Dr Gengfa Fang received his Master in Telecommunications from Zhejiang University and PhD in Wireless Communications from the Institute of Computing Technology, Chinese Academy of Sciences in 2002 and 2007 accordingly. From Oct. 2007 to May 2009, he was a Researcher at the Canberra Research Lab of National ICT Australia (NICTA) on WCDMA Femtocell project. From Jun. 2010 to Dec 2010, he was working on Rural Broadband Access project at CSIRO as a Research Scientist. From 2009 to 2015, he was with the Department of Engineering Macquarie University. In 2006 he moved to UTS where he is now a Senior Lecturer. He has published over 100 papers, patents on embedded wireless network systems, MAC protocols, cross-layer design, wireless resource management and allocation for 5G, IoT and Medical Body Area Networks. His research has been supported by CSIRO, NICTA, NXP, Zarlink, Quantenna Communications and Intel.
Wang, H., Nguyen, D., Dutkiewicz, Fang & Mueck 2017, 'Negotiable Auction based on Mixed Graph: A Novel Spectrum Sharing Framework', IEEE Transactions on Cognitive Communications and Networking.View/Download from: UTS OPUS
Fang, G., Orgun, M.A., Shankaran, R., Dutkiewicz, E. & Zheng, G. 2016, 'Truthful Channel Sharing for Self Coexistence of Overlapping Medical Body Area Networks.', PLoS ONE, vol. 11, no. 2, pp. 1-19.View/Download from: UTS OPUS or Publisher's site
As defined by IEEE 802.15.6 standard, channel sharing is a potential method to coordinate inter-network interference among Medical Body Area Networks (MBANs) that are close to one another. However, channel sharing opens up new vulnerabilities as selfish MBANs may manipulate their online channel requests to gain unfair advantage over others. In this paper, we address this issue by proposing a truthful online channel sharing algorithm and a companion protocol that allocates channel efficiently and truthfully by punishing MBANs for misreporting their channel request parameters such as time, duration and bid for the channel. We first present an online channel sharing scheme for unit-length channel requests and prove that it is truthful. We then generalize our model to settings with variable-length channel requests, where we propose a critical value based channel pricing and preemption scheme. A bid adjustment procedure prevents unbeneficial preemption by artificially raising the ongoing winner's bid controlled by a penalty factor . Our scheme can efficiently detect selfish behaviors by monitoring a trust parameter of each MBAN and punish MBANs from cheating by suspending their requests. Our extensive simulation results show our scheme can achieve a total profit that is more than 85% of the offline optimum method in the typical MBAN settings.
Lei, C., Bie, H., Fang, G., Gaura, E., Brusey, J., Zhang, X. & Dutkiewicz, E. 2016, 'A low collision and high throughput data collection mechanism for large-scale super dense wireless sensor networks', Sensors (Switzerland), vol. 16, no. 7.View/Download from: UTS OPUS or Publisher's site
© 2016 by the authors; licensee MDPI, Basel, Switzerland. Super dense wireless sensor networks (WSNs) have become popular with the development of Internet of Things (IoT), Machine-to-Machine (M2M) communications and Vehicular-to-Vehicular (V2V) networks. While highly-dense wireless networks provide efficient and sustainable solutions to collect precise environmental information, a new channel access scheme is needed to solve the channel collision problem caused by the large number of competing nodes accessing the channel simultaneously. In this paper, we propose a space-time random access method based on a directional data transmission strategy, by which collisions in the wireless channel are significantly decreased and channel utility efficiency is greatly enhanced. Simulation results show that our proposed method can decrease the packet loss rate to less than 2% in large scale WSNs and in comparison with other channel access schemes for WSNs, the average network throughput can be doubled.
Lei, C., Bie, H., Fang, G., Mueck, M. & Zhang, X. 2016, 'An Efficient Backoff Algorithm Based on the Theory of Confidence Interval Estimation', IEICE TRANSACTIONS ON COMMUNICATIONS, vol. E99B, no. 10, pp. 2179-2186.View/Download from: UTS OPUS or Publisher's site
Tong, X., Fang, G., Nguyen, D.N., Lin, J. & Cabrera, E. 2016, 'An Energy-Balanced Routing Algorithm in Wireless Seismic Sensor Network', Journal of Computational and Theoretical Nanoscience, vol. 13, no. 10, pp. 6823-6833.View/Download from: UTS OPUS or Publisher's site
Due to unpredictable geological outdoor environments and imbalances in energy consumption of seismometer nodes in the wireless seismic sensor networks (WSSN), some seismometer nodes fail much earlier than others due to power loss. This would cause hot spot problems, network partitions, and significantly shorten network lifetime. In this paper, we designed an energy-balanced routing algorithm (EBRA) to ensure balanced energy consumption from all seismometer nodes in the WSSN and to enhance the connectivity and lifetime of the WSSN. By aiming at minimizing the imbalance in the residual energy, we divide the routing algorithm into two parts: clustering formation and inter-cluster routing. In clustering formation, we design an energy-balanced clustering algorithm, which selects the cluster head dynamically, based on residual energy, distance between the seismometer node and data collector. The clustering algorithm mitigates hot spot problems by balancing energy consumption among seismometer nodes. In regards to inter-cluster routing, we can relate it to the pareto-candidate set. To reduce the average multi-hop delay from cluster heads to the data collector, we optimize the pareto-candidate set by Hamming distance. In the design of EBRA, we consider minute details such as energy consumed by transmitting bits and impact of average multi-hop delay. This adds to the novelty of this work compared to the existing studies. Simulation results demonstrated a reduction in the average multi-hop delay by 87.5% with network size of 200 nodes in ten different data collector locations. Our algorithm also improves the network lifetime over the others three schemes by 7.8%, 23% and 45.4%, respectively.
Cheng, Q., Fang, G., Nguyen, D. & Dutkiewicz 2016, 'Novel Pilot Decontamination Methods for Massive MIMO Systems Under Practical Scenarios', 16th International Symposium on Communications and Information Technologies (ISCIT), International Symposium on Communications and Information Technologies, IEEE, Qingdao, PEOPLES R CHINA.View/Download from: UTS OPUS or Publisher's site
Saadat, A., Fang, G., Dutkiewicz, E., Mueck, M. & Srikanteswara, S. 2016, 'Enhanced QoS for domestic licensees in border areas through game theory based licensed shared access', 2016 16th International Symposium on Communications and Information Technologies, ISCIT 2016, International Symposium on Communications and Information Technologies, IEEE, Qingdao, PEOPLES R CHINA, pp. 44-47.View/Download from: Publisher's site
© 2016 IEEE.In this paper, we propose a non-coordinated Licensed Shared Access (LSA) model which enables Mobile Network Operators (MNOs) acting as domestic licensees to provide enhanced Quality of Service (QoS) in border areas. The proposed model allows the domestic licensees to rely on their backup strategies while utilizing available spectrum resources, to avoid severe interference and maintain their QoS, whenever foreign incumbents initiate their operation in similar frequency spectrum across the border. The proposed model is presented as an LSA based game theoretic algorithm. We prove its convergence to an equilibrium point after finite iterations, both analytically and through simulations.
Zhong, Y., Zhou, Z., Jiang, T., Heimlich, M., Dutkiewicz, E. & Fang, G. 2016, 'Classification of animals and people based on radio-sensor network', 2016 16th International Symposium on Communications and Information Technologies, ISCIT 2016, International Symposium on Communications and Information Technologies, IEEE, Qingdao, China, pp. 113-116.View/Download from: UTS OPUS or Publisher's site
© 2016 IEEE.Personnel detection embedded in foliage is extremely important to border patrol, perimeter protection and search-and-rescue operations. In this paper, we explore the utility of radio-sensor network (RSN) to distinguish between humans and animals. We explore the phenomenon that signals are always affected by the presence of obstacles and identify human based on the received signals by transceivers, which leads to a potential low-cost way for personnel detection without specific sensors. In our study, the impulse radio ultra-wideband (IR-UWB) technology is selected for the RF transceiver due to the fact that it is not only energy efficient, but also robust against interferences. The principle component analysis (PCA) is applied to extract the feature vector, and a support vector machine is used as the target classifier. Experiment result with an average accuracy of 97.5% based on actual data collected in a cornfield indicates that this approach has a good capability to distinguish between human and animals in a foliage environment.
He, Y., Dutkiewicz, E., Fang, G. & Shi, J. 2014, 'Downlink capacity in Cloud Radio Access Networks with Fractional Frequency Reuse', International Symposium on Wireless Personal Multimedia Communications, WPMC, International Symposium on Wireless Personal Multimedia Communications, IEEE, Sydney, Australia, pp. 424-428.View/Download from: UTS OPUS or Publisher's site
© 2014 National Institute of Information and Communicatio. A distributed antenna system (DAS) architecture is believed to be able to enhance capacity performance of Cloud Radio Access Networks (C-RAN), especially for users near the cell boundary. Many schemes have been proposed to plan Fractional Frequency Reuse (FFR) on resource allocation. Some of them have leveraged the Coordinated multi-point transmission (CoMP) to improve the cell-edge performance. In this paper, we investigate and compare the capacity of Single User with Multiple-Input-Single-Output (SU-MISO) and Multiple Users with Multiple-Input-Multiple-Output (MU-MIMO) in C-RAN of multiple transmitting remote antenna units with FFR.
Wang, H., Dutkiewicz, E., Fang, G. & Mueck, M.D. 2015, 'Framework of joint auction and mixed graph for Licensed Shared Access systems', 2015 IEEE International Symposium on Dynamic Spectrum Access Networks, DySPAN 2015, IEEE International Dynamic Spectrum Access Networks Symposium, IEEE, Stockholm, Sweden, pp. 154-163.View/Download from: UTS OPUS or Publisher's site
© 2015 IEEE. Licensed Shared Access offers an opportunity to further increase data rates in 5G networks. Considering that different commercial operators have no knowledge of each other, their base stations should be coordinated by a management entity to enable them to access the licensed shared spectrum without interference. An auction mechanism is often used as an efficient tool for resource allocation where rivalry is high. In this paper, we propose an on-line auction framework using a mixed graph due to the spatial reusability of spectrum. This proposed scheme allows each base station to make a concession by asking for a second shrinking interference-free area if its initial area overlaps some other base stations. We use a mixed graph to model the interference between them, because a mixed graph can quantify the interference much closer to the practical cases than an undirected graph does. We also propose to take the bid comparison into account when grouping the independent nodes in the interference graph. These two feathers together make the spectrum spatial efficiency improved, which leads to a higher revenue and a better buyer satisfaction.
Zhou, J., Dutkiewicz, E., Liu, R.P., Fang, G. & Liu, Y. 2014, 'Modified Elite Chaotic Immune Clonal Selection Algorithm for sever resource allocation in cloud computing systems', Proceedings of the 2014 International Symposium on Wireless Personal Multimedia Communications, International Symposium on Wireless Personal Multimedia Communications, IEEE, Sydney, Australia, pp. 226-231.View/Download from: UTS OPUS or Publisher's site
Cloud computing is a promising technology to improve computational efficiency for both IT enterprise and individuals. Resource allocation in cloud computing is very challenging as both server computing power and network bandwidth are limited. The computational efficiency of cloud computing system can be significantly improved if the resources are allocated in a balanced fashion. However, resource allocation in cloud computing is a multi-constrained nonlinear optimization problem. The computational complexity for an exhaustive search over all combinations of resource allocations is too high for practical implementation. In this paper, we develop a Modified Elite Chaotic Immune Clonal Selection Algorithm to increase the overall efficiency of the system. An elite strategy and chaotic approaches are designed to improve population diversity and escape from local optima. Performance comparisons are made with simulated annealing algorithm (SA) and three other heuristic algorithms. Simulation results show that the Modified Elite Chaotic Immune Clonal Selection Algorithm solves the resource allocation problem with higher system resource efficiency than all other heuristic algorithms.
He, Y., Dutkiewicz, E., Fang, G. & Shi, J. 2014, 'Differential capacity bounds for distributed antenna systems under low SNR conditions', 2014 IEEE International Conference on Communications, ICC 2014, IEEE International Conference on Communications, IEEE, Australia, pp. 5550-5554.View/Download from: UTS OPUS or Publisher's site
A distributed antenna system (DAS) architecture is believed to be able to enhance capacity performance of Cloud Radio Access Networks (C-RAN), especially for users near the cell boundary who experience low Signal-Noise-Ratio (SNR). However, the problem of finding the analytical bounds on the capacity of DAS with the rising number of antennas in low SNR rigime has not been fully studied. In this paper, we investigate a case in C-RAN of multiple transmitting base stations and a single receiving user under low SNR conditions. We derive closed-form upper and lower bounds in efficiently computable expressions for differential capacity (DCAP) using the moment generating function (MGF) of SNR. Bounds accuracy is evaluated and compared to results in current literature. Numerical results corroborate our analysis and the analytic bounds on DCAP is tight in the low SNR regime. Furthermore, The upper bound approximates better compared with the one obtained in  under two different channel models. These lower and upper bounds provide more accurate capacity measures which can be used in the evaluation of DAS performance and C-RAN design. © 2014 IEEE.
Yang, X., Cui, Q., Dutkiewicz, E., Huang, X., Tao, X. & Fang, G. 2014, 'Anti-noise-folding regularized subspace pursuit recovery algorithm for noisy sparse signals', 2014 IEEE Wireless Communications and Networking Conference (WCNC), IEEE Wireless Communications and Networking Conference, IEEE, Istanbul, Turkey, pp. 275-280.View/Download from: UTS OPUS or Publisher's site
© 2014 IEEE. Denoising recovery algorithms are very important for the development of compressed sensing (CS) theory and its applications. Considering the noise present in both the original sparse signal x and the compressive measurements y, we propose a novel denoising recovery algorithm, named Regularized Subspace Pursuit (RSP). Firstly, by introducing a data pre-processing operation, the proposed algorithm alleviates the noise-folding effect caused by the noise added to x. Then, the indices of the nonzero elements in x are identified by regularizing the chosen columns of the measurement matrix. Afterwards, the chosen indices are updated by retaining only the largest entries in the Minimum Mean Square Error (MMSE) estimated signal. Simulation results show that, compared with the traditional orthogonal matching pursuit (OMP) algorithm, the proposed RSP algorithm increases the successful recovery rate (and reduces the reconstruction error) by up to 50% and 86% (35% and 65%) in high noise level scenarios and inadequate measurements scenarios, respectively.
Jayawickrama, B.A., Dutkiewicz, E., Oppermann, I., Mueck, M. & Fang, G. 2013, 'Downlink Power Allocation Algorithm for Licence-exempt LTE Systems Using Kriging and Compressive Sensing Based Spectrum Cartography', 2013 IEEE Global Communications Conference (GLOBECOM), IEEE Global Telecommunications Conference, IEEE, Atlanta, GA, USA.View/Download from: UTS OPUS or Publisher's site
Licence-exempt secondary Long Term Evolution systems have been proposed recently, in attempt to meet the needs of rapidly growing wireless mobile applications. However, where the secondary network is spread over a large geographical area, traditional detect-and-avoid algorithms are less effective in providing interference protection to Primary Users while maximising the secondary throughput. Spectrum cartography is an emerging technique that can be used to discover spectrum holes in space. We propose a downlink power allocation algorithm using Kriging Spatial Interpolation and Compressive Sensing based spectrum cartography in an environment where large scale shadow fading is prominent. We evaluate the performance of our approach by simulating a secondary Urban Microcell network operating in TV White Space. Simulation results show a significant improvement in interference and throughput, in comparison to traditional detect-and-avoid algorithms.
Zhou, J., Dutkiewicz, E., Liu, R.P., Fang, G. & Liu, Y. 2014, 'QoS routing based on parallel elite clonal quantum evolution for multimedia wireless sensor networks', IEEE Wireless Communications and Networking Conference, IEEE Wireless Communications and Networking Conference, IEEE, Istanbul, Turkey, pp. 2498-2503.View/Download from: UTS OPUS or Publisher's site
© 2014 IEEE. Quality of Service (QoS) routing is one of the key enabling techniques for multimedia wireless sensor networks (WSNs). However, the multi-constraints QoS routing problem is an NP-hard problem, and the computational complexity of an exhaustive search over all the paths is too high for large scale multimedia WSNs. In this paper, a novel parallel elite clonal quantum evolutionary algorithm is proposed to solve the multi-constraints QoS routing problem. The proposed algorithm minimizes the energy consumption, while guaranteeing QoS performance, including delay, bandwidth, delay jitter and packet loss rate, in multimedia WSNs. The algorithm is tested by extensive simulations and its performance is compared with the genetic algorithm and ant colony optimization. Simulation results demonstrate that the proposed algorithm achieves lower energy consumption at a faster convergence rate than the other two evolutionary algorithms.
Yang, Y., Fang, G., Dutkiewicz, E. & Li, Y. 2013, 'A new 3D statistical method for mobile channel model', Advances in Intelligent Systems and Computing, IEEE Congress on Evolutionary Computation, Springer, China, pp. 945-951.View/Download from: UTS OPUS or Publisher's site
3-dimension statistical method is used to simulate the popular micro-cell propagation model: COST231-Walfish-Ikegami model . The extended model allows for improved path loss estimation by consideration the character of the urban environment parameters are lognormal random variables rather than deterministic. The numerical calculation results and trial measurement data is presented. Based on the measurement and modelling results, we find that the 3D COST231-WI model fits very well with the measurement result in the metropolitan scenario. The conclusion is useful and helpful to network planning in the future. © 2013 Springer-Verlag.
Jayawickrama, B.A., Dutkiewicz, E., Oppermann, I., Fang, G. & Ding, J. 2013, 'Improved performance of spectrum cartography based on compressive sensing in cognitive radio networks', 2013 IEEE International Conference on Communications (ICC), IEEE International Conference on Communications, IEEE, Budapest, Hungary.View/Download from: UTS OPUS or Publisher's site
Spectrum cartography is the process of constructing a map showing Radio Frequency signal strength over a finite geographical area. Multiple research groups have recently proposed to use spectrum cartography in the context of discovering spectrum holes in space that can be exploited locally in cognitive radio networks. In our novel approach, we exploit the sparsity of primary users in space to formulate the cartography process as a compressive sensing problem. Further, we present a novel algorithm for solving the cartography problem that builds on the well-known Orthogonal Matching Pursuit algorithm. We evaluate the performance of our approach by simulating a cognitive radio network where primary users are low power wireless microphones. Our simulation results show a significant improvement in reconstruction error, in comparison to two existing compressive sensing based methods.
Jayawickrama, B.A., Dutkiewicz, E. & Fang, G. 2012, 'Spectrum Sensing Error Optimisation in Cognitive Radio Networks', 2012 International Symposium on Communications and Information Technologies, ISCIT 2012, International Symposium on Communications and Information Technologies, IEEE, Gold Coast, Australia.View/Download from: UTS OPUS or Publisher's site
Fang, G., Dutkiewicz, E., Huq, M.A., Vesilo, R. & Yang, Y. 2011, 'Medical body area networks: Opportunities, challenges and practices', 11th International Symposium on Communications and Information Technologies, ISCIT 2011, International Symposium on Communications and Information Technologies, IEEE, Hangzhou, China, pp. 562-567.View/Download from: UTS OPUS or Publisher's site
Medical Body Area Network (MBAN) is a new wireless communications technology designed to sense human's vital signals through tiny nodes in, on and around the human body wirelessly. MBAN will play an important role in enabling ubiquitous and non-invasive telemetry and healthcare systems in the future. In this paper, we firstly explore the opportunities of MBAN from the point of new applications, and then we analyze the enabling technologies and challenges to achieve the goal of MBAN, which includes energy efficiency, robustness, high data rate for video support and network co-existence issues. Finally, we describe our MQWIN400 radio platform which was designed to work at 400MHz MICS band, as well as the related research activities and experimental results. © 2011 IEEE.
Zhai, H., Jiang, H., Sun, Y., Li, J., Liu, J., Fang, G. & Dutkiewicz, E. 2011, 'LHCDS: A novel deployment strategy of proxy caches for P2P traffic in ISP networks', Proceedings - 11th IEEE International Conference on Computer and Information Technology, CIT 2011, International Conference on Communications and Information Technology, IEEE, Pafos, Cyprus, pp. 224-230.View/Download from: UTS OPUS or Publisher's site
Peer-to-Peer (P2P) systems have brought two serious problems for Internet Services Providers (ISPs): traffic surges and network congestion. Proxy caching for P2P traffic is an effective means of easing the burden imposed by P2P traffic on ISPs. The deployment strategy of proxy caches has a significant impact on their effect on ISPs. It has two important components: one is cache operation that is what P2P traffic caches monitor and serve; the other is cache deployment algorithm that is where to deploy caches. In this paper, we propose a deployment strategy of proxy caches, called LHCDS (Cache Deployment Strategy for Lower and Higher networks), including a new type of cache operation and its corresponding deployment algorithm. It can serve P2P traffic not only from the local lower access network to the higher transit ISP's network but also within the higher transit ISP's network itself. In LHCDS, caches are deployed at or near core routers of the transit ISP. We develop several deployment algorithms based on the new cache operation. We then evaluate the algorithms, and conclude that the proposed greedy algorithm is a viable and practical algorithm whose performance is close to optimal. Experiments also show that ISPs can achieve more P2P traffic decrease on links using LHCDS than previous strategies. © 2011 IEEE.
Zheng, C., Dutkiewicz, E., Liu, R.P., Vesilo, R., Fang, G. & Zhou, Z. 2011, 'Opportunistic routing in multi-channel cognitive radio networks', 11th International Symposium on Communications and Information Technologies, ISCIT 2011, International Symposium on Communications and Information Technologies, IEEE, Hangzhou, China, pp. 532-537.View/Download from: UTS OPUS or Publisher's site
Cognitive radio (CR) is an exciting technology to improve spectrum utilization. However, spectrum availability can change very fast due to primary user's activity, which makes most of existing CR routing protocols fail to work because they are designed for cognitive radio networks (CRNs) with slow variation of spectrum availability. Opportunistic routing is a promising routing paradigm for CRNs with fast variation of spectrum availability. We propose a multi-channel spectrum aware opportunistic routing (MSAOR) algorithm based on link delay analysis. By introducing channel access probability to characterize the opportunistic CR link, access delay is integrated into queuing delay. Our analysis shows that our algorithm achieves a lower link delay than the existing routing algorithm SAOR (spectrum aware opportunistic routing). Our simulation results also show that our MSAOR algorithm can reduce end-to-end delay by up to 50%, can increase the supported offered load by up to 190% and is more robust than SAOR. © 2011 IEEE.