Halabi Hasbullah

A survey of simulators, emulators and testbeds for wireless sensor networks

Simulators, emulators and testbeds are invaluable tools for performance evaluation of algorithms and protocols in wireless sensor networks (WSNs). It is extremely difficult to choose an appropriate tool for performance testing without the horizontal and vertical analysis of existing tools. This paper presents a survey of thirty five performance evaluation tools for WSNs. Unlike most other studies, tools were selected based on their popularity, support for WSNs, active maintenance and the help available. On the horizontal dimension, prominent competitors at each stage were selected. For vertical analysis, tools for simulation, emulation and testbeds were categorized accordingly. We believe that this survey will aid researchers, application and tool developers while selecting an appropriate tool for their implementation. We have highlighted an open research issue to have an integrated tool that supports modeling, simulation, emulation and testbed implementation for algorithm validation, performance evaluation and proof-of-concept implementation in WSNs.

Mobile Sink based Routing Protocol (MSRP) for Prolonging Network Lifetime in Clustered Wireless Sensor Network

In WSN, sensors near the sink have to relay the data of the nodes away from the sink and as a result they drain their energy very quickly. It result in network partitioning and can significantly limit the network lifetime. This problem is termed as hotspot problem. Recently, formation of hot spot or energy hole near the sink has emerged as a critical issue for data gathering in WSN. In this paper, we address hotspot problem and purposed Mobile Sink based Routing Protocol (MSRP) for Prolonging Network Lifetime in Clustered Wireless Sensor Network. In MSRP, mobile sink moves in the clustered WSN to collect sensed data from the CHs within its vicinity. During data gathering mobile sink also maintains information about the residual energy of the CHs. Mobile sink based on the residual energy of CHs move to the CHs having higher energy. Consequently, the hotspot problem is minimized as the immediate neighbor of the sink is high energy node and it changes because of regular sink movement. It results in a balanced use of WSN energy and improves network life time. To evaluate the performance of the proposed strategy intensive simulation are carried out using OMNet-4.0. Performance of the proposed strategy is compared to the static sink and multiple sinks strategies, using metrics such as energy per packet, and throughput. The simulation results demonstrate that MSRP is effective in prolonging the network lifetime as well as in improving throughput than static sink and multiple sink strategies.

Indoor positioning in Bluetooth networks using fingerprinting and lateration approach

Global Positioning System (GPS) is a well known navigation system for outdoor applications; however this technology does not work in indoor environments. In order to overcome this limitation, Bluetooth technology can be employed. Furthermore, Bluetooth technology provides an accurate and low cost solution for short range wireless communication. Most of the digital devices provide the Bluetooth functionality which also makes it a good candidate for indoor positioning. In this paper, we use Bluetooth devices for indoor positioning and use signal based parameters such as received power level for position estimation. The accuracy of indoor positioning system is greatly dependant on the parameters selected for estimation and the measurements obtained from the environment. However, the measurements are corrupted by various environmental conditions such as temperature, reflection, presence of obstacles, human body and other communication signals. Therefore, we need to filter the measurements. This paper presents an experimental relationship between the received power level and distance using the standard radio propagation model. The idea behind this study is to provide an accurate distance estimate for Trilateration approach. Based on the experiments performed, the average error is minimized from 5.87 meters to 2.67 meters using gradient filter. The use of gradient filter improves the accuracy by 45 %.

Localized motion-based connectivity restoration algorithms for wireless sensor and actor networks

In wireless sensor and actor networks maintaining inter-actor connectivity is very important in mission-critical applications where actors have to quickly plan optimal coordinated response to detected events. Failure of one or multiple actors may partition the inter-actor network into disjoint segments, and thus hinders the network operation. Autonomous detection and rapid recovery procedures are highly desirable in such a case. This paper presents DCR, a novel distributed partitioning detection and connectivity restoration algorithm to tolerate the failure of actors. DCR proactively identifies actors that are critical to the network connectivity based on local topological information, and designates appropriate, preferably non-critical, backup nodes. Upon failure detection, the backup actor initiates a recovery process that may involve coordinated relocation of multiple actors. We also present an extended version of DCR, named RAM, to handle one possible case of a multi-actor failure. The proposed algorithms strive to avoid procrastination, localize the scope of recovery and minimize the movement overhead. Simulation results validate the performance of the proposed algorithms.

Classes of attacks in VANET

Last few years, vehicular network has been taken more attention of researchers and automotive industries due to life saving factor. Vehicular Ad hoc Network (VANET) needs security to implement the wireless environment and serves users with safety and non safety applications. Attackers generate different attacks in this life saving vehicular network. In this paper, we propose five different classes of attacks and every class is expected to provide better perspective for the VANET security. The main contribution of this paper is the proposed solution for classification and identification of different attacks in VANET.

Volunteer-instigated connectivity restoration algorithm for Wireless Sensor and Actor Networks

Due to their applications, Wireless Sensor and Actor Networks (WSANs) have recently been getting significant attention from the research community. In these networks, maintaining inter-actor connectivity is of a paramount concern in order to plan an optimal coordinated response to a detected event. Failure of an actor may partition the inter-actor network into disjoint segments, and may thus hinder inter-actor coordination. This paper presents VCR, a novel distributed algorithm that opts to repair severed connectivity while imposing minimal overhead on the nodes. In VCR the neighbors of the failed actor volunteer to restore connectivity by exploiting their partially utilized transmission range and by repositioning closer to the failed actor. Furthermore, a diffusion force is applied among the relocating actors based on transmission range in order to reduce potential of interference, and improve connectivity. VCR is validated through simulation and is shown to outperform contemporary schemes found in the literature.

VANET Security Framework for Trusted Grouping Using TPM Hardware

Vehicular Ad hoc Network (VANET) is a network of vehicles on the roads, of which the success of its applications is highly dependent upon the underlying security mechanism. The default trial asymmetric PKI/ECDSA security mechanism is known for its high computational cost, thus lacking applicability in life-critical safety messaging. Alternative security schemes, such as symmetric methods provide faster communication at the expense of reduced security. Hence, hybrid and hardware based solutions were proposed by researchers to ease the issue. However, these solutions either do not support the existing VANET PKI standard or have larger message size. In this paper, we present a hardware based security framework that uses both standard asymmetric PKI and symmetric cryptography for faster and secure safety message exchange. The proposed framework is expected to improve security mechanism in VANET by developing trust relationship among the neighboring nodes, hence forming trusted groups. The trust is established via Trusted Platform Module (TPM) and group communication.

Prevention of DoS Attacks in VANET

Privacy and Security have become an indispensable matter of attention in the Vehicular Ad-Hoc Network, which is vulnerable to many security threats these days. One of them is the Denial of Service (DoS) attacks, where a malicious node forges a large number of fake identities, i.e., Internet Protocol (IP) addresses in order to disrupt the proper functioning of fair data transfer between two fast-moving vehicles. In this paper, a distributed and robust approach is presented to defend against DoS attacks. In this proposed scheme, the fake identities of malicious vehicles are analyzed with the help of consistent existing IP address information. Beacon packets are exchanged periodically by all the vehicles to announce their presence and to become aware of the next node. Each node periodically keeps a record of its database by exchanging the information in its environment. If some nodes observe that they have similar IP addresses in the database, these similar IP addresses are identified as DoS attacks. However, it can be expected that security attacks are likely to increase in the coming future due to more and more wireless applications being developed onto the well-known exposed nature of the wireless medium. In this respect, the network availability is exposed to many types of attacks. A DoS attack on the network availability is being elaborated in this paper. A model of a product interaction for DoS prevention has been developed called “IP-CHOCK” that will lead to the prevention of DoS attacks. The proposed approach will be able to locate malicious nodes without the requirement of any secret information exchange and special hardware support. Simulation results demonstrate that the detection rate increases when optimal numbers of nodes are forged by the attackers.

Partitioning Detection and Connectivity Restoration Algorithm for Wireless Sensor and Actor Networks

Recently, Wireless Sensor and Actor Networks have been receiving a growing attention from the research community because of their suitability for critical applications. Maintaining inter-actor connectivity becomes extremely crucial in such situations where actors have to quickly plan optimal coordinated response to detected events. Failure of critical actor partitions the inter-actor network into disjoint segments, and thus hinders the network operation. Autonomous detection and rapid recovery procedures are highly desirable in such case. This paper presents PCR, a novel distributed partitioning detection and connectivity restoration algorithm. PCR proactively identifies critical actors based on local topological information and designate appropriate backup nodes (preferably non-critical) to handle their failure. A backup actor detects the failure and initiates a recovery process that may involve coordinated multi-actor relocation. The purpose is to avoid procrastination, localize the scope of recovery process and minimize the movement overhead. Simulation results validate the performance of PCR that outperforms contemporary schemes found in literature.

Energy balanced clustering in wireless sensor network

In this paper, clustering in terms of energy efficiency in WSN is explored and proposed Energy Balanced Clustering in Wireless Sensor Network (EBC). Algorithms for energy balanced cluster formation, cluster head selection, intra cluster and inter cluster communication in WSN are proposed. Furthermore, using OMNet-4.0 simulation performance of proposed protocol is compared with LEACH and EEMC using parameters like energy per packet and throughput. Simulation results demonstrate that EBC is effective in prolonging the network lifetime as well as in improving throughput, than LEACH and EEMC.