ERA: Effective Rate Adaptation for WLANs

Biaz, Saad; Wu, Shaoen

doi:10.1007/978-3-540-79549-0_79

Cited by 10 publications

(4 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to the authors, this difference between simulation and experimental results probably comes from implementation issues with RTS/CTS that result in data frame losses even when the channel is reserved and is not limited by SINR. Some other works [5,7,8,11,13,20,35,39,48,51] are prone to a similar problem, since they were implemented only in a simulator and made strong assumptions that are hard to confirm using real hardware.…”

Section: Automatic Rate Control Algorithmsmentioning

confidence: 95%

Increasing throughput in dense 802.11 networks by automatic rate adaptation improvement

Cardoso

Rezende

2011

Wireless Netw

View full text Add to dashboard Cite

Rate control algorithms for commercial 802.11 devices strongly rely on packet losses for their adaptation. As a result, they give poor performance in dense networks because they are not able to distinguish packet losses related to channel error from packet losses due to collision. In this paper, we evaluate automatic rate adaptation algorithms in IEEE 802.11 dense networks. A certain number of works in the literature address this problem, but they demand modifications of the IEEE standard, or depend on some special feature not available in off-the-shelf devices. In this context, we propose a new automatic rate control algorithm which is simple, easy to implement, standards-compliant, and wellsuited for crowded 802.11 networks. Our approach consists of measuring the contention level, inferring the collision probability, and choosing transmission rates which maximize throughput. Results from simulation and real experiments show throughput improvement of up to 100% from our mechanism.

show abstract

Section: Automatic Rate Control Algorithmsmentioning

confidence: 95%

Increasing throughput in dense 802.11 networks by automatic rate adaptation improvement

Cardoso

Rezende

2011

Wireless Netw

View full text Add to dashboard Cite

show abstract

“…The parameter settings of our scheme are p = 0.6, n default = 3, and n fail = 11. AARF (Adaptive Automatic Rate Fallback) (1) and ERA (Effective Rate Adaptation) (3) decrease the rate every time two consecutive transmissions fail. On the other hand, to increase the rate, they respectively need at least 10 and 8 consecutive successful transmissions.…”

Section: A Rate Adaptation Scheme According To Channel Conditions In mentioning

confidence: 99%

Extended Summaries

2011

IEEJ Trans.EIS

View full text Add to dashboard Cite

Laser ultrasound can be used for noncontact depth measurement of open surface cracks, which can be applied to online monitoring of surface cracks in high temperature components. Crack depth measurement can be performed by using (a) surface waves in the frequency domain, (b) surface waves in the time domain, or by (c) time of flight diffraction (TOFD). A comparison of these methods showed that the use of surface waves in the time domain is best suited for online monitoring.Crack depth measurement using surface waves in the time domain is shown schematically in Fig. 1. Surface waves generated using a generation laser are detected using a laser interferometer. The propagation distance of the surface wave which travels around the crack depends on the crack depth, so the crack depth can be obtained from the time delay of the surface wave.Experiments using a SUS316 specimen with a slant slit, whose depth a varied continuously from 0 mm to 5 mm, showed that the time delay of the surface wave varied linearly with respect to the slit depth for a > 2.3 mm, as shown in Fig. 2. The applicable range for depth measurement is estimated to be a > 2 mm.Since the propagation speed of the surface wave depends on the specimen temperature, the time delay changes with temperature. Therefore, in order to monitor the crack depth accurately, regardless of the specimen temperature, it is necessary to eliminate the effect due to temperature change. For example, the time delay for a constant slit depth of 2 mm changed by 0.26 µs over the temperature range 25°C to 500°C. On the other hand, the time delay for slit depths 2 mm and 3 mm at 500°C differed by 0.35 µs. Therefore, the change in the time delay for a temperature change from 25°C to 500°C is equivalent to that for a slit depth change of approximately 0.7 mm. Since a measurement resolution of about 0.3 mm is required for online monitoring of crack depth, some method for correcting for the temperature change is required.In order to eliminate the effect due to temperature change, a method using two surface waves was developed, which is shown in Fig. 3. Two generation lasers are used. The first laser generates a surface wave which travels around the crack (roundabout wave), and the second laser generates a surface wave which does not interact with the crack (reference wave). The time delay of the roundabout wave includes the effects of temperature change and crack depth, whereas the time delay of the reference wave only includes the effect of temperature change. Therefore, the time delay of the reference wave can be used to correct the time delay of the roundabout wave. Using this method, the time delay of the roundabout wave (for a constant crack depth) was corrected to a constant value from 25°C to 500°C. The standard deviation was comparable to the case of constant temperature, indicating that effects of temperature change were successfully corrected.The results showed that laser ultrasound can be applied to monitoring of crack depth, and that the effect of temperature change can be c...

show abstract

“…The 802.11 WLAN standards do not have any inbuilt algorithm to control the multiple transmission rates. Many existing rate adaptation schemes (Biaz and Wu, 2008;Chen et al, 2012;Holland et al, 2001;Kamerman and Monteban, 1997;Pang et al, 2005;Schmidt et al, 2012;Senthil Kumar and Krishnan, 2010;Wong et al, 2006) has proved their throughput increase using various rate control mechanisms and IEEE standards. Based on the survey of the rate control mechanisms, the primary aim of the authors was in improving the throughput by selecting an optimal rate than in minimizing the delay.…”

Section: Introductionmentioning

confidence: 99%

A Guaranteed Time and Rate Control Method for Improving QoS in WLAN

Anitha¹,

Jayakumari²

2016

American Journal of Applied Sciences

View full text Add to dashboard Cite

Wireless Local Area Network is a mobile network, which connects the users in a small specific area. The devices within the area connect with each other through the wireless access points. The main requirements for the connection between the wireless devices are the time and the power. The transmission time between the wireless devices should be less and the power should be effective for the transmission to avoid the loss. With these considerations, we propose a novel method which hybrids the guaranteed time and power. The proposed method is designed for the network, which quickly responds to the slight changes and the normal networks. Guaranteed time slots are used for the time management and the rate control is used for the guaranteed power. This method works well in both the sensitive and insensitive areas. The performance of the proposed work is accurately analyzed using the analytical and the simulation methods. The numerical results obtained is accurate with the simulation results obtained using the ns-2.34 simulator. The throughput obtained is higher for the sensitive areas with minimum delay than the insensitive areas and closely matches the analytical results.

show abstract

ERA: Effective Rate Adaptation for WLANs

Cited by 10 publications

References 11 publications

Increasing throughput in dense 802.11 networks by automatic rate adaptation improvement

Increasing throughput in dense 802.11 networks by automatic rate adaptation improvement

Extended Summaries

A Guaranteed Time and Rate Control Method for Improving QoS in WLAN

Contact Info

Product

Resources

About