy Balancing LEACH Algorithm for Wireless Sensor Networks

Wireless sensor networks (WSNs) have been considered as a promising method for reliably monitoring both civil and military environments under hazardous or dangerous conditions. Due to such environments, the power supplies for sensors in the network are not usually rechargeable or replaceable. Therefore, the energy efficiency is critical for the lifetime and cost of WSN. Numerous mechanisms have been proposed to reduce the impact of communication protocols on the overall energy dissipation of WSN. The low-energy adaptive clustering hierarchy (LEACH) and another improved centralized LEACH deploy randomized rotation of cluster-heads to evenly distribute the energy load among all sensors in a WSN. This paper proposes an improved LEACH (LEACH-C) algorithm called partition-based LEACH (pLEACH), which firstly partitions the network into optimal number of sectors, and then selects the node with the highest energy as the head for each sector, using the centralized calculations. The simulation results and analysis show that pLEACH could achieve much better performance of WSN in terms of the energy dissipation, network lifetime and quality of communication.

A Partition-Based LEACH Algorithm for Wireless Sensor Networks

Wireless sensor networks (WSN) have been considered as a promising method for reliably monitoring both civil and mili-tary environments under hazardous or dangerous conditions. Due to such environments, the power supplies for sensors in the network are not usually rechargeable or replaceable. There-fore, the energy efficiency is critical for the lifetime and cost of WSN. Numerous mechanisms have been proposed to reduce the impact of communication protocols on the overall energy dissipation of WSN. The low-energy adaptive clustering hierarchy (LEACH) deploys randomized rotation of cluster-heads to evenly distribute the energy load among all sensors in a WSN. This paper proposes an improved LEACH algorithm called partition-based LEACH (pLEACH), which firstly parti-tions the network into optimal number of sectors, and then selects the node with the highest energy as the head for each sector, using the centralized calculations. The simulation re¬sults and analysis show that pLEACH could achieve much better performance of WSN in terms of the energy dissipation and network lifetime.

A Bit collision detection based Query Tree protocol for anti-collision in RFID system

Anti-collision algorithms in the RFID system can be divided into two categories: ALOHA based and binary tree based algorithm. Each of them has its own advantages or disadvantages. The QT protocol, as a classic binary tree based algorithm, was proposed to achieve the reliable throughput of identification by using prefix to avoid collisions. This paper proposes an improved QT protocol called Bit collision detection based Query Tree (BQT) by adopting individual bit collision detection, which can detect the collision in each bit. It can reduce the collision for the tags which have the same prefix and accelerate identification process. The simulation results and analysis show that our BQT protocol could reduce the collisions and achieve much better performance on tag identification.

A partition-based centralized LEACH algorithm for wireless sensor networks using solar energy

Wireless Sensor Network (WSN) has been considered as a promising method for reliably monitoring both civil and military environments under hazardous conditions. Due to such condition, the power supply for sensor in the network cannot be usually rechargeable or replaceable. Thus, instead of battery replacement, we develop a solar energy recharging hardware to charge the battery of sensors to prolong the lifetime of each sensor recharging in the network. The proposed method, however, has a problem. Each node cannot be charged with the same amount of power depending on its physical location. The classic LEACH protocol deploys the randomize rotation of cluster-heads to evenly distribute the energy load among sensors without considering the unbalanced residual energy of each node. So some enhanced solar aware LEACH protocols have been proposed, but it is not much efficient for prolonging the lifetime of network. This paper proposes an advanced LEACH algorithm which prioritizes each sensor for the cluster--head election according to its current energy and rate of energy harvesting. The simulation results and analysis show that our proposed algorithm could outperform existing methods in terms of the number of alive nodes.

Distributed Bottleneck Node Detection in Wireless Sensor Network

Wireless sensor networks (WSNs) have been considered as a promising method for reliably monitoring both civil and military environments under hazardous or dangerous conditions. Due to the special property and difference from the traditional wireless network, the lifetime of the whole network is the most important aspect. The bottleneck nodes widely exist in WSNs and lead to decrease the lifetime of the whole network. In order to find out the bottleneck nodes, the traditional centralized bottleneck detection method MINCUT has been proposed as a solution for WSNs. However they are impractical for the net-works which have a huge number of nodes. This paper first proposes a distributed algorithm which can lower the algorithm complexity and find out the bottleneck nodes quickly. We also give two simple suggestions to solve the bottleneck problem. The simulation results and analysis show that our algorithm achieves much better performance and our solutions can relax the bottleneck problem, resulting in the prolonging of the network lifetime.

RFID reader and tag multi-hop communication for port logistics

The RFID technology has attracted much attention these days due to the far better efficiency than the barcode and magnetic card system. As an important usage, the 433 MHz active RFID tag was already adopted to the container ports in the United States and Europe for container loading and unloading automation and equipment location. However, for the complete automation, one problem should be solved before. Current RFID systems support only the direct (single-hop) communication between readers (interrogators) and tags within their RF transmission range. Then besides containers, there are a lot of equipments such as crane, yard tractor, and forklift in ports; and being made of metal, they interfere the RF transmission, resulting in the occurrence of the dead-zone. In the dead-zone, tags cannot receive any signal from readers. Several solutions may be possible to this problem. Among them, this paper suggests the most economical solution where RFID tags in the dead-zone communicate with readers via neighbor tags in the multi-hop manner. The new RFID communication architecture must be carefully designed in order to maintain the compatibility with the previous standard. Our experiment shows that the proposed method works well even in the case where some tags are out of the RF range of reader.

A bit collision detection based Query Tree protocol for sensor tags in logistics management

The advantages of wireless sensors and RFID technology have been widely acknowledged. Based on the two advanced technologies, we improved our current RFID system by replacing passive tags with active sensor tags. Toward better performance on new system demands, in this paper, we proposes an improved QT protocol called SQT (Sensor tag based Query Tree protocol) which combines the basic principle of QT protocol and a new bit collision detection mechanism for sensor tags identification by a mobile reader. Analysis shows that the SQT protocol reduces identification collisions, which accelerates the identification process. Simulation results substantiate the significant performance improvement by the SQT protocol for sensor tags identification.

A Bit Collision Detection Based Hybrid Query Tree Protocol for Anti-collision in RFID System

In radio frequency identification (RFID) systems, the anti-collision protocol is a key topic that has attracted a great deal of research interest. The protocols can be divided into two categories: ALOHA-based and binary query tree (QT) algorithms. The ALOHA-based protocols avoid collisions by distributing tags into different stochastic timeslots. In contrast, the QT-based protocols achieve a reliable throughput of identification and avoid collisions by using prefix matching. This paper proposes an improved QT protocol called BHQT (Bit collision detection based Hybrid Query Tree) which combining the basic principle of QT and a new bit collision detection mechanism for tag identification by a mo-bile reader. Analysis shows that the BHQT protocol reduces tag collisions, which accelerates the tag identification process in mobile identification. Simulation re¬sults substantiate the significant performance improvement by the BHQT protocol for tag identification.

An Energy Efficient MAC Protocol Based on IEEE 802.11 DCF for Wireless Sensor Networks in Port Logistics

Wireless sensor networks have been considered as a promising method for reliably monitoring and information collection. As a rule, the power supplies for sensors in the network are not usually rechargeable or replaceable. Therefore, the energy efficiency is critical for the lifetime. However, due to the high density of sensor nodes, a lot of energy has been wasted on medium access competition because of the serious collisions. To resolve this problem, DCF, the primary medium access control (MAC) technique of IEEE 802.11, has been implemented in our current network, whereas, the obtained throughput and energy efficiency cannot be satisfied with the system requirements. In this paper, we proposed an energy efficient MAC protocol (EEMP) based on basic DCF for our target application. Depending on the EEMP, not only throughput, but also energy efficiency has been enhanced satisfactorily. The simulation results and analysis show that our EEMP protocol can provide higher throughput and lower energy consumption.

A Geographic Location Based Reliable Data Transmission Protocol for Wireless Sensor Networks

Wireless sensor networks (WSNs) have been considered as a promising method for reliably monitoring both civil and military environments under hazardous or dangerous conditions. Depending on different applications, data transmission in the WSNs maybe mixed with the demands for reliability awareness, energy efficiency and time sensitivity. Therefore, Reliable data transmission with the lowest energy consumption and time delay is an important issue in current research. In this paper, we propose a geographic location based reliable data transmission protocol over multipath in the WSNs. It does not only provide the desired reliability for data transmission, but also minimize the energy consumption and time delay while transmitting. The simulation re¬sults and analysis show that our Geographic Location based Reliable Data transmission over multipath (GLRD) protocol can provide reliable data transmission and achieve much better performance on transmission time delay and energy consumption.