Irfan Awan

Adaptive decentralized re-clustering protocol for wireless sensor networks

Wireless sensor networks are composed of a large number of sensor nodes with limited energy resources. One critical issue in wireless sensor networks is how to gather sensed information in an energy efficient way since the energy is limited. The clustering algorithm is a technique used to reduce energy consumption. It can improve the scalability and lifetime of wireless sensor network. In this paper, we introduce an adaptive clustering protocol for wireless sensor networks, which is called Adaptive Decentralized Re-Clustering Protocol (ADRP) for Wireless Sensor Networks. In ADRP, the cluster heads and next heads are elected based on residual energy of each node and the average energy of each cluster. The simulation results show that ADRP achieves longer lifetime and more data messages transmissions than current important clustering protocol in wireless sensor networks.

Performance evaluation of dynamic probabilistic broadcasting for flooding in mobile ad hoc networks

Abstract In mobile ad hoc networks (MANETs), flooding is a required message dissemination technique for network-wide broadcast. The conventional blind flooding algorithm causes broadcast storm problem, a high number of unnecessary packet rebroadcasts thus resulting in high contention and packet collisions. This paper proposes a new probabilistic approach that dynamically fine-tunes the rebroadcasting probability of a node for routing request packets (RREQs) according to the number of neighbour nodes. We evaluate the performance of the proposed approach for the ad hoc on demand distance vector (AODV) routing protocol and compared against the blind flooding, fixed probabilistic and adjusted probabilistic flooding [L.M.M.M. Bani-Yassein, M. Ould-Khaoua et al., Performance analysis of adjusted probabilistic broadcasting in mobile ad hoc networks, International Journal of Wireless Information Networks 13(2) (2006) 127–140; M.B. Yassein, M.O. Khaoua et al., Improving route discovery in on-demand routing protocols using local topology information in MANETs, Proceedings of the ACM international workshop on Performance Monitoring, Measurement, and Evaluation of Heterogeneous Wireless and Wired Networks, Terromolinos, Spain, ACM Press, 2006, pp. 95–99.] approaches. The simulation results show that our proposed approach demonstrates better performance than blind flooding, fixed probabilistic and adjusted flooding approaches.

Analysis of grid service composition with BPEL4WS

The open grid services infrastructure (OGSI) defines a distributed system framework by integrating grid and Web services technologies to facilitate resource sharing. In OGSI, Web services are supplemented with additional features in order to meet the requirements of grid computing. However, the issue of grid service composition is not well addressed in the OGSI framework. We apply BPEL4WS (business process execution language for Web services) as a business workflow description language for the composition of grid services. We provide an in depth analysis of BPEL4WS and OGSI in terms of their similarities and differences in areas such as life cycle management, Web service instantiation and instance group management. Based on our analysis we propose a high-level architecture to compliment OGSI with BPEL4WS for defining process workflow among grid services. We describe a prototype system which shows how the proposed architecture can be used in modelling or orchestrating grid services with BPEL4WS.

Energy efficient clustering protocol to enhance lifetime of wireless sensor network

A sensor node is a tiny device that includes a sensing subsystem, a processing subsystem and a wireless communication subsystem. The sensor nodes have limited resources in terms of memory, energy and computational resources. Clustering has been proposed by researches to group a number of nodes to form a cluster that managed by cluster head. However, most existing clustering protocols consume large amount of energy due to cluster formation overhead and cluster head responsibilities. We proposed an energy efficient clustering protocol (EECPL) to enhance lifetime of wireless sensor networks. The main goal of EECPL is to distribute the energy load among all sensor nodes to minimize the energy consumption and maximize the network lifetime of wireless sensor networks. EECPL organizes sensor nodes into clusters and uses ring topology to send data packets so that each sensor node receives data from a previous neighbor and transmits data to a next neighbor. Upon receiving the aggregated data from previous neighbors, cluster senders transmit the aggregated data to the base station. EECPL is shown to achieve significant energy savings, balance the energy consumption among sensor nodes and reduce communication overhead.

Dynamic/Static Clustering Protocol for Wireless Sensor Network

Wireless sensor networks consist of a large number of small, low-cost and low-power nodes that coordinate with one another for environmental sensing. The sensor nodes are restricted in power, memory and computational resources. There is a need to design protocols that adapt much better to the constraints of the sensor network environment. In this paper, we propose clustering protocol called dynamic/static clustering protocol DSC by extend LEACH-centralized (low-energy adaptive clustering hierarchy). The clusters in our scheme are fixed for 10 rounds then the clusters formation take place again. We compare the performance of DSC with LEACH-C. Our experiment results show that DSC outperforms LEACH-C in term of communication overhead, network lifetime and energy dissipated over time.

Botnet detection techniques: review, future trends, and issues

In recent years, the Internet has enabled access to widespread remote services in the distributed computing environment; however, integrity of data transmission in the distributed computing platform is hindered by a number of security issues. For instance, the botnet phenomenon is a prominent threat to Internet security, including the threat of malicious codes. The botnet phenomenon supports a wide range of criminal activities, including distributed denial of service (DDoS) attacks, click fraud, phishing, malware distribution, spam emails, and building machines for illegitimate exchange of information/materials. Therefore, it is imperative to design and develop a robust mechanism for improving the botnet detection, analysis, and removal process. Currently, botnet detection techniques have been reviewed in different ways; however, such studies are limited in scope and lack discussions on the latest botnet detection techniques. This paper presents a comprehensive review of the latest state-of-the-art techniques for botnet detection and figures out the trends of previous and current research. It provides a thematic taxonomy for the classification of botnet detection techniques and highlights the implications and critical aspects by qualitatively analyzing such techniques. Related to our comprehensive review, we highlight future directions for improving the schemes that broadly span the entire botnet detection research field and identify the persistent and prominent research challenges that remain open.

Performance Evaluation Study of Intrusion Detection Systems

Abstract With the thriving technology and the great increase in the usage of computer networks, the risk of having these network to be under attacks have been increased. Number of techniques have been created and designed to help in detecting and/or preventing such attacks. One common technique is the use of Network Intrusion Detection / Prevention Systems NIDS. Today, number of open sources and commercial Intrusion Detection Systems are available to match enterprises requirements but the performance of these Intrusion Detection Systems is still the main concern. In this paper, we have tested and analyzed the performance of the well know IDS system Snort and the new coming IDS system Suricata. Both Snort and Suricata were implemented on three different platforms (ESXi virtual server, Linux 2.6 and FreeBSD) to simulate a real environment. Finally, in our results and analysis a comparison of the performance of the two IDS systems is provided along with some recommendations as to what and when will be the ideal environment for Snort and Suricata.

A second order sliding mode control design of a switched reluctance motor using super twisting algorithm

Abstract A novel robust technique for speed control application of variable reluctance motor is proposed. The suggested scheme is model based and uses a mathematical model of an SR motor, and Second Order Sliding Mode Control (SOSMC) with super-twisting algorithm. Sliding mode controllers for SR motor were reported before but super twisting SOSMC have an added advantage of reduced chattering which is one of the main focuses of this work. The proposed controller gives fast dynamic response with no overshoot and nearly zero steady state error. The effectiveness of the proposed controller and its robustness to parameter variations is also confirmed by simulation results.

Analytical modeling for spectrum handoff decision in cognitive radio networks

Cognitive Radio (CR) is an emerging technology used to significantly improve the efficiency of spectrum utilization. Although some spectrum bands in the primary users licensed spectrum are intensively used, most of the spectrum bands remain underutilized. The introduction of open spectrum and dynamic spectrum access lets the secondary (unli- censed) users, supported by cognitive radios; opportunistically utilize the unused spec- trum bands. However, if a primary user returns to a band occupied by a secondary user, the occupied spectrum band is vacated immediately by handing off the secondary users call to another idle spectrum band. Multiple spectrum handoffs can severely degrade qual- ity of service (QoS) for the interrupted users. To avoid multiple handoffs, when a licensed primary user appears at the engaged licensed band utilized by a secondary user, an effec- tive spectrum handoff procedure should be initiated to maintain a required level of QoS for secondary users. In other words, it enables the channel clearing while searching for target vacant channel(s) for completing unfinished transmission. This paper proposes prioritized proactive spectrum handoff decision schemes to reduce the handoff delay and the total ser- vice time. The proposed schemes have been modeled using a preemptive resume priority (PRP) M/G/1 queue to give a high priority to interrupted users to resume their transmission ahead of any other uninterrupted secondary user. The performance of proposed handoff schemes has been evaluated and compared against the existing spectrum handoff schemes. Experimental results show that the schemes developed here outperform the existing schemes in terms of average handoff delay and total service time under various traffic arri- val rates as well as service rates.

Performance Analysis of DSR & Extended DSR Protocols

Ad hoc network is group of wireless nodes to establish a network without any fixed infrastructure or centralized supervision/management. In such a network, topology changes dynamically and due to limitations of bandwidth, transmission range and power routing becomes an important issue. A lot of work has been done infield of routing in ad-hoc network since 1990. Dynamic Source Routing protocol (DSR) provides simple and efficient routing for multihop ad-hoc network of mobile nodes. This paper presents a simulation based performance analysis and comparison between traditional DSR and extended DSR. It utilises a specially designed framework which builds on the Global Mobile Information System Simulator (GloMoSim). Some optimizations of DSR have already been implemented in GloMoSim. Several different simulation results show that performance got better by traditional (already implemented) DSR.