Distance based LEACH Protocol in Wireless Sensor Network

Vol. 5  Issue 2
Year: 2016
Issue:Jul-Sep
Title:Distance based LEACH Protocol in Wireless Sensor Network
Author Name:Urvashi Pathania
Synopsis:
Wireless Sensor Networks are composed of innumerable little accuse, low control devices with sense, local processing and wireless communication capabilities. Minimizing energy expenditure and maximizing the networks natural life are considerable issues in the devise of routing protocol for sensor networks. In this paper, the author has analyzed the competence of LEACH protocol in extending the subsistence for energy-constrained Wireless Sensor Networks. Based on LEACH protocol, a new text of LEACH protocol distance based leach protocol that is to be energy consumption protocol in Wireless Sensor Network is surveyed.

Enhanced Dynamic Route Adjustment Scheme in Wireless Sensor Networks

Vol. 5  Issue 2
Year: 2016
Issue:Jul-Sep
Title:Enhanced Dynamic Route Adjustment Scheme in Wireless Sensor Networks
Author Name:D. Ganesh and S. Nagalingeswari
Synopsis:
Wireless Sensor Network is the application of ad-hoc network. Wireless Sensor Network has several nodes which consists of mobility and more than one base stations. Wireless Sensor Network having a dynamic nature. Mobility of sensor nodes is a challenging task in the networks. Data distribution to a mobile sink is more difficult than to rest of the nodes in the sensor network. If the path is failed, then another route should be selected which is the shortest and best route for efficient data delivery. In the existing work, virtual grid dynamic route adjustment scheme deals with the selection of best path whenever the path fails. It reduces the cost of the selected path by selecting the required hops. In the proposed work, Distance enhanced grid routing algorithm is used to select the new path by selecting the limited number of hops than the existing method. Here, the authors have been providing security from attacker by using asymmetric cryptographic algorithm for efficient data delivery in a shortest distance.

A Route Weight Assignment Method for Predictive Congestion Control in WSN

Vol. 5  Issue 2
Year: 2016
Issue:Jul-Sep
Title:A Route Weight Assignment Method for Predictive Congestion Control in WSN
Author Name:Shaik Nasrin and N. Sai Lohitha
Synopsis:
Wireless Sensor Network is a self configurable network with densely deployed sensor nodes. These sensor nodes cooperatively communicate each other and monitor the conditions of the physical environment and is restricted to bandwidth, memory, energy, etc. In Wireless Sensor Network, when an event is detected, the node senses and become active in gathering and data transmission, which cause congestion and results in a large number of packet drops, low throughputs, high energy consumption with a significant amount of wasted energy due to retransmission and increased delay. This paper presents the congestion prediction using probabilistic methods and congestion control using rate control. The rate controlling methods uses the allocation of rate mechanisms are namely rate regulation, rate reduction and split protocol to minimize packet drops, energy consumption of nodes and improve queue utilization, throughput. Each and every method has its own advantages and disadvantages. The SP has a limitation of packet delay while considering the neighbor nodes. To overcome the limitation, a route weight assignment method is proposed. The proposed method is implementing by using Ns2.

An Energy Efficient Routing Protocol in Wireless Sensor Network

Vol. 5  Issue 2
Year: 2016
Issue:Jul-Sep
Title:An Energy Efficient Routing Protocol in Wireless Sensor Network
Author Name:Harjeet Kaur and Beant Kaur
Synopsis:
Wireless Sensor Network is one of the vast areas of research for scholars. In this, energy consumption is a major problem and various protocols are applied till date to reduce it. The main purpose of this paper is to study some of the protocols such as direct transmission, MTE and LEACH. Nowadays, LEACH is a focused area to gain better results. So much research has already been done in this field, but still a lot more can be done to improve the overall performance. After analyzing all these, the authors have tried to decrease the power consumption of WSN using LEACH protocol. The experimental results show that there is an improvement in all parameter terms and more rounds have been energized when compared to basic LEACH. Simulation of the improved LEACH has been carried out on MATLAB and results have been verified and compared with parameters such as dead nodes, alive nodes, sending packets to Cluster Head or base station, etc.

Secure Energy Efficient LEACH (EE_LEACH) Protocol for Wireless Sensor Networks

Vol. 5  Issue 2
Year: 2016
Issue:Jul-Sep
Title:Secure Energy Efficient LEACH (EE_LEACH) Protocol for Wireless Sensor Networks
Author Name:A. Hima Bindu and V.V. Rama Prasad
Synopsis:
Wireless Sensor Network (WSN) is an infrastructureless network with large number of sensing nodes that can monitor areas such as physical or environmental conditions (i.e., temperature, sound, pressure) to collect and report data to the Base Station (BS). Networks face several challenges like energy, and power. Since the sensor nodes are not battery replaceable, the limited energy resource is a main challenge in facing security for WSNs. Hence, network lifetime becomes a major criteria and can be improved by energy efficient routing and secure energy efficient routing for WSN. Routing protocols that provides an effective design in data gathering are energy efficient cluster-based routing protocols. The existing approach (EE-LEACH) provides a WSN with less energy consumption. However, it concentrates mainly in energy resource, but lacks in providing security resources to the network. This paper presents a proposed Energy Efficient LEACH protocol using lightweight secure LEACH (LS_LEACH), where a broadcast authentication algorithm is integrated to produce authenticity. Moreover, the experimental results show the development of proposed EE_LEACH protocol and existing protocol in terms of system throughput, energy consumption and network lifetime. It is obviously shown that the proposed method will provide better network performance and improves the network lifetime.

Influence of Compressive Sensing on Performance Metrics of Wireless Sensor Networks – A Survey

Vol. 5  Issue 1
Year: 2016
Issue:Apr-Jun
Title:Influence of Compressive Sensing on Performance Metrics of Wireless Sensor Networks – A Survey
Author Name:N. Subhashini and M. Murugan
Synopsis:
Compressive sensing outperforms the traditional limits of the sampling theory. Based on the principle of sparsity and incoherence, the Compressive sensing retrieves the original signal with the least number of samples compared to the conventional method. Wireless sensor network consists of a large number of sensor nodes or motes with varying size depending upon the application. The spatially distributed nodes transmit the data sensed from the field in cooperation with other nodes to the fusion center. If the monitoring field is wide, the data collected from the field is also large consuming more energy, bandwidth and capacity of the network. Increase in the energy consumption of the node results in the decrease in the lifetime of the node. Hence, to increase the lifetime of the node, the data traffic in the network is reduced by associating compressive sensing with the wireless sensor network. This paper deals with the variation of the performance metrics of wireless sensor networks, in the presence of compressive sensing.

Design of a Wideband Bandpass Filter using Two Cross-Coupled Three Short Ended Section

Vol. 5  Issue 1
Year: 2016
Issue:Apr-Jun
Title:Design of a Wideband Bandpass Filter using Two Cross-Coupled Three Short Ended Section
Author Name:Ajay Kumar Yadav, Vipin Kumar Upaddhyay and Dileep Kumar Yadav
Synopsis:
A new compact wideband band pass filter is designed by using two short-ended cross coupled sections between the input and output port up to some length. Shorting of section improves its cutoff frequencies fall off. It also helps in size reduction and its covered area. It has measured 3dB pass band of (2 to 4.86) GHz band. The circuit size is reduced considerably and its size is (17.86×10.95) mm. This structure comprised of basically a ring resonator in which cross coupling and short ended section is provided. This wideband BPF is mainly applicable for IEEE defined S-Band applications. This wide band BPF was designed using ANSYS HFSS.

N-Shape Dielectric Resonator Antenna for Wireless Communication

Vol. 5  Issue 1
Year: 2016
Issue:Apr-Jun
Title:N-Shape Dielectric Resonator Antenna for Wireless Communication
Author Name:Roshni Gupta, Mangal Singh and Dipali Soren
Synopsis:
This paper presents the simulation study of an ultra-wideband Dielectric Resonator Antenna (DRA). The simulation study has been carried out using CST Microwave Studio Software. The design procedure and simulation results of the rectangular dielectric resonator antenna and N-shaped dielectric resonator antenna are compared. The proposed antenna is designed on FR4 substrate with dielectric constant of = 4.6 and the overall size of the proposed DR antenna r 2 is 20 × 35 mm . The dielectric resonator of N- shape is only 5.12 mm thickness and a very low permittivity constant (10.2). The simulated DR antenna operates from 4.4 to 11.7 GHz to cover most of the existing wireless mobile standards. The radiation pattern is Omni-directional and has a simulated gain values up to 4 dB and the total efficiency of antenna is 99%. The results are showing acceptable performance in terms of return loss, VSWR, radiation pattern and realized gain. The results presented here may be useful in designing the portable personal communication device antennas and in analyzing the performance of these antennas for wireless communication.

Performance Analysis of Evolutionary Algorithm for PAPR Reduction in OFDM System

Vol. 5  Issue 1
Year: 2016
Issue:Apr-Jun
Title:Performance Analysis of Evolutionary Algorithm for PAPR Reduction in OFDM System
Author Name:Prabhneet Kaur and Mangal Singh
Synopsis:
Orthogonal Frequency Division Multiplexing (OFDM) is a wireless transmission technique in which the digital data are transmitted in a radio environment at a very high speed. But one of the major drawbacks of OFDM system is, high peak to average power ratio which demands costly linear amplifiers with wide dynamic range. In this paper, less-complexity based partial transmit sequence technique is used for reducing the PAPR of OFDM system. PTS techniques can improve the PAPR statistics of an OFDM signals, but the computational complexity is a potential problem for the implementation in practical systems. Inorder to reduce this computational complexity, an optimization algorithm can be used. This paper shows the comparison between two population-based stochastic search techniques which is widely used in many scientific and engineering fields. Here, the Differential Evolutionary (DE) algorithm is compared with the Genetic Algorithm (GA).

CPW-Fed Printed Slot Antenna for Wireless and Future Mobile Broad-Band Applications

Vol. 5  Issue 1
Year: 2016
Issue:Apr-Jun
Title:CPW-Fed Printed Slot Antenna for Wireless and Future Mobile Broad-Band Applications
Author Name:Girijesh Giri, G.S. Tripathi and Sudhanshu Verma
Synopsis:
In this paper, coplanar waveguide fed patch antenna with quad band application is presented. The proposed antenna 3 has a compact size of (50×30×1.6 mm ). The design consist four bands from (1.66 GHz to 2.2 GHz) centered at 1.80 GHz, is better for wireless application from (3.55GHz to 3.8 GHz) centered at 3.5 GHz for WIMAX, from (4.30 GHz to 5.07 GHz ) centered at 4.7 GHz and from (5.7 GHz to 6.02 GHz ) centered at 5.8 GHz for WLAN application. A good return loss of more than -20 dB are achieved which are making it compatible for various mobile broadband application. The objective of the proposed antenna is to cover the various L band and C band applications. Further, the proposed antenna has low profile which makes easy installation in different devices. The whole simulation is done by using HFSS-13 software.

Extending Implementation- A Castalia with a Multimedia Sensor Node Framework

Vol. 5  Issue 1
Year: 2016
Issue:Apr-Jun
Title:Extending Implementation- A Castalia with a Multimedia Sensor Node Framework
Author Name:Hanafy M. Ali
Synopsis:
Currently available Wireless Sensor Network (WSN) tools may be adapted for the Wireless Multimedia Sensor Network (WMSN). However, this requires more effort to configure and tune such tools for the requirements of current WMSN. On the other hand, many extensions for available WSN tools were developed to extend their functionalities in order to support WMSN. Although this seems to solve the problem, such extensions are usually developed as layers or plugins over the existing ones, which introduce many performance issues. In this paper, Castalia is extended to support the multimedia content simulation. First, the general multimedia requirements are discussed and defined, then the Castalia is enhanced by adding the defined requirements.

Study and Comparison of Distributed Energy Efficient Clustering Protocols in Wireless Sensor Network: A Review.

Vol. 4  Issue 4
Year: 2016
Issue:Jan-Mar 
Title:Study and Comparison of Distributed Energy Efficient Clustering Protocols in Wireless Sensor Network: A Review.
Author Name:Anamika, Ashok Kumar, H.L. Mandoria and B.K. Pandey
Synopsis:
In the past years, the wireless sensor networks are a emerging and trending technology because of its interesting applications to replace humans to monitor the physical and environmental conditions in industrial, civilians and military uses. The sensor nodes are battery operated, therefore these networks are energy constrained. An optimum trade-off is required in between energy dissipation, accuracy and latency in data transmission in Wireless Sensor Networks for longer network lifetime and effective message or throughput. The main goal of Research in Wireless Sensor Network is to devise novel energy efficient routing solutions to save the energy of motes, thereby maximizing the lifetime of sensor nodes. Topology control or clustering of sensor nodes can balance the load among sensor nodes, which increases the network lifetime and the scalability period of sensor nodes in Wireless Sensor Network. This paper provides a review on various hierarchical energy efficient clustering protocols along with the applications of the Wireless Sensor Networks.

A Survey on Energy Efficient Routing Protocols in Wireless Sensor Networks

Vol. 4  Issue 4
Year: 2016
Issue:Jan-Mar 
Title:A Survey on Energy Efficient Routing Protocols in Wireless Sensor Networks
Author Name:K.V. Praveen Kumar, B.M. Thippeswamy, S. Reshma, M.K. Banga, V. Udaya Rani and K.R. Venugopal
Synopsis:
Energy efficiency is one of the critical issues in the Wireless Sensor Networks (WSNs), since sensor devices are tiny and integrated with a limited capacity battery. In most of the advanced applications, WSNs operate in very harsh areas and not under supervision of human controls. Routing protocols play a significant role in energy balancing by incorporating the techniques that can reduce control overhead, proper data aggregation method and feasible path selection. It demands a unique requirement due to its frequent topology changes and distributive nature. One of the major concerns in the design of routing protocol in WSNs is efficient energy usage and prolonging Network lifetime. This paper mainly discusses different issues related to energy efficiency in routing protocols of all categories. It incorporates most recent routing protocols which improves the energy efficiency in various application environments. This paper also provides comprehensive details of each protocol which emphasize their principles and explore their advantages and limitations. These protocols belong to different classifications based on Network Structures, communication model, topology and QoS parameters. It also includes more relevant and prominent comparisons with all recent State-of-Art works.

Design of a C-Shaped Microstrip Antenna with Slotted Patch for Wi-Max and WLAN

Vol. 4  Issue 4
Year: 2016
Issue:Jan-Mar 
Title:Design of a C-Shaped Microstrip Antenna with Slotted Patch for Wi-Max and WLAN
Author Name:Abhinav Arya, R.K. Prasad and R.K. Chauhan
Synopsis:
C-shaped microstrip patch antenna with slotted patch has been proposed in this paper. Its design is easy and consist of two L-shape slots in lower patch as well as upper patch. A square shape is also placed between the patch and the feeding point. The design is used for WI-MAX as well as WLAN at 3.5-3.7 GHz frequency range. The results are measured at -6 db because of mobile services. The simulation is done using HFSS. All the results have better DC biasing parameters.

A Multiband Slot Antenna with Enhanced Bandwidth for Wi-MAX and WLAN Applications

Vol. 4  Issue 4
Year: 2016
Issue:Jan-Mar 
Title:A Multiband Slot Antenna with Enhanced Bandwidth for Wi-MAX and WLAN Applications
Author Name:Tanuj Kumar Gond, R.K. Chauhan and R.K. Prasad
Synopsis:
The design of the slot antenna with three bands for worldwide interoperability for microwave access (Wi-Max) and Wireless Local Area Network (WLAN) has been presented. This antenna consists of a leaf shaped slot and a triangular parasitic patch. Area of the designed antenna is 40×40 mm2 and height of the designed antenna is 1.6 mm. For the purpose of feeding, a 50Ω microstrip line is used in this design. To improve the bandwidth and gain of the designed antenna, a triangular parasitic patch is used. After doing a parametric study on the parameters of the designed antenna a triple frequency band is presented. Simulated bandwidth, defined by -10db return loss can reach an operating bandwidth of 4GHz at the operating frequency 4.5GHz. The simulated result signifies that the effective bandwidth of the designed antenna is 84.15% from 2.65GHz to 6.55GHz with -10db return loss. After getting the simulated results, the designed antenna can cover the frequency band 3.27-3.97 GHz for Wi-Max systems and 5.17-5.93 GHz for the IEEE 802.11a WLAN systems.

Enhancing Mobility Management and Supporting 3D Visualization

Vol. 4  Issue 4
Year: 2016
Issue:Jan-Mar 
Title:Enhancing Mobility Management and Supporting 3D Visualization
Author Name:Hanafy M. Ali
Synopsis:
The mobility manager specifies the way the nodes move through space during simulation. It holds location state that other modules can access at any time using a function call, and it notifies the wireless channel periodically of the position of a node. According to Castalia Manual, it implements only one mobility pattern module, the simple Line Mobility Manager. This will allow the user to define a simple line as a path for his node. Therefore, nodes can only move with this line. The user just describes the destination point of a line segment (starting point is the starting location of the node) and thus defines a trajectory for the node to move back and forth. Additionally, Castalia has no 3D visualization engine, and therefore users cannot visualize their simulated nodes and space in 3D. In this paper, an enhanced mobility manager will be presented to overcome many drawbacks of Castalia's traditional mobility manager. The presented mobility manager can deal with paths rather than lines. This will allow users to simulate nodes moving with any possibilities within the simulation space. Additionally, a 3D visualization engine will be integrated so that users can visualize their simulated 3D spaces and node easily.

A Review on Optimized FFT/IFFT Architectures for OFDM Systems

Vol. 4  Issue 3
Year: 2015
Issue:Oct-Dec 
Title:A Review on Optimized FFT/IFFT Architectures for OFDM Systems
Author Name:E. Sujatha, C. Subhas, M. N. Giri Prasad and N. Padmaja
Synopsis:
This paper surveys, the widely adopted architectures of FFT/IFFT processor for MIMO OFDM systems. Emerging trends in mobile communication pose many architectural challenges to achieve high data throughput, less hardware complexity, low power consumption, high speed MIMO-OFDM systems. FFT/IFFT processor is one of the highest computational complexity modules in the system, to meet IEEE 802.11n requirements. The main concern of application of pipeline FFT/IFFT architectures is performance and power reduction. At the same time, application of memory based FFT/IFFT architectures are preferred when complexity is a main concern. High throughput rate can be achieved by the use of parallel data path schemes and higher radix and mixed radix FFT algorithms are used to reduce power consumptions and hardware complexity of the OFDM system. The unfolding mixed radix multipath delay feedback FFT architecture is used to deal efficiently with multiple data sequences. In Single-path delay feedback style, a reconfigurable complex multiplier and bit-parallel multipliers to achieve a ROM-less FFT/IFFT processor for low power consumption. This paper presents a comparative study on different efficient pipeline FFT/IFFT processor for OFDM applications in terms of scope of optimization and hardware complexity. Finally, this survey paper suggests open research challenges in this emerging area.

Analysis of OFDM with DQPSK Modulation

Vol. 4  Issue 3
Year: 2015
Issue:Oct-Dec 
Title:Analysis of OFDM with DQPSK Modulation
Author Name:Akanksha Shakya and Sandeep Sharma
Synopsis:
The Orthogonal Frequency Division Multiplexing (OFDM) technique has become extremely well-liked technique in the last two decades. It is a bandwidth efficient signalling scheme for bandwidth digital communications. The present and upcoming generation of communication system depends mainly on such technique, because of its skill to combat multipath fading channels using the analogous concept of cyclic prefix (Guard Interval).With OFDM, it is possible to use a differential coding/differential detection either in the time or frequency domain bank on the condition of transmission channels with the adoption of DQPSK as a method of subcarrier modulation. It is crucial to understand the concepts behindOFDM. In whole architecture, the entire mathematicalmanoeuvring occur in transmitter and receiver block i.e. IFFT and FFT block correspondingly. The speed augmentation is the key contribution of the main processing blocks in OFDM system. In this paper, the authors will discuss the basics of OFDM system using 4 sub carriers over the AWGN channel providing DQPSK modulation. Simulation has been performed on the MATLAB so that, the graphical output will be optimized for interaction and some of its prospective and consequences have been studied.

Enhanced Leach Clustering Based on Event Location

Vol. 4  Issue 3
Year: 2015
Issue:Oct-Dec 
Title:Enhanced Leach Clustering Based on Event Location
Author Name:Ravi Teja, Raunaq Nayar, Satyam Aggarwal and S. Indu
Synopsis:
The wireless sensor networks need to be energy efficient in order to improve the lifetime of the sensor nodes involved in the network as well minimizing the redundant packets transmitted to the sink. To ensure such a situation, there is a need to ensure that only those sensors which are in proximity to the source of useful and desirable information (also termed as event of information) should be kept active in the sensor network. In this paper, the authors proposed a novel enhanced energy efficient leach algorithm based on energy and distance which can be used to ensure that useful packets get transmitted to the sink and simultaneously minimizing power consumption of network to ensure longer lifetime of the sensor nodes in the network.

Miniaturized I – Slotted Multiband PIFA for Wireless Applications

Vol. 4  Issue 3
Year: 2015
Issue:Oct-Dec 
Title:Miniaturized I – Slotted Multiband PIFA for Wireless Applications
Author Name:Manika Gupta, Beant Kaur and Garima Saini
Synopsis:
In this paper, a novel approach of multi band planar inverted-F Antenna for wireless communication applications has been presented. The multi band antenna has been designed by using one rectangular parasitic element which is placed under I - slotted radiating element to achieve multiband operating frequencies. This multi band PIFA can be operated at various operating frequencies which are PCS1900 UL Band (1.90 GHz), IMT – E2600 (2.59 GHz), 4G LTE Band38 (2.59 GHz), LTE Band22/42 Band (3.50 GHz), WiMAX (3.5 GHz) and WLAN/HIPERLAN (5.4 GHz) applications. The proposed antenna comprises of a Flame Retardant 4 (FR4) dielectric substrate, which is constructed below the rectangular patch, a shorting plate which supports the radiating element and acts as a connector between the top patch and the ground plane. The ground plane is located under the substrate. The overall dimension of the proposed antenna is 27mm×30mm×3.8mm. Efforts has been made to keep the height (3.8mm)minimum possible so that, the antenna can be easily placed in the housing of handheld devices. The simulated results have shown a gain of 3 – 7 dB and radiation pattern gives almost omni – directional pattern at different targeted frequencies. The antenna layout in terms of antenna design, return loss, VSWR, gain and radiation pattern has been shown in this paper.

Code Division for Multiple Access: Opportunities and - Perhaps - Pitfalls

Vol. 4  Issue 3
Year: 2015
Issue:Oct-Dec 
Title:Code Division for Multiple Access: Opportunities and - Perhaps - Pitfalls
Author Name:Anuja Mishra and Sharad Mohan Shrivastava
Synopsis:
Code division for multiple access is a key technology used in the 3 Generation (3G) wireless technologies. CDMA is a multiple access technology in which, different users are allocated with different codes. There is an increasing use of CDMA for mobile networks, where the current CDMA service covers 10million users, with the expectation of more than 100 million within the first decade of the next century, without new spectrum allocation. This paper analyses some interesting properties of PN sequence and further elaborates about various methods of generation of PN sequences. This paper will be discussing about, Nomenclature of CDMA, CDMA at transmitter and receiver sections, CDMA as Spread Spectrum System, Code generation in CDMA, CDMA codes, properties and PN sequences and Bit Error Rate ( BER ) ofCDMA.

Layer Functionality in Spectrum Management

Vol. 4  Issue 3
Year: 2015
Issue:Oct-Dec 
Title:Layer Functionality in Spectrum Management
Author Name:Maninder Kaur
Synopsis:
Radio Communication Networks rely on the radio frequency spectra which are the set of frequencies ranging from3 KHz to 300 GHz. With increasing demand for wireless communication, this radio frequency spectra has become an expensive commodity. Thus, the efficient use the spectrum resources have become an essential issue. The alternative to inefficient fixed spectrum allocation is the sharing of the spectra amongst the licensed and unlicensed users. Cognitive radio, which is a form of wireless communication is the key technology which provides the best solution by allowing a group of secondary users to share the radio spectrum originally allocated to the primary users. This sharing of the spectrum is termed as Dynamic Spectrum Access (DSA) or Dynamic Spectrum Allocation. The major components of the DSA are the spectrum sensing, spectrum decision, spectrum sharing and spectrum mobility.Management of these tasks collectively is termed as spectrum management. These tasks are handled with the assistance of different layers of the OSI model namely, physical layer, link layer, network layer, transport layer and application layer. This paper reviews the role of different layers of the OSI model in the working of a cognitive radio leading to spectrum management.

A Review on Frequency Reconfigurable Microstrip Antennas

Vol. 4  Issue 2
Year: 2015
Issue:Jul-Sep
Title:A Review on Frequency Reconfigurable Microstrip Antennas
Author Name:T. S. Sheriba and M. Murugan
Synopsis:
The need for a simpler system that satisfies multiple requirements and standards has increased due to the rapid progress in the field of communication. The development of reconfigurable antennas has turned out to be a boon to such systems due to its dynamic characteristics, simple structure, light weight, better gain and radiation properties. The fast growing wireless technologies demands a highly complex system to satisfy the standards. This hardware complexity has posed a challenge to the research field in a way to make simple structures with effective characteristics. The researchers have presently succeeded in transforming these complex hardwares like filters at front end into simple antenna structures. This survey concentrates on various research works carried out in the field of frequency reconfiguration in microstrip antennas that has considerably reduced the complexity in structures and thereby the antenna size. Keywords: Frequency Reconfiguration, PIN Diodes, Varactor, Micro-Electro-Mechanical System(MEMS), Optical Antennas, Holographic Antennas, Ultra Wideband Antennas, Tunable Materials, Multipixel Antenna, Slot Antennas, Mechanically Reconfigurable Antennas.

HHT and DWT Based MIMO-OFDM for Various Modulation Schemes: A Comparative Approach

Vol. 4  Issue 2
Year: 2015
Issue:Jul-Sep
Title:HHT and DWT Based MIMO-OFDM for Various Modulation Schemes: A Comparative Approach
Author Name:N. Padmaja and E. Ramyakrishna
Synopsis:
This paper presents a comparative study of HHT and DWT Based MIMO-OFDM for BPSK, QPSK and QAM modulation schemes in AWGN and Raleigh Fading Channel. Angular diversity is used in radars to mitigate the impairment caused by rapid fluctuations in Radar Cross Section (RCS) of the target. The antennas are placed in separate locations so that the target is seen from different angles. Such systems are called Statistical Multiple Input Multiple Output (MIMO) or MIMO radars with distributed antennas. This statistical MIMO radar exploits angular diversity to mitigate the impacts of RCS fluctuations. The channel capacity in AWGN channel is better when compared to the Rayleigh fading noise channel, since the SNR is high with low BER for any signal in any type of modulation technique. So that AWGN channel gives good results. Wavelet based OFDM has a lot of advantages compared to the FFT based OFDM. There is no need for cyclic prefix, flexibility and gives an optimal resolution. HHT based MIMO-OFDM gives better SNR and low BER compared to the FFT and DWT based MIMO-OFDM. In DWT MIMO OFDM, wavelets are applicable in almost all the areas of communications schemes with OFDM, which is a durable applicant for next peers of wireless schemes. Comparing different types of modulation schemes such as BPSK,QPSK and QAM, BPSK gives good results. So, finally HHT based MIMO OFDM in AWGN channel by using BPSK modulation technique gives better results compared to the DWT based MIMO OFDM.

Design and Analysis of Double T-Shaped Triangular Microstrip Patch Antenna

Vol. 4  Issue 2
Year: 2015
Issue:Jul-Sep
Title:Design and Analysis of Double T-Shaped Triangular Microstrip Patch Antenna
Author Name:Anup Kumar Chaturvedi and R.K. Prasad
Synopsis:
This paper explains a detailed analysis on the design and implementation of 2x1 microstrip patch antenna array of given specifications using HFSS v15 software. The objective of this paper is to increase the antenna gain with reduced antenna size. The design has a dielectric material FR4 with dielectric substrate permittivity of 4.4, tangent loss of 0.002 and height of 1.6 mm. The microstrip patch antenna array is designed for WLAN and Ultra wide band Frequency applications, at an operating frequency of 3.6GHz and 6GHz with microstrip line feed and power dividers.

Energy Aware MAC Protocols for Wireless Sensor Networks

Vol. 4  Issue 2
Year: 2015
Issue:Jul-Sep
Title:Energy Aware MAC Protocols for Wireless Sensor Networks
Author Name:K. Nirmal Raja and M. Marsaline Beno
Synopsis:
Wireless Sensor Networks (WSN) are battery-operated computing and sensing devices. The sensor nodes' lifetime is mainly influenced by its battery lifetime. Hence in a WSN MAC, energy conservation and self-configuration are primary goals, while per-node fairness and latency are less important. WSN devices include a low-rate, short-range wireless radio (10–100 kbps, <100 m). Radio communication is often the most power intensive operation and also the major contributor to the overall nodes' energy consumption, and hence the radio must incorporate energy-efficient sleep and wake-up modes. In this paper, three low power RF protocols such as SimpliciTI, TI-MAC, ZStack radio developed by Texas Instruments (TI) were implemented on CC2530 to form a simple data gathering star network. A contention-based MAC mechanism (CSMA/CA) is followed. The wireless protocols are tested for its operation and the performance measures such as the energy consumption of each node and the average energy of the received packets are measured for each protocol and compared.

A Study on Access Point Selection Schemes in Wireless LAN

Vol. 4  Issue 2
Year: 2015
Issue:Jul-Sep
Title:A Study on Access Point Selection Schemes in Wireless LAN
Author Name:P. Dileep Kumar Reddy and K. Sireesha 
Synopsis:
In recent years, Wireless Local Area Networks (WLANs) are widely deployed everywhere due to low-cost and easy installation. Selecting the best access point is the major research problem. The stations in the network should get associated with the suitable Access Points (AP) that result in higher throughput. In IEEE 802.11 wireless networks, the simple association strategy is to get associated to the AP with the strongest Received Signel Strength Indication (RSSI) value, which may cause load imbalance and eventually traffic overhead. Also, this strategy may not result in effective throughput as it does not consider the other parameters like channel conditions, traffic type, access point load. Several other strategies that use decision metrics like load information, position of AP, potential bandwidth, round trip time have been proposed after a long research work, but has failed in perfect association with an access point. Thus, access point selection is still a critical problem. A new metric or combination of metrics has to be derived that facilitates the effective selection of an AP, that maximizes the throughput. This paper presents the existing AP selection strategies in the context of WLAN. This paper also provides directions to design the metrics of AP selection method in a WLAN.