Power-Performance Tradeoffs for Mobile Devices in Next Generation WiFi Networks

Overview

The recent 802.11n standard marked the beginning of the next generation WiFi radios offering higher bitrates up to 600 Mbps, longer range, and more reliable coverage compared to legacy 802.11a/b/g. The more recent 802.11ac further pushes the envelope promising Gbps bitrates. However, higher data rates come at the cost of higher energy 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. Also, the increasing demand for computational features such as multimedia in mobile devices has led to the use of complex computational hardware and peripherals for graphics and memory with their 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 plan to develop a set of models describing the power-performance tradeoffs in WiFi-capable mobile devices and the impact of different features of the next generation WiFi standards on these tradeoffs. The models will be developed based on extensive measurement studies using different popular devices in a variety of scenarios. 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 developed, with considerations to varying factors that affect the power consumption, such as the applications, environment, and usage profile, through power modeling and measurements. The results will be combined with the WiFi models and a holistic power model and profile will be developed.

The second part of this project focuses on the design and implementation of novel power saving, rate adaptation, network management, and beamforming 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 types of mobile devices in WLANs with maximum performance and power savings for all types of devices.

Funding

This project is sponsored by the National Science Foundation under Grant CNS-1422304.

People

Faculty:

• Dimitrios Koutsonikolas
• Ramalingam Sridhar

• Swetank Kumar Saha
• Ramanujan K Sheshadri
• Li Sun

• Mohit Arora
• Tejeet Paresh Desai
• Pratham Malik
• Apurva Paradkar

• Vinay Agrawal
• Haotian Deng
• Pratik Deshpande
• Pranav Inamdar
• Ninad Warty
• Wei Zheng

Publications

• Characterizing Mobile User Habits: The Case for Energy Budgeting.
  Ramanujan K. Sheshadri, Ioannis Pefkianakis, Henrik Lundgren, Dimitrios Koutsonikolas, Anna-Kaisa Pietilainen, Augustin Soule, and Jaideep Chandrashekar.
  To appear in Proceedings of the 18th IEEE Global Internet Symposium (GI 2015), Hong Kong, April 27, 2015. (acceptance rate 32%)


• Power-Throughput Tradeoffs of 802.11n/ac in Smartphones.
  Swetank Kumar Saha, Pratik Deshpande, Pranav P Inamdar, Ramanujan K. Sheshadri, and Dimitrios Koutsonikolas.
  In Proceedings of IEEE INFOCOM 2015, Hong Kong, April 26 - May 1, 2015. (acceptance rate 19%)


• Modeling WiFi Active Power/Energy Consumption in Smartphones.
  Li Sun, Ramanujan K. Sheshadri, Wei Zheng, and Dimitrios Koutsonikolas.
  In Proceedings of the 34th IEEE International Conference on Distributed Computing Systems (ICDCS 2014), Madrid, Spain, 30 June - 3 July, 2014. (acceptance rate 13.2%)


• A First Look at 802.11n Power Consumption in Smartphones.
  Ninad Wart, Ramanujan K. Sheshadri, Wei Zheng, and Dimitrios Koutsonikolas.
  In Proc. of the ACM Mobicom International Workshop on Practical Issues and Applications in Next Generation Wireless Networks (PINGEN), Istanbul, Turkey, August 26, 2012.