Simulation and Performance Evaluation of the Intel Rate Adaptation Algorithm

Abstract

With the rise of the complexity of the IEEE 802.11 standard, rate adaptation algorithms have to deal with a large set of values for all the different parameters which impact the network throughput. Simple trial-and-error algorithms can no longer explore solution space in reasonable time and smart solutions are required. Most of the WiFi controllers rely on proprietary code and the used rate adaptation algorithms in these controllers are unknown. Very few WiFi controllers provide their rate adaptation algorithms when they do not rely on the Minstrel-HT algorithm, which is implemented in the Linux kernel. Intel WiFi controllers come with their own rate adaptation algorithms that are implemented in the Intel IwlWifi Linux Driver which is open-source. In this paper, we have reverse-engineered the Intel rate adaptation mechanism from the source code of the IwlWifi Linux driver, and we give, in a comprehensive form, the underlying rate adaptation algorithm named Iwl-Mvm-Rs. We describe the different mechanisms used to seek the best throughput adapted to the network conditions. We have also implemented the Iwl-Mvm-Rs algorithm in the ns-3 simulator. Thanks to this implementation, we can evaluate the performance of Iwl-Mvm-Rs in different scenarios (static and with mobility, with and without fast fading). We also compare the performances of Iwl-Mvm-Rs with the ones of Minstrel-HT and IdealWifi, also implemented in the ns-3 simulator.

Leveraging Antenna Orientation to Optimize Network Performance of Fleets of UAVs

“…The received throughput remains fairly stable during this phase as the only source of change is the RAA decisions. We can however observe that when MinstrelHt is used, it takes more time to reach the stabilized received throughput, which is consistent with the previous observations made about the algorithm in [7]. The convergence time for the antenna orientation algorithm and the convergence time on the received throughput for the simulations using the directional antenna are plotted on Figure 6 (with the box plot representation).…”

“…MinstrelHT is used in the ath9k driver. The Intel rate adaptation algorithm is used on Intel WiFi interfaces and on Intel Aero Ready-to-Fly UAV [7]. Ideal is another rate adaptation algorithm implemented in ns-3 and supporting 802.11ac.…”

“…Ideal is another rate adaptation algorithm implemented in ns-3 and supporting 802.11ac. These three algorithms have different behaviors and lead to different performance, as studied in [7]. Our evaluation will thus also study the impact of these three algorithms on the performance of our solution.…”

“…There exist many different rate adaptation algorithms [14] and a large number of Wi-Fi interfaces use proprietary solutions for which the used algorithm is unknown. These algorithms can lead to very different performance for the same scenario, as shown in [7]. We thus think that it is difficult to design a generic antenna orientation solution leveraging the used rate adaptation algorithm.…”

Delivering Video-on-Demand services with IEEE 802.11p to major non-urban roads: A stochastic performance analysis

“…Note that transmissions of frames can occur at different rates depending on the radio channel assessment (typically estimated by a frame error rate [23,24]). An 802.11p sender can dynamically adapt its transmission rate within the range of 3 and 27 Mbps.…”