Download or read book A QoS Capable Architecture for IEEE 80211 Wireless LAN and the Prototype Implementation on Linux written by Dong Liu and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing popularity of wireless handheld devices with multimedia functionality and IEEE 802.11 based network connectivity generated the need for Quality of Service (QoS) support of real time applications deployed over the wireless LANs. However, the time varying nature of wireless link and network is a serious challenge when attempting to provide Quality of Service support. This thesis proposes a low cost/complexity QoS capable wireless LAN architecture. We designed a distributed network congestion control scheme based on current commercial available hardware. The proposed technique was implemented on a Linux based testbed. Its performance was assessed through extensive experiments. Our evaluation test work includes two parts. First an IEEE802.11b wireless LAN testbed is established and a thorough network capacity measurement test is performed. The actual performance of real wireless LAN products is evaluated in a typical indoor environment. Furthermore, the impacts of multiple competing stations and nearby radio noise are also evaluated in this testbed. In the second part, the QoS capable wireless architecture prototype is implemented using Linux operating system Redhat 7.3 and Orinoco Golden IEEE802.11b wireless network card. The performance evaluation is conducted using the prototype implemented on the IEEE802.11 b wireless LAN testbed.

Download or read book A QoS Capable Architecture for IEEE 802 11 Wireless LAN and the Prototype Implementation on Linux written by Dong Liu and published by . This book was released on 2008 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book End to end QoS Guarantee in Heterogeneous Wired cum wireless Networks written by Ming Li and published by . This book was released on 2003 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: With information access becoming more and more ubiquitous, there is a need for providing QoS support for communication that spans wired and wireless networks. For the wired side, RSVP/SBM has been widely accepted as a flow reservation scheme in IEEE 802 style LANs. In this paper, we investigate the integration of RSVP and a RSVP-like flow reservation scheme in wireless LANs, as an end-to-end solution for QoS guarantee in wired-cum-wireless networks. We propose WRESV, an RSVP-like flow reservation and admission control scheme for IEEE 802.11 wireless LAN. Using WRESV, wired/wireless integration can be easily implemented by cross-layer interaction at the Access· Point. Main components of the integration are RSVP-WRESV parameter mapping, and the initiation of new reservation messages, depending on where senders/receivers are located. In addition, we also propose various optimizations for supporting multicast session, mobility management, and admission control.

Download or read book End to End QoS Network Design written by Tim Szigeti and published by Cisco Press. This book was released on 2013-11-21 with total page 1089 pages. Available in PDF, EPUB and Kindle. Book excerpt: End-to-End QoS Network Design Quality of Service for Rich-Media & Cloud Networks Second Edition New best practices, technical strategies, and proven designs for maximizing QoS in complex networks This authoritative guide to deploying, managing, and optimizing QoS with Cisco technologies has been thoroughly revamped to reflect the newest applications, best practices, hardware, software, and tools for modern networks. This new edition focuses on complex traffic mixes with increased usage of mobile devices, wireless network access, advanced communications, and video. It reflects the growing heterogeneity of video traffic, including passive streaming video, interactive video, and immersive videoconferences. It also addresses shifting bandwidth constraints and congestion points; improved hardware, software, and tools; and emerging QoS applications in network security. The authors first introduce QoS technologies in high-to-mid-level technical detail, including protocols, tools, and relevant standards. They examine new QoS demands and requirements, identify reasons to reevaluate current QoS designs, and present new strategic design recommendations. Next, drawing on extensive experience, they offer deep technical detail on campus wired and wireless QoS design; next-generation wiring closets; QoS design for data centers, Internet edge, WAN edge, and branches; QoS for IPsec VPNs, and more. Tim Szigeti, CCIE No. 9794 is a Senior Technical Leader in the Cisco System Design Unit. He has specialized in QoS for the past 15 years and authored Cisco TelePresence Fundamentals. Robert Barton, CCIE No. 6660 (R&S and Security), CCDE No. 2013::6 is a Senior Systems Engineer in the Cisco Canada Public Sector Operation. A registered Professional Engineer (P. Eng), he has 15 years of IT experience and is primarily focused on wireless and security architectures. Christina Hattingh spent 13 years as Senior Member of Technical Staff in Unified Communications (UC) in Cisco’s Services Routing Technology Group (SRTG). There, she spoke at Cisco conferences, trained sales staff and partners, authored books, and advised customers. Kenneth Briley, Jr., CCIE No. 9754, is a Technical Lead in the Cisco Network Operating Systems Technology Group. With more than a decade of QoS design/implementation experience, he is currently focused on converging wired and wireless QoS. n Master a proven, step-by-step best-practice approach to successful QoS deployment n Implement Cisco-validated designs related to new and emerging applications n Apply best practices for classification, marking, policing, shaping, markdown, and congestion management/avoidance n Leverage the new Cisco Application Visibility and Control feature-set to perform deep-packet inspection to recognize more than 1000 different applications n Use Medianet architecture elements specific to QoS configuration, monitoring, and control n Optimize QoS in rich-media campus networks using the Cisco Catalyst 3750, Catalyst 4500, and Catalyst 6500 n Design wireless networks to support voice and video using a Cisco centralized or converged access WLAN n Achieve zero packet loss in GE/10GE/40GE/100GE data center networks n Implement QoS virtual access data center designs with the Cisco Nexus 1000V n Optimize QoS at the enterprise customer edge n Achieve extraordinary levels of QoS in service provider edge networks n Utilize new industry standards and QoS technologies, including IETF RFC 4594, IEEE 802.1Q-2005, HQF, and NBAR2 This book is part of the Networking Technology Series from Cisco Press®, which offers networking professionals valuable information for constructing efficient networks, understanding new technologies, and building successful careers.

Download or read book Wireless Local Area Networks Quality of Service written by Osama S. Aboul-Magd and published by Standards Information Network. This book was released on 2008-03-18 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is part of the IEEE Standards Wireless Networks Series. This book describes Wireless Local Area Networks Quality of Service enhancements. Those enhancements enable the support of real-time applications such as voice and video. The scope of the book includes: - Overview of QoS mechanisms and architectures. - WLAN QoS mechanisms and relationship to QoS general architectures. - Performance analysis and case studies. WLAN QoS planning and engineering are challenging tasks to both network operators and end users. This book is an attempt to satisfy the need for better understanding of WLAN QoS features as well as the related engineering challenges. The reader will be able to understand WLAN QoS mechanisms and features in a simple and clear way beyond that obtained by just reading standard documents. The reader of the book should be able to understand: - WLAN QoS basic operation. How WLAN QoS is related to other QoS architectures especially IP QoS, and the related interworking issues. - How to tackle WLAN QoS main issues including admission control, scheduling, and buffer management. How to engineer a WLAN-based network to support QoS-based applications.

Download or read book Provision of QoS for Multimedia Services in IEEE 802 11 Wireless Network written by and published by . This book was released on 2006 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Implementation of the IEEE 802.11 technology for wireless local area networks (WLANs) has created a new opportunity to support real time and multimedia applications. The IEEE 802.11 defines a Medium Access Control (MAC), and Physical Layers (PHYs), which provides rates from 1 to 54 Mbit/s depending on specification. In IEEE 802.11 network, the PHY rate to be used for the transmission is completely determined by the source node and is closely connected with the wireless channel performance. The varying nature of WLAN channel over time can degrade the QoS level of multimedia service, which calls for elaboration of advanced QoS mechanism supporting multimedia services. The research works applied to video transmission over WLAN mostly concentrate on using a link adaptation techniques or optimisation of video stream by cross-layer signalling. It appears to be not sufficient as far as a provision of QoS for multimedia services is considered. In the paper, a new mechanism of QoS enhancement respecting also modifications in transport and network layers is discussed. A general description of this mechanism is presented with special emphasize on new approach to the multimedia rate control. The paper covers the verification of the proposal by simulation method as well as a discussion of some selected results of simulation.

Download or read book Internet QoS written by Zheng Wang and published by Morgan Kaufmann. This book was released on 2001 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1 The Big Picture -- 2 Integrated Services -- 3 Differentiated Services -- 4 Multiprotocol Label Switching -- 5 Internet Traffic Engineering.

Download or read book QoS Provisioning for IEEE 802 11 MAC Protocols written by Ye Ge and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this dissertation, we investigate the issue of Quality of Service (QoS) provisioning for IEEE 802.11 MAC protocols. We propose a multiple class p-persistent version of the IEEE 802.11 protocol to support QoS differentiation in wireless local area networks (WLANs). A theoretical analysis model is proposed to predict the performance of this protocol. Through analytical modeling and simulation, we demonstrate that by assigning appropriate different transmission probabilities to wireless nodes of different classes, it is feasible to provide service differentiation and achieve the targeted throughput ratio among different classes, while at the same time, maximizing the total channel utilization. We also consider several implementation issues to practically implement the proposed work conforming to the IEEE 802.11 standard. In particular, we derive an approximate solution for the analytical model to reduce the computational complexity and estimate the performance deterioration due to such an approximate solution. We point out that as long as the average packet collision period is much longer than the basic slot duration in the backoff algorithm, (which is true in all the 802.11 family standards such as 802.11, 802.11b, 802.11a and 802.11g, as well as many potential new systems with higher transmission rates,) the loss in channel utilization is limited when the approximate solution is used to determine the protocol parameters. We associate the contention window based backoff scheme in the current 802.11 mac protocol to the proposed p-persistent MAC protocol through a simple relation between the contention window, $cw$, and the persistent probability, p. We also propose a simple yet effective mechanism to on-line estimate the number of active stations in a QoS basic service set (QBSS) so as to handle the network dynamics and optimize system parameters dynamically. By extending the analytical model, we study the impact of AIFS values in IEEE 802.11e on rate differentiation between different traffic classes, demonstrate that the per flow throughput ratio between different traffic classes is a function of both the persistent probability (or the contention window size) and AIFS values. Under the asymptotic condition, we derive a closed-form relation. Through analytical modeling and simulation, we evaluate the effect of tuning AIFS values to provide throughput differentiation. We recommend to only adjust the persistent probability p or equivalently the contention window size cw to achieve the desired rate differentiation, while keeping the AIFS values of all traffic classes to the same value (e.g., at DIFS). This keeps the dimension of design freedom small and the parameter fine-tuning process tractable.

Download or read book QoS Enhancements in IEEE 802 11 Wireless LANs to Support Real time Services written by Irshad Ali Qaimkhani and published by . This book was released on 2008 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book QoS Evaluation of the WLAN IEEE 802 11e written by Mina Youssef and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book QoS Engineering for a Wireless Hybrid Network of IEEE 802 16 IEEE 802 11e written by Kamal Gakhar and published by . This book was released on 2007 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: La thèse porte sur l'ingénierie de la Qualité de Service sur un réseau radio mixant les technologies IEEE 802.16 et IEEE 802.11. Le projet IROISE, qui suscite cette étude, définit une architecture dans laquelle des points d'accès sont reliés à un Point de Présence (POP) d'opérateur par une BLR ~= 40Ghz, et les points d'accès 802.11 sont accessibles à des usagers fixes, ou peu mobiles (marche à pied). l'argument du projet est d'étudier comment supporter des services nécessitant soit une bande passante garantie, soit de la QoS (en matière de délai ou de gigue) sur une telle architecture. la thèse portera sur la spécification des mécanismes à mettre en oeuvre dans les équipements de la plaque IROISE afin de supporter ces services . Ces équipements sont essentiellement les serveurs localisés au niveau du POP et les équipements couplant technologies IEEE 802.16 et IEEE 802.11.

Download or read book Enhanced Admission Control and QoS Provisioning in IEEE 802 11 Wireless LANs written by Yi Liu and published by . This book was released on 2007 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A New Framework for QoS Provisioning in Wireless LANs Using the P Persistent MAC Protocol written by Kiran Babu Anna and published by . This book was released on 2010 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: The support of multimedia traffic over IEEE 802.11 wireless local area networks (WLANs) has recently received considerable attention. This dissertation has proposed a new framework that provides efficient channel access, service differentiation and statistical QoS guarantees in the enhanced distributed channel access (EDCA) protocol of IEEE 802.11e. In the first part of the dissertation, the new framework to provide QoS support in IEEE 802.11e is presented. The framework uses three independent components, namely, a core MAC layer, a scheduler, and an admission control. The core MAC layer concentrates on the channel access mechanism to improve the overall system efficiency. The scheduler provides service differentiation according to the weights assigned to each Access Category (AC). The admission control provides statistical QoS guarantees. The core MAC layer developed in this dissertation employs a P-Persistent based MAC protocol. A weight-based fair scheduler to obtain throughput service differentiation at each node has been used. In wireless LANs (WLANs), the MAC protocol is the main element that determines the efficiency of sharing the limited communication bandwidth of the wireless channel. In the second part of the dissertation, analytical Markov chain models for the P-Persistent 802.11 MAC protocol under unsaturated load conditions with heterogeneous loads are developed. The Markov models provide closed-form formulas for calculating the packet service time, the packet end-to-end delay, and the channel capacity in the unsaturated load conditions. The accuracy of the models has been validated by extensive NS2 simulation tests and the models are shown to give accurate results. In the final part of the dissertation, the admission control mechanism is developed and evaluated. The analytical model for P-Persistent 802.11 is used to develop a measurement-assisted model-based admission control. The proposed admission control mechanism uses delay as an admission criterion. Both distributed and centralized admission control schemes are developed and the performance results show that both schemes perform very efficiently in providing the QoS guarantees. Since the distributed admission scheme control does not have a complete state information of the WLAN, its performance is generally inferior to the centralized admission control scheme. The detailed performance results using the NS2 simulator have demonstrated the effectiveness of the proposed framework. Compared to 802.11e EDCA, the scheduler consistently achieved the desired throughput differentiation and easy tuning. The core MAC layer achieved better delays in terms of channel access, average packet service time and end-to-end delay. It also achieved higher system throughput than EDCA for any given service differentiation ratio. The admission control provided the desired statistical QoS guarantees.

Download or read book IEEE Trial use Recommended Practice for Multi vendor Access Point Interoperability Via an Inter Access Point Protocol written by and published by . This book was released on 2003 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Enabling Techniques Design for QoS Provision in Wireless Communications written by Penghui Mi and published by . This book was released on 2012 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Guaranteeing Quality of Service (QoS) has become a recognized feature in the design of wireless communications. In this thesis, the problem of QoS provision is addressed from di erent prospectives in several modern communication systems. In the first part of the thesis, a wireless communication system with the base station (BS) associated by multiple subscribers (SS) is considered, where di erent subscribers require di erent QoS. Using the cross-layer approach, the conventional single queue finite state Markov chain system model is extended to multiple queues' scenario by combining the MAC layer queue status with the physical layer channel states, modeled by finite state Markov channel (FSMC). To provide the diverse QoS to di erent subscribers, a priority-based rate allocation (PRA) algorithm is proposed to allocate the physical layer transmission rate to the multiple medium access control (MAC) layer queues, where di erent queues are assigned with di erent priorities, leading to their di erent QoS performance and thus, the diverse QoS are guaranteed. Then, the subcarrier allocation in multi-user OFDM (MU-OFDM) systems is stuied, constrained by the MAC layer diverse QoS requirements. A two-step cross-layer dynamic subcarrier allocation algorithm is proposed where the MAC layer queue status is firstly modeled by a finite state Markov chain, using which MAC layer diverse QoS constraints are transformed to the corresponding minimum physical layer data rate of each user. Then, with the purpose of maximizing the system capacity, the physical layer OFDM subcarriers are allocated to the multiple users to satisfy their minimum data rate requirements, which is derived by the MAC layer queue status model. Finally, the problem of channel assignment in IEEE 802.11 wireless local area networks (WLAN) is investigated, oriented by users' QoS requirements. The number of users in the IEEE 802.11 channels is first determined through the number of di erent channel impulse responses (CIR) estimated at physical layer. This information is involved thereafter in the proposed channel assignment algorithm, which aims at maximum system throughput, where we explore the partially overlapped IEEE 802.11 channels to provide additional frequency resources. Moreover, the users' QoS requirements are set to trigger the channel assignment process, such that the system can constantly maintain the required QoS.

Download or read book Software Defined Radio Prototyping of IEEE 802 11 Wireless LAN Protocols written by Shravan Kumar Surineni and published by . This book was released on 2004 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation Modelling of QoS Enhancements in IEEE 802 11 Networks and the Effects of Channel Modelling written by Tinotenda Leslie Mundangepfupfu and published by . This book was released on 2011 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: