Download or read book Throughput and Fairness in A Hybrid Channel Access Scheme for Ad Hoc Networks written by and published by . This book was released on 2003 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel hybrid channel access scheme that combines sender-initiated and receiver-initiated collision-avoidance handshakes is proposed for multi-hop ad hoc networks. The scheme is based on the observation that a receiver-initiated scheme is more appropriate when receivers are more knowledgeable of the contention around themselves and can compete for the channel more effectively. By adaptively sharing the burden of initiating the collision-avoidance handshake between the nodes that experience different levels of contention, better fairness may be achieved with almost no degradation in throughput. An attractive feature of the new scheme is that it is a simple extension to the existing IEEE 802.11 MAC protocol, and it maintains compatibility with the standard. The new scheme involves adding very simple queue management and book-keeping work mechanisms. Simulation experiments of the IEEE 802.11 MAC protocol and the new scheme show that, although the proposed hybrid scheme does not solve the fairness problem conclusively, it does alleviate the fairness problem in some cases without sacrificing much throughput and simplicity. The difficulty of improving fairness for TCP-based flows is demonstrated. A promising topic for future work consists of combining the new hybrid scheme with some proposed mechanisms that try to approximate fair queueing for ad hoc networks to achieve some QoS assurances. Without explicit information exchange among nodes, the fairness problem cannot be solved conclusively.
Download or read book A New Hybrid Channel Access Scheme for Ad Hoc Networks written by and published by . This book was released on 2002 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many contention-based channel access schemes have been proposed for multi-hop ad hoc networks in the recent past, and they can be divided into two categories, sender-initiated and receiver-initiated, according to the collision avoidance handshake in use. The sender-initiated scheme is adopted in the IEEE 802.11 Medium Access Control (MAC) protocol, which is by far the most popular and studied protocol. However, the IEEE 802.11 MAC protocol can experience serious fairness problems due to location-dependent contention and the binary exponential backoff it uses. On the other hand, a receiver-initiated collision avoidance handshake is more effective at the receiver's side. Hence, the authors propose a hybrid channel access scheme that combines both sender-initiated and receiver-initiated collision avoidance schemes. The new scheme involves only some additional queue management and book-keeping work while maintaining compatibility with the existing IEEE 802.11 protocol. Simulation experiments show that the new scheme is very effective, as it can achieve much better fairness than the original sender-initiated scheme with almost no degradation in throughput. The hybrid scheme also eliminates the need for a good traffic estimator, which is usually mandatory in pure receiver-initiated schemes.
Download or read book Universal Multiservice Networks written by Mário Marques Freire and published by Springer. This book was released on 2011-04-06 with total page 567 pages. Available in PDF, EPUB and Kindle. Book excerpt: On behalf of the Organizing and Program Committees of the 3rd European Conference on Universal Multiservice Networks (ECUMN 2004), it is our great pleasure to introduce the proceedings of ECUMN 2004, which was held during October 25–27, 2004, in Porto, Portugal. In response to the Call for Papers, a total of 131 papers were submitted from 29 countries. Each paper was reviewed by several members of the Technical Program Committee or by external peer reviewers. After careful assessment of thereviews,53paperswereacceptedforpresentationin13technicalsessions;half of them originated from countries outside Europe (mainly Asia). This illustrates the strong interest of this conference beyond its original geographical area. The conference program covered a variety of leading-edge research topics which are of current interest, such as wireless networks, mobile ad hoc networks, sensor networks, mobility management, optical networks, quality of service and tra?c, transport protocols, real-time and multimedia, Internet technologies and applications, overlay and virtual private networks, security and privacy, and network operations and management. Together with three plenary sessions from France T ́ el ́ ecom, Siemens, and Cisco Systems, these technical presentations - dressed the latest research results from the international industry and academia and reported on ?ndings on present and future multiservice networks.
Download or read book Medium Access Control in Ad Hoc Networks with Omni directional and Directional Antennas written by Yu Wang and published by . This book was released on 2004 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: An ad hoc network is a dynamic network formed on demand by a group of nodes without the aid of any pre-existing network infrastructure. An efficient and effective medium access control (MAC) protocol which regulates nodes access to the shared channel(s) is essential in an ad hoc network. Our work is focused on the throughput and fairness properties of existing omni-directional MAC protocols as well as enhancement of their performance with directional antennas via both analytical and simulation approaches. In the first part, we present the first analytical modeling of collision avoidance MAC protocols including the popular IEEE 802.11 MAC protocol in multi-hop ad hoc networks. We show that in ad hoc networks with a lot of hidden terminals, collision avoidance even if done correctly, can still limit achievable throughput significantly because of the much reduced spatial reuse. Then we advance the analytical modeling to evaluate those MAC protocols which use directional antennas and can achieve much higher throughput through directing transmissions and receptions to desired directions only. We show that the gain in spatial reuse outweighs that of collision avoidance and hence an aggressive all-directional scheme is more advantageous than other hybrid schemes that take conservative (or unnecessary) tradeoff between collision avoidance and spatial reuse. All the analytical work has provided very useful insight on the interaction between spatial reuse, interference reduction and collision avoidance that previous work lacked.
Download or read book AD HOC NETWORKS written by Prasant Mohapatra and published by Springer Science & Business Media. This book was released on 2006-01-16 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: AD HOC NETWORKS: Technologies and Protocols is a concise in-depth treatment of various constituent components of ad hoc network protocols. It reviews issues related to medium access control, scalable routing, group communications, use of directional/smart antennas, network security, and power management among other topics. The authors examine various technologies that may aid ad hoc networking including the presence of an ability to tune transmission power levels or the deployment of sophisticated smart antennae. Contributors to this volume include experts that have been active in ad hoc network research and have published in the premier conferences and journals in this subject area. AD HOC NETWORKS: Protocols and Technologies will be immensely useful as a reference work to engineers and researchers as well as to advanced level students in the areas of wireless networks, and computer networks.
Download or read book Improving the Performance of Wireless LANs written by Nurul Sarkar and published by CRC Press. This book was released on 2014-01-08 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: While there are countless books on wireless networks, few actually quantify the key performance-limiting factors of wireless local area networks (WLANs) and describe various methods for improving WLAN performance. Fulfilling these needs, Improving the Performance of Wireless LANs: A Practical Guide provides both theoretical background and empirical
Download or read book Security Design and Architecture for Broadband and Wireless Network Technologies written by Chilamkurti, Naveen and published by IGI Global. This book was released on 2013-04-30 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: While wireless technologies continue to provide an array of new challenges and multi-domain applications for business processes and solutions, there still remains to be a comprehensive understanding of its various dimensions and environments. Security, Design, and Architecture for Broadband and Wireless Network Technologies provides a discussion on the latest research achievements in wireless networks and broadband technology. Highlighting new trends, applications, developments, and standards, this book is essential for next generation researchers and practitioners in the ICT field.
Download or read book Networking 2004 written by Nikolas Mitrou and published by Springer Science & Business Media. This book was released on 2004-04-28 with total page 1551 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the Third IFIP-TC6 Networking Conference, NETWORKING 2004, held in Athens, Greece, in May 2004. The 103 revised full papers and 40 revised short papers were carefully reviewed and selected from 539 submissions. The papers are organized in topical sections on network security; TCP performance; ad-hoc networks; wavelength management; multicast; wireless network performance; inter-domain routing; packet classification and scheduling; services and monitoring; admission control; competition in networks; 3G/4G wireless systems; MPLS and related technologies; flow and congestion control; performance of IEEE 802.11; optical networks; TCP and congestion; key management; authentication and DOS prevention; energy aspects of wireless networks; optical network access; routing in ad-hoc networks; fault detection, restoration, and tolerance; QoS metrics, algorithms, and architecture; content distribution, caching, and replication; and routing theory and path computation.
Download or read book Handbook of Wireless Local Area Networks written by Mohammad Ilyas and published by CRC Press. This book was released on 2005-05-25 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Wireless Local Area Networks: Applications, Technology, Security, and Standards captures the current state of wireless LANs, and serves as the single comprehensive reference on the subject. Addressing challenges related to the further development of WLAN technology, the Handbook covers the entire spectrum of topics from basic concepts t
Download or read book NETWORKING 2007 Ad Hoc and Sensor Networks Wireless Networks Next Generation Internet written by Ian F. Akyildiz and published by Springer Science & Business Media. This book was released on 2007-04-27 with total page 1278 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 6th International IFIP-TC6 Networking Conference, NETWORKING 2007, held in Atlanta, GA, USA in May 2007. The 99 revised full papers and 30 poster papers were carefully reviewed and selected from 440 submissions. The papers are organized in topical sections on ad hoc and sensor networks: connectivity and coverage, scheduling and resource allocation, mobility and location awareness, routing, and key management; wireless networks: mesh networks, mobility, TCP, MAC performance, as well as scheduling and resource allocation; next generation inte.
Download or read book Hybrid Channel Access Scheduling in Ad Hoc Networks written by and published by . This book was released on 2002 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the hybrid activation multiple access (HAMA) protocol for ad hoc networks. Unlike previous channel access scheduling protocols that activate either nodes or links only, HAMA is a node-activation channel access protocol that also maximizes the chance of link activations using time- and code-division schemes. HAMA only requires identifiers of the neighbors within two hops from each node to schedule channel access. Using this neighborhood information, each node determines whether to transmit in the current time slot on a dynamically assigned spreading code. A neighbor protocol supplements HAMA with up-to-date two-hop neighborhood information by reliably propagating the one-hop neighbor updates through a novel random access technique. The throughput and delay characteristics of HAMA in randomly-generated multihop wireless networks are studied by analyses and simulations. The results of the analyses show that HAMA achieves higher channel utilization in ad hoc networks than a distributed scheduling scheme based on node activation, similar throughout as a well-known scheduling algorithm based on complete topology information, and much higher throughout than the ideal CSMA and CSMA/CA protocols.
Download or read book Applied Informatics and Communication Part II written by Dehuai Zeng and published by Springer Science & Business Media. This book was released on 2011-08-02 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt: The five volume set CCIS 224-228 constitutes the refereed proceedings of the International conference on Applied Informatics and Communication, ICAIC 2011, held in Xi'an, China in August 2011. The 446 revised papers presented were carefully reviewed and selected from numerous submissions. The papers cover a broad range of topics in computer science and interdisciplinary applications including control, hardware and software systems, neural computing, wireless networks, information systems, and image processing.
Download or read book Throughput and Fairness of Collision Avoidance Protocols in Ad Hoc Networks written by and published by . This book was released on 2004 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless ad hoc networks have received increasing interest in recent years because of their potential to be used in a variety of applications without the aid of any pre-existing network infrastructure. Due to the scarce channel bandwidth available in ad hoc networks, the design of efficient and effective medium access control (MAC) protocols that regulate nodes' access to a shared channel has become the subject of active research in recent years. Many MAC protocols have been proposed to mitigate the adverse effects of hidden terminals through collision avoidance. In Section 1, The authors present an analytical modeling to derive the saturation throughput of these sender-initiated collision avoidance protocols in multi-hop ad hoc networks with nodes randomly placed according to a two-dimensional Poisson distribution. They show that the sender-initiated collision-avoidance scheme achieves much higher throughput than the ideal CSMA scheme with a separate channel for acknowledgments. They also show that the collision-avoidance scheme can accommodate far fewer competing nodes within a region in a network infested with hidden terminals than in a fully connected network, if reasonable throughput is to be maintained. Simulations of the IEEE 802.11 MAC protocol and one of its variants validate the predictions made in the analysis. The simulation results also reveal the fairness problem in IEEE 802.11, which refers to the severe throughput degradation of some nodes due to their unfavorable locations in the network and the commonly used binary exponential backoff (BEB) algorithm that always favors the node that last succeeds. Section 2 introduce a framework to address the fairness problem and propose a topology-aware fair access (TAFA) scheme to realize the framework. Simulation results show that TAFA can solve the fairness problem in UDP-based applications with negligible degradation in throughput. Section 3 concludes this chapter with directions for future work.
Download or read book Networking written by and published by . This book was released on 2004 with total page 1568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Comprehensive Study of Power efficient Rendezvous Schemes for Wireless Sensor Networks written by Judy Lin and published by . This book was released on 2005 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cognitive Radio Oriented Wireless Networks written by Dominique Noguet and published by Springer. This book was released on 2016-05-28 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the thoroughly refereed conference proceedings of the 11th International Conference on Cognitive Radio Oriented Wireless Networks, CROWNCOM 2016, held in Grenoble, France, May 30 – April 1, 2016. The 62 revised full papers presented were carefully reviewed and selected from numerous submissions and cover the evolution of cognitive radio technology pertaining to 5G networks. The papers are clustered to topics on dynamic spectrum access/management, networking protocols for CR, modeling and theory, HW architecture and implementations, next generation of cognitive networks, standards and business models, emerging applications for cognitive networks.
Download or read book Proceedings of the Eleventh National Conference on Communications written by and published by Allied Publishers. This book was released on 2005 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt:
