Wajdi Fawzi Mohammed Al-Khateeb

ENFAT-AODV: The fault-tolerant routing protocol for high failure rate Wireless Sensor Networks

As more and more real Wireless Sensor Networks (WSN) applications have been tested and deployed over the last decade, the research community of WSN realizes that several issues need to be revisited from practical angles, such as reliability and availability. Furthermore, fault-tolerance is one of the main issues in WSNs since it becomes critical in real deployed environments where network stability and reduced inaccessibility times are important. Basically, wireless sensor networks suffer from resource limitations, high failure rates and faults caused by the defective nature of wireless communication and the wireless sensor itself. This can lead to situations, where nodes are often interrupted during data transmission and blind spots occur in the network by isolating some of the devices. In this paper, we address the reliability issue by designing an enhanced fault-tolerant mechanism for Ad hoc On-Demand Distance Vector (AODV) routing protocol used in WSN called the ENhancement of FAult-Tolerant AODV (ENFAT-AODV) routing protocol. We design and implement a backup route scheme by creating a backup path for every node in the network. When a node gets failure to deliver the data packet through the main route, it immediately employs the backup route to become a new main path for the next data packet delivery to reduce a number of data packets dropped and to maintain the continuity of data packet transmission in presence of some faults (node or link failures). Furthermore, with high failure rate, this proposed routing protocol improves the throughput and the average End-to-End delay and decrease the control packet load in the network. Consequently, the reliability, availability and maintainability of the network are achieved. The simulation shows that proposed routing scheme is better than the AODV routing.

Effect of weather conditions on quality of Free Space Optics links (with focus on Malaysia)

Free space optics (FSO) is a promising optical technology that has a great chance to compliment the traditional wireless communications, through provision of high bandwidth, excellent security and reaching places where cable technology could never reach. Quality of FSO links however is greatly affected by weather conditions and link distance. Since there is no known analysis on the effect of weather conditions in Malaysia, this paper offers and attempt to analyze and simulate FSO links under typical local weather and terrain. The simulations under various weather conditions, ranging from light to heavy rain, clear weather to light and heavy haze, would help in determining system quality and design requirements, such as desired transmit power, receiver sensitivity, maximum range, etc. The quality analysis of the links in this paper is done in terms of BER, attenuation and link margin.

Environmental effects on free space earth-to-satellite optical link based on measurement data in Malaysia

FSO is a developing technology that has a great chance to compliment the traditional wireless communications and offer some inherent advantages compared to microwave links due to transmitting higher speed of data, easily deployment, and no license spectrum required. However, FSO is very vulnerable to the climatological phenomena such as fog, snow, rain, and haze that reduce the link availability. Most researches and studies are focusing on improving the FSO system for terrestrial link based on data in temperate region. Therefore, this paper is aiming to provide the feasibility analysis on performing FSO from earth to satellite in Malaysia as the performance of FSO is dependent on local weather conditions and in tropical region, the attenuations are dominant by rain and haze. The analysis is based on measurement of rain intensity, visibility and variation of optical free space signal level which has been done at Faculty of Engineering, International Islamic University (IIUM) Kuala Lumpur campus. From the terrestrial data, it will be scaled up for earth to satellite especially Low Earth Orbit (LEO) satellite and will be compared with calculated of FSO earth-to-satellite data. The analysis will determine the operability of FSO for long distance and as a benchmark for future design.

An enhancement of fault-tolerant routing protocol for Wireless Sensor Network

As more and more real Wireless Sensor Networks (WSN) applications have been tested and deployed over the last decade, the research community of WSN realizes that several issues need to be revisited from practical angles, such as reliability and availability. Furthermore, fault-tolerance is one of the main issues in WSNs since it becomes critical in real deployed environments where network stability and reduced inaccessibility times are important. Basically, wireless sensor networks suffer from resource limitations, high failure rates and faults caused by the defective nature of wireless communication and the wireless sensor itself. This can lead to situations, where nodes are often interrupted during data transmission and blind spots occur in the network by isolating some of the devices. In this paper, we address the reliability issue by designing an enhanced fault-tolerant mechanism for Ad hoc On-Demand Distance Vector (AODV) routing protocol applied in WSN called the ENhanced FAult-Tolerant AODV (ENFAT-AODV) routing protocol. We apply a backup route technique by creating a backup path for every node on a main path of data transmission. When a node gets failure to deliver a data packet through the main path, it immediately utilizes its backup route to become a new main path for the next coming data packet delivery to reduce a number of data packets dropped and to maintain the continuity of data packet transmission in presence of some faults (node or link failures). Furthermore, with increased failure rate, this proposed routing protocol improves the throughput, reduces the average jitter, provides low control overhead and decreases the number of data packets dropped in the network. As a result, the reliability, availability and maintainability of the network are achieved. The simulation results show that our proposed routing protocol is better than the original AODV routing.

Availability Analysis of Terrestrial Free Space Optical Link under the Impact of Rain Condition

Availability is one of the main factors to measure the QoS of any telecommunication networks. An accurate availability prediction for Free Space Optical link of carrier class grade is needed. In tropical areas, rain is the most dominant factor affecting the FSO link availability. In this paper, the effect of rain attenuation on the availability of FSO links is analyzed by examining the impact distance of different FSO systems. As the rain attenuation of FSO is independent of wavelength, the analysis of rain attenuation will be based on rain intensity. ITU-R (Carbonneau and Japan) models have been used for the analysis. From the results, Carrier class availability with good enough resolution for estimated availability can be predicted. This paper provides recommendations to FSO researchers in general and local telecom service provider in particular about possible availability figures that can be useful for deployment of FSO link as a last mile solution, back-up for fiber optic and other applications.

The Enhanced Fault-Tolerant AODV Routing Protocol for Wireless Sensor Network

As more and more real Wireless Sensor Networks (WSN) applications have been tested and deployed over the last decade, the research community of WSN realizes that several issues need to be revisited from practical angles, such as reliability and availability. Basically, wireless sensor networks suffer from resource limitations, high failure rates and faults caused by the defective nature of wireless communication and the wireless sensor itself. This can lead to situations, where nodes are often interrupted during data transmission and blind spots occur in the network by isolating some of the devices. In this paper, we address the reliability issue by designing an enhanced fault-tolerant mechanism for Ad hoc On-Demand Distance Vector (AODV) routing protocol used in WSN called the ENhancement of FAult Tolerant (ENFAT) ADOV routing protocol. We design and implement a backup route algorithm by creating a backup path for every node in the network. When a node gets failure to deliver the data packet through the main route, it immediately employs the backup route to become a new main path to reduce a number of data packets dropped and to maintain the continuity of data packet delivery. Moreover, this proposed routing protocol satisfies the tradeoff between the faulttolerance and the low transmission delay. Consequently, the reliability, availability and maintainability of the network are achieved. The simulation shows that proposed routing scheme is better than the AODV routing. Keywords- wireless sensor network

Rain fade analysis for practical free space optic link in tropical region

Attenuation due to rainfall can severely degrade the FSO links operating under tropical weather. It restricts the distance of FSO communication systems and limits the availability for line-of-sight terrestrial link. Practical FSO link has been setup, monitored and analyzed. A commercially available FSO system was installed at 800 m length together with rain fall intensity measurement facility at IIUM Kuala Lumpur campus. This paper is focused on the effect of rain on the FSO link. The rain attenuation on link has been synchronized in real time with rain fall intensity meter to enable link measurement. The measured rain intensity data was used to compare with ITU-R rain attenuation prediction model to validate the model. The measured rain attenuation on link was compared with that predicted by ITU-R prediction model recommended for the microwave link

Implementation of Internet based remote control and monitoring

Remote monitoring and control of a multiunit industrial facility can be achieved by utilizing the Internet. Electrical, mechanical and a variety of devices are switched on, off, and regulated from distant terminals. Commercially available components were used to build the system. Various aspects related to the method of access, security, standards, and current trends are discussed. An eight unit system has been implemented and tested. The system proved to be effective and easy to operate with a user friendly program, which can be readily adapted to deal with 256 units simultaneously. The wiring is reduced by using the ordinary power lines of the building to convey messages to and from the respective units. The system is also suitable for implementation by security and SCADA systems.

A Secure Authentication Scheme for Bluetooth Connection

Recently, Bluetooth technology is widely used by organizations and individuals to provide wireless personal area network (WPAN) because the radio frequency (RF) waves can easily penetrate obstacles and can propagate without direct line-of-sight (LoS). However, there are serious security challenges associated with wireless communication systems since they are easier to eavesdrop, disrupt and jam than the wired systems. Bluetooth technology uses either legacy pairing or secure and simple pairing (SSP), however both are vulnerable to attacks such as eavesdropping and man-in-the-middle (MITM) attacks. Therefore, this paper has proposed a secure protocol that uses a double encryption to identify the slave. The implementation of this proposal is based on the Arduino Integrated Development Environment (IDE) as software and a Bluetooth (BT) Shield connected to an Arduino Uno R3 boards as hardware. The result was verified on a Graphical User Interface (GUI) built in Microsoft Visual Studio 2010. It has shown that the proposed scheme works perfectly and the protocol thwarts the passive and active eavesdropping which exist during SSP. These attacks are defeated by avoiding the exchange of passwords and public keys in plain text. Therefore, this protocol is expected to be implemented by the Bluetooth Specification Interest Group (SIG) to enhance the security in Bluetooth connection.

Analysis of Free Space Optics Link Availability with Real Data Measurement in Tropical Weather

Free Space Optical communications (FSO) has attracted a lot of attention for a variety of applications in telecommunications field. The unlicensed, higher speed, broader and unlimited bandwidth, low cost solutions, and shortest deployment period are some of the drives to deploy FSO. However, weather attenuation has a big impact on the transmission line of FSO. In temperate region a thorough studies are available on the link availability due to weather effect. In tropical region however most of FSO links install especially in Malaysia are as a backup system. There is no analysis on the FSO link availability under tropical weather condition. Therefore, the objective of this paper is to provide an analysis on the FSO link availability with real data measured in tropical weather condition. Based on one year measurement of rain attenuation and rain intensity, link availability of 99.99% can be achieved for a link distance of 1.25km and fade margin of 25dB. The outcome of this research is expected to give a foundation for the design and development of a long range FSO link under tropical weather condition.