[Show abstract][Hide abstract] ABSTRACT: Cognitive radio-based wireless sensor network is the next-generation sensor network paradigm. Important to this emerging sensor network is the need to reduce energy consumption, paving way for ‘green’ communication among sensor nodes. Therefore, in this paper, we have proposed an energy-efficient, learning-inspired, adaptive and dynamic channel decision and access technique for cognitive radio-based wireless sensor networks. Using intelligent learning technique based on the previous experience, the cognitive radio-based wireless sensor network agent decides which available channel to access based on the energy-efficiency achievable by transmitting using the channel. From simulation results, we found that as the channel packet availability increases, the energy-efficiency of the channel increase. This lends credence to the fact that the proposed learning-inspired algorithm is significantly energy-efficient for cognitive radio-based wireless sensor networks.
International Journal of Multimedia and Ubiquitous Engineering 02/2015; 10(2):11-24. DOI:10.14257/ijmue.2015.10.2.02
[Show abstract][Hide abstract] ABSTRACT: Cognitive radio-based wireless sensor network is a new paradigm in sensor networks research. It is considered to revolutionize next generation sensor networks. Therefore, it is of paramount importance to develop an efficient channel access technique suitable for cognitive radio-based wireless sensor network. In this paper we have proposed a channel access framework for cognitive radio-based wireless sensor networks which is based on reinforcement learning technique. We have used Q-learning approach to develop a simple access algorithm. We have analyzed the effect of sensing time on the probability of detection, probability of misdetection and probability of false alarm. These parameters were compared using different detection threshold values and significant simulation results were discussed.
[Show abstract][Hide abstract] ABSTRACT: Cognitive sensor networking is an emerging wireless technology to efficiently utilize the available radio resources for dense deployment sensor nodes. Spectrum sensing is the key enabling of cognitive radio to detect the unoccupied channels for data transmission. In order to deal with shadowing and multipath fading in sensing channels, cooperative spectrum sensing is designed to increase the reliability of the sensed signal. In this paper, an optimised local decision rule is implemented for the case that the received observations from primary user are possibly correlated due to the sensing channel impairments. As the priority information is unavailable in the real systems, Neyman-Pearson criterion is used as the cost function. Then, a discrete iterative algorithm based on Gauss-Seidel process is applied to optimize the local cognitive user decision rules under a fixed fusion rule. This method with low complexity can minimise the cost function using the golden section search in finite number of iterations. ROC curve is depicted using the achieved probability of detection and false alarm by numerical examples to illustrate the efficiency of the suggested algorithm. Simulation results confirm the superiority of the proposed method comparing to the conventional topologies and decision rules.
[Show abstract][Hide abstract] ABSTRACT: Recent advancements in the field of cognitive radio technology have paved way for cognitive radio-based wireless sensor networks. This has been tipped to be the next generation sensor. Spectrum sensing and energy efficient channel access are two important operations in this network. In this paper, we propose the use of machine learning and decision making capability of reinforcement learning to address the problem of energy efficiency associated with channel access in cognitive radio aided sensor networks. A simple learning algorithm was developed to improve network parameters such as secondary user throughput, channel availability in relation to the sensing time. Comparing the results obtained from simulations with other channel access without intelligent learning such as random channel assignment and dynamic channel assignment, the learning algorithm produced better performance in terms of throughput, energy efficiency and other quality of service requirement of the network application.
[Show abstract][Hide abstract] ABSTRACT: Recent technology advance in wireless sensor networks (WSNs) has enabled the growth of various applications that can assist or enhance existing systems. For instance, the technology provided by IEEE 802.15.4 protocol that operates in 2.4GHz ISM band is suitable to be used in many applications since it is a low cost and low power wireless communication. In this paper, we present a performance study of node placement for training monitoring system for cyclist using IEEE 802.15.4 technology. A series of experiments were carried out to obtain the best node placement in the system in order to minimize the packet loss during data transmission on track cycling. Details of experiments' results are presented and data collected will be used further to design the training monitoring system.
2014 IEEE Asia-Pacic Conference on Applied Electromagnetics (APACE 2014); 12/2014
[Show abstract][Hide abstract] ABSTRACT: In cognitive radio (CR), the secondary user (SU) needs to hand off its ongoing communication to an idle channel in order to avoid interference to the primary user (PU). Spectrum hand off issue becomes challenging in CR mobile ad hoc networks (CR-MANETs) because of the uncertainty in spectrum availability, broad range of spectrum bands and lack of central entity. The purpose of this study is to design a unified spectrum handoff (USH) scheme for CR-MANETs that considers the spectrum heterogeneity and its availability over time and space. A local flow hand off is performed when spectrum hand off cannot be carried out due to the SUs mobility. To improve further USH, preemptive unified spectrum handoff (PUSH) algorithm is proposed in which two different preemptive hand off threshold regions are defined. The PUSH algorithm also predicts the cognitive link availability considering the PU interference boundary. Although the PUSH scheme improves the hand off performance, the number of spectrum hand offs due to the PU activity should be reduced in this scheme. Therefore, the PC-PUSH (Power Controller-PUSH) scheme is proposed in which the fuzzy logic is used to improve the PUSH in terms of the number of spectrum handoffs because of the PU activity. The PC-PUSH decreases the interference to the PUs, while reducing the number of spectrum handoffs. The results show that the proposed scheme improves the link maintenance probability, decreases the hand off delay, and reduces the number of spectrum handoffs.
[Show abstract][Hide abstract] ABSTRACT: Cognitive radio-based wireless sensor network is the new paradigm in sensor network technology. It is a combination of the traditional sensor network and cognitive radio technology. Apparent challenge to this new sensor network outlook is the problem of energy efficiency. In this paper, we present the energy-efficient channel decision using reinforcement learning-based algorithm. The proposed algorithm is a learning-based algorithm in which a learning agent decides its action in a particular state based on its learned experience in the past. Hence, future decisions are based on reward or punishment obtained from previous actions. Results of simulations carried out shows that the proposed algorithm performs nearly 70% better in terms of energy-efficiency compared with random channel selection scheme.
International Conference on Frontiers of Communications, Networks and Applications (IET ICFCNA 2014), Kuala Lumpur; 11/2014
[Show abstract][Hide abstract] ABSTRACT: Wireless mesh networks (WMNs) have gain attention from researchers in telecommunication engineering field due to its potential to provide low cost internet broadband access, wireless local area network coverage and network connectivity for stationary or mobile host. This network consists of multiple wireless routers that are used to relay each other's packet in multi-hop fashion. Hence, routing protocol plays an important part in maintaining the connectivity of WMNs. In this paper, two routing protocols, Ad hoc On-demand Distance Vector (AODV) and Hybrid Wireless Mesh Routing Protocol (HWMP) are compared in terms of their performance in WMNs. A random wireless mesh topology with router nodes is modelled in Network Simulator 3 by assuming that the router nodes are connected to its client nodes. The simulations are performed in two different topologies with varied number of nodes. Three merits are taken into account when making the comparisons which are packet delivery fraction, throughput, and end-to-end delay. The simulation results demonstrate that HWMP is more suitable to be applied in WMNs compared to AODV.
2013 IEEE International RF and Microwave Conference (RFM); 12/2013
[Show abstract][Hide abstract] ABSTRACT: In this paper, we present the end-to-end interference aware concept of Cognitive wireless mesh network (CWMN). CWMN is the leading upcoming technology with the advantage of cognitive radio (CR). We demonstrate that the end-to-end interference model has the ability to perform better from SINR base model. To enhance the utilization of the unused spectrum the channel selection strategy should have some awareness mechanism to avoid interference. In this paper, novel interference aware channel assignment (IACA) algorithm is proposed. The end-to-end delay, packet delivery ratio and the throughput is used to estimate the performance of the proposed algorithm. The numerical results demonstrate that the proposed algorithm is closer to the optimum resource utilization. Keywords— cognitive radio (CR), interference, channel assignment (CA), wireless mesh networks, primary user (PUs), secondary users (SUs).
Malaysia International Conference on Communications, Malaysia; 11/2013
[Show abstract][Hide abstract] ABSTRACT: Cognitive radio wireless mesh network (CRWMN) is expected as an upcoming technology with the potential advantages of both cognitive radio (CR) and the wireless mesh networks (WMN). In CRWMN, co-channel interference is one of the key limiting factors that affect the reception capabilities of the client and reduce the achievable transmission rate. Furthermore, it increases the frame loss rate and results in underutilization of resources. To maximize the performance of such networks, interference related issues need to be considered. Channel assignment (CA) is one of the key techniques to overcome the performance degradation of a network caused by the interferences. To counter the interference issues, we propose a novel CA technique which is based on link capacity, primary user activity and secondary user activity. These three parameters are fed to the proposed weightage decision engine to get the weight for each of the stated parameters. Thus, the link capacity based channel assignment (LCCA) algorithm is based on the weightage decision engine. The end-to-end delay, packet delivery ratio and the throughput is used to estimate the performance of the proposed algorithm. The numerical results demonstrate that the proposed algorithm is closer to the optimum resource utilization.
[Show abstract][Hide abstract] ABSTRACT: Graphical abstract Abstract Recently, technological advance in Android application has grown rapidly especially in health care application along with the development of smartphone. The utilization of wireless sensor networks with the mobile wireless health devices has provided us with an alternative solution in health monitoring instead of using the traditional approach with higher cost. Therefore, the objective of this project is to develop and implement a training monitoring system for cyclist based on android application. In this system, wireless sensor nodes are assigned to collect the required data such as cyclist's heart rate and cadence. All the data are then sent to the mobile device used by cyclist via wireless communication. The data collected are first stored in device's internal memory before they are transferred to the server. This project involved programming of hardware using specific software such as Eclipse Juno Android SDK and SQLite database. The system also includes the graphical user interface (GUI) design using Java language for application on smartphone. In addition, the simple Dropbox command is used to design the server for data storage. All the stages of implementations are integrated in one whole system and can be run as an application by cyclist. The developed system is proven to be cost effective and reliable as well as easy for customization. Abstrak Baru-baru ini, kemajuan teknologi dalam pembangunan aplikasi Android telah mengalami pertumbuhan yang pesat terutama dalam pembangunan penjagaan kesihatan seiring dengan pembangunan telefon pintar. Penggunaan rangkaian pengesan wayarles bersama peranti kesihatan mudah alih telah memberikan penyelesaian alternatif kepada kita dalam memantau kesihatan berbanding dengan penggunaan kaedah tradisional yang memakan kos yang tinggi. Oleh itu, objektif projek ini adalah untuk membangunkan dan melaksanakan sistem pemantauan latihan bagi pelumba basikal berdasarkan aplikasi android. Dalam sistem ini, nod pengesan wayarles berfungsi untuk mengutip data yang diperlukan seperti kadar degupan jantung pelumba basikal dan juga kadar putaran pedal. Kesemua data kemudiannya dihantar ke peranti mudah alih yang digunakan oleh pelumba basikal melalui komunikasi wayarles. Data yang dikumpulkan akan disimpan di dalam memori dalaman peranti sebelum dipindahkan ke dalam pelayan. Projek ini melibatkan kerja-kerja pengaturcaraan peralatan menggunakan perisian tertentu seperti Eclipse Android SD dan SQLite pengkalan data. Sistem ini juga merangkumi penciptaan antaramuka bergrafik pengguna menggunakan bahasa Java untuk aplikasi telefon pintar. Tambahan juga, arahan mudah Dropbox digunakan untuk tujuan penyimpanan data di dalam pelayan. Di akhir projek ini, semua peringkat pelaksanaan diintegrasikan dalam sistem yang sama dan boleh digunakan sebagai suatu aplikasi oleh pelumba basikal. Sistem yang dilaksanakan ini telah dibuktikan efektif dari segi kos dan mudah untuk disesuaikan untuk aplikasi lain. Kata kunci: Android; sistem pemantauan latihan; aplikasi kesihatan
[Show abstract][Hide abstract] ABSTRACT: This paper presents a novel collaborative beamforming (CB) method of wireless sensor network (WSN) by organizing sensor node location in a circular arrangement. Appropriate selection of active CB nodes and cluster is needed each time to perform CB. The nodes are modeled in circular array location in order to consider it as a circular antenna array (CAA). This newly proposed circular collaborative beamforming (CCB) is further presented to solve two different objectives, that is, sidelobe level (SLL) suppression and first null beamwidth (FNBW). Analyses obtained are compared to those from previous work. The findings demonstrate a better CB performance of intelligent capability, and the difference is shown in normalized power characteristic.
International Journal of Distributed Sensor Networks 07/2013; 2013. DOI:10.1155/2013/125423 · 0.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This paper describes the performance of singular value decomposition (SVD) estimation techniques for multiband orthogonal frequency-division multiplexing (OFDM) of ultra-wideband (UWB) system in Saleh-Valenzuela channel modelling. The performance of SVD estimation is compared against LS and MMSE methods corresponding to zero-padded of a UWB system. The crucial limitation in UWB system is strictly low power transmission leads to many challenges in designing the system. However, most of the conventional channel estimation in frequency domain requires either pre-storing a large matrix or performing real-time matrix inversion, which should be avoided for UWB low complexity implementation. The intuition of this paper is to analyse further the complexity of SVD techniques against least squares (LS) and minimum mean square error (MMSE) estimation method. Consequently, this work implies that the SVD method gives an improvement of 3–5 dB if compared to the LS method while a significant complexity reduction of 57.8% as compared to MMSE methods.
TENCON 2013 - 2013 IEEE Region 10 Conference (31194); 01/2013
[Show abstract][Hide abstract] ABSTRACT: Multiple Description Coding (MDC) is a useful source coding method for concealing error in lossy networks. Network coding (NC) permits intermediate nodes within a network to apply algebraic mathematic process on independent streams in transmitter and receiver. This paper attempts to protect data and conceal errors happen in the network by joining MDC and p-cycle NC. First, input data (image) is zero padded and downsampled to four subimages. Then Wavelet and Lloyd-max quantization is applied to subimages. Later, four compressed and coded descriptions are transmitted through network and p-cycle network coding is applied to them in the network. Any lost description can be recovered exactly at the receiver part. In this method, no feedback system is needed. Results show that in the fixed bit rate, the PSNR (Peak Signal to Noise Ratio) of our reconstructed image and also subjective evaluation is better than previous work. Furthermore, proposed method has high throughput compared to another work.
Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology (ECTI-CON), 2013 10th International Conference on; 01/2013
[Show abstract][Hide abstract] ABSTRACT: Relaying is one of the technical specifications in LTE (Long Term Evolution)-Advanced. It is proposed to improve throughput at the cell edge and shadowing area. To enable relaying function in LTE-Advanced, current signaling should be modified because LTE does not support relaying technique. The enhancement work of LTE, proposed two architectures for RN (Relay Node) implementation which is called Architecture A and Architecture B. There are three alternatives in Architecture A and one alternative in Architecture B. This paper focused on the Architecture A. The control plane and user plane are discussed before the HO (Handover) signaling for each alternative in the Architecture A. L3 RN (Layer3 Relay Node) is considered in this architecture and work. The proposed signaling is based on HO scenario from a RN to a Target eNB (evolved NodeB) in a different cell.
[Show abstract][Hide abstract] ABSTRACT: Computer and wireless communication require Internet accessibility at anytime and anywhere; this includes in a high-speed mobile station such as in speedy trains, fast moving cars as vehicle-to-infrastructure communication. However, wireless Quality of Service (QoS) provisioning in such an environment is more challenging. This increased the development of numerous schemes concerning the need of smooth handover of the mobile nodes. Conversely, transport layer (L4 in ISO layers) protocols such as stream control transmission protocol can support such a seamless handover in high-speed mobility users. This article highlights on the issues of moving users in mobile WiMAX networks. An adaptation of transport layer protocol of the high mobility vehicle that supports seamless handover can guarantee and maintain QoS for rapid handover rates. The results show an improvement of L4 protocol in terms of delay time and throughput in order to enable efficient and robust mobility aware protocols.
EURASIP Journal on Wireless Communications and Networking 07/2012; 2012(1). DOI:10.1186/1687-1499-2012-229 · 0.72 Impact Factor