Abstract
Problem statement: Deployment of real time services over 802.11 wireless networks requires quality of service (QoS) differentiation mechanisms for different traffic types. This required investigations into the performance of the Medium access (MAC) schemes like Distributed Coordinated Function (DCF) and Enhanced DCF with respect to the stringent QoS requirements imposed by the real time services. Motivation for this research was to find the suitability of 802.11 MAC schemes for real time traffic. Approach: In this study, various available MAC schemes were experimentally evaluated for QoS provisioning in 802.11 wireless networks. Performance evaluation was done based on important QoS metrics like access delay, jitter, packet loss, Round Trip Time (RTT) and throughput of the traffic. Experimental Testbed based was established using off the shelf hardware and open source software. The traffic was captured in real time and analyzed thereafter for various QoS metrics. Results: The results indicated that there is considerable QoS improvement using 802.11e EDCF with reconfigured queues over the ordinary DCF mechanism. Results were obtained on experimental testbed using various types of UDP and TCP traffic. Conclusion: It can be concluded that proper differentiation and scheduling of traffic specific to application, helps in providing better QoS over the 802.11 wireless networks and improves their suitability for deployment of real time services.
Highlights
IEEE 802.11 based wireless Networks have become the favorite choice of the service providers for providing data and Internet services in university campuses, hotels, airports and other public places with high population density
Variation in Round Trip Time (RTT) of ICMP traffic depends upon Congestion windows size, Arbitrary Inter-frame spacing (AIFSN), TxOP and maximum packet limits of priority queue
Other quality of service (QoS) metrics are influenced by other parameters
Summary
IEEE 802.11 based wireless Networks have become the favorite choice of the service providers for providing data and Internet services in university campuses, hotels, airports and other public places with high population density. IEEE 802.11 standards were originally developed to provide wireless alternative to the wired local area networks. Over the time, these standards have become very popular but certain problems like seamless mobility and wired equivalent quality of service are still major issues with such networks. Quality of service is a big hindrance for deployment of these networks for real time services like voice over IP. The basic 802.11 MAC layer uses the Distributed Coordination Function (DCF)[1] to share the medium between multiple stations. DCF relies on CSMA/CA and optional 802.11 RTS/CTS to share the medium between the stations. IEEE has approved Enhanced DCF[2] based 802.11e as a standard defining set of Quality of Service enhancements for wireless LAN applications. The protocol enhances the base IEEE 802.11 Media Access Control (MAC) layer
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
