FARUK NASIR - Academia.edu (original) (raw)

Papers by FARUK NASIR

The rise in global cases of emergencies as a result of man-made and natural disaster, necessitate... more The rise in global cases of emergencies as a result of man-made and natural disaster, necessitates the need for a robust and reliable means of communication networks. The partial or complete, disruption of telecommunications infrastructure as a result of disaster has caused delays in emergency response and disaster relief efforts, leading to loss of lives and damage to properties. Although, modern telecommunications networks have reliability and resiliency to physical damage, however, the risks associated with communications failures remain a major issue as the severity of the damages may depend on the underlying technologies and architecture used. It is however important to also note that each technology option available for public safety network has its own unique characteristics. Some of these options are widely deployed for commercial purposes in Nigeria, while others are still in the developmental stages. This paper therefore outlines some of the existing, new and affordable technological options, available today that can be deployed for public safety and disaster telecommunications networks in Nigeria. Furthermore, the paper recommends that the national broadband network plan needs to be aligned to the current commercial deployments of the 4G Long Term Evolution (LTE) wireless services, this is to ensure that the pace is maintained with the changes in the technology and leveraging cost efficiencies for the public safety networks.

Science, Technology and Arts Research Journal, 2016

Continuous demand, by end users, has become an issue with respect to the scarce resources of the ... more Continuous demand, by end users, has become an issue with respect to the scarce resources of the radio frequency spectrum. In this paper we conducted a 24-hour outdoor measurement of spectrum occupancy, in both rural and urban areas in Kwara State, Nigeria, spanning across the frequency range of 48.5 MHz – 880 MHz. The results obtained show that the mean average duty cycle for TV bands 1-4 and CDMA band in rural and urban locations are 2.58 % and 12.02% and 0.25% and 3.13% respectively. Findings from this measurements show that there is ample opportunity for deployment of cognitive radio for a more efficient utilization of the spectrum.

Wireless Engineering and Technology, 2012

The growing demand for wireless services coupled with the limited availability of suitable electr... more The growing demand for wireless services coupled with the limited availability of suitable electromagnetic spectrum is increasing the need for more efficient RF spectrum utilization. Spectrum allocated to TV operators can potentially be shared by wireless data services, either when the primary service is switched off or by exploiting spatial reuse opportunities. This paper describes a dynamic spectrum access scheme for use in the TV bands which uses cognitive radio techniques to determine the spectrum availability. The approach allows secondary users (SU) to operate in the presence of the primary users (PU) and the OPNET simulation and modelling software has been used to model the performance of the scheme. An analysis of the results shows that the proposed scheme protects the primary users from harmful interference from the secondary users. In comparison with the 802.11 MAC protocol, the scheme improves spectrum utilization by about 27% while limiting the interference imposed on the primary receiver.

Mobile communication systems have been firmly established as a key and convenient means of commun... more Mobile communication systems have been firmly established as a key and convenient means of communication that enables efficient and effective business operation. The power consumption of wireless access networks has become a major economic and environmental issue. This paper investigates energy consumption of base transceivers stations (BTS), schemes that could potentially increase energy efficiency were described and the potential of reusing the conserved energy highlighted. Analysis of results shows that by optimizing 60 BTS’s, the energy consumption drops by 36.83% with 127.4MWh per month reserve, this correspond to powering 35 extra BTS’s with demand of 3.64224MWh per month or 69 houses for 10 hours daily power supply with energy demand of 1.8452MWh per month and 440 houses with total power demand of 289.8KWh per month. It was found that, number of sites optimized, duration of power consumption and its demand has significant effects on the number of extra BTS’s / houses powered.

In this Letter, the authors propose a technique that allows a secondary user (SU) to reuse the sp... more In this Letter, the authors propose a technique that allows a secondary user (SU) to reuse the spectrum allocated to TV broadcast system. The approach is based on protection view point and an SU is allowed to transmit outside the noise limited contour (grade B contour) with additional protection margin. An algorithm was developed that predicts the grade B contour and makes a decision on the availability of the spectrum. The keep-out distance was obtained using the existing path loss models and a model developed based on field strength measurements conducted in the very high frequency (VHF) and ultra high frequency (UHF) broadcast frequencies. Results of simulation indicate that the extra margin does not follow a linear curve as expected, but strongly depends on the operating frequency and terrain profile of the area. In addition, the measured model's prediction deviates significantly from the other models' prediction.

The field of education has undoubtedly been affected by the penetrating influence of information ... more The field of education has undoubtedly been affected by the penetrating influence of information and communication technology, characterized by improved access to the internet, and the increasing use of computing devices. However, education in Africa generally and specifically in Nigeria and other developing countries still face a 21 st Century challenge in making education available and accessible to all. To this end therefore, this paper presents a conceptual approach, as to how tailor made e-learning services could be realized and integrated with a real time video conference server and any existing learning management system in order to facilitate a synchronous virtual learning environment in making education accessible and available to both remote students (distance learning students) and onsite users in Universities and other related educational institutes. It proposes a functional framework to exemplify educational services such as file sharing to enhance collaboration, a digital resource center for retrieval of both free and paid relevant academic resource. A conference room for real time classroom participation which learning platform should provide in order to enhance both teaching and learning performance of course instructors and their students respectively is also proposed. It provides an operational design which describes how custom made e-learning portal integrated with an Open source Video Conference server could be realized, in facilitating a synchronous virtual learning service. Furthermore, it proposes a Virtual Learning Network architecture to show how both remote and onsite students could optimize quality network access in realizing these electronic learning services.

Unfairness is one of the major problems in WMN as each node operates not only as a host but also ... more Unfairness is one of the major problems in WMN as each node operates not only as a host but also as a router, forwarding packets on behalf of other nodes that may not be within the direct wireless transmission range of their destinations and thereby adding delay and affecting the throughputs of the node. Addressing end-to-end unfairness in wireless mesh network is necessary for the network to be scalable otherwise; the expected network scalability will not be met. The unfairness investigation shows that the end-to-end unfairness in a wireless mesh network will affect the network scalability. Modification to the network layer has been proposed to include an additional queue, a weighted fair scheduler and a classifier to separate locally generated flow from the relayed flows at each node. This will make the traffic flows from all the sources in the network to achieve equal throughput at the destination irrespective of the number of hops traversed. Another unfairness issues is also investigated at the MAC layer as a result of adopting existing single hop MAC protocol to be used in this multi-hop mesh network.

A time domain numerical procedure is presented for a simulation of electromagnetic wave phenomena... more A time domain numerical procedure is presented for a simulation of electromagnetic wave phenomena. The technique is an adaptation of the finite-difference time domain (FDTD) approach usually applied to model electromagnetic wave propagation. In this paper a simple 2D implementation of FDTD algorithm in mathematica environment is presented. Source implementation and the effect of conductivity on the incident field are investigated. Simple illustrations of propagation in a non-conducting, partial conducting and conducting medium are provided. For the computational space, Cartesian grids of fixed size were used as it makes grid generation to be relatively easy. The numerical data generated by the program code were sampled at various time steps from t0=1 to 90 along the computational space. The simulation results show the advancement of the pulse into the medium at various time stepping, shift in the peak of the amplitude was observed on the pulse for all the time steps. An attempt to further show the attenuation as the wave propagates into the stratified medium is made. The amplitude of the pulse falls sharply from 0.006 to 11 10 1  x for t0=1 and t0=50. The results indicate the working of the model and it could be used to study the behavior of the wave as it does propagate across the medium.

Regulatory bodies have called for alternative spectrum management models and techniques that woul... more Regulatory bodies have called for alternative spectrum management models and techniques that would allow efficient utilization of the TV white space since the proposed cognitive radio technique may not be realized in the nearest future. For effective utilization of the spatial TV white space, and coexistence between the primary and secondary users, a reliable prediction technique is required to accurately estimate the service contours of the primary users. In this article, we present the effects of empirical path loss propagation models in predicting the TV service contour using optimized model which is based on measurements of path loss in the study area and other conventional models such as the ITU-R, COST 231, HATA, Egli and CCIR models. Results of simulations show that measured path loss models' prediction deviates significantly from the other models that provide large protection zone around the primary cell and, thus reduce the spatial utilization of the spectrum. It was also found that the -114 dBm FCC rule for empty white space is highly conservative and significantly affects the availability of the white space.

The rise in global cases of emergencies as a result of man-made and natural disaster, necessitate... more The rise in global cases of emergencies as a result of man-made and natural disaster, necessitates the need for a robust and reliable means of communication networks. The partial or complete, disruption of telecommunications infrastructure as a result of disaster has caused delays in emergency response and disaster relief efforts, leading to loss of lives and damage to properties. Although, modern telecommunications networks have reliability and resiliency to physical damage, however, the risks associated with communications failures remain a major issue as the severity of the damages may depend on the underlying technologies and architecture used. It is however important to also note that each technology option available for public safety network has its own unique characteristics. Some of these options are widely deployed for commercial purposes in Nigeria, while others are still in the developmental stages. This paper therefore outlines some of the existing, new and affordable technological options, available today that can be deployed for public safety and disaster telecommunications networks in Nigeria. Furthermore, the paper recommends that the national broadband network plan needs to be aligned to the current commercial deployments of the 4G Long Term Evolution (LTE) wireless services, this is to ensure that the pace is maintained with the changes in the technology and leveraging cost efficiencies for the public safety networks.

Science, Technology and Arts Research Journal, 2016

Continuous demand, by end users, has become an issue with respect to the scarce resources of the ... more Continuous demand, by end users, has become an issue with respect to the scarce resources of the radio frequency spectrum. In this paper we conducted a 24-hour outdoor measurement of spectrum occupancy, in both rural and urban areas in Kwara State, Nigeria, spanning across the frequency range of 48.5 MHz – 880 MHz. The results obtained show that the mean average duty cycle for TV bands 1-4 and CDMA band in rural and urban locations are 2.58 % and 12.02% and 0.25% and 3.13% respectively. Findings from this measurements show that there is ample opportunity for deployment of cognitive radio for a more efficient utilization of the spectrum.

Wireless Engineering and Technology, 2012

The growing demand for wireless services coupled with the limited availability of suitable electr... more The growing demand for wireless services coupled with the limited availability of suitable electromagnetic spectrum is increasing the need for more efficient RF spectrum utilization. Spectrum allocated to TV operators can potentially be shared by wireless data services, either when the primary service is switched off or by exploiting spatial reuse opportunities. This paper describes a dynamic spectrum access scheme for use in the TV bands which uses cognitive radio techniques to determine the spectrum availability. The approach allows secondary users (SU) to operate in the presence of the primary users (PU) and the OPNET simulation and modelling software has been used to model the performance of the scheme. An analysis of the results shows that the proposed scheme protects the primary users from harmful interference from the secondary users. In comparison with the 802.11 MAC protocol, the scheme improves spectrum utilization by about 27% while limiting the interference imposed on the primary receiver.

Mobile communication systems have been firmly established as a key and convenient means of commun... more Mobile communication systems have been firmly established as a key and convenient means of communication that enables efficient and effective business operation. The power consumption of wireless access networks has become a major economic and environmental issue. This paper investigates energy consumption of base transceivers stations (BTS), schemes that could potentially increase energy efficiency were described and the potential of reusing the conserved energy highlighted. Analysis of results shows that by optimizing 60 BTS’s, the energy consumption drops by 36.83% with 127.4MWh per month reserve, this correspond to powering 35 extra BTS’s with demand of 3.64224MWh per month or 69 houses for 10 hours daily power supply with energy demand of 1.8452MWh per month and 440 houses with total power demand of 289.8KWh per month. It was found that, number of sites optimized, duration of power consumption and its demand has significant effects on the number of extra BTS’s / houses powered.

In this Letter, the authors propose a technique that allows a secondary user (SU) to reuse the sp... more In this Letter, the authors propose a technique that allows a secondary user (SU) to reuse the spectrum allocated to TV broadcast system. The approach is based on protection view point and an SU is allowed to transmit outside the noise limited contour (grade B contour) with additional protection margin. An algorithm was developed that predicts the grade B contour and makes a decision on the availability of the spectrum. The keep-out distance was obtained using the existing path loss models and a model developed based on field strength measurements conducted in the very high frequency (VHF) and ultra high frequency (UHF) broadcast frequencies. Results of simulation indicate that the extra margin does not follow a linear curve as expected, but strongly depends on the operating frequency and terrain profile of the area. In addition, the measured model's prediction deviates significantly from the other models' prediction.

The field of education has undoubtedly been affected by the penetrating influence of information ... more The field of education has undoubtedly been affected by the penetrating influence of information and communication technology, characterized by improved access to the internet, and the increasing use of computing devices. However, education in Africa generally and specifically in Nigeria and other developing countries still face a 21 st Century challenge in making education available and accessible to all. To this end therefore, this paper presents a conceptual approach, as to how tailor made e-learning services could be realized and integrated with a real time video conference server and any existing learning management system in order to facilitate a synchronous virtual learning environment in making education accessible and available to both remote students (distance learning students) and onsite users in Universities and other related educational institutes. It proposes a functional framework to exemplify educational services such as file sharing to enhance collaboration, a digital resource center for retrieval of both free and paid relevant academic resource. A conference room for real time classroom participation which learning platform should provide in order to enhance both teaching and learning performance of course instructors and their students respectively is also proposed. It provides an operational design which describes how custom made e-learning portal integrated with an Open source Video Conference server could be realized, in facilitating a synchronous virtual learning service. Furthermore, it proposes a Virtual Learning Network architecture to show how both remote and onsite students could optimize quality network access in realizing these electronic learning services.

Unfairness is one of the major problems in WMN as each node operates not only as a host but also ... more Unfairness is one of the major problems in WMN as each node operates not only as a host but also as a router, forwarding packets on behalf of other nodes that may not be within the direct wireless transmission range of their destinations and thereby adding delay and affecting the throughputs of the node. Addressing end-to-end unfairness in wireless mesh network is necessary for the network to be scalable otherwise; the expected network scalability will not be met. The unfairness investigation shows that the end-to-end unfairness in a wireless mesh network will affect the network scalability. Modification to the network layer has been proposed to include an additional queue, a weighted fair scheduler and a classifier to separate locally generated flow from the relayed flows at each node. This will make the traffic flows from all the sources in the network to achieve equal throughput at the destination irrespective of the number of hops traversed. Another unfairness issues is also investigated at the MAC layer as a result of adopting existing single hop MAC protocol to be used in this multi-hop mesh network.

A time domain numerical procedure is presented for a simulation of electromagnetic wave phenomena... more A time domain numerical procedure is presented for a simulation of electromagnetic wave phenomena. The technique is an adaptation of the finite-difference time domain (FDTD) approach usually applied to model electromagnetic wave propagation. In this paper a simple 2D implementation of FDTD algorithm in mathematica environment is presented. Source implementation and the effect of conductivity on the incident field are investigated. Simple illustrations of propagation in a non-conducting, partial conducting and conducting medium are provided. For the computational space, Cartesian grids of fixed size were used as it makes grid generation to be relatively easy. The numerical data generated by the program code were sampled at various time steps from t0=1 to 90 along the computational space. The simulation results show the advancement of the pulse into the medium at various time stepping, shift in the peak of the amplitude was observed on the pulse for all the time steps. An attempt to further show the attenuation as the wave propagates into the stratified medium is made. The amplitude of the pulse falls sharply from 0.006 to 11 10 1  x for t0=1 and t0=50. The results indicate the working of the model and it could be used to study the behavior of the wave as it does propagate across the medium.

Regulatory bodies have called for alternative spectrum management models and techniques that woul... more Regulatory bodies have called for alternative spectrum management models and techniques that would allow efficient utilization of the TV white space since the proposed cognitive radio technique may not be realized in the nearest future. For effective utilization of the spatial TV white space, and coexistence between the primary and secondary users, a reliable prediction technique is required to accurately estimate the service contours of the primary users. In this article, we present the effects of empirical path loss propagation models in predicting the TV service contour using optimized model which is based on measurements of path loss in the study area and other conventional models such as the ITU-R, COST 231, HATA, Egli and CCIR models. Results of simulations show that measured path loss models' prediction deviates significantly from the other models that provide large protection zone around the primary cell and, thus reduce the spatial utilization of the spectrum. It was also found that the -114 dBm FCC rule for empty white space is highly conservative and significantly affects the availability of the white space.