Yasser Gadallah

Classification of Wireless Sensor Networks Deployment Techniques

One of the main design aspects of Wireless Sensor Networks (WSNs) is the deployment strategy of the sensors. In general, WSN deployment methods fall under two categories: planned deployment and random deployment. In this paper, we focus on planned deployment which is defined as selectively deciding the locations of the sensors to optimize one or more design objectives of the WSN under some given constraints. There have been a large number of studies which proposed algorithms for solving the planned deployment problem. In this paper, we present a novel classification of the algorithms proposed in the literature for planned deployment of WSNs, based on the mathematical approach used for modeling and solving the deployment problem. Four distinct mathematical approaches are presented: Genetic Algorithms, Computational Geometry, Artificial Potential Fields and Particle Swarm Optimization. For each approach, we provide a discussion of its background and basic mathematical foundation. We then review the algorithms which belong to each approach and provide a comparison between them in terms of their objectives, assumptions and performance. Based on our extensive survey, we discuss the strengths and limitations of the four approaches and compare them in terms of the different WSN design factors.

Classification of LTE Uplink Scheduling Techniques: An M2M Perspective

The Internet of Things (IoT) aims at connecting a very large number of devices using an Internet-like architecture. Machine-to-machine (M2M) networks are considered the main component of the IoT. Long-term evolution (LTE) and LTE-advanced (LTE-A) are excellent candidates for supporting M2M communications due to their native IP connectivity and scalability for massive number of devices. Therefore, LTE schedulers should be capable of satisfying the needs of M2M devices such as timing constraints and specific quality of service (QoS) requirements. In this paper, we present a survey on uplink scheduling techniques over LTE and LTE-A from an M2M perspective. We focus on the aspects associated with M2M communications; namely, power efficiency, QoS support, multihop connectivity, and scalability for massive number of devices.

BAT: A Balanced Alternating Technique for M2M Uplink Scheduling over LTE

Machine-to-Machine (M2M) scheduling over Long Term Evolution (LTE) networks is an essential research area for future communications. This is due to the strong expectations that M2M communications will be a main element of the overall traffic over 5G networks. The diversity of M2M applications strongly motivates studying the problem of resource allocation in the uplink direction where the M2M traffic is dominant. M2M communications impose requirements that differ from those required by Human-to-Human (H2H) communications. We present a classification of M2M scheduling techniques from the perspective of these requirements. We then propose an M2M uplink scheduling algorithm that offers a balance between throughput and delay requirements. It is also adaptive to traffic characteristics since it considers both channel state and system deadlines in an adjustable manner according to network needs. Finally, we conduct experiments to compare the performance of the proposed technique to that of other schedulers that belong to the different M2M scheduler categories.

Wireless Sensor Network deployment using a variable-length genetic algorithm

The Sensor Deployment Problem (SDP) is one of the most studied problems in the field of Wireless Sensor Networks (WSNs). It can generally be defined as selecting the sensors locations in a specified Region of Interest (RoI) to achieve one or more design objectives of the WSN. Two of the commonly required design objectives are maximizing coverage and minimizing the deployment cost of the WSN. In this paper, we address the SDP of covering a finite set of target locations in a specified RoI using non-homogenous, non-isotropic sensors with minimum sensor deployment cost. We propose a novel approach for solving the SDP using a Variable-Length Genetic Algorithm (VLGA). We apply our proposed algorithm on a WSN surveillance case-study to evaluate its performance. Based on the experimental results, we show that our proposed algorithm outperforms an existing approach which uses a Fixed-Length GA (FLGA) in terms of the quality of obtained solutions, speed of convergence and scalability.

An IP-based arrangement to connect wireless sensor networks to the Internet of Things

Wireless sensor networks (WSNs) are considered one of the main building blocks of the Internet of Things (IoT). Therefore, connecting these networks to data recipients globally becomes a basic ingredient for the success of the entire IoT paradigm. We introduce a practical solution for connecting these networks to global data consumers via the existing Internet infrastructure. Our proposed solution takes into consideration the limited resources of the WSN nodes especially energy. It also stems from actual characteristics of practical deployments of these networks as well as the current and expected future state of the technology. We present the elements of our solution and discuss the different features which are offered by these elements. We then conduct an experimental evaluation which compares our solution to other existing solutions from the standpoint of network performance and the associated resource requirements that are imposed by these solutions.

WSN Application Traffic Characterization for Integration within the Internet of Things

The Internet of Things (IoT) aims to connect the growing number of sensing and monitoring devices to humans or other devices with the goal of exchanging data or controlling these devices. IoT can be considered as the set of technologies that allow small devices e.g. sensors, which constitute wireless sensor networks (WSNs) that perform specific tasks, to communicate over the Internet Protocol (IP). Cellular networks, especially LTE, are an attractive technology to provide Internet connectivity to these potentially remote devices. In order to allow the cellular networks to connect these devices reliably to the Internet, the traffic of WSNs should be studied to understand their unique requirements on the cellular infrastructure. This is because the existing cellular networks have been traditionally designed mainly to support human to human communication in which case the traffic is completely different than that of WSNs. This paper aims to shed some light on the possible integration challenges that are imposed by the integration of WSNs and LTE which manifest themselves in the difference in traffic characteristics. We perform some experiments to explore the behavior of specific WSN application traffic. We then discuss the possible adaptation that is required for the successfully integration of the two technologies.

An Ant Colony Optimization Approach for the Deployment of Reliable Wireless Sensor Networks

A reliable wireless sensor network (WSN) is defined as a network that functions satisfactorily, in terms of both its coverage and connectivity to the sink(s), throughout its intended mission time. Deploying reliable WSNs is especially important for critical Internet of Things (IoT) applications, such as industrial, structural health-monitoring, and military applications. In such applications, failure of the WSN to carry out its required tasks can have serious effects, and hence, cannot be tolerated. However, the deployment of reliable WSNs is a challenging problem. This is primarily attributed to the fact that sensor nodes are subject to random failures due to different factors, such as hardware failures, battery depletion, harsh environmental conditions, and so on. In this paper, the problem of deploying a WSN with a specified minimum level of reliability at a minimum deployment cost is addressed. This problem is coined the minimum cost reliability constrained sensor node deployment problem (MCRC-SDP). The MCRC-SDP is proved to be an NP-Complete. An ant colony optimization algorithm coupled with a local search heuristic is proposed as a solution. Extensive experimental results demonstrate the effectiveness of the proposed approach in finding high-quality solutions to the problem.

A framework for cooperative intranet of Things wireless sensor network applications

The Internet of Things (IoT) is generally based on mobile and stationary communication objects. These objects communicate the information that they collect to other potentially remote objects for processing. We view the IoT as composed of numerous intranets of Things. Each intranet of Things (ioT), which may belong to an organization or an enterprise, may contain several applications. Each of these applications monitors phenomena and collects data that could be of interest to a certain party. Nevertheless, ensuring that these potentially separate and different applications are managed uniformly is not an easy task for the ioT operators. We therefore need to establish an arrangement by which we facilitate the co-existence, cooperation and management of these applications. In this study, we introduce a unified framework to facilitate the management of existing mobile and static wireless sensor network (WSN) applications as well the introduction of new WSN applications for a given ioT. This framework includes network and application maintenance tasks as well as the tasks required to connect these applications to the IoT. We provide a solid example on how this framework can be implemented. Finally, we present some experimental results on the performance of this example implementation from different perspectives.

Minimizing the probability of collision in wireless sensor networks using cooperative diversity and optimal power allocation

Transmission collision is one of the main reasons of performance degradation in dense wireless sensor networks (WSNs). Transmission collision can cause throughput reduction, excessive delay and packet loss. One of the methods to minimize the probability of packet collision is the reduction of the collision area (area around sending nodes where collision may take place). In this study we investigate the problem of collision probability minimization through the use of cooperative transmissions and optimal power allocation in WSNs. We formulate the problem as a constrained optimization problem subject to an outage probability constraint. We determine the optimal transmission power of the source and the relay nodes which minimizes the collision area. Results show that the proposed technique significantly reduces the collision area while keeping the outage performance below the targeted value. Results also show that the proposed technique outperforms the direct transmission system as well as the cooperative system with equal transmission power.

ECTP: Enhanced Collection Tree Protocol for practical wireless sensor network applications

In many wireless sensor network (WSN) applications, there are many practical considerations that need to be factored into the design of the underlying networking protocols. For example, the need to involve more than one sink node, i.e. more than one data destination, in the network could be one of the main requirements. This requirement stems from the need for the WSN to monitor several phenomena with potentially different interested parties for each monitored phenomenon. The synchronized operation of the WSN nodes is another important requirement in order to ensure that the actions taken as a result of a detected event are timely and accurate. Several routing protocols have been proposed for WSNs in the past. However, when these protocols are put in practical use, it was found their inability to provide the robust performance that is required for many sensitive applications. In this paper, we propose a new multi-sink routing protocol, which we call ECTP, which we target for the oil and gas industry. In such an application, the reliable synchronized data delivery to multiple destinations (sinks) is required. We perform several practical experiments using actual WSN hardware to evaluate the proposed protocol. We discuss the results of these experiments and propose future directions for this research.