IGAA: An Efficient Optimization Technique for RFID Network Topology Design in Internet of Things

[[abstract]]Most RFID applications in the Internet of Things (IoTs) use multiple readers to read the IDs of multiple tags and form the RFID network. In such a network, unguarded reader deployment may generate over-crowded readers, cause interferences and, as a result, increases the deployment cost while degrading tag detection. Seeing that desirable reader deployment is crucial for RFID system performance, this paper introduces an optimization-based IGAA approach which outperforms existing RFID topology designs by turning up more favorable reader deployment and system performance. The new approach employs an advanced multi-objective fitness function and improved genetic annealing algorithms (GAA) to pursue a better RFID topology design. By involving an improved gene-stirring operation to help preserve good genes and locate optimal solutions for reader deployment, it is simple in operation but effective in practice. Experimental evaluation shows that when compared with related approaches, IGAA can yield better solution quality with less search time.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙本[[booktype]]電子

An Efficient Video Content Delivery Strategy for Radio Access Network Environments

[[abstract]]When a radio access network (RAN) environment cannot handle the tremendous mobile data traffic, users may experience degraded or declined services. To help process the large number of user video requests in RANs, a content delivery network (CDN) architecture has been recently introduced, which establishes a number of cache servers outside the source server for users to get the needed data from the nearest cache server. To upgrade the performance of a wireless CDN, this paper presents a new caching strategy based on analytical results of real user video request traces and specific caching considerations for videos with different popularity degrees. The new strategy first caches videos with high popularity to all helpers and then caches those with low popularity to the remaining helper storage to enhance the overall request hits. Performance evaluation exhibits that, when compared with other caching strategies, our new strategy is able to yield better request hits with low complexity and average delay time.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙本[[booktype]]電子

Scalable Grouping Random Key Predistribution in Large Scale Wireless Sensor Networks

[[abstract]]The security issue in a wireless sensor network (WSN) has been drawing considerable research attention in recent years. Key management, a basic security service, becomes the core design for various security services, such as encryption and authentication. To increase the connectivity of each key in a large-scale WSN and to enlarge its maximum supportable network size, this paper presents a scalable grouping (SG) random key predistribution scheme. The SG scheme divides all nodes into several groups and uses the one-way function to generate group-to-group pairwise keys. To improve resilience against node capture, i.e., to fortify the security strength, the scheme takes on the concept that the link key is composed of some shared keys. For any two nodes with two or more shared keys, the SG scheme uses the exclusive-OR operation to compose the link key -- assuring the link key used to secure a link is nearly unique. Experimental results show that the SG scheme is able to generate better resilience against node capture and higher scalability than existing random key based schemes.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙

A-MAC: A MAC Protocol Using Alternative Wakeup Schedules to Achieve Energy Efficiency for Wireless Sensor Networks

100學年度研究獎補助論文[[abstract]]This paper presents a new MAC protocol to achieve energy efficiency and low transmission latency for the static wireless sensor networks. The proposed new protocol is called A-MAC, an Alternative MAC, which assigns modified alternative wakeup schedules to different sensor nodes to minimize the probability of transmission collision. In A-MAC, after all sensor nodes are deployed, the base station will start an initial process to set a height for each node. When the height of each node (= the node's hop counts to the BS) is decided, the active interval of nodes whose height difference = 1 will be set to be continuous to reduce transmission latency, whereas the active interval of nodes with the same height will stagger to avoid collision (i.e., to reduce the probability of simultaneous transmission). Operating by such alternative wakeup schedules, the new protocol is able to smooth data transmission and meanwhile conserve energy consumption for the energyconstrained wireless sensor networks.[[notice]]補正完畢[[journaltype]]國內[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]紙本[[countrycodes]]TW

RMCC: An Efficient Cooperative Caching Scheme for Mobile Ad-hoc Networks

[[abstract]]For mobile ad-hoc networks (MANETs), caching data is important and useful. By exercising cache cooperation between mobile nodes, cooperative caching schemes can improve data accessibility and system performance. Seeing that the cache hit ratios tend to degrade due to high node mobility, restricted battery energy and limited wireless bandwidth in a MANET, we introduce a new cooperative caching scheme, the Regionally Maintained Cooperative Caching (RMCC) scheme, to solve the problem. RMCC allows one node in a region to cache a data item while the other nodes in the same region to cache the path to the node when to acquire the same item. Such a design helps generate more cache space and wider cached data variety for nodes in one region, and as a result attains higher cache hit ratios as well as lower data access latency. Experimental evaluation shows that the proposed RMCC outperforms other schemes in terms of cache hit ratios, in-cache ratios and amounts of required file packets.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]電子版[[booktype]]紙

Efficient Atomic Broadcast in Cloud Computing

[[conferencetype]]國際[[conferencedate]]20130523~20130525[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Xian, Chin

Efficient and Secure Trust Negotiation over the Internet

[[incitationindex]]EI[[conferencetype]]國際[[conferencedate]]20121217~20121220[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]Taipei, Taiwa

A Node Revocation Scheme Using Public-Key Cryptography in Wireless Sensor Networks

100學年度研究獎補助論文[[abstract]]Generally deployed in an unattended environment, a sensor network can be easily assaulted or compromised by adversaries. Network security becomes a major problem. A distributed node revocation scheme is effective in reducing the damages a compromised node may cause to a sensor network, but its operation tends to consume large-scale memory space of the hardware-constrained sensor nodes. To reduce such complexity, this paper presents a new distributed voting revocation scheme based on the one-way hash chain, the certificate revocation list and the public-key cryptography. Performance evaluation shows that our scheme outperforms the other target schemes in enhancing network security at reasonable calculation cost which is acceptable to the sensor nodes.[[notice]]補正完畢[[journaltype]]國內[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]紙本[[countrycodes]]TW

On RFID Network Topology Design for Internet of Things

[[abstract]]This paper introduces a new optimization-based IGAA approach to pursue a better RFID topology design with more favorable reader deployment and system performance. The new approach adopts an advanced multi-objective fitness function and improved genetic annealing algorithms (GAA) to enhance and outperform existing RFID topology designs. The operation is simple and effective: Involving a gene-stirring operation to help preserve good genes and locate optimal solutions for reader deployment. Experimental evaluation shows that when compared with related approaches, IGAA can yield better solution quality with less search time.[[conferencetype]]國際[[conferencedate]]20141220~20141223[[booktype]]紙本[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Hainan, Chin

Efficient Vehicular Ad-hoc Networks Routing Based on Junctions

[[abstract]]In vehicular ad-hoc networks, high mobility tends to break established paths and cause bandwidth waste because of path reconstruction. To improve the situation, this study presents a new position-based protocol. The new protocol uses control packets to collect approaching-the-junction information and, based on the information, lets moving vehicles adapt their routing paths dynamically when arriving at a junction. Compared with existing protocols which pre-store massive routing paths in a vehicle, the protocol can accurately relay packets to the destination by significantly reduced control packets. Transmission efficiency is therefore enhanced. Performance evaluation exhibits that the proposed protocol is suitable for practice in highly topology-changing vehicle-to-vehicle environments because it can accurately select targets for packet relay at less routing and storage cost.[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙本[[booktype]]電子