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A Remote Capacity Utilization Estimator For Wlans, Yi Ding
A Remote Capacity Utilization Estimator For Wlans, Yi Ding
Doctoral
In WLANs, the capacity of a node is not fixed and can vary dramatically due to the shared nature of the medium under the IEEE 802.11 MAC mechanism. There are two main methods of capacity estimation in WLANs: Active methods based upon probing packets that consume the bandwidth of the channel and do not scale well. Passive methods based upon analyzing the transmitted packets that avoid the overhead of transmitting probe packets and perform with greater accuracy. Furthermore, passive methods can be implemented locally or remotely. Local passive methods require an additional dissemination mechanism in order to communicate the capacity …
Throughput Enhancement Through Combined Fragmentation And Rate Method In Ieee 802.11b Wlans, Marek Bykowski, Karol Kowalik, Brian Keegan, Mark Davis
Throughput Enhancement Through Combined Fragmentation And Rate Method In Ieee 802.11b Wlans, Marek Bykowski, Karol Kowalik, Brian Keegan, Mark Davis
Conference papers
IEEE 802.11 allows for fragmentation tuning and rate selection. Their combined usage is referred sometimes to link adaptation. However, the algorithms of link adaptation are beyond the 802.11 standards. In this paper we investigate the benefits arising from proper use of link adaptation. Particularly, we develop a mathematical model describing the fragmented transmission in 802.11b. We examine potential benefits of it over AWGN and fading channels. More significantly we combine fragmentation tuning with bit-rate selection to yield the highest achievable throughput performance for any given channel conditions. Finally, we propose an algorithm that performs the optimal link adaptation.
The Capability Of The Edca Mechanism To Support Voice Traffic In A Mixed Voice/Data Transmission Over 802.11e Wlans: An Experimental Investigation, Miroslaw Narbutt, Mark Davis
The Capability Of The Edca Mechanism To Support Voice Traffic In A Mixed Voice/Data Transmission Over 802.11e Wlans: An Experimental Investigation, Miroslaw Narbutt, Mark Davis
Conference papers
In this paper we experimentally evaluate the capability of the EDCA mechanism to support voice traffic in a mixed voice/data transmission over 802.11e WLANs. In particular we investigate how real-time voice transmission can be supported by tuning four EDCA parameters, namely AIFSN, CWmin, CWmax and TXOP and how this impacts on background data transmission. The experimental set-up involves fifteen VoIP terminals sending bi-directional traffic between wired and wireless subnets and another station injecting various types of heavy background load to the wireless subnet. End-to-end voice transmission quality is predicted from time-varying transmission impairments with the use of the latest Appendix …
Experimental Investigation On Voip Performance And The Resource Utilization In 802.11b Wlans, Miroslaw Narbutt, Mark Davis
Experimental Investigation On Voip Performance And The Resource Utilization In 802.11b Wlans, Miroslaw Narbutt, Mark Davis
Conference papers
In a shared medium network like the 802.11b WLAN, predicting the quality of VoIP calls from the resource usage of the wireless medium is highly desirable. Analyzing the bandwidth usage at the L2/MAC layer may be especially useful for potential QoS provisioning and call admission schemes. This paper experimentally investigates the relationship between resource utilization in WLANS and the quality of VoIP calls transmitted over wireless medium. Specifically we evaluate how the amount of free bandwidth influences transmission impairments (i.e. delay, loss and jitter) and thus call quality. Resource utilization (under the MAC bandwidth components framework) is calculated by a …
Gauging Voip Call Quality From 802.11 Wlan Resource Usage, Miroslaw Narbutt, Mark Davis
Gauging Voip Call Quality From 802.11 Wlan Resource Usage, Miroslaw Narbutt, Mark Davis
Conference papers
In this paper we experimentally study the relationship between resource utilization in the wireless LAN and the quality of VoIP calls transmitted over the wireless medium. Specifically we evaluate how its overall capacity is shared between three basic MAC bandwidth components (load, access and free) as the number of VoIP calls increases and how it influences transmission impairments (delay, loss and jitter) and thus call quality. Resource utilization (under the MAC bandwidth components framework) is calculated by a WLAN probe application that passively “sniffs” packets at the L2/MAC layer of the wireless medium and analyses their headers and temporal characteristics. …
A Wireless Traffic Probe For Radio Resource Management And Qos Provisioning In Ieee 802.11 Wlans, Mark Davis
A Wireless Traffic Probe For Radio Resource Management And Qos Provisioning In Ieee 802.11 Wlans, Mark Davis
Conference papers
The emergence of real-time services such as voice over IP (VoIP) and video streaming imposes stringent requirements on the performance of a network if quality of service (QoS) targets are to be achieved. In the case of wireless networks, some form of radio resource management (RRM) is typically required to allocate the available resources among the contending stations in accordance with their needs and respective priorities. A critical aspect of any RRM scheme is the ability to monitor resource usage and to determine the resource requirements on a per-station basis. In this paper we describe a wireless traffic probe for …