A. Halim Zaim

A hybrid intrusion detection system design for computer network security

Intrusions detection systems (IDSs) are systems that try to detect attacks as they occur or after the attacks took place. IDSs collect network traffic information from some point on the network or computer system and then use this information to secure the network. Intrusion detection systems can be misuse-detection or anomaly detection based. Misuse-detection based IDSs can only detect known attacks whereas anomaly detection based IDSs can also detect new attacks by using heuristic methods. In this paper we propose a hybrid IDS by combining the two approaches in one system. The hybrid IDS is obtained by combining packet header anomaly detection (PHAD) and network traffic anomaly detection (NETAD) which are anomaly-based IDSs with the misuse-based IDS Snort which is an open-source project. The hybrid IDS obtained is evaluated using the MIT Lincoln Laboratories network traffic data (IDEVAL) as a testbed. Evaluation compares the number of attacks detected by misuse-based IDS on its own, with the hybrid IDS obtained combining anomaly-based and misuse-based IDSs and shows that the hybrid IDS is a more powerful system.

Genetic Algorithm Application in Optimization of Wireless Sensor Networks

There are several applications known for wireless sensor networks (WSN), and such variety demands improvement of the currently available protocols and the specific parameters. Some notable parameters are lifetime of network and energy consumption for routing which play key role in every application. Genetic algorithm is one of the nonlinear optimization methods and relatively better option thanks to its efficiency for large scale applications and that the final formula can be modified by operators. The present survey tries to exert a comprehensive improvement in all operational stages of a WSN including node placement, network coverage, clustering, and data aggregation and achieve an ideal set of parameters of routing and application based WSN. Using genetic algorithm and based on the results of simulations in NS, a specific fitness function was achieved, optimized, and customized for all the operational stages of WSNs.

Wireless sensor networks for space and Solar-system missions

Wireless sensor networks (WSNs) are multi-hop self-organizing networks which include a huge number of nodes integrating environmental measuring, data processing and wireless communications in order to apprehend, collect and process information to achieve defined tasks. A diverse set of applications for WSNs encompassing different fields have already emerged including environmental applications, inventory monitoring, military applications, intrusion detection, health applications, motion tracking, machine malfunction detection and etc. Among these application areas the use of WSNs can adapted to Space and Solar-system missions. In the last years, space-based WSNs have gained increasing attention from both the research communities and companies involved in space research. This paper outlines the usage of a space-based wireless sensor networks (SB-WSNs), which applies the concept of terrestrial wireless sensor networks to the space.

Evaluation of call blocking probabilities in LEO satellite networks

In this paper, we present a new method for calculating call blocking probabilities (CBPs) in a low Earth orbit satellite network that carries voice calls. The calculation of the CBPs uses the Erlang-B formula, but the traffic intensity has been modified to take into the time and location in which the calls are made. Copyright

Delay efficient STEM by pipelining

Abstract Wireless sensor networks are comprised of energy constraint, battery powered small devices that sense the environment and transmit the data to the sink in order to take action according to data. Since the sensors are small energy constraint devices energy consumption is the main problem for wireless sensor networks. Energy spent during data communication is much more than spent during in-sensor computing. Most of the effort is spent on designing protocols in order to conserve energy. This paper proposes an improved version of energy efficient MAC protocol STEM by including pipelining mechanism. Results show that the proposed method overperform the original version of STEM by sustaining less delay.

A comparative study based on power usage performance for routing protocols in wireless sensor network

Because of the low-power energy nodes used in a network, energy plays a pivotal role in the lifetime of wireless sensor networks (WSNs). This study elaborates on a routing method featured with optimum energy consumption in wireless sensor networks. Some of routing protocols with high energy efficiency (LEACH, Director Diffusion, Gossiping, PEGASIS, and EESR) were examined. We also looked through strategies of the protocol for WSNs such as data aggregation and clustering, routing, different node role assignments, and data-center methods. The routing protocols were compared regarding variety of metrics influencing requirements of the specific application and WSNs in general.

Half cycling dynamic bandwidth allocation with prediction on EPON

This study is about a prediction approach for our previous dynamic bandwidth allocation algorithm for Ethernet Passive Optical Networks (EPON). Our previous work (hcDBA) is based on half cycle timing for bandwidth allocation. That can be handled as a middle way between online and offline bandwidth allocation schemes. In PONs, prediction is used for bandwidth allocation to grant loaded nodes with early responses. However, due to the versatile nature of data traffic, prediction algorithms have a handicap to provide a better solution in classical approaches. In this study, a novel prediction approach integrated with hcDBA algorithm described. Performance comparison of hcDBA with & without prediction and IPACT algorithm is given. According to the simulation results, prediction on hcDBA seems to give some performance improvements in terms of access-delay.

Traffic characterization study on EPON upstream channel

Metropolitan ring networks are usually used to connect the high speed backbone networks with access networks. Until now, the metropolitan network and the access network are gained much attention of researchers. However they have been investigated in separate ways. There is no work in which the end-to-end performance from end-users of the access network to metropolitan network is evaluated. How to simulate a complete end-to-end network while keeping basic characteristics of access and metro traffic is an emergence problem to evaluate the end-to-end performance. In reality, a complete end-to-end network in which hundreds of Ethernet Passive Optical Network (EPON) are connected to metro ring networks cannot be simulated because of the huge amount of traffic generated from the access network side. In this paper, we aim to obtain trace files of incoming traffic at the entrance of Optical Line Terminal (OLT) by running simulations of an EPON network which implements Interleaved Polling with Adaptive Cycle Time (IPACT). Then, the generated traffic pattern will be characterized in order to find corresponding traffic model among well known traffic models and this model will be used as output traffic of OLTs. After, we can use this traffic model without simulating a complete EPON network. Through various simulations, we observe that the generated traffic that comes to OLT is similar to the traffic obtained with Poisson sources

Energy and distance factor based routing protocol for wireless sensor networks using mobile agents

The wireless sensor networks are networks of compact micro-sensors for data acquisition or monitoring some environment characteristics, such as temperature, sound, vibration, pressure and motion. These sensors are embedded devices capable of data communication. In many applications, sensor nodes are distributed or deployed over a geo-graphically large area. Due to their structure, data of measured values must be transferred among stations through these sensor nodes. For this reason a successful, energy efficient, fault tolerant routing protocol should be implemented to pre-vent data loss and other challenges within limited energy levels. This paper presents an agent based routing algorithm for wireless sensor networks, based on the selection of the idea of active nodes. Our proposed routing algorithm is related with energy and distance factors of each nodes. The main objective is to increase the lifetime of a sensor network while not compromising data delivery. Critical tasks such as measuring, analyzing and monitoring of energy levels of nodes are handled by these autonomous mechanisms.

QoS mobility-aware algorithm using early update for Host Identity Protocol

In this article, we are interested in improving the handover quality of Host Identity Protocol (HIP) in the case of micro mobility by (i) proposing the Local Rendezvous Server architecture as a first attempt to minimize the handover delay in the mobility process, (ii) introducing an adaptive early update mechanism to improve the handover quality during mobility by introducing early HIP (eHIP) and finally (iii) we propose a method that minimizes the total radio resource utilization in our architecture subject to the QoS constraints of Mobile Nodes (MNs) especially the delay of real-time applications. We prove through simulations that our scheme can achieve significant gains in terms of radio resource utilization while taking into account the mobility of MNs along with the respect of their QoS parameters for their ongoing real-time applications.