Anas Al-Roubaiey

Video transmission enhancement in presence of misbehaving nodes in MANETs

Mobile Ad-hoc NETworks (MANET) are infrastructureless networks where self-configuring mobile nodes are connected by wireless links. Because of its decentralized operation, these nodes rely on each other to store and forward packets. Video transmission over MANETs is more challenging than over conventional wireless networks due to rapid topology changes and lack of central administration. Most of the proposed MANET protocols assume that all nodes are working within a cooperative and friendly network context. However, misbehaving nodes that exhibit abnormal behaviors can disrupt the network operation and affect the network availability by refusing to cooperate to route packets due to their selfish or malicious behavior. In this paper, we examine the effect of packet dropping attacks on video transmission over MANETs. We also study the effects of mitigation using intrusion detection systems to MANET in presence of video traffic. To the best of our knowledge, this is the first attempt to study multimedia over such environments. We propose a novel intrusion detection system, which is an adaptive acknowledgment scheme (AACK) with the ability to detect misbehaved nodes and avoid them in other transmissions. The aim of AACK scheme is to overcome watchdog weaknesses due to collisions and limited transmission power and also to improve TWOACK scheme. To demonstrate the performance of our proposed scheme, simulation experiments are performed. The results of our experiments show that MPEG4 is more suitable for our simulation environment than H264 video traffic. The simulation results show that AACK scheme provides better network performance with less overhead than other schemes; it also shows that AACK outperforms both TWOACK and watchdog in video transmission applications in the presence of misbehaving nodes.

AACK: Adaptive Acknowledgment Intrusion Detection for MANET with Node Detection Enhancement

A Mobile Ad-hoc NETwork (MANET) is an infrastructureless network consisting of self-configuring mobile nodes connected by wireless links. Nodes rely on each other to store and forward packets. Most of the proposed MANET protocols assume cooperative and friendly network context, and do not address security issues. Furthermore, MANETs are highly vulnerable for passive and active attacks because of their open medium, rapidly changing topology, lack of centralized monitoring. Encryption and authentication solutions, which are considered as the first line of defense, are not sufficient to protect MANETs from packet dropping attacks. Most of the current Intrusion Detection Systems (IDSs) for MANETS rely on the Watchdog technique. In this research we study the behavior of this technique and propose a novel mechanism, named: Adaptive ACKnowledgment (AACK), for solving two significant problems: the limited transmission power and receiver collision. This mechanism is an enhancement to the TWOACK scheme where its detection overhead is reduced while the detection efficiency is increased. NS2 is used to simulate and evaluate the proposed scheme and compare it against the TWOACK and Watchdog methods. The obtained results show that the new AACK scheme outperforms both of the TWOACK and Watchdog methods in terms of network packet delivery ratio and routing overhead.

Real-time QoS-aware video streaming: a comparative and experimental study

Due to its flexibility, scalability, real-time, and rich QoS features, Data Distribution Service (DDS) middleware provides seamless integration with high-performance, real-time, and mission-critical networks. Unlike traditional client-server communication models, DDS is based on the publish/subscribe communication model. DDS improves video streaming quality through its efficient and high-performance data delivery mechanism. This paper studies and investigates how DDS is suitable for streaming real-time full-motion video over a communication network. Experimental studies are conducted to compare video streaming using a the VLC player with the DDS overlay. Our results depict the superiority of DDS in provisioning quality video streams at the cost of low network bandwidth. The results also show that DDS is more scalable and flexible and is a promised technology for video distribution over IP networks where it uses much less bandwidth while maintaining high quality video stream delivery.

A survey on developing publish/subscribe middleware over wireless sensor/actuator networks

Publish/subscribe (Pub/Sub) interaction paradigm is receiving more attention in commercial and academic research nowadays. It is an effective interaction scheme for large-scale distributed systems due to its ability of decoupling communicating entities in time, space, and synchronization. The decoupling properties are well-suited for Wireless Sensor Network (WSN) applications because of their special characteristics such as data-centricity, dynamicity, and many-to-many communications. Many studies have been conducted to adapt Pub/Sub communication model to WSN. In this paper, we review the Pub/Sub interaction paradigm in the context of WSN. Moreover, we classify, analyze and synthesize different Pub/Sub based solutions proposed recently for WSN and discuss the open problems and new research directions in this area. Also, we propose a new reference model for pub/sub middleware in wireless sensor and actuator networks. To the best of our knowledge this is the first survey on this specific subject.

A publish/subscribe middleware cost in wireless sensor networks: A review and case study

Electronic devices and sensor networks have witnessed great advancements. Consequently, their limited resources (CPU, memory, bandwidth, and power) are becoming suitable to accommodate some of the enterprise networks solutions. One possible and effective solution is Middleware technology that is able to provide several advantages such as simplifying applications development, portability, scalability, and Quality of Service (QoS). Recently, A publish/subscribe (pub/sub) middleware in Wireless Sensor Network (WSN) has gained a lot of attention from both the industry and the academic communities. This paper provides a review to the state-of-the-art of some of these solutions. This paper also investigates the capabilities of these solutions and conducts a comparison study. In addition, a case study is carried out to estimate the cost of adding a middleware to a WSN. Furthermore, a study is performed to the middleware effect on the overall network performance.

Wireless video streaming over Data Distribution Service middleware

High-quality video transmission over wireless local area networks is one of the most challenging issues nowadays. The Data Distribution Service (DDS) is a promising middleware that can be used for video distribution over WLANs. DDS has a rapid implementation in high-performance and mission-critical networks. This paper evaluates the performance parameters such as throughput and jitter when video transmission is introduced in a 802.11g networks using DDS. Furthermore, it investigates the DDS QoSs that affects video streaming over WLANs which is important when deploying end-to-end video streaming services with quality of service guarantee.

Performance Enhancement of Limited-Bandwidth Industrial Control Systems

Due to its portability, reliability, flexibility, real time and rich set of QoS support, Data Distribution Service (DDs) middleware became one of the best solutions for real time distributed manufacturing systems. Most of these systems are composed of heterogeneous networked devices where network bandwidth represents a very important resource. Those devices include limited-resources devices, such as sensors, actuators and controllers. Thus, controlling such resource will significantly enhance the overall performance of the network in terms of resource utilization, delay, and throughput; moreover, it reduces the cost of using leased network bandwidth by limiting the amount of bandwidth as much as needed. In this paper we propose a solution for controlling the limited-bandwidth networked manufacturing systems by using DDS; and we describe the DDS QoS polices that support manufacturing systems to control network bandwidth. Furthermore, we evaluate DDS middleware performance over Bluetooth channel by measuring latency, throughput and jitter; and examining different QoS parameters to show their effect on improving the existing limited-bandwidth networks.

Scalable Wireless Video Streaming over Real-Time Publish Subscribe Protocol (RTPS)

Enabling Real-Time video streaming over wireless networks faces challenges of time-varying channel conditions and the limited network resources. The instability of wireless networks lead to problems such as limited and time-varying bandwidth and traffic congestion when transmitting a burst of video streams. The time-varying wireless channel conditions expose the transmitted video packets to be delayed or dropped. However, in Real-Time video streaming each frame must be delivered and decoded by its playback time. As a result, efficient Real-Time video streaming requires an efficient video quality of service (QoS) transmission control mechanism to adapt to the network changes. Recently, layer coding (LC) enables Real-Time and scalable video streaming to clients of heterogeneous capabilities by dropping upper enhancement layers without the need of re-encoding and with less bit rate. However, layer coding still facing unfair layer protection problem in which packets from the base or lower layers might be dropped while there is a chance to drop packets from the upper enhancement layers. Loosing packets from the base layer can significantly affect the delivered video quality and sometimes lead to an interruption especially in error-prone networks as wireless networks. Architectural solutions at the middleware level introduce higher flexibility, more efficiency in development time and more QoS control. In this paper, we investigate the behavior of video streaming over Real-Time publish-subscribe based middleware. We propose and develop an unequal layer protection mechanism for Real-Time video streaming based on the Data Distribution Service (DDS) middleware, and show the performance of our approach over IEEE 802.11g WLAN networks. Our approach shows a graceful degradation of video quality while maintaining a robust video streaming free of visible error or interruptions.

Mobile Radio Frequency Charger for Wireless Sensor Networks in the Smart Grid

Smart grid is the future vision for supplying energy. It integrates the advances in power engineering as well as information technology and telecommunication in one cohesive network. However, this vision poses several challenges; one of the key challenges is the continuous monitoring of the state of every component (e.g. voltage, current, temperature, energy consumption, energy prices, etc.) in the system. Wireless sensor network is a promising candidate for fulfilling this task. This work suggests a new realistic approach for providing energy for the deployed sensor nodes using mobile charger. The aim is to sustain the operation of the sensor network in terms of data transmission and coverage. The proposed approach integrates the cluster formation process using LEACH-C with the recharging process by defining the required emitted energy as well as the locations to be visited by the mobile charger. The main objectives are to maximize the nodes battery utilization, distribute power effectively from the energy harvester, and optimize the distance between mobile charger and sensor nodes. We tested our approach using NS2 simulator. The simulation results have shown the achievement of the above objectives.

The Impact of Sensor Node Distribution on Routing Protocols Performance: A Comparitive Study

The contemporary routing algorithms were built and tested under the assumption of uniformly distributed sensor nodes. However, this assumption is not always true. In some industrial applications and due to the scope of the ongoing monitoring process, sensors are installed and condensed in some area, while they are sparse in other areas. In this work, we investigate the impact of sensor node deployment distributions on the performance of different flavors of LEACH routing algorithm. Further, we study the impact of base station location, and different data loads. A comparison between LEACH and LEACH-C is conducted. The results show that different sensor distributions leads to significant differences in network performance. Furthermore, it shows that LEACH-C out performs LEACH almost in all distributions variations and base station locations.