Chi Hsuan Wang

OSGi-based smart home architecture for heterogeneous network

With the development of home network and service applications, different protocols and transmission modes are proposed. More digital devices and home appliance compliance to the protocols in the development. The proposed protocols are usually unable to communicate with each other; we design and implement a service-oriented smart-home architecture to integrate popular protocols such as UPnP, Jini, DPWS on OSGi framework and collaborating Tmote, Zigbee and Bluetooth to converge various service oriented applications. Furthermore, with the well-developed Tmote, Zigbee and Bluetooth technology, majority of devices developed with these technologies supported, we propose the three new base drivers to integrate different devices communication on our platform. Additionally, we propose a Service Resolving Bundle to complement the drawbacks of OSGi mechanisms. This architecture with service-oriented mechanisms accommodates applications implemented across different domains and allows system components to interact with one another.

An Adaptive Scenario-Based Reasoning System Across Smart Houses

The intelligent smart home provides homeowners with various services that incorporate knowledge reasoning. However, programmers must consider such constraints as scenarios in different houses, scenarios of different users, and even different resources. That is infrastructure deployment and scenario designing are time consuming. Actually, designing a home based on the behaviors of family members is more reasonable compare with having users adapt to the functionalities of a home. Therefore, developing an efficient reasoning system for smart homes has gained considerable attention. This work presents a smart home reasoning system called the adaptive scenario-based reasoning (ASBR) system. This system learns from user preferences using adaptive history scenarios and it is a convenient method for rebuilding reasoned knowledge compare with other smart homes. Ontology based contextual information is able to be extracted from a smart home and considered as a set of scenarios. Additionally, the system derives personalized habits and store in web ontology language (OWL) files. This work then presents a novel scenario reconstruction method under computational and resource restriction. Finally, an experiment is designed for a realistic smart home and some scenarios are used to discuss the results.

Hierarchical Distributed Source Coding Scheme and Optimal Transmission Scheduling for Wireless Sensor Networks

Distributed source coding (DSC) can be used to compress multiple correlated sensor measurements. These sensors send their compressed data to a central station for joint decoding. However, the issue on designing an optimal transmission scheduling scheme of DSC packets for WSNs have not been well addressed in the literature. In this work, we proposed a novel DSC coding scheme—hierarchical coding scheme, which exploits inter-node coding dependency in sensing-driven and correlated manner. In addition, the interaction between hierarchical coding topology and transmission is considered. We optimize the transmission schedule of DSC nodes to achieve better decoding quality. Our approach can be practically applied to any WSN topologies with correlated source coding nodes. Simulation shows that our work can achieve higher decoding accuracy and compression rate than previous approaches, and the decoding accuracy would not have much degradation under the error-prone wireless environment.

An Agent-Based Smart Home System and Its Service-Scheduling Mechanism: Design and Implementation

This investigation presents an agent-based smart (ABS) home system that automates home-service operations. The ABS home system comprises three subsystems, namely user interface, home gateway, and home functionality. ABS home users can request services with handheld devices through an ABS user interface, and receive them through an agent cooperation mechanism. This investigation has designed three agents and implemented them in the agent platform: the manager agent schedules the service processes; the service agent manages service requests, and the task agent executes service operations. With home-functionality subsystems including location servers, message centers, and multimedia centers in ABS homes, services are conveniently provided, efficient, and comfortably manipulated. The Universal Plug and Play feature adopts IP network technology to control, manage, and transfer data among functionality devices in ABS homes. The proposed service-scheduling mechanism provides services that are conveniently provided, efficient, and comfortably manipulated. This study presents an implementation of the ABS home system to illustrate the feasibility of the proposed architecture. The study also presents a performance evaluation to demonstrate the effectiveness of the proposed mechanism.

Using Direction of Arrival to Estimate Obstacle Areas in Cognitive Sensor Environments

We propose a mechanism to form hole-like shapes with each of several sensor nodes equipped with a directional antenna called CS-DOA. In the system, we use an adaptive beamformer that can receive useful signals and adjust receiving angles through direction-of-arrival (DOA) estimations. We analyze single sources and links with sensor nodes to form a path around a given hole’s margins. This work’s proposed mechanism uses different receiving angles to detect a single source, and through the source message, we can detect and determine the given hole’s margins. We use cognitive radio to estimate the energy of sensor nodes. We also propose energy consumption control via a game scheme to prolong sensor nodes’ lifetime. This innovative mechanism increases performance and convenience, and improves our ability to make rigorous calculations regarding environmental topography.

Coding-Based Contention Forwarding Protocol for Cyber-Physical Systems

The COPE network coding system proposed and implemented by Sachin Katti et al. exploits a physical-layer broadcast characteristic and network coding technique. Though previous studies focus on estimating COPE performance or proposed methods to improve it, there is currently no effective approach to increase network coding throughput. Network coding techniques can be applied to high-traffic network environments, but a large number of transmissions leads to a high collision rate. This paper proposes three mechanisms to exploit the characteristic of network coding. Applying intra-node contention, inter-node contention, and coding-based contention forwarding protocol provides a packet with more coding opportunities from the source to the destination. This system also considers the issue of multiple access categories in large wireless environments, such as a Cyber-Physical System. Simulation result shows that two-stage contentions and coding-based contention forwarding can significantly increase throughput in a network coding network.

Using Direction of Arrival to Detect Cognitive Traffic Sign in City Environments

This paper proposes a novel cognitive traffic signs approach. We considered several traffic signs including: right turn ban, “Be careful pedestrian!”, “Car Park” etc. The cognitive radio devices on the traffic signs transmit signals to the on-board-unit (OBU) on the car. We assume that radio frequency devices are attached to the traffic signs in the urban area. Traffic signals are transmitted to cars at every t time. We consider the use of direction of arrival model on the OBU unit on the car to receive the signal. The radio devices must be the same direction as the driving direction in two-way street such that cars in the opposite direction will not received the signals. Driving direction and the traffic signs are usually in the same direction. The current study evaluates the performance of the approach by conducting computing simulations.

Exponential replicate broadcasting mechanism for adaptive bandwidth allocation in mobile networks

This paper proposes an exponential replicate broadcasting (ERB) algorithm for data dissemination to improve data access efficiency. The proposed ERB algorithm first constructs a broadcast tree to determine the broadcast frequency of each data and splits the broadcast tree into some broadcast wood to generate the broadcast program. In addition, this paper develops an analytical model to derive the mean access latency of the generated broadcast program. In light of the derived results, both the index channels bandwidth and the data channels bandwidth can be optimally allocated to maximize bandwidth utilization. This paper presents experiments to help evaluate the effectiveness of the proposed strategy. From the experimental results, it can be seen that the proposed mechanism is feasible in practice.

Using Cellular Automata to Reduce Congestion for Tourist Navigation Systems in Mobile Environments

Tourist navigation systems have become an important area of research because they help people increase the quality of their travel. This work proposes an adaptive recommendation mechanism that relies on a congestion-aware scheduling method for multiple groups of travelers on multi-destination trips. The recommendation scheme uses the cell (number of groups) mechanism of the cellular automata model for group system distribution. To reduce congestion while visiting multiple destinations, we present a tour group with adaptive recommendations from a system to yield a high quality tour experience. When faced with congestion, the system proposes a path by which the group visits a secondary destination first and then visits the primary destination. Simulation results reveal the strengths of the proposed “adaptive recommendation mechanism” model in terms of decreasing the average wait time, congestion, and the ratio of congestion avoidance to the number of groups.

SmartMote: An Adaptive Update Mechanism for Wireless Ad-Hoc Sensor Network

This paper describes a novel update mechanism for large wireless ad-hoc sensor networks (WASNs). In wireless sensor networks, the nodes may have to be reprogrammed, especially for design-implement-test iterations. Manually reprogramming is a very cumbersome work, and may be infeasible if nodes of the network are unreachable. In addition, replacing the executed application on a node by transmitting the complete program image is inefficient for small changes in the code either. It consumes a lot of bandwidth and time. Therefore, an on-the-fly update mechanism is required. This paper exploits programmable packets to update sensor behaviors. To reduce the code transferred and power consumption, a group management architecture is developed. This architecture helps reduce power consumption and increase node number that control by Leader Node in WASNs. The proposed update mechanism, SmartMote, has been implemented on the Tmote-based Octopus II sensor node. Performance evaluation as well as measurement is conducted in the paper to illustrate the significance of the proposed mechanism.