inproceedings by Nayeem Morshed
All over the world, the existing spectrum is already been saturated with ever increasing demand. ... more All over the world, the existing spectrum is already been saturated with ever increasing demand. Every day huge number of users is joined to the existing fixed band frequency but the bandwidth is not increasing. To solve this issue the cognitive radio is the best choice. Spectrum or white space detection is an essential and very important issue in cognitive radio communication. The aim of channel detection is to find out efficiently the presence or absence of primary or licensed frequency. In this paper, we have developed a Libelium Waspmote sensor based cognitive radio detection scheme which is very easy to use, energy and cost effective. The reason for selecting this type of sensor is it supports IEEE 802.11 b/g and the Tx/Rx antenna transmission and reception sensitivity can be changed by the software. It can scan the available channel resource within its range and can store the data files. Also the security of this type of sensor supports the highest level of wireless security that is Wireless Protected Access V2 or WPA2. It is Windows based which is very common worldwide. The application runs in background without interrupting the PC/Laptop users. It is able to find efficient spectrum hole (Ideal channel) for a secondary or cognitive user to use the primary or licensed band without interrupting the primary user.
Mobile Ad hoc Network (MANET) consists of a collection of wireless mobile nodes that are capable ... more Mobile Ad hoc Network (MANET) consists of a collection of wireless mobile nodes that are capable of communicating with each other without the use of a network infrastructure. The main procedure for data transmission in ad hoc network is routing. In this paper, we evaluate the performance characteristics and behavior of few ad hoc communicating protocols namely Ad Hoc On Demand Routing Vector (AODV), Dynamic Source Routing (DSR) and Destination Sequenced Distance Vector (DSDV) Routing Protocols in MANET. Performance comparison is based on performance metrics such as throughput, end-to-end delay and normalized routing load are evaluated using network simulator (NS-2.35) varying number of nodes and number of pause time.
Current lifestyles promote the development and advancement in wireless technologies, especially i... more Current lifestyles promote the development and advancement in wireless technologies, especially in Wireless Sensor Networks (WSN) due to its several benefits. WSN offers a low cost, low data rate, flexible routing, longer lifetime, and low-energy consumption suitable for unmanned and long term monitoring. Among huge WSN applications, some key applications are smart houses, environmental monitoring, military applications, and other monitoring applications. As a result, ubiquitous increase in the number of wireless devices occupying the 2.4GHz frequency band. This causes a dense wireless connection followed by interference problem to WSN in the 2.4GHz frequency band. WSN is most affected by the interference issue because it has a lower data rate and transmission power compared to WLAN. Despite efforts made by researchers, to the author's knowledge, the interference issue is still a major problem in wireless networks. This paper aims to review the coexistence and interference issues of existing wireless technologies in the 2.4GHz Industrial, Scientific and Medical (ISM) band.
articles by Nayeem Morshed
Cognitive radio (CR) is the latest type of wireless technoloy that is proposed to mitigate spectr... more Cognitive radio (CR) is the latest type of wireless technoloy that is proposed to mitigate spectrum saturation problem. İn cognitve radio, secondary user will use primary user's spectrum during primary user's absence without interupting primary user's transmission. This paper focuses on practical cognitive radio network development process using Android based smart phone for the data transmission. Energy detector based sensing method was proposed and used here because it doesnot require primary user's information. Bluetooth and Wi-fi are the two available types of spectrum that was sensed for CR detection. Simulation showed cognitive radio network can be developed using Android based smart phones. So, a complete application was developed using Java based Android Eclipse program. Finally, the application was uploaded and run on Android based smart phone to form and verify CR network for channel sensing and resource allocation. The observed efficiency of the application was around 81{\%}.
A prudential feature extraction technique is proposed in this study for breast tumor early detect... more A prudential feature extraction technique is proposed in this study for breast tumor early detection. A small size UWB planar antenna with a gain and directivity of 6.09 dB and 8.15 dBi respectively, has also been proposed for smooth wave propagation through the breast model. A system is developed by integrating a small size UWB biomedical antenna and feature extraction technique for artificial neural network (ANN) for early tumor detection. Tumor's size detection accuracy of the system has been investigated experimentally by applying radar based microwave imaging technique. Forward scattering signals (received by the receiving antenna) are considered for four characteristic features, maximum, minimum, average and standard deviation values (Voltage/meter) for pattern recognition and tumor signature investigation. The range of malignant tumor sizes used in this study is 1 mm to 9 mm in diameter. The proposed system is able to detect tumor existence and size with ∼100{\%} and Delivered by Publishing Technology to: Universiti Malaysia Perlis ∼99{\%} accuracy respectively within reasonable time delay, showing its superiority.
This paper presents an experimental performance analysis of 2.4 GHz wireless local area network (... more This paper presents an experimental performance analysis of 2.4 GHz wireless local area network (WLAN), while the nearby Wi-Fi Direct users communicate with the same channel. Structured WLAN APs were considered as primary users (PUs) and the smartphones as secondary users (SUs) for this study. At present spectrum saturation problem is a critical issue due to a large number of users join every day to this fix band of network. To support more users in a specific area needs more WLAN access points (APs) to avoid saturation. 2.4 GHZ WLAN only has 13 separate mutual channels, among them only 3 channels are non-overlapped with each other. As a result interference may often occur during the time of transmission. Wi-Fi Direct technology uses the same channels as the WLAN AP to communicate within smartphones (SUs). If the SUs use the same overlapped channel with the nearby APs, it interferes to the PUs and increase bit error rate (BER) for both users. In this paper, we studied the performance of PU channels while the SUs use the same overlapped channel and non-overlapped channel. The result shows the throughput performance degrades up to 12.5{\%} during the period of SU activities over same channel.
This paper presents channel utilization and noise floor measurement of IEEE 802.11n 2.4 GHz wirel... more This paper presents channel utilization and noise floor measurement of IEEE 802.11n 2.4 GHz wireless local area network (WLAN) for standalone channel and non-overlapped channel in a cognitive radio network. Spectrum is getting saturated day by day with a huge number of increasing application as well as increasing number of smartphone users. Most of the case, the smartphone users get connected with nearby WLAN access points (APs) for real time audio or video streaming, playing games, social networking, stock market updates and so on. As a single AP has limitations to the total number of users, so it may necessary to use more than one AP to cover this increasing number of devices specially in office, universities, student hostel areas. Recently in an experimental survey, we found there are 1193 different APs are using among 8 student residential hostels at Universiti Malaysia Perlis. In this paper, we investigated the utilization and noise floor level of a channel while nearby smartphones use Wi-Fi Direct to communicate between them using non- overlapped channels. In the results, we found an interesting outcome, i.e., even a non-overlapped channel used by nearby smartphones, increased the noise floor level up to 3.5 dBm and channel utilization level up to 3{\%} of WLAN channels.
Spectrum saturation problem is a major issue in wireless communication systems all over the world... more Spectrum saturation problem is a major issue in wireless communication systems all over the world. Huge number of users is joining each day to the existing fixed band frequency but the bandwidth is not increasing. These requirements demand for efficient and intelligent use of spectrum. To solve this issue, the Cognitive Radio (CR) is the best choice. Spectrum sensing of a wireless heterogeneous network is a fundamental issue to detect the presence of primary users' signals in CR networks. In order to protect primary users (PUs) from harmful interference, the spectrum sensing scheme is required to perform well even in low signal-to-noise ratio (SNR) environments. Meanwhile, the sensing period is usually required to be short enough so that secondary (unlicensed) users (SUs) can fully utilize the available spectrum. CR networks can be designed to manage the radio spectrum more efficiently by utilizing the spectrum holes in primary user's licensed frequency bands. In this paper, we have proposed an adaptive threshold detection method to detect presence of PU signal using free space path loss (FSPL) model in 2.4 GHz WLAN network. The model is designed for mobile sensors embedded in smartphones. The mobile sensors acts as SU while the existing WLAN network (channels) works as PU. The theoretical results show that the desired threshold range detection of mobile sensors mainly depends on the noise floor level of the location in consideration.
Papers by Nayeem Morshed
AIP Conference Proceedings, 2017
Spectrum saturation problem is a major issue in wireless communication systems all over the world... more Spectrum saturation problem is a major issue in wireless communication systems all over the world. Huge number of users is joining each day to the existing fixed band frequency but the bandwidth is not increasing. These requirements demand for efficient and intelligent use of spectrum. To solve this issue, the Cognitive Radio (CR) is the best choice. Spectrum sensing of a wireless heterogeneous network is a fundamental issue to detect the presence of primary users’ signals in CR networks. In order to protect primary users (PUs) from harmful interference, the spectrum sensing scheme is required to perform well even in low signal-to-noise ratio (SNR) environments. Meanwhile, the sensing period is usually required to be short enough so that secondary (unlicensed) users (SUs) can fully utilize the available spectrum. CR networks can be designed to manage the radio spectrum more efficiently by utilizing the spectrum holes in primary user’s licensed frequency bands. In this paper, we have proposed an adaptive t...
2017 International Conference on Networking, Systems and Security (NSysS), 2017
There's a huge demand for spectrum, but in conventional system radio spectrum is inefficientl... more There's a huge demand for spectrum, but in conventional system radio spectrum is inefficiently used. To overcome this problem and increase array use of spectrum, cognitive radio (CR) technology concept was proposed. CR is the greatest mechanism for use spectrum efficiently. The main objective of CR is to use scarce and limited natural resources efficiently without any interference to the primary users (PUs). Among most challenging problems in cognitive radio systems is spectrum sensing concepts. Energy detection, Matched filter detection and Cyclostationary detections are most common strategies for spectrum sensing. This study has been performed based on Energy detection spectrum method. The reason for choosing Energy detection technique, it doesn't need any earlier information from the PU transmission. Also, the particular result of energy detection method degrades with lower sign to noises ratio (SNR) level signal location. General detection performance of Energy detection is highly dependent upon noise, especially while the SNR is very low for PU. Considering this issue, this paper presents an adaptive threshold model for efficient Energy detection technique to enhance the detection performance at low SNR level. Simulation outcomes show, the detection performance using offered system model is more preferable than fixed threshold at low SNR signal locations.
2015 International Conference on Advances in Electrical Engineering (ICAEE), 2015
There is a huge demand of spectrum now a days, but in conventional system radio spectrum is very ... more There is a huge demand of spectrum now a days, but in conventional system radio spectrum is very scared resource. To avoid interference and improve spectrum saturation, Cognitive Radio (CR) concept was proposed. CR is the greatest mechanism for use spectrum efficiently. The main objective of CR is to use this limited spectrum resources without interfering the primary users (PUs). This paper explains the several spectrum sensing methods that used in CRso far and also deals benefit-drawback of each sensing method. We explained the cooperative spectrum sensing and it's all forms; and also the multi-dimensional spectrum sensing concept. Cooperative sensing shares its sensing data with others and utilizes the sensing outcomes of others. As a result the probabilities of miss detection and probabilities of false alarm decreased. Finally, we provided an overview of CR for opportunistic spectrum access and future research challenges regarding spectrum sensing issues.
A prudential feature extraction technique is proposed in this study for breast tumor early detect... more A prudential feature extraction technique is proposed in this study for breast tumor early detection. A small size UWB planar antenna with a gain and directivity of 6.09 dB and 8.15 dBi respectively, has also been proposed for smooth wave propagation through the breast model. A system is developed by integrating a small size UWB biomedical antenna and feature extraction technique for artificial neural network (ANN) for early tumor detection. Tumor's size detection accuracy of the system has been investigated experimentally by applying radar based microwave imaging technique. Forward scattering signals (received by the receiving antenna) are considered for four characteristic features, maximum, minimum, average and standard deviation values (Voltage/meter) for pattern recognition and tumor signature investigation. The range of malignant tumor sizes used in this study are 1 mm to 9 mm in diameter. The proposed system is able to detect tumor existence and size with ~100% and ~99% a...
IOSR Journal of Computer Engineering, 2014
2014 2nd International Conference on Electronic Design (ICED), 2014
All over the world, the existing spectrum is already been saturated with ever increasing demand. ... more All over the world, the existing spectrum is already been saturated with ever increasing demand. Every day huge number of users is joined to the existing fixed band frequency but the bandwidth is not increasing. To solve this issue the cognitive radio is the best choice. Spectrum or white space detection is an essential and very important issue in cognitive radio communication. The aim of channel detection is to find out efficiently the presence or absence of primary or licensed frequency. In this paper, we have developed a Libelium Waspmote sensor based cognitive radio detection scheme which is very easy to use, energy and cost effective. The reason for selecting this type of sensor is it supports IEEE 802.11 b/g and the Tx/Rx antenna transmission and reception sensitivity can be changed by the software. It can scan the available channel resource within its range and can store the data files. Also the security of this type of sensor supports the highest level of wireless security t...
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inproceedings by Nayeem Morshed
articles by Nayeem Morshed
Papers by Nayeem Morshed