The much higher data rates offered by the new generation of WiFi radios, supported by the 802.11n and 802.11ac standards, come at the cost of increased power consumption. This concern is particularly heightened for smartphones, where radio interfaces can account for up to 50% of the total power budget under typical use. Consequently, existing smartphones do not implement all the features offered by the standards, trading performance for savings in power consumption. This tradeoff can in turn significantly impact the performance and power consumption of other devices in a heterogeneous WLAN. At the same time, the increasing demand for computational features such as multimedia in mobile devices has led to the use of complex computational hardware for graphics and memory with increased contribution to the overall energy consumption. This calls for a holistic approach to power analysis that considers both the communication and the computational paradigms of these devices.
In the first part of this project, we are developing a set of measurement-based models describing the power-performance tradeoffs of WiFi in mobile devices and the impact of different features of the next generation WiFi standards on these tradeoffs. We further seek to develop realistic power models that consider diverse components of the system and their interactions, beyond just the CPU, as well as models for power-performance tradeoffs at the system level. Power analysis of the computational elements and peripherals will be performed, with considerations to varying factors that affect the power consumption, such as the applications, environment, and usage profile, through modeling and measurements. The results will be combined with the WiFi models towards a holistic power profile.
The second part of this project focuses on the design and implementation of novel power saving, rate adaptation, and network management protocols for a variety of wireless devices (smartphones, tablets, laptops, APs). The protocols will be designed based on the models developed in the first part of the project with the following two design goals: (i) to maximize power savings for power-constrained devices without compromising their performance, (ii) to allow co-existence of heterogeneous devices in WLANs with maximum performance and power savings for all types of devices.
802.11n/ac datasets (throughput, power, energy) from our ICDCS 2014 and TMC 2016 papers are available on WiNS Lab Download Center.
This project is sponsored by the National Science Foundation under Grant CNS-1422304.