Edith C.-H. Ngai

On the Intruder Detection for Sinkhole Attack in Wireless Sensor Networks

In a wireless sensor network, multiple nodes would send sensor readings to a base station for further processing. It is well-known that such a many-to-one communication is highly vulnerable to the sinkhole attack, where an intruder attracts surrounding nodes with unfaithful routing information, and then performs selective forwarding or alters the data passing through it. A sinkhole attack forms a serious threat to sensor networks, particularly considering that such networks are often deployed in open areas and of weak computation and battery power. In this paper, we present a novel algorithm for detecting the intruder in a sinkhole attack. The algorithm first finds a list of suspected nodes, and then effectively identifies the intruder in the list through a network flow graph. The algorithm is also robust to deal with cooperative malicious nodes that attempt to hide the real intruder. We have evaluated the performance of the proposed algorithm through both numerical analysis and simulations, which confirmed the effectiveness and accuracy of the algorithm. Our results also suggest that its communication and computation overheads are reasonably low for wireless sensor networks.

Cloud gaming: architecture and performance

Recent advances in cloud technology have turned the idea of cloud gaming into a reality. Cloud gaming, in its simplest form, renders an interactive gaming application remotely in the cloud and streams the scenes as a video sequence back to the player over the Internet. This is an advantage for less powerful computational devices that are otherwise incapable of running high-quality games. Such industrial pioneers as Onlive and Gaikai have seen success in the market with large user bases. In this article, we conduct a systematic analysis of state-of-the-art cloud gaming platforms, and highlight the uniqueness of their framework design. We also measure their real world performance with different types of games, for both interaction latency and streaming quality, revealing critical challenges toward the widespread deployment of cloud gaming.

An efficient intruder detection algorithm against sinkhole attacks in wireless sensor networks

In a wireless sensor network, multiple nodes would send sensor readings to a base station for further processing. It is known that such a many-to-one communication is highly vulnerable to a sinkhole attack, where an intruder attracts surrounding nodes with unfaithful routing information, and then performs selective forwarding or alters the data passing through it. A sinkhole attack forms a serious threat to sensor networks, particularly considering that the sensor nodes are often deployed in open areas and of weak computation and battery power. In this paper, we present a novel algorithm for detecting the intruder in a sinkhole attack. The algorithm first finds a list of suspected nodes through checking data consistency, and then effectively identifies the intruder in the list through analyzing the network flow information. The algorithm is also robust to deal with multiple malicious nodes that cooperatively hide the real intruder. We have evaluated the performance of the proposed algorithm through both numerical analysis and simulations, which confirmed the effectiveness and accuracy of the algorithm. Our results also suggest that its communication and computation overheads are reasonably low for wireless sensor networks.

A Survey on Mobile Social Networks: Applications, Platforms, System Architectures, and Future Research Directions

Mobile social networks (MSNs) have become increasingly popular in supporting many novel applications since emerging in the recent years. Their applications and services are of great interest to service providers, application developers, and users. This paper distinguishes MSNs from conventional social networks and provides a comprehensive survey of MSNs with regard to platforms, solutions, and designs of the overall system architecture. We review the popular MSN platforms and experimental solutions for existing MSN applications and services and present the dominant mobile operating systems on which MSNs are implemented. We then analyze and propose the overall architectural designs of conventional and future MSN systems. In particular, we present the architectural designs from two perspectives: from the client side to the server side, and from the wireless data transmission level to the terminal utilization level. We further introduce and compare the unique features, services, and key technologies of two generations of architectural designs of MSN systems. Then, we classify the existing MSN applications and propose one special form of MSN, i.e., vehicular social network, and demonstrate its unique features and challenges compared with common MSNs. Finally, we summarize the major challenges for on-going MSN research and outline possible future research directions.

Trust- and clustering-based authentication services in mobile ad hoc networks

A mobile ad hoc network is a kind of wireless communication network that does not rely on a fixed infrastructure and is lack of any centralized control. These characteristics make it vulnerable to security attack, so protecting the security of the network is essential. Like many distributed systems, security in ad hoc networks widely relies on the use of key management mechanisms. However, traditional key management systems are not appropriate for them. We aim at providing a secure and distributed authentication service in ad hoc networks. We propose a secure public key authentication service based on our trust model and network model to prevent nodes from obtaining false public keys of the others when there are malicious nodes in the network. We perform an overall evaluation of our proposed approach by simulations. The experimental results indicate clear advantages of our approach in providing effective security in mobile ad hoc networks.

Green Internet of Things for Smart World

Smart world is envisioned as an era in which objects (e.g., watches, mobile phones, computers, cars, buses, and trains) can automatically and intelligently serve people in a collaborative manner. Paving the way for smart world, Internet of Things (IoT) connects everything in the smart world. Motivated by achieving a sustainable smart world, this paper discusses various technologies and issues regarding green IoT, which further reduces the energy consumption of IoT. Particularly, an overview regarding IoT and green IoT is performed first. Then, the hot green information and communications technologies (ICTs) (e.g., green radio-frequency identification, green wireless sensor network, green cloud computing, green machine to machine, and green data center) enabling green IoT are studied, and general green ICT principles are summarized. Furthermore, the latest developments and future vision about sensor cloud, which is a novel paradigm in green IoT, are reviewed and introduced, respectively. Finally, future research directions and open problems about green IoT are presented. Our work targets to be an enlightening and latest guidance for research with respect to green IoT and smart world.

Multidimensional context-aware social network architecture for mobile crowdsensing

This article proposes a multidimensional context-aware social network architecture, which aims to provide a mobile ecosystem to enable context awareness in the development and utilization of mobile crowdsensing applications. This mobile ecosystem is constructed to provide context awareness capabilities for different roles (i.e., users or developers) in the system and facilitate interactions between them. This system can ease the development of context-aware mobile applications, and enable context-aware mobile crowdsensing considering environmental, personal, and social information. We present a flow of context-aware solutions designed on this system, and highlight the orchestrations and advantages of different context-aware schemes in the system for different types of users (requesters and participants) in mobile crowdsensing. We demonstrate the feasibility of the proposed mobile ecosystem by presenting a novel context-aware mobile crowdsensing application called Smart City, and evaluate the system performance based on this application.

SoNIC: classifying interference in 802.15.4 sensor networks

Sensor networks that operate in the unlicensed 2.4 GHz frequency band suffer cross-technology radio interference from a variety of devices, e.g., Bluetooth headsets, laptops using WiFi, or microwave ovens. Such interference has been shown to significantly degrade network performance. We present SoNIC, a system that enables resource-limited sensor nodes to detect the type of interference they are exposed to and select an appropriate mitigation strategy. The key insight underlying SoNIC is that different interferers disrupt individual 802.15.4 packets in characteristic ways that can be detected by sensor nodes. In contrast to existing approaches to interference detection, SoNIC does not rely on active spectrum sampling or additional hardware, making it lightweight and energy-efficient. In an office environment with multiple interferers, a sensor node running SoNIC correctly detects the predominant interferer 87% of the time. To show how sensor networks can benefit from SoNIC, we add it to a mobile sink application to improve the applications packet reception ratio under interference.

A real-time communication framework for wireless sensor-actuator networks

Wireless sensor-actuator network (WSAN) comprises of a group of distributed sensors and actuators that communicate through wireless links. Sensors are small and static devices with limited power, computation, and communication capabilities responsible for observing the physical world. On the other hand, actuators are equipped with richer resources, able to move and perform appropriate actions. Sensors and actuators cooperate with each other: While sensors perform sensing, actuators make decisions and react to the environment with the right actions. WSAN can be applied in a wide range of applications, like environmental monitoring, battlefield surveillance, chemical attack detection, intrusion detection, space missions, etc. Since actuators perform actions in response to the sensed events, real-time communications and quick reaction are necessary. To provide effective applications by WSAN, two major problems remain: how to minimize the transmission delay from sensors to actuators, and how to improve the coordination among the actuators for fast reaction. To tackle these problems, we designed a real-time communication framework to support event detection, reporting, and actuator coordination. This paper explores the timely communication and coordination problems among the sensors and actuators. Moreover, we proposed two self-organized and distributed algorithms for event reporting and actuator coordination. Some preliminary results are presented to demonstrate the advantages of our approach

Global source mobility in the content-centric networking architecture

The Content-Centric Networking (CCN) architecture, a clean-slate network design, borrows its routing concepts from IP. If content is located on mobile sources, CCN also inherits some of the mobility problems known from IP. In this paper, we explore the design space of CCN mobility solutions by revisiting well-known IP approaches that aim to solve a remarkably similar problem. While mobility solutions may be quite similar in both architectures, we find that a locator/identifier split should be implemented at the network layer in CCN to prevent temporary, topology-dependent information to leak into content that ought to be permanent. Mobility handling further benefits from CCNs security model and multipath forwarding. To provide a starting point for further research, we present a simple mobility approach based on an explicit locator/identifier split.