Feedback-Based Adaptation for Improved Power Consumption

Abstract

Abstract-In this paper we present a feedback-based adaptation mechanism that adjusts the transmission power of a wireless card on commodity PCs depending on the quality of the connection. Our purpose is to manage the available power in order to achieve lower power consumption without negatively affecting the user's perception of connection quality. We based our implementation on an existing theoretical model and focused on resolving problems and removing assumptions which made it inefficient in real life implementation. The initial model manages to minimize the power consumption in networks with exactly two nodes. In this paper, we extend the model to consider the possibility of the existence of a base station, where any number of nodes can be connected. Our objectives for the base station are to minimize the power consumption and guarantee continuous connectivity for all mobile nodes. We implement the adaptation mechanism for a specific adapter with open sources drivers thus allowing necessary modifications. We conduct a number of real world experiments. The results indicate that power consumption can be significantly reduced for nodes that are either almost stationary or slowly moving (e.g. at walking speed), without any significant increase in packet loss. The results are quite important as nowadays mobile devices with limited battery life time use tethering to become base stations for other devices like in ad-hoc networks.

A Signal Adaptation Mechanism for Power Optimization of Wireless Adapters

“…It requires however the existence of possible communication over multiple radio interfaces, which may not always be the case. In (Bouras, et al, 2013), a mechanism focused on the adjustment of the transmission power of the wireless card according to the state of the network has achieved to optimize the power consumption of the wireless cards in ad-hoc networks. This mechanism manages the power consumption of both the base station and the connected peers, which might limit the capabilities of the base station, and renders it unable to transmit to its maximum distance.…”

“…The second mechanism in this paper extends the first mechanism (Bouras, et al, 2013). Instead of using only the RSSI to measure the efficiency of the mechanism, we also utilize the Signal-To-Noise ratio to improve the power performance of the adapters.…”

“…We propose a feedback based Signal Adaptation Mechanism (SAM) which would guarantee fair connection quality with the lowest possible transmission power. SAM is based on the previous mechanism (Bouras, et al, 2013) but the SNR metric has also been used in order to measure the quality of the connection. Moreover, SAM is completely independent of the driver and portable.…”