The Smart Grid, regarded as the next generation power grid, uses two-way flows of electricity and information to create a widely distributed automated energy delivery network. In this article, we survey the literature till 2011 on the enabling technologies for the Smart Grid. We explore three major systems, namely the smart infrastructure system, the smart management system, and the smart protection system. We also propose possible future directions in each system. colorred{Specifically, for the smart infrastructure system, we explore the smart energy subsystem, the smart information subsystem, and the smart communication subsystem.} For the smart management system, we explore various management objectives, such as improving energy efficiency, profiling demand, maximizing utility, reducing cost, and controlling emission. We also explore various management methods to achieve these objectives. For the smart protection system, we explore various failure protection mechanisms which improve the reliability of the Smart Grid, and explore the security and privacy issues in the Smart Grid.

/pdf/smart-grid-the-new-and-improved-power-grid-a-survey-4jypbbgv3j.pdf

Smart Grid — The New and Improved Power Grid: A Survey

Smart Grid - The New and Improved Power Grid:

Power Aware Routing in Mobile Ad Hoc Networks

In this paper, the analysis of recent advances in genetic algorithms is discussed. The genetic algorithms of great interest in research community are selected for analysis. This review will help the new and demanding researchers to provide the wider vision of genetic algorithms. The well-known algorithms and their implementation are presented with their pros and cons. The genetic operators and their usages are discussed with the aim of facilitating new researchers. The different research domains involved in genetic algorithms are covered. The future research directions in the area of genetic operators, fitness function and hybrid algorithms are discussed. This structured review will be helpful for research and graduate teaching.

/pdf/a-review-on-genetic-algorithm-past-present-and-future-2o5y8ru178.pdf

A review on genetic algorithm: past, present, and future

コンピュータ・サイエンス : ACM computing surveys

In mobile ad hoc networks, data transmission is performed within an untrusted wireless environment. Various kinds of attack have been identified and corresponding solutions have been proposed. Wormhole attack is one of the serious attacks which forms a serious threat in the networks, especially against many ad hoc wireless routing protocols and location-based wireless security system. We identify two types of wormhole attacks. In the first type, malicious nodes do not take part in finding routes, meaning that, legitimate nodes do not know their existence. In the second type, malicious nodes do create route advertisements and legitimate nodes are aware of the existence of malicious nodes, just do not know they are malicious. Some researchers have proposed detection mechanisms for the first type. In this paper, we propose an efficient detection method called delay per hop indication (DelPHI). By observing the delays of different paths to the receiver, the sender is able to detect both kinds of wormhole attacks. This method requires neither synchronized clocks nor special hardware equipped mobile nodes. The performance of DelPHI is justified by simulations.

/pdf/delphi-wormhole-detection-mechanism-for-ad-hoc-wireless-5bpbjm3j8f.pdf

DelPHI: wormhole detection mechanism for ad hoc wireless networks

Routing is a process of finding a network path from a source node to a destination node. The execution time and the memory requirement of a routing algorithm increase with the size of the network. In order to deal with the scalability problem, large networks are often structured hierarchically by grouping nodes into different domains. The internal topology of each domain is then aggregated into a simple topology that reflects the cost of routing across that domain. This process is called topology aggregation. For delay-bandwidth sensitive networks, traditional approaches represent the property of each link in the aggregated topology as a delay-bandwidth pair, which corresponds to a point on the delay-bandwidth plane. Since each link after aggregation may be the abstraction of many physical paths, a single delay-bandwidth pair results in significant information loss. The major contribution of this paper is a novel quality-of-service (QoS) parameter representation with a new aggregation algorithm and a QoS-aware routing protocol. Our QoS representation captures the state information about the network with much greater accuracy than the existing algorithms. Our simulation results show that the new approach achieves very good performance in terms of delay deviation, success ratio, and crankback ratio.

/pdf/routing-with-topology-aggregation-in-delay-bandwidth-4cf83rx6rk.pdf

Routing with topology aggregation in delay-bandwidth sensitive networks

Recently, a time synchronization algorithm called pairwise broadcast synchronization (PBS) is proposed. With PBS, a sensor can be synchronized by overhearing synchronization packet exchange among its neighbouring sensors without sending out any packet itself. In an one-hop sensor network where every node is a neighbour of each other, a single PBS message exchange between two nodes would facilitate all nodes to synchronize. However, in a multi-hop sensor network, PBS message exchanges in several node pairs are needed in order to achieve network-wide synchronization. To reduce the number of message exchanges, these node pairs should be carefully chosen. In this paper, we investigate how to choose these ldquoappropriaterdquo sensors aiming at reducing the number of PBS message exchanges while allowing every node to synchronize. This selection problem is shown to be NP-complete, for which the greedy heuristic is a good polynomial-time approximation algorithm. Nevertheless, a centralized algorithm is not suitable for wireless sensor networks. Therefore, we develop a distributed heuristic algorithm allowing a sensor to determine how to synchronize itself based on its neighbourhood information only. The protocol is tested through extensive simulations. The simulation results reveal that the proposed protocol gives consistent performance under different conditions with its performance comparable to that of the centralized algorithm.

/pdf/a-distributed-multihop-time-synchronization-protocol-for-lskyo40ird.pdf

A distributed multihop time synchronization protocol for wireless sensor networks using Pairwise Broadcast Synchronization

The transmission of energy is monitored in the smart grid through deploying sensors in all the components, including the overhead transmission lines. There are many poles/towers supporting a long overhead transmission line. Naturally, sensors are deployed on the location close to the poles/towers on each span. Due to the limited transmission range of the wireless transceiver module of a sensor, researchers generally assume that data generated by a sensor have to be delivered to the substation through a set of sensors in-between. This results in a linear network model. In this paper, we first analyze the performance of this model in handling the traffics extracted from an existing testbed. We realize that the linear network model may not be sufficient to support future smart grid applications which may have diversified requirements on data delivery. We then study a new network model in which sensor/relay nodes can also communicate with other nodes using a wide area network such as the cellular network. In this new model, the network formed can be reconfigured based on the application requirements to deliver information to the substations efficiently and effectively.

/pdf/on-wireless-sensors-communication-for-overhead-transmission-tzm6xkhmzz.pdf

On Wireless Sensors Communication for Overhead Transmission Line Monitoring in Power Delivery Systems

With increasing demand for multimedia applications, local area network (LAN) technologies are rapidly being upgraded to provide support for quality of service (QoS). In a network that consists of an interconnection of multiple LANs via bridges, the QoS of a flow depends on the length of an end-to-end forwarding path. In the IEEE 802.1D standard for bridges, a spanning tree is built among the bridges for loop-free frame forwarding. Albeit simple, this approach does not support all-pair shortest paths. In this paper, we present a novel bridge protocol, the Spanning Tree Alternate Routing (STAR) Bridge Protocol, that attempts to find and forward frames over alternate paths that are provably shorter than their corresponding tree paths. Being backward compatible to IEEE 802.1D, our bridge protocol allows cost-effective performance enhancement of an existing extended LAN by incrementally replacing a few bridges in the extended LAN by the new STAR bridges. We develop a strategy to ascertain bridge locations for maximum performance gain. Our study shows that we can significantly improve the end-to-end performance when deploying our bridge protocol.

/pdf/star-a-transparent-spanning-tree-bridge-protocol-with-210la82uj4.pdf

King-Shan Lui

Papers

DelPHI: wormhole detection mechanism for ad hoc wireless networks

Routing with topology aggregation in delay-bandwidth sensitive networks

A distributed multihop time synchronization protocol for wireless sensor networks using Pairwise Broadcast Synchronization

On Wireless Sensors Communication for Overhead Transmission Line Monitoring in Power Delivery Systems

STAR: a transparent spanning tree bridge protocol with alternate routing