Choong Seon Hong

Security in wireless sensor networks: issues and challenges

Wireless sensor network (WSN) is an emerging technology that shows great promise for various futuristic applications both for mass public and military. The sensing technology combined with processing power and wireless communication makes it lucrative for being exploited in abundance in future. The inclusion of wireless communication technology also incurs various types of security threats. The intent of this paper is to investigate the security related issues and challenges in wireless sensor networks. We identify the security threats, review proposed security mechanisms for wireless sensor networks. We also discuss the holistic view of security for ensuring layered and robust security in wireless sensor networks

Security Issues in Wireless Mesh Networks

Wireless mesh network (WMN) is a new wireless networking paradigm. Unlike traditional wireless networks, WMNs do not rely on any fixed infrastructure. Instead, hosts rely on each other to keep the network connected. Wireless Internet service providers are choosing WMNs to offer Internet connectivity, as it allows a fast, easy and inexpensive network deployment. One main challenge in design of these networks is their vulnerability to security attacks. In this paper, we investigate the principal security issues for WMNs. We study the threats a WMN faces and the security goals to be achieved. We identify the new challenges and opportunities posed by this new networking environment and explore approaches to secure its communication.

Data-Centric Multiobjective QoS-Aware Routing Protocol for Body Sensor Networks

In this paper, we address Quality-of-Service (QoS)-aware routing issue for Body Sensor Networks (BSNs) in delay and reliability domains. We propose a data-centric multiobjective QoS-Aware routing protocol, called DMQoS, which facilitates the system to achieve customized QoS services for each traffic category differentiated according to the generated data types. It uses modular design architecture wherein different units operate in coordination to provide multiple QoS services. Their operation exploits geographic locations and QoS performance of the neighbor nodes and implements a localized hop-by-hop routing. Moreover, the protocol ensures (almost) a homogeneous energy dissipation rate for all routing nodes in the network through a multiobjective Lexicographic Optimization-based geographic forwarding. We have performed extensive simulations of the proposed protocol, and the results show that DMQoS has significant performance improvements over several state-of-the-art approaches.

Multi-Constrained QoS Geographic Routing for Heterogeneous Traffic in Sensor Networks

Sensor nodes report the sensed data packets to the sink and depending on the application these packets may have diverse attributes: time-critical (TC) and non time-critical (NTC). In such a heterogeneous traffic environment, designing a data dissemination framework that can achieve both the reliability and delay guarantee while preserving the energy efficiency, namely multi-constraint QoS (MCQoS), is a challenging problem. This paper proposes a new aggregate routing model and a localized algorithm (DARA) that implements the model. DARA is designed for multi-sink multipath location aware network architecture. Delay-differentiated multi-speed packet forwarding and in-node packet scheduling mechanisms are also incorporated with DARA. The simulation results demonstrate that DARA effectively improves the reliability, delay guarantee and energy efficiency.

Design and Implementation of Control Mechanism for Standby Power Reduction

In other to save energy, several countries recently made laws related to standby power consumption. To success this exertion, we should consider not only power reduction of consumer electronics itself but also efficient automatic control in networked home environment. In this paper, we present a design approach and implementation result of control mechanism for standby power reduction. Proposed mechanism has the host-agent based structure and uses the IEEE 802.15.4 based ZigBee protocol for communication and security between host and agents. We verified reliability of proposed mechanism and reduction effect of standby power; also, we applied implemented device to scenario which is similar to user living pattern. Experimental results demonstrate that in the proposed mechanism, standby power consumption of Agent which is connected to consumer electronics can be reduced by 203 mW.

Design of a QoS-Aware Routing Mechanism for Wireless Multimedia Sensor Networks

In wireless sensor networks, majority of routing protocols considered energy efficiency as the main objective and assumed data traffic with unconstrained delivery requirements. However, the introduction of image and video sensors demands certain quality of service (QoS) from the routing protocols and underlying networks. Managing real-time data requires both energy efficiency and QoS assurance in order to ensure efficient usage of sensor resources and correctness of the collected information. In this paper, we present a novel QoS-aware routing protocol to support high data rate for wireless multimedia sensor networks. Being multi-channel multi-path the foundation, the routing decision is made according to the dynamic adjustment of the required bandwidth and path-length-based proportional delay differentiation for real-time data. The proposed protocol works in a distributed manner to ensure bandwidth and end- to-end delay requirements of real-time data. At the same time, the throughput of non-real-time data is maximized by adjusting the service rate of real-time and non-real-time data. Results evaluated in simulation demonstrate a significant performance improvement in terms of average delay, average lifetime and network throughput.

Medium access control for power line communications: an overview of the IEEE 1901 and ITU-T G.hn standards

Power lines are becoming increasingly popular for high-speed communications, while at the same time reliable communications over them poses several unique challenges. Recently, two standardization bodies, the Institute of Electrical and Electronics Engineers (IEEE) and the International Telecommunication Union (ITU), addressed in their IEEE 1901 and ITU-T G.hn standards, respectively, both the medium access control and the physical layer specifications of power line communications. In this article, we provide an overview of these standards from the media access control technology perspective, and the similarities and dissimilarities between the IEEE 1901 and ITU-T G.hn standards are discussed, as well as potential performance issues. We use a top-down approach to analyze the features and technologies of the standards.

Caching in the Sky: Proactive Deployment of Cache-Enabled Unmanned Aerial Vehicles for Optimized Quality-of-Experience

In this paper, the problem of proactive deployment of cache-enabled unmanned aerial vehicles (UAVs) for optimizing the quality-of-experience (QoE) of wireless devices in a cloud radio access network is studied. In the considered model, the network can leverage human-centric information, such as users’ visited locations, requested contents, gender, job, and device type to predict the content request distribution, and mobility pattern of each user. Then, given these behavior predictions, the proposed approach seeks to find the user-UAV associations, the optimal UAVs’ locations, and the contents to cache at UAVs. This problem is formulated as an optimization problem whose goal is to maximize the users’ QoE while minimizing the transmit power used by the UAVs. To solve this problem, a novel algorithm based on the machine learning framework of conceptor-based echo state networks (ESNs) is proposed. Using ESNs, the network can effectively predict each user’s content request distribution and its mobility pattern when limited information on the states of users and the network is available. Based on the predictions of the users’ content request distribution and their mobility patterns, we derive the optimal locations of UAVs as well as the content to cache at UAVs. Simulation results using real pedestrian mobility patterns from BUPT and actual content transmission data from Youku show that the proposed algorithm can yield 33.3% and 59.6% gains, respectively, in terms of the average transmit power and the percentage of the users with satisfied QoE compared with a benchmark algorithm without caching and a benchmark solution without UAVs.

An Efficient and Reliable MAC in VANETs

Vehicular Ad hoc Network (VANET) is developed to enhance the safety, comfort and efficiency of driving. The IEEE 802.11p/WAVE and IEEE 1609.4 family are standards intended to support wireless access in VANETs. In this paper, we propose an Efficient and Reliable MAC protocol for VANETs (VER-MAC) which allows nodes to broadcast safety packets twice during both the control channel interval and service channel interval to increase the safety broadcast reliability. By using the additional data structures, nodes can transmit service packets during the control channel interval to improve the service throughput.

SERP : secure energy-efficient routing protocol for densely deployed wireless sensor networks

In this paper, we present secure energy-efficient routing protocol (SERP) for densely deployed wireless sensor networks which aims to achieve robust security for transmitted sensor readings with an energy-efficient network backbone. When the sensors with limited energy budgets are deployed in hazardous environment, ensuring energy efficiency and security of the sensor readings becomes a crucial task. Here, we address how to deal with such a deployment scenario. Our protocol ensures secure transmission of data from the source sensors to the base station in a way that it can best utilize the available amount of energy in the network. We use one-way hash chain and pre-stored shared secret keys for ensuring data transmission security. In SERP, first, a sink rooted tree structure is created as the backbone of the network. This energy-efficient network structure is used for authenticated and encrypted data delivery from the source sensors to the base station. To introduce data freshness, SERP includes an optional key refreshment mechanism which could be applied depending on the application at hand. Our analysis and simulation results show that SERP provides a good level of confidentiality and authenticity of data that are transmitted from the sensors to the base station. It also helps for energy-efficient structuring of the network so that the maximum lifetime of the network could be achieved.