Performance Evaluation of VoIP in Mobile WiMAX; Simulation and Emulation studies

Worldwide Interoperability for Microwave Access (WiMAX) is an acronym for IEEE 802.16 family which is a leading contemporary broadband wireless Access (BWA) technology. IEEE 802.16e is intended for mobile WiMAX, which supports vehicular mobility with the stringent quality of service (QoS) parameters for various data traffics. Voice over IP (VoIP) provides low cost, modern telephony which can become a better alternative for classical telephony; however there are some issues need to be addressed prior to the deployment of any new technology. Significance of simulation study results can be verified and assessed by emulation testbed results. It is expected that both the results should match closely with each other. This paper makes an effort to study the performance evaluation of VoIP for a mobile user and how the QoS parameters vary for different speeds. The simulation and emulation of a mobile WiMAX system using EXata 2.0.1 are performed. The effectiveness of the comparison of results is discussed

Investigating the QoS of Voice over IP using WiMAX Access Networks in a Campus Network

VoIP is a very rapid evolving communication technology which supports transportation of voice data via IP based networks. In parallel, IEEE 802.16e standard based WiMAX is a new emerging access technology and the first generation of 4G broadband access wireless technology with an enhanced in-built quality of service (QoS) provision with many benefits including cost reduction, high quality as well as other value added network service solutions especially for communications Service Providers with emphasis on real time services. WiMAX promises manifold benefits in terms of optimal network performance across a long distance in contrast to other wireless technologies such as Wi-Fi and 3G cellular technologies. Hence, this research attempts to identify some of the network performance parameters that Service Providers will focus on to develop a VoIP over WiMAX communication tool that will serve as a voice communication broadband replacement technology to old circuit-switch voice communication. This study adopted a simulation-based network performance analysis to investigate the effects of the application of different voice encoder schemes on QoS of VoIP system deployed with IEEE 802.16e standard WiMAX network. Through different network simulation experiments using realistic network scenarios in OPNET environment, this research provided an in-depth network performance comparative analysis of VoIP over WiMAX using performance parameters which indicate QoS such as voice jitter, voice packet ETE delay, packet-sent-packet-received, WiMAX network delay, voice packet delay variation and throughput. The obtained simulation experiment results indicated that choice of suitable codec scheme can affect the QoS of VoIP traffic over WiMAX network. The results also indicated that the choice of suitable voice encoder scheme with a small number of voice frame-size per packet have a significant impact over VoIP traffic performance when deployed with WiMAX access technology. Keywords: WiMAX, QoS, End-to-End delay, Jitter, IEEE 802.16e, PSTN, OPNET, Simulation, Wi-Fi, Code

Experimental performance of DCCP over live satellite and long range wireless links

We present experimental results for the performance over satellite and long range wireless (WiMax) links of the new TCP-Friendly Rate Control (TFRC) congestion control mechanism from the Datagram Congestion Control Protocol (DCCP) proposed for use with real-time traffic. We evaluate the performance of the standard DCCP/CCID3 algorithm and identify two problem areas: the measured DCCP/CCID3 rate is inferior to the rate achievable with standard TCP and a significant rate oscillation continuously occurs making the resulting rate variable even in the short term. We analyse the links and identify the potential causes, i.e. long and variable delay and link errors. As a second contribution, we propose a change in the DCCP/CCID3 algorithm in which the number of feedback messages is increased from the currently standard of at least one per return trip time. Although it is recognised that the increase in control traffic may decrease the overall efficiency, we demonstrate that the change results in higher data rates which are closer to what is achievable with TCP on those networks and that the overhead introduced remains acceptable

WEIRD Testbeds with Fixed and Mobile WiMAX Technology for User Applications, Telemedicine and Monitoring of Impervious Areas

Wireless Metropolitan Area Networks based on IEEE 802.16d/e standards are soon to be deployed in several countries. However, there is lack of published literature with results from actual test¬beds. This paper introduces the work done in the EU Sixth Framework Programme Project WEIRD to design and set up WiMAX testbeds in four EU countries. We describe the method¬ology followed, detail our implementation and present results from the testbeds, as deployed in the first phase of WEIRD. The testbeds are used to demonstrate how WiMAX technology can be used to extend the connectivity of the pan-European data com¬munications network (GEANT2) to isolated and impervious ar¬eas and, furthermore, to assure end-to-end quality of service to novel applications

WEIRD Testbeds with Fixed and Mobile WiMAX Technology for User Applications, Telemedicine and Monitoring of Impervious Areas

Wireless Metropolitan Area Networks based on IEEE 802.16d/e standards are soon to be deployed in several countries. However, there is lack of published literature with results from actual test¬beds. This paper introduces the work done in the EU Sixth Framework Programme Project WEIRD to design and set up WiMAX testbeds in four EU countries. We describe the method¬ology followed, detail our implementation and present results from the testbeds, as deployed in the first phase of WEIRD. The testbeds are used to demonstrate how WiMAX technology can be used to extend the connectivity of the pan-European data com¬munications network (GEANT2) to isolated and impervious ar¬eas and, furthermore, to assure end-to-end quality of service to novel applications.SIGARCH, Create-NetPublishedInnsbruck, Austria1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attiveope