[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.
Full-text · Article · Feb 2015 · International Journal of Multimedia and Ubiquitous Engineering
[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.
[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).
[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: 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.
Full-text · Article · Jul 2012 · EURASIP Journal on Wireless Communications and Networking
[Show abstract][Hide abstract] ABSTRACT: The IEEE 802.16j amendment has been developed to improve the performance of the IEEE 802.16e standard in terms of its network capacity and coverage area via employment of relay stations. An optional feature of cooperative relay has been initiated to fully utilize multihop network environment. This work focuses on the selection of cooperative relay path/paths through cross-layer approach to forward data from source to destination. The selection scheme jointly considers the signal-to-noise ratio (SNR) from physical (PHY) layer and buffer status from medium access control (MAC) layer. The SNR of the communication link between the basestation and the mobile station has to be compared to a certain threshold before making decision on the optimal cooperative relaying mode. Numerical and simulation results show that cooperative relaying improves the throughput and delay of the IEEE 802.16j system. In addition, the average transmission time of cooperative relay system decreases when the parameter from the MAC layer is considered in the relay selection scheme.
[Show abstract][Hide abstract] ABSTRACT: Cooperative relay has been an interesting research area for the past years as it promotes higher data rates and robust to wireless environment. IEEE Work Group initiated the use of relay stations in the IEEE 802.16e standard and it is called IEEE 802.16j. This paper proposed a multi-hop cooperative relay system with space-time codes (STC), with the integration of relay selection. In changing environment, data transmission signals through wireless channels can be degraded by factors like shadowing, fading etc. Cooperative relay system is believed to offer robustness by multipath routes to destination. The cooperative relay system in this work adopted the virtual MIMO (multiple input multiple output) concept. Analysis of performances are made between topologies of space-time cooperative relay systems and compared with cooperative relay transmission.
[Show abstract][Hide abstract] ABSTRACT: Allocating slots dynamically to the service flows in heterogeneous wireless network is highly complex and non-linear. Since the link quality is continuously changing, a wireless network employing adaptive modulation like WiMAX, allocating slot in such network is based on the link quality. In this paper, we present link aware packet scheduling algorithm using packet's earliest deadline and buffer status called LAEDF, the proposed algorithm is suitable for service flows in WiMAX. The wireless link is estimated based on computed total path loss between the subscriber station (SS) and the base station for each scheduling packet. The simulation shows that the proposed algorithm has achieved higher throughput with fairness among service flows when compared with fixed modulation earliest deadline scheduling algorithm (FMEDF).
Preview · Article · Jan 2011 · International Journal of Communication Networks and Information Security
[Show abstract][Hide abstract] ABSTRACT: There has been an alarming increase in demand for highly efficient and reliable scheme to ultimately support delay sensitive application and provide the necessary quality of service (QoS) needed. Multimedia applications are very susceptible to delay and its high bandwidth requirement. Consequently, it requires more sophisticated and low complexity algorithm to mitigate the aforementioned problems. In order to strategically select best optimal solution, there is dramatic need for efficient and effective optimization scheme to satisfy different QoS requirements in order to enhance the network performance. Multi-objective particle swarm optimization can be extremely useful and important in delay and mission-critical application. This is primarily due to its simplicity, high convergence and searching capability. In this paper, an optimal parameter selection strategy for time stringent application using particle swarm optimization has been proposed. The experimental result through well-known test functions clearly shows that multi-objective particle swarm optimization algorithm has extremely low computational time and it can be potentially applicable for delay sensitive applications.
Full-text · Article · Jan 2011 · Communications in Computer and Information Science
[Show abstract][Hide abstract] ABSTRACT: There is dramatic need to achieve optimal performance in wireless multimedia network due to its heterogeneous nature, media content and different quality of service (QoS) requirements from different applications. It is very obvious that supporting multimedia applications and services over wireless is very challenging task, and it requires low complexity and highly efficient scheme to cope with the unpredictable channel condition. In this paper, we develop a biologically-inspired strategy for optimal video streaming application. The optimal parameters configuration selected provide the best QoS settings to enhance the video streaming quality over wireless LAN. The scenario has been simulated in NS-2 environment, it clearly shows that the video quality has been improve by selecting minimum configuration to ultimately support video application. The PSO-based approach outperforms other techniques used to compare the performance of the develop scheme in terms of perceived video quality by more than 0.5dB. The experimental simulation has been used to verify the efficiency and potential application of the PSO in wireless multimedia communication.
[Show abstract][Hide abstract] ABSTRACT: In this article, some aspects of cognitive radio (CR) technologies and cooperation strategies are discussed. The findings show that cooperative sensing enhances decision making by collaborating cognitive users (CUs). Primary users (PU) protection increases by OR rule and opportunistic access increases for CUs if collaborated using AND rule. It can also be observed that cooperative relaying benefits from path-loss saving, power gain due to the fact that the relay may add additional transmit power, and diversity gain in the presence of fading. In addition, the network performance is also enhanced by the increase in achievable data rates when using cooperative relay when compared with the rates achieved without relay. Cooperative communication technique can further enhance the transmission capacity of a communication system, while CR technique can improve the spectrum utilization ratio. Doubtless, the integration of the two technologies will have a great impact on network architecture, terminals, service models, and applications of future wireless mobile communication.
[Show abstract][Hide abstract] ABSTRACT: A Software Defined Radio (SDR) is a radio which can tune to any frequency band, transmit and receive different modulations and different physical parameters across a large frequency spectrum by using a programmable hardware and powerful software. An SDR performs significant amounts of signal processing in a general purpose computer, or a reconfigurable piece of digital electronics or the combination of both. In this paper, we seek to explore the viability of using GNU Radio; an open source SDR implementation and the Universal Software Radio Peripheral (USRP); an SDR hardware platform, to transmit and receive the OFDM radio signal with QPSK and BPSK modulation. Quality of Service (QoS) in terms of Packet Received Ratio (PRR) on the data transmitted will then be investigated and analyzed.
[Show abstract][Hide abstract] ABSTRACT: IEEE 802.16j MMR WiMAX networks allow the number of hops between the user andthe MMR-BS to be more than two hops. The standard bandwidth request procedure inWiMAX network introduces much delay to the user data and acknowledgement of theTCP packet that affects the performance and throughput of the network. In this paper,we propose a new scheduling scheme to reduce the bandwidth request delay in MMRnetworks. In this scheme, the MMR-BS allocates bandwidth to its direct subordinate RSswithout bandwidth request using Grey prediction algorithm to estimate the requiredbandwidth of each of its subordinate RS. Using this architecture, the access RS canallocate its subordinate MSs the required bandwidth without notification to the MMR-BS.Our scheduling architecture with efficient bandwidth demand estimation able to reducedelay significantly.
[Show abstract][Hide abstract] ABSTRACT: This paper presents a method of optimizing sensor node coordination in order to reassign the nodes in linear array arrangement to form a linear antenna array. This linear sensor node array (LSNA) is constructed within random sensor node deployment. The LSNA should be optimized as closely comparable as a conventional uniform linear array (ULA) to minimize the beamforming performance errors. Beamforming has been introduced in wireless sensor networks (WSNs) in order to increase the transmission range of individual sensor nodes. The performance of the two methods: LSNA and ULA are compared in adaptive manner. The results of the constructed adaptive LSNA demonstrated an excellent agreement compared to the conventional ULA.
[Show abstract][Hide abstract] ABSTRACT: Conventional Wireless Sensor Network (WSN) mainly deals with scalar data such as temperature, humidity, pressure and light which are very suitable for low rate and low power IEEE 802.15.4 based networking technology. The commercial off-theshelf (COTS) CMOS camera has fostered researchers to push WSN a step further. The unique properties of multimedia data delivery pose novel challenges for resource-constrained sensor network. Transmitting raw data is very costly while limited processing power prevents sophisticated multimedia processing. This paper presents the development of a low cost, low power WSN hardware platform named TelG embedded with an operating system called WiseOS, system software, and also a simple best effort JPEG images transmission over the network. The experimental results from the testbed illustrate that the performance of our designed WSN platform are comparable to the existing ones in the market in terms of packet reception rate (PRR) and received signal strength intensity (RSSI) with respect to the distance. It also shows that the end-to-end delay increases proportionally with the number of hops. At an average data rate of 48.38Kbps, we conclude that our platform not only can support real-time multimedia data delivery but also a low voice coding standard such as G.729a (8kbps)