Ahmad Zulhusny Rozali
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Preferred name
Ahmad Zulhusny Rozali
Official Name
Ahmad Zulhusny, Rozali
Translated Name
Rozali, Ahmad Zulhusny
Main Affiliation
Scopus Author ID
55749582100
Researcher ID
ABE-4647-2020

Research Output

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Speed optimisation of the mobile PAN coordinator for QoS enhancement in IoT networks

2016 , Ahmad Zulhusny Rozali , Robert Stewart , Sean Kennedy

The Internet of Things (IoT) network is typified by deployments such as a Wireless Sensor Network (WSN). These WSN's are commonly deployed within a target area for a specific task such as farm monitoring and asset movement control. A group of sensors are typically led by a Personal Area Network Coordinator (PANC). In some situations like in large scale greenhouse monitoring, mobile PANC are required to eliminate energy-hole issues and hence improve the performance of the WSN. The energy-hole issue is a problem caused by the depleted cluster head nodes. In this paper we analyse the performance of a WSN with a mobile PANC. Using inputs from previous empirical studies we designed a scenario of a mobile PAN coordinator using a simulation package. The performance was evaluated. The mobile PANC speed and contact time is monitored and the average network throughput and delay are measured. Based on an analysis of these results a comprehensive set of guidelines are provided for operators of IoT networks. These guidelines optimise the network performance and ultimately lead to cost savings for network providers.

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A simulation study of wireless network performance

2014 , Ahmad Zulhusny Rozali , Robert Stewart , Sean Kennedy

WSN technology has now become ubiquitous due to its flexibility, efficiency and affordability. For example the nodes in a WSN can be easily deployed in any targeted area and last for many years. The nodes can supply reliable data from within the environment with minimal disturbance to the target area.However challenges remain in providing real-time communication in some communication hostile conditions. It may not always be possible to leave the sensors in situ but instead data collection is through the use of mobile a WSN. For example as a vehicle fitted with sensing devices passes through an area of interest data is collected and relayed at certain gateway nodes back to a backhaul network for processing.In this paper our aim is to analyse the interference caused by a mobile jammer node to the stationary transmitter and receiver nodes in a network by using the OPNET Modeler software. This is early stage work aimed at developing a mobile WSN node in our future research.

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Resource allocation to mitigate channel interference in mobile wireless sensor networks

2015 , Ahmad Zulhusny Rozali , Robert Stewart , Sean Kennedy

Wireless Sensor Networks (WSNs) are formed with multiple sensor nodes that use the IEEE 802.15.4 protocol. The WSN can operate in 16 different channels in the unlicensed Industrial, Scientific and Manufacturing (ISM) 2.4 GHz spectrum. The WLAN or IEEE 802.11g/n protocol also operates in the same spectrum. Additional problems arise when the WSN is mobile. Mobile WSN's are more efficient in scenarios where mobility is needed to collect data from remote target areas. Moving nodes may encounter overlapping frequencies from WLAN coexistence in its journey. Therefore, WSN channels have to be allocated intelligently to avoid channels overlapping with the WLAN. However with mobile WSN the WLAN networks encountered may have random spectrum allocation depending on the WLAN technology in place. A good resource allocation approach is needed for the sensor nodes to dynamically change their working channel to avoid the overlapping channels which cause interference to the network (either WSN or WLAN) which impacts the service delivery. This paper focuses on the interference when the mobile WSN and WLAN both exist in the same building. The analysis presented is based on the percentage of packets dropped and percentage of packet re-transmitted for each sensor node in the experiments. The outcome of this research will be valuable to research and development of WSN applications in terms of reliable service delivery.

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