Bücher von Dinesh Sharma

Quality of service (QoS) is one of the important issues for both customers and service provider¿s point of view. All the parameters related to QoS are having different importance for all customers and applications. So to maintain the Quality of Service (QoS) in fixed wireless access networks, the network planning is to be done carefully. Network planning is a complicated process consisting of several steps and involves through estimation by outdoor field propagation models. The basic requirements for network planning is to meet coverage and quality. The environmental factors such as area, foliage, rain, dust storms etc also greatly affect network planning to maintain the Quality of Service (QoS). A propagation model has been estimated for performance analysis in terms of received signal strength and error. In this book analysis has been made to achieve prediction accuracy of different propagation path loss models for Jaipur city of Rajasthan. On the basis of this analysis a best model is selected and modified for Jaipur (Rajasthan) India.

For wireless communication systems, the antenna is one of the most critical components. A good design of the antenna can relax system requirements and improve overall system performance. This book gives the design of a rectangular microstrip edge-fed and patch antenna array with a centre frequency of 13 GHz for Satellite applications whose frequency range is from 12 to 18GHz. A single element and 2×2 microstrip rectangular patch antennas was designed and simulated by using HFSS tool. The proposed patch antennas are used for RADAR and Satellite applications. The proposed antenna will be simulated for suitable frequencies in different applications for improving some antenna parameters like gain, return losses, radiation pattern, VSWR, etc.

Distinguishing itself from the mass of political biographies of Barack Obama, this first interdisciplinary study of Obama's Indonesian and Hawai'ian years examines their effect on his adult character, political identity, and global world-view.

A wireless body area network (WBAN) is a wireless network of wearable computing devices. The rapid growth in physiological sensors, low power integrated circuits and wireless communication has enabled a new generation of wireless censor networks. A WBAN is a recent trend in medical field where wearable devices which can measure signals such as heart beat and pulse rate are connected in a wireless network. The major challenge it faces is path loss during transmission of the signal. Both LOS and NLOS conditions are considered. This book helps to select the best way to propagate the signal in WBAN. Societal relevance includes monitoring, traffic, crops, infrastructure and health. It allows inexpensive and continuous health monitoring with real-time updates of medical records through the internet. This technology leads to concepts like telemedicine and mHealth which are previously thought impossible.

Wireless communication is one of the most dynamic and vibrant areas of technology development in the communication field today. It has been found that severe climatic conditions disturb the propagation of electromagnetic signals at higher frequencies (greater than 30 MHz). The disturbance is mainly due to molecular absorption by oxygen for frequencies ranging between 60 and 118 GHz and due to water vapour in 22, 183 and 325 GHz bands. Rain and fog has the most significant impact, since the size of the rain drops is of the order of the wavelength of the transmitted signal. This results in energy absorption by the rain drops themselves, and as a secondary effect energy is scattered by the drops. The frequency selective absorption characteristics of the atmosphere can be approximated by a transfer function. In most of the practical channels when the signal propagates through the atmosphere the effect of many factors on the signal has to be considered along with the free space propagation channel assumption. The main objective of this study is, therefore, to find out whether, and how, the different climatic conditions are influencing radio wave propagation in GSM frequency bands in general and in Narnaul, Haryana (India) in particular. To carry out this investigation, the records of radio wave propagation along with path loss during different climatic conditions have been analyzed. On the strength of these analyses, a propagation path loss model has been developed by proposing suitable correction factors due to different climatic conditions. The validation of this developed path loss model has been verified by taking reference models and by applying practically in different urban areas. The effect of these climatic conditions on the link budget has also been analyzed.