Download or read book Performance Analysis and Enhancement for IEEE 802 11e Wireless Networks written by 張緯康 and published by . This book was released on 2006 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Analysis of IEEE 802 11A Signals Under Different Operational Environments written by Roy Chan Hsiung Wei and published by . This book was released on 2004-09 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the rapid employment of wireless networks commercially, the military is seeking viable solutions for providing high-speed wireless network throughout the battle space. The IEEE 802.11a wireless LAN presents an attractive solution providing up to 54 Mbps data-link bandwidth. Moreover, it operates in the less congested 5-GHz U-NII band and possesses more operating channels. This research implemented two prototype systems using low-cost commercially available hardware. The Cisco Aironet 1400 wireless bridge and the Proxim Tsunami MP.11a wireless system were chosen for their superior specifications and for their reputation of being market leaders in IEEE 802.11 wireless products. The performances of the prototype systems were evaluated in three operational environments (land, water and vegetation). The data collected were then compared to the theoretical performance.

Download or read book Performance Analysis and Enhancement of IEEE 802 11e EDCA Protocols written by Rami Ali Mohammed Abudayyeh and published by . This book was released on 2011 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis and Improvement of Medium Access Control Protocols in Wireless Networks written by Jia Hu and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to efficiently utilize the scarce wireless resource as well as keep up with the ever-increasing demand for Quality-of-Service (QoS) of multimedia applications, wireless networks are undergoing rapid development and dramatic changes in the underlying technologies and protocols. The Medium Access Control (MAC) protocol, which coordinates the channel access and data transmission of wireless stations, plays a pivotal role in wireless networks. Performance modelling and analysis has been and continues to be of great theoretical and practical importance in the design and development of wireless networks. This research is devoted to developing efficient and cost-effective analytical tools for the performance analysis and enhancement of MAC protocols in Wireless Local Area Networks (WLANs) under heterogeneous multimedia traffic. To support the MAC-layer QoS in WLANs, the IEEE 802.11e Enhanced Distributed Channel Access (EDCA) protocol has proposed three QoS differentiation schemes in terms of Arbitrary Inter-Frame Space (AIFS), Contention Window (CW), and Transmission Opportunity (TXOP). This research starts with the development of new analytical models for the TXOP scheme specified in the EDCA protocol under Poisson traffic. A dynamic TXOP scheme is then proposed to adjust the TXOP limits according to the status of the transmission queue. Theoretical analysis and simulation experiments show that the proposed dynamic scheme largely improves the performance of TXOP. To evaluate the TXOP scheme in the presence of ii heterogeneous traffic, a versatile analytical model is developed to capture the traffic heterogeneity and model the features of burst transmission. The performance results highlight the importance of taking into account the heterogeneous traffic for the accurate evaluation of the TXOP scheme in wireless multimedia networks. To obtain a thorough and deep understanding of the performance attributes of the EDCA protocol, a comprehensive analytical model is then proposed to accommodate the integration of the three QoS schemes of EDCA in terms of AIFS, CW, and TXOP under Poisson traffic. The performance results show that the TXOP scheme can not only support service differentiation but also improve the network performance, whereas the AIFS and CW schemes provide QoS differentiation only. Moreover, the results demonstrate that the MAC buffer size has considerable impact on the QoS performance of EDCA under Poisson traffic. To investigate the performance of EDCA in wireless multimedia networks, an analytical model is further developed for EDCA under heterogeneous traffic. The performance results demonstrate the significant effects of heterogeneous traffic on the total delay and frame losses of EDCA with different buffer sizes. Finally, an efficient admission control scheme is presented for the IEEE 802.11e WLANs based on analytical modelling and a game-theoretical approach. The admission control scheme can maintain the system operation at an optimal point where the utility of the Access Point (AP) is maximized with the QoS constraints of various users.

Download or read book MAC Layer Performance Analysis and Improvement and QoS Enhancement for IEEE 802 11 Wireless LANs written by Zhenning Kong and published by . This book was released on 2004 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Analysis of IEEE 802 11A Signals Under Different Operational Environments written by and published by . This book was released on 2004 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the rapid employment of wireless networks commercially, the military is seeking viable solutions for providing high-speed wireless network throughout the battle space. The IEEE 802.11a wireless LAN presents an attractive solution providing up to 54 Mbps data-link bandwidth. Moreover, it operates in the less congested 5-GHz U-NII band and possesses more operating channels. This research implemented two prototype systems using low-cost commercially available hardware. The Cisco Aironet 1400 wireless bridge and the Proxim Tsunami MP.11a wireless system were chosen for their superior specifications and for their reputation of being market leaders in IEEE 802.11 wireless products. The performances of the prototype systems were evaluated in three operational environments (land, water and vegetation). The data collected were then compared to the theoretical performance.

Download or read book Wireless Multimedia Communications written by K.R. Rao and published by CRC Press. This book was released on 2018-10-03 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the rapid evolution of multimedia communications, engineers and other professionals are generally forced to hoard a plethora of different texts and journals to maintain a solid grasp on essential ideas and techniques in the field. Wireless Multimedia Communications provides researchers and students with a primary reference to help readers take maximum advantage of current systems and uncover opportunities to propose new and novel protocols, applications, and services. Extract the Essentials of System Design, Analysis, Implementation A complete technical reference, the text condenses the essential topics of core wireless multimedia communication technologies, convergence, QoS, and security that apply to everything from networking to communications systems, signal processing, and security. From extensive existing literature, the authors distill the central tenets and primary methods of analysis, design, and implementation, to reflect the latest technologies and architectural concepts. The book addresses emerging challenges to inform the system standardization process and help engineers combat the high error rates and stringent delay constraints that remain a significant challenge to various applications and services. Keep Pace with Detailed Techniques to Optimize Technology The authors identify causes of information loss in point-to-point signal transmission through wireless channels, and then they discuss techniques to minimize that loss. They use examples that illustrate the differences in implementing various systems, ranging from cellular voice telephony to wireless Internet access. Each chapter has been carefully organized with the latest information to serve dual purposes as an easy-to-reference guide for professionals and as a principal text for senior-level university students.

Download or read book Performance Analysis and Enhancement of IEEE 802 11 Distributed Coordination Function written by Tushnim Bhattacharyya and published by . This book was released on 2005 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Simulation Modeling and Analysis of Wireless Local Area Networks Supporting the IEEE 802 11 Standard written by Jaikwan Joo and published by . This book was released on 1998-12-01 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research to improve the performance of the IEEE 802.11 has been ongoing since 1990. The focus of this research has investigated the use of the MAC and Physical layers for improving throughput. An adaptive MAC protocol, CATER (Code Adapts To Enhance Reliability) is based on the proposed MAC standard for wireless local area networks (WLAN)-802. 11. IEEE 802.11 uses a fixed Pseudo-Noise (PN) code for spreading the information signal, implying a fixed process gain at the receiver. When the channel degrades, IEEE 802.11 offers only retransmissions at the MAC layer to contend with the corrupted medium. However, CATER allows communicating stations to reconfigure their transceivers to use a longer PN code after a prescribed number of failed retransmissions. The longer PN code increases the process gain of the receiver and reduces the error rate. This thesis analyzes the performance of CATER as changing the factor: Start (the number of transmission before the channel is reconfigured) and Max (additional frame transmissions during reconfigure), PN code length, the number of station, and implementing Forward Error Correction (FEC). CATER provides better throughput for smaller Start and larger Max at a high bit error rate (10-3). When CATER uses a PN code length of 63, the throughput is increased by 101 percent at high bit error rate (BER). However, 802.11 is better than CATER at low BER ( 10-3).

Download or read book Performance Analysis of the IEEE 802 11 Wireless LAN Standard written by Craig Sweet and published by . This book was released on 1999 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quality of Service Architectures for Wireless Networks Performance Metrics and Management written by Adibi, Sasan and published by IGI Global. This book was released on 2010-01-31 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book further explores various issues and proposed solutions for the provision of Quality of Service (QoS) on the wireless networks"--Provided by publisher.

Download or read book Performance Analysis of the IEEE 802 11 based Wireless Networks in the Presence of Hidden Stations written by Fu-Yi Hung and published by . This book was released on 2009 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: The IEEE 802.11 is the most widely used standard in WLAN currently. It can support not only a WLAN with an access point but also an ad hoc wireless network. The key for being able to support various wireless networks is the Distribution Coordination Function (DCF) which is one of channel access methods in the IEEE 802.11 Medium Access Control (MAC) protocol. The DCF is a random access method where each station has the right to initiate a transmission without any central coordination. Hence, this method is useable not only in infrastructure network configurations but also in distributed and self-organized wireless networks. However, this random access method unavoidably introduces the hidden station problem that multiple stations simultaneously transmit packets to a common destination resulting in packet collision at the destination. This problem results from that DCF does not support the destination coordinating the traffic inside its transmission range. The hidden station problem is unique to wireless networks and significantly degrades the performance of wireless networks, but this problem has been ignored in previous studies. We propose our research work that model and analyze the performance of wireless networks including the hidden station effect in access-point and ad hoc type wireless networks. In access-point based wireless networks, we present a modified two-dimensional Markov chain model that characterizes the network performance in the presence of hidden stations. This model generalizes the existing work on IEEE 802.11 DCF performance modeling, and it is validated by comparison with ns-2 simulation. Second, in wireless ad hoc networks, the hidden station effect is different from that in an access-point based wireless network. Furthermore, this effect largely depends on the sender-receiver distance and physical carrier-sensing range. We devise a spatiotemporal analytical model that estimates the number of hidden stations based on the sender-receiver distance and physical carrier-sensing range. In addition, we also use our two-dimensional Markov chain model to evaluate the network performance under the hidden station effect in wireless ad hoc network. This result is in agreement with the result obtained by ns-2 simulation.

Download or read book Performance Enhancements of IEEE 802 11e EDCA in Time varying Wireless Networks written by Le Tan and published by . This book was released on 2007 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wireless Technologies Concepts Methodologies Tools and Applications written by Management Association, Information Resources and published by IGI Global. This book was released on 2011-08-31 with total page 2875 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains the latest research, case studies, theories, and methodologies within the field of wireless technologies.

Download or read book Web Artificial Intelligence and Network Applications written by Leonard Barolli and published by Springer. This book was released on 2019-03-14 with total page 1172 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of the book is to provide latest research findings, innovative research results, methods and development techniques from both theoretical and practical perspectives related to the emerging areas of Web Computing, Intelligent Systems and Internet Computing. As the Web has become a major source of information, techniques and methodologies that extract quality information are of paramount importance for many Web and Internet applications. Data mining and knowledge discovery play key roles in many of today’s prominent Web applications such as e-commerce and computer security. Moreover, the outcome of Web services delivers a new platform for enabling service-oriented systems. The emergence of large scale distributed computing paradigms, such as Cloud Computing and Mobile Computing Systems, has opened many opportunities for collaboration services, which are at the core of any Information System. Artificial Intelligence (AI) is an area of computer science that build intelligent systems and algorithms that work and react like humans. The AI techniques and computational intelligence are powerful tools for learning, adaptation, reasoning and planning. They have the potential to become enabling technologies for the future intelligent networks. Recent research in the field of intelligent systems, robotics, neuroscience, artificial intelligence and cognitive sciences are very important for the future development and innovation of Web and Internet applications.

Download or read book Performance Analysis of a Secure IEEE 802 11B Wireless Network Incorporating Personal Digital Assistants written by John Lee Camp and published by . This book was released on 2002-06-01 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research results of this thesis indicate very poor performance of a Wireless Local Area Network (WLAN) utilizing PDAs. Network throughput is adversely effected most by VPN implementation and slightly by increased file size. The client distance factor has virtually no effect on the throughput. The impact of each of these factor levels is small when compared to the magnitude of the overall mean throughput (

Download or read book Advances in Network Based Information Systems written by Leonard Barolli and published by Springer. This book was released on 2017-08-21 with total page 1195 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the latest research findings, innovative research results, methods and development techniques from both theoretical and practical perspectives related to the emerging areas of information networking and their applications. It includes the Proceedings of the 20th International Conference on Network-Based Information Systems (NBiS-2017), held on August 24–26, 2017 in Toronto, Canada. Today’s networks and information systems are evolving rapidly. Further, there are dynamic new trends and applications in information networking such as wireless sensor networks, ad hoc networks, peer-to-peer systems, vehicular networks, opportunistic networks, grid and cloud computing, pervasive and ubiquitous computing, multimedia systems, security, multi-agent systems, high-speed networks, and web-based systems. These networks are expected to manage the increasing number of users, provide support for a range of services, guarantee the quality of service (QoS), and optimize their network resources. In turn, these demands are the source of various research issues and challenges that have to be overcome – and which these Proceeding address.