Zurina Mohd Hanapi

An Energy Aware Distributed Clustering Algorithm Using Fuzzy Logic for Wireless Sensor Networks with Non-uniform Node Distribution

AbstractClustering routing protocols are more adequate for Wireless Sensor Networks (WSNs) due to the higher energy utilization rate and scalability. However, non-uniform node deployment makes the cluster-based routing protocols less efficient, since the energy consumption of the nodes is more imbalanced. In this paper, an Energy Aware Distributed Clustering using Fuzzy Logic (EADC-FL) routing algorithm is proposed for the network with non-uniform node distribution. EADC-FL selects the most appropriate nodes as the cluster heads to save more energy in data transmission phase. It considers the energy of the sensor nodes as the primary parameter to elect the candidate cluster heads. Afterwards, it takes into consideration the node degree and node centrality of the sensor nodes by using Fuzzy Logic to identify the final cluster heads. EADC-FL constructs the clusters in equal sizes to make the energy consumption of cluster members balanced and uses a cluster-based routing algorithm to balance the energy consumption among the cluster heads. Moreover, the proposed algorithm performs clustering on demand instead of each round in order to reduce the energy dissipation of the network due to the overhead of consecutive clustering phases. The results demonstrate that EADC-FL significantly decreases the energy consumption and extends the network lifetime of network with non-uniform node distribution .

Comparative study of high-speed Linux TCP variants over high-BDP networks

Transmission Control Protocol (TCP) has been profusely used by most of internet applications. Since 1970s, several TCP variants have been developed in order to cope with the fast increasing of network capacities especially in high Bandwidth Delay Product (high-BDP) networks. In these TCP variants, several approaches have been used, some of these approaches have the ability to estimate available bandwidths and some react based on network loss and/or delay changes. This variety of the used approaches arises many consequent problems with different levels of dependability and accuracy. Indeed, a particular TCP variant which is proper for wireless networks, may not fit for high-BDP wired networks and vice versa. Therefore, it is necessary to conduct a comparison between the high-speed TCP variants that have a high level of importance especially after the fast growth of networks bandwidths. In this paper, high-speed TCP variants, that are implemented in Linux and available for research, have been evaluated using NS2 network simulator. This performance evaluation presents the advantages and disadvantages of these TCP variants in terms of throughput, loss-ratio and fairness over high-BDP networks. The results reveal that, CUBIC and YeAH overcome the other high-speed TCP variants in different cases of buffer size. However, they still require more improvement to extend their ability to fully utilize the high-speed bandwidths, especially when the applied buffer is near-zero or less than the BDP of the link.

A framework based on RSA and AES encryption algorithms for cloud computing services

Cloud computing is an emerging computing model in which resources of the computing communications are provided as services over the Internet. Privacy and security of cloud storage services are very important and become a challenge in cloud computing due to loss of control over data and its dependence on the cloud computing provider. While there is a huge amount of transferring data in cloud system, the risk of accessing data by attackers raises. Considering the problem of building a secure cloud storage service, current scheme is proposed which is based on combination of RSA and AES encryption methods to share the data among users in a secure cloud system. The proposed method allows providing difficulty for attackers as well as reducing the time of information transmission between user and cloud data storage.

A Scheduled Activity Energy Aware Distributed Clustering Algorithm for Wireless Sensor Networks with Nonuniform Node Distribution

Nonuniform node deployment makes the cluster-based routing protocol less efficient in wireless sensor networks (WSNs). Energy aware distributed clustering (EADC) is one of the cluster-based routing protocols proposed for networks with nonuniform node distribution, which can effectively balance the energy consumption among the nodes. However, due to the nonuniform node distribution, there is a redundancy in sensed and transmitted data in dense area. This unnecessary energy consumption is not considered in EADC. Therefore, in this paper, a new algorithm called scheduled activity EADC (SA-EADC) is proposed. SA-EADC exploits the redundant nodes and turns them off for the current round. The redundant nodes are scheduled based on their residual energy to work alternatively. The results show that SA-EADC significantly decreases the energy consumption and extends the network lifetime without degradation in coverage and sensing reliability of the network.

Comparison of ECC and RSA Algorithm in Resource Constrained Devices

Nowadays, the usage of resource constrained devices is increasing and these devices are primarily working with sensitive data. Consequently, data security has become crucial for both producers and users. Limitation of resources is deemed as the major issue that makes these devices vulnerable. Attackers might exploit these limitations to get access to the valuable data. Therefore, carefully chosen and practically tested encryption algorithm must be applied to increase the device efficiency and mitigate the risk of sensitive data loss. This study will compare elliptic curve cryptography (ECC) algorithm with Key size of 160-bit and Rivest-Shamir-Adleman (RSA) algorithm with Key size of 1024-bit. As a result of this study utilizing ECC in resource constrained devices has advantages over RSA but ECC needs continues enhancement to satisfy the limitations of newly designed chips.

Adaptive multi-polling scheduler for QoS support of video transmission in IEEE 802.11e WLANs

The 802.11E Task Group has been established to enhance quality of service (QoS) provision for time-bounded services in the current IEEE 802.11 medium access control protocol. The QoS is introduced throughout hybrid coordination function controlled channel access (HCCA) for the rigorous QoS provision. In HCCA, the station is allocated a fixed transmission opportunity (TXOP) based on its TSPEC parameters so that it is efficient for constant bit rate streams. However, as the profile of variable bit rate traffics is inconstant, they are liable to experience a higher delay especially in bursty traffic case. In this paper, we present a dynamic TXOP assignment algorithm called adaptive multi-polling TXOP scheduling algorithm (AMTXOP) for supporting the video traffics transmission over IEEE 802.11e wireless networks. This scheme invests a piggybacked information about the size of the subsequent video frames of the uplink streams to assist the hybrid coordinator accurately assign the TXOP according to actual change in the traffic profile. The proposed scheduler is powered by integrating multi-polling scheme to further reduce the delay and polling overhead. Extensive simulation experiments have been carried out to show the efficiency of the AMTXOP over the existing schemes in terms of the packet delay and the channel utilization.

Agile-SD: A Linux-based TCP congestion control algorithm for supporting high-speed and short-distance networks

Recently, high-speed and short-distance networks are widely deployed and their necessity is rapidly increasing everyday. This type of networks is used in several network applications; such as Local Area Networks (LAN) and Data Center Networks (DCN). In LANs and DCNs, high-speed and short-distance networks are commonly deployed to connect between computing and storage elements in order to provide rapid services. Indeed, the overall performance of such networks is significantly influenced by the Congestion Control Algorithm (CCA) which suffers from the problem of bandwidth under-utilization, especially if the applied buffer regime is very small. In this paper, a novel loss-based CCA tailored for high-speed and Short-Distance (SD) networks, namely Agile-SD, has been proposed. The main contribution of the proposed CCA is to implement the mechanism of agility factor. Further, intensive simulation experiments have been carried out to evaluate the performance of Agile-SD compared to Compound and Cubic which are the default CCAs of the most commonly used operating systems. The results of the simulation experiments show that the proposed CCA outperforms the compared CCAs in terms of average throughput, loss ratio and fairness, especially when a small buffer is applied. Moreover, Agile-SD shows lower sensitivity to the buffer size change and packet error rate variation which increases its efficiency.

Cooperation stimulation mechanisms for wireless multihop networks

In wireless multihop networks such as wireless sensor networks (WSNs) and mobile ad hoc networks (MANETs), nodes have to rely on their peer neighbours in transmitting packets to intended destinations. A successful rate of communication in these networks is assured if all nodes in the network fully cooperate to relay packets for each other. However, due to the existence of nodes with various motives, cooperativeness cannot be ensured and the communication goal is not achieved. Consequently, many cooperation stimulation approaches have been proposed to address node selfishness by using, broadly, incentive-based and punishment-based approaches. These schemes consist of several components including monitoring mechanisms, that need to be optimized in order to provide effective ways to detect and manage selfish nodes in the networks. This paper summarizes existing cooperation stimulation mechanisms and discusses important issues in this field such as false judgment and node collusion, whereby the root of these kinds of problems originates from the inability to obtain accurate evaluation on the behaviour of a node.

Impact of blackhole and Sybil attacks on dynamic windows secured implicit geographic forwarding routing protocol

Dynamic windows implicit geographic forwarding (DWSIGF) routing protocol promises a minimal selection on attacker as a hop node. However, it was tested only on blackhole attack with a single optimal attacker. Thus, a thorough investigation was performed to examine whether the protocol is secure against other routing attacks. This study presents a comprehensive analysis of an impact of blackhole and Sybil attacks on the DWSIGF. The analyses on blackhole attack were carried out on a single and multiple attackers using priority selection, random selection, an optimal relay, non-optimal relay, with and without clear to send (CTS) rushing attack. While on the other hand, the Sybil attacks analyses were investigated on the impact of single attacker using optimal and non-optimal relay over increasing traffic loads and growing number of Sybil attackers. The study showed that the DWSIGF promised a superior protection against blackhole/selective forwarding and Sybil attacks with minimum attacker selection and high performance in packet delivery ratio even without inserting any security mechanism in the routing protocol.

FuGeF: A Resource Bound Secure Forwarding Protocol for Wireless Sensor Networks

Resource bound security solutions have facilitated the mitigation of spatio-temporal attacks by altering protocol semantics to provide minimal security while maintaining an acceptable level of performance. The Dynamic Window Secured Implicit Geographic Forwarding (DWSIGF) routing protocol for Wireless Sensor Network (WSN) has been proposed to achieve a minimal selection of malicious nodes by introducing a dynamic collection window period to the protocol’s semantics. However, its selection scheme suffers substantial packet losses due to the utilization of a single distance based parameter for node selection. In this paper, we propose a Fuzzy-based Geographic Forwarding protocol (FuGeF) to minimize packet loss, while maintaining performance. The FuGeF utilizes a new form of dynamism and introduces three selection parameters: remaining energy, connectivity cost, and progressive distance, as well as a Fuzzy Logic System (FLS) for node selection. These introduced mechanisms ensure the appropriate selection of a non-malicious node. Extensive simulation experiments have been conducted to evaluate the performance of the proposed FuGeF protocol as compared to DWSIGF variants. The simulation results show that the proposed FuGeF outperforms the two DWSIGF variants (DWSIGF-P and DWSIGF-R) in terms of packet delivery.