Subjective Audio Quality over a Secure IEEE 802.11n Draft 2.0 Wireless Local Area Network

This thesis investigates the quality of audio generated by a G.711 codec and transmission over an IEEE 802.11n draft 2.0 wireless local area network (WLAN). Decline in audio quality due to additional calls or by securing the WLAN with transport mode Internet Protocol Security (IPsec) is quantified. Audio quality over an IEEE 802.11n draft 2.0 WLAN is also compared to that of IEEE 802.11b and IEEE 802.11g WLANs under the same conditions. Audio quality is evaluated by following International Telecommunication Union Telecommunication Standardization Sector (ITU-T) Recommendation P.800, where human subjects rate audio clips recorded during various WLAN configurations. The Mean Opinion Score (MOS) is calculated as the average audio quality score given for each WLAN configuration. An 85% confidence interval is calculated for each MOS. Results suggest that audio quality over an IEEE 802.11n draft 2.0 WLAN is not higher than over an IEEE 802.11b WLAN when up to 10 simultaneous G.711 calls occur. A linear regression of the subjective scores also suggest that an IEEE 802.11n draft 2.0 WLAN can sustain an MOS greater than 3.0 (fair quality) for up to 75 simultaneous G.711 calls secured with WPA2, or up to 40 calls secured with both WPA2 and transport mode IPsec. The data strongly suggest that toll quality audio (MOS ≥ 4.0) is not currently practical over IEEE 802.11 WLANs secured with WPA2, even with the G.711 codec

A Network Algorithm for 3D/2D IPTV Distribution using WiMAX and WLAN Technologies

The final publication is available at link.springer.comThe appearance of new broadband wireless technologies jointly with the ability to offer enough quality of service to provide IPTV over them, have made possible the mobility and ubiquity of any type of device to access the IPTV network. The minimum bandwidth required in the access network to provide appropriate quality 3D/2D IPTV services jointly with the need to guarantee the Quality of Experience (QoE) to the end user, makes the need of algorithms that should be able to combine different wireless standards and technologies. In this paper, we propose a network algorithm that manages the IPTV access network and decides which type of wireless technology the customers should connect with when using multiband devices, depending on the requirements of the IPTV client device, the available networks, and some network parameters (such as the number of loss packets and packet delay), to provide the maximum QoE to the customer. The measurements taken in a real environment from several wireless networks allow us to know the performance of the proposed system when it selects each one of them. The measurements taken from a test bench demonstrate the success of our system.This work has been partially supported by the Polytechnic University of Valencia, though the PAID-15-10 multidisciplinary projects, by the Instituto de Telecomunicacoes, Next Generation Networks and Applications Group (NetGNA), Portugal, and by National Funding from the FCT - Fundacao para a Ciencia e a Tecnologia through the PEst-OE/EEI/LA0008/2011 Project.Lloret, J.; Cánovas Solbes, A.; Rodrigues, JJPC.; Lin, K. (2013). A Network Algorithm for 3D/2D IPTV Distribution using WiMAX and WLAN Technologies. Multimedia Tools and Applications. 67(1):7-30. https://doi.org/10.1007/s11042-011-0929-4S730671Abukharis S, MacKenzie R, Farrell TO (2009) Improving QoS of Video Transmitted Over 802.11 WLANs Using Frame Aggregation. London Communications Symposium.. London, United Kingdom, September 03–04Alejandro Canovas, Fernando Boronat, Carlos Turro and Jaime Lloret (2009) Multicast TV over WLAN in a University Campus Network, The Fifth International Conference on Networking and Services (ICNS 2009), Valencia (Spain), April 20–25Alfonsi B (2005) “I want my IPTV: Internet Protocol television predicted a winner,” IEEE Distributed Systems Online, vol.6, no.2Birlik F, Gurbuz Ö, Ercetin O (2009) IPTV Home Networking via 802.11 Wireless Mesh Networks: An Implementation Experience. IEEE Trans. on Consumer Electronics, Vol. 55, No. 3Cai LX, Ling X, Shen X, Mark JW, Cai L (2009) Supporting voice and video applications over IEEE 802.11n WLANs. Wireless Networks 15:443–454Cunningham G, Perry P, Murphy J, Murphy L (2009) Seamless Handover of IPTV Streams in a Wireless LAN Network. Transactions on Broadcasting, IEEE 55(4):796–801Dai Z, Fracchia R, Gosteau J, Pellati P, Vivier G (2008) Vertical Handover Criteria and Algorithm in IEEE802.11 and 802.16 Hybrid Networks, IEEE International Conference on Communications, 2008. ICC’08. Beijing, China, 19–23Gidlund M, Ekling J (2008) VoIP and IPTV distribution over wireless mesh networks in indoor environment. IEEE Trans Consum Electron 54(4):1665–1671Hellberg C, Greene D, Boyes T (2007) Broadband network architectures: designing and deploying triple-play services. Prentice Hall PTR Upper Saddle River, NJ, USAHsu H-T, Kuo F-Y, Lu P-H (2010) Design of WiFi/WiMAX dual-band E-shaped patch antennas through cavity model approach. Microw Opt Technol Lett 52(2):471–474IEEE 802.11 Working Group, At http://www.ieee802.org/11/index.shtml [last access: July 2011]IEEE Std 802.11™-2007 - IEEE Standard for Information Technology— Telecommunications and information exchange between systems— Local and metropolitan area networks—Specific requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) SpecificationsIEEE Std 802.16™-2009, IEEE Standard for Local and metropolitan area networks, Part 16: Air Interface for Broadband Wireless Access Systems. At http://standards.ieee.org/getieee802/download/802.16-2009.pdf [last access: July 2011]inCode Telecom group Inc. (2006) The Quad-Play—the First Wave of the Converged Services Evolution. White paper, FebruaryIPTV Focus Group, Available at http://www.itu.int/ITU-T/IPTV/ [last access: July 2011]Jindal S, Jindal A, Gupta N (2005) Grouping WI-MAX, 3 G and WI-FI for wireless broadband, The First IEEE and IFIP International Conference in Central Asia on Internet 2005, September 26–29, Bishkek, KyrgyzstanJin-Yu Zhang, Man-Gui Liang (2008) “IPTV QoS Implement Mechanism in WLAN,” Int. Conference on Intelligent Information Hiding and Multimedia Signal Processing. pp 117-120, 15–17Karen Fernanda Medina Velez and Ivonne Alexandra Revelo Arias (2006) Diseño y planificación de una red inalámbrica basada en los estandares IEEE 802.16 (WIMAX) y 802.11 (WIFI) para proveer de internet de banda ancha a poblaciones de las provincias de Loja y Zamora Chinchipe, Tesis Electrónica y Telecomunicaciones (IET), Escuela Politécnica Nacional, Quito, EcuadorKnightson K, Morita N, Towle T (2005) NGN architecture: generic principles, functional architecture, and implementation. IEEE Commun Mag 43(10):49–56Lai C, Min Chen (2011) Playback-Rate Based Streaming Services for Maximum Network Capacity in IP Multimedia Subsystem, IEEE System Journal, doi: 10.1109/JSYST.2011.2165190Lee K-H, Trong ST, Lee B-G, Kim Y-T (2008) QoS-Guaranteed IPTV Service Provisioning in Home Network with IEEE 802.11e Wireless LAN,” IEEE Network Operations and Management Symposium. pp 71-76Marcelo Atenas, Sandra Sendra, Miguel Garcia, Jaime Lloret (2010) IPTV Performance in IEEE 802.11n WLANs, IEEE Global Communications Conference (IEEE Globecomm 2010), Miami (USA), December 6–10Miguel Garcia, Jaime Lloret, Miguel Edo, Raquel Lacuesta (2009) IPTV Distribution Network Access System Using WiMAX and WLAN Technologies, International Symposium on High Performance Distributed Computing (HPDC 2009), Munich (Germany), June 11–13Park AH, Choi JK (2007) “QoS guaranteed IPTV service over Wireless Broadband network”, The 9th Int. 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IEEE 802.11n MAC frame aggregation mechanisms for next-generation high-throughput WLANs [Medium access control protocols for wireless LANs]

IEEE 802.11n is an ongoing next-generation wireless LAN standard that supports a very highspeed connection with more than 100 Mb/s data throughput measured at the medium access control layer. This article investigates the key MAC enhancements that help 802.11n achieve high throughput and high efficiency. A detailed description is given for various frame aggregation mechanisms proposed in the latest 802.11n draft standard. Our simulation results confirm that A-MSDU, A-MPDU, and a combination of these methods improve extensively the channel efficiency and data throughput. We analyze the performance of each frame aggregation scheme in distinct scenarios, and we conclude that overall, the two-level aggregation is the most efficacious

Performance evaluation of the IEEE 802.11n random topology WLAN with QoS application

The IEEE 802.11n supports high data rate transmissions due its physical layer Multiple Input ‎Multiple Output (MIMO) advanced antenna system and MAC layer enhancement features (frame ‎aggregation and block acknowledgement). As a result this standard is very suitable for multimedia ‎services through its Enhanced Distributed Channel Access (EDCA). This paper focuses on ‎evaluating the Quality of Service (QoS) application on the performance of the IEEE 802.11n ‎random topology WLAN. Three different number of nodes (3, 9 and 18) random topology with one ‎access point are modeled and simulated by using the Riverbed OPNET 17.5 Modular to ‎investigate the Wireless Local Area Network (WLAN) performance for different spatial streams. ‎The result clarified the impact of QoS application and showed that its effect is best at the 18 node ‎number topology. For a 4x4 MIMO, when QoS is applied and with respect to the no QoS ‎application case, simulation results show a maximum improvement of 86.4%, 33.9%, 52.2% and ‎‎68.9% for throughput, delay, data drop and retransmission attempts, respectively.

Cross-layer design and optimization of medium access control protocols for wlans

This thesis provides a contribution to the field of Medium Access Control (MAC) layer protocol design for wireless networks by proposing and evaluating mechanisms that enhance different aspects of the network performance. These enhancements are achieved through the exchange of information between different layers of the traditional protocol stack, a concept known as Cross-Layer (CL) design. The main thesis contributions are divided into two parts. The first part of the thesis introduces a novel MAC layer protocol named Distributed Queuing Collision Avoidance (DQCA). DQCA behaves as a reservation scheme that ensures collision-free data transmissions at the majority of the time and switches automatically to an Aloha-like random access mechanism when the traffic load is low. DQCA can be enriched by more advanced scheduling algorithms based on a CL dialogue between the MAC and other protocol layers, to provide higher throughput and Quality of Service (QoS) guarantees. The second part of the thesis explores a different challenge in MAC layer design, related to the ability of multiple antenna systems to offer point-to-multipoint communications. Some modifications to the recently approved IEEE 802.11n standard are proposed in order to handle simultaneous multiuser downlink transmissions. A number of multiuser MAC schemes that handle channel access and scheduling issues and provide mechanisms for feedback acquisition have been presented and evaluated. The obtained performance enhancements have been demonstrated with the help of both theoretical analysis and simulation obtained results

Improving the Performance of Wireless LANs

This book quantifies the key factors of WLAN performance and describes methods for improvement. It provides theoretical background and empirical results for the optimum planning and deployment of indoor WLAN systems, explaining the fundamentals while supplying guidelines for design, modeling, and performance evaluation. It discusses environmental effects on WLAN systems, protocol redesign for routing and MAC, and traffic distribution; examines emerging and future network technologies; and includes radio propagation and site measurements, simulations for various network design scenarios, numerous illustrations, practical examples, and learning aids

VOIP Model for ICT Rural Communities Telecentre in Sintok

Transmission of Voice over Internet Protocol (VoIP) on packet switching networks is one of the rapidly emerging real-time applications. VoIP is a formation of audio and voice communication. It receive voice signal activities then encoded in digital form and divided into small parts of information as like voice data network packets. These data network packets are decoded and transmitted voice in signals then sender and receiver having a voice conversion. In a voice conversion, the clients send and receive packets in a bidirectional method. Each client work as a sender and as a receiver depends on the direction of traffic flow over network. The aim of this proposal is to propose a VOIP model for ICT rural community’s telecaster in Sintok

Video QoS/QoE over IEEE802.11n/ac: A Contemporary Survey

The demand for video applications over wireless networks has tremendously increased, and IEEE 802.11 standards have provided higher support for video transmission. However, providing Quality of Service (QoS) and Quality of Experience (QoE) for video over WLAN is still a challenge due to the error sensitivity of compressed video and dynamic channels. This thesis presents a contemporary survey study on video QoS/QoE over WLAN issues and solutions. The objective of the study is to provide an overview of the issues by conducting a background study on the video codecs and their features and characteristics, followed by studying QoS and QoE support in IEEE 802.11 standards. Since IEEE 802.11n is the current standard that is mostly deployed worldwide and IEEE 802.11ac is the upcoming standard, this survey study aims to investigate the most recent video QoS/QoE solutions based on these two standards. The solutions are divided into two broad categories, academic solutions, and vendor solutions. Academic solutions are mostly based on three main layers, namely Application, Media Access Control (MAC) and Physical (PHY) which are further divided into two major categories, single-layer solutions, and cross-layer solutions. Single-layer solutions are those which focus on a single layer to enhance the video transmission performance over WLAN. Cross-layer solutions involve two or more layers to provide a single QoS solution for video over WLAN. This thesis has also presented and technically analyzed QoS solutions by three popular vendors. This thesis concludes that single-layer solutions are not directly related to video QoS/QoE, and cross-layer solutions are performing better than single-layer solutions, but they are much more complicated and not easy to be implemented. Most vendors rely on their network infrastructure to provide QoS for multimedia applications. They have their techniques and mechanisms, but the concept of providing QoS/QoE for video is almost the same because they are using the same standards and rely on Wi-Fi Multimedia (WMM) to provide QoS

Advanced Wireless LAN

The past two decades have witnessed starling advances in wireless LAN technologies that were stimulated by its increasing popularity in the home due to ease of installation, and in commercial complexes offering wireless access to their customers. This book presents some of the latest development status of wireless LAN, covering the topics on physical layer, MAC layer, QoS and systems. It provides an opportunity for both practitioners and researchers to explore the problems that arise in the rapidly developed technologies in wireless LAN

Design and optimization of QoS-based medium access control protocols for next-generation wireless LANs

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.In recent years, there have been tremendous advances in wireless & mobile communications, including wireless radio techniques, networking protocols, and mobile devices. It is expected that different broadband wireless access technologies, e.g., WiFi (IEEE 802.11) and WiMAX (IEEE 802.16) will coexist in the future. In the meantime, multimedia applications have experienced an explosive growth with increasing user demands. Nowadays, people expect to receive high-speed video, audio, voice and web services even when being mobile. The key question that needs to be answered, then, is how do we ensure that users always have the "best" network performance with the "lowest" costs in such complicated situations? The latest IEEE 802.11n standards attains rates of more than 100 Mbps by introducing innovative enhancements at the PHY and MAC layer, e.g. MIMO and Frame Aggregation, respectively. However, in this thesis we demonstrate that frame aggregation's performance adheres due to the EDCA scheduler's priority mechanism and consequently resulting in the network's poor overall performance. Short waiting times for high priority flows into the aggregation queue resolves to poor channel utilization. A Delayed Channel Access algorithm was designed to intentionally postpone the channel access procedure so that the number of packets in a formed frame can be increased and so will the network's overall performance. However, in some cases, the DCA algorithm has a negative impact on the applications that utilize the TCP protocol, especially the when small TCP window sizes are engaged. So, the TCP process starts to refrain from sending data due to delayed acknowledgements and the overall throughput drops. In this thesis, we address the above issues by firstly demonstrating the potential performance benefits of frame aggregation over the next generation wireless networks. The efficiency and behaviour of frame aggregation within a single queue, are mathematically analysed with the aid of a M=G[a;b]=1=K model. Results show that a trade-off choice has to be taken into account over minimizing the waiting time or maximizing utilization. We also point out that there isn't an optimum batch collection rule which can be assumed as generally valid but individual cases have to be considered separately. Secondly, we demonstrate through extensive simulations that by introducing a method, the DCA algorithm, which dynamically determines and adapts batch collections based upon the traffic's characteristics, QoS requirements and server's maximum capacity, also improves e ciency. Thirdly, it is important to understand the behaviour of the TCP ows over the WLAN and the influence that DCA has over the degrading performance of the TCP protocol. We investigate the cause of the problem and provide the foundations of designing and implementing possible solutions. Fourthly, we introduce two innovative proposals, one amendment and one extension to the original DCA algorithm, called Adaptive DCA and Selective DCA, respectively. Both solutions have been implemented in OPNET and extensive simulation runs over a wide set of scenarios show their effectiveness over the network's overall performance, each in its own way.This study was supported by the Engineering and Physical Sciences Research Council (EPSRC)