H. Zainol Abidin

Video quality of service in Diffserv-aware multiprotocol label switching network

The current trend set by service providers of enhancing the degree of provisions in IP networks while maintaining the optimum quality, has promoted many research activities. These activities include those which aim to introduce improved quality of services for popular Internet services and applications. In this paper, quality of services (QoS) of video transmission on Differentiated Services (DiffServ) with multiprotocol label switching (MPLS) network is being simulated and evaluated by a network Simulator, OPNET. The need of integration of MPLS with DiffServ particularly for the video traffic has been demonstrated in the simulation. The objective of this work is to study the influence of the QoS mechanism via DiffServ-MPLS on network parameters such as packet loss, delay and throughput for different video resolutions. The comprehensive study showed general improvement in the throughput and packet loss particularly of video transmission when using DiffServ-aware MPLS network as compared to when only MPLS or DiffServ is employed.

Provisioning WSN Coverage via minimax based sensor node placement scheme

Wireless Sensor Network (WSN) which is capable of sensing, storing data, processing data and transmitting data has been widely applied in providing effective surveillance. Optimum sensor node placement in the surveillance area is needed since the number of sensor nodes that can be deployed are limited. The positions of sensor nodes must be able to provide maximum coverage with a longer lifetime. This paper describes an initial stage of an ongoing project. A Sensor node placement technique which is based on the minimax algorithm is proposed where surveillance locations will be monitored by the closest sensor nodes. Performance study has been carried out by evaluating the performance of the minimax scheme in terms of coverage ratio and uniformity. Uniformity is a performance metric that can be used to estimate WSN lifetime. Simulation results show that WSN with higher sensor nodes will provide a higher coverage ratio and more uniformly distributed sensor nodes. (5 pages)

Multi-objective biological mimicry optimization algorithm for WSN sensor node placement

An optimum sensor nodes arrangement in a Wireless Sensor Network (WSN) would be able to provide a WSN with maximum coverage, minimum energy consumption and guaranteed connectivity. A sensor node placement algorithm called Multi-objective Territorial Predator Scent Marking Algorithm (MOTPSMA) that imitates the behavior of territorial predators in marking their territories with their odours is introduced in this paper. The MOTPSMA deployed in this paper uses the minimum uncovered area and minimum energy consumption as the objective functions subject to full connectivity constraint. The performance of the proposed technique is then compared with an Integer Linear Programming (ILP) algorithm in terms of coverage ratio, connectivity and energy consumption. Simulation results show that the WSN deployed with the proposed sensor node placement scheme provides better performance with larger coverage ratio, full connectivity and lower energy consumption.

Implementation of a One-LLID-per-Queue DBA Algorithm in EPON

The advantages of Ethernet passive optical network (EPON) are setting it to be a natural ubiquitous solution for the access network. In the upstream direction of EPON, the directional property of the splitter requires that the traffic flow be mitigated to avoid collision. A dynamic bandwidth allocation (DBA) scheme is desirable in optimizing the bandwidth usage further. In this paper, a global priority DBA mechanism is discussed. The mechanism aims to reduce the overall delay while enhancing the throughput and fairness. This study was conducted using MATLAB where it was compared to two other algorithms in the literature. The results show that the delay is reduced up to 59% and the throughput and fairness index are improved up to 10% and 6%, respectively.

Effects of varying fiber length towards packet delay in Passive Optical Network

Passive Optical Network (PON) testbed has been the interests of many researchers nowadays to study the non-linear effects of fibers that could not be captured using simulations. The length of the fiber is significant because cost savings could be made with longer fiber by reducing the electronic equipment and real-estate required at the local exchange or wire center. In this paper, we vary the fiber length ranges from 5 km, 10 km, 15 km and 20 km to study the effects they produce towards the packet delay. The experiment is done in a Peripheral Interface Controller (PIC) based PON testbed, and validated by National Instrument - Universal Software Radio Peripheral (NI-USRP) based PON testbed. The results show that the percentage difference between each fiber length is very minor, where we can observe as high as 0.12% between 10 km to 5 km fiber length, 0.65% between 15 km to 10 km fiber length, 0.3% between 20 km to 10 km fiber length and only 1.1% between 20 km to 5 km fiber length.

WSN based intruder detection system based on Territorial Predator Scent Marking Algorithm (TPSMA) sensor node placement scheme

An effective sensor node placement in a Wireless Sensor Network (WSN) is one of the ways to provide a WSN with maximum coverage, maximum connectivity, minimum deployment cost and minimum energy consumption. Territorial Predator Scent Marking Algorithm (TPSMA) has been recently proposed by the authors. This paper presents an intruder detection system based on TPSMA. The performance of the TPSMA intruder detection system are evaluated based on coverage ratio and connectivity probability through simulation and hardware experimentation. The results show that the simulation and hardware experimental results are of similar trend with some expected differences due to various factors.

Traffic modelling for Ethernet Passive Optical Network using MATLAB

Ethernet Passive Optical Network (EPON) has gained the interest of many researchers nowadays as it is one of the best technologies to overcome congestion in the local loop between the customer and local exchange. Many network simulators exist in order to study EPON, but the simplest method to study EPON is using MATLAB. However, in order to study EPON using MATLAB, the traffics need to be generated as according to Ethernet traffic to avoid an impairment in the network design. This paper proposes a traffic modeling in MATLAB based on the source code obtained in NS-2 so that it can be used as a discrete event simulator for EPON. The results obtained show that the traffic generated is in line with the results generated in NS-2; and hence valid to be used in EPON.