Investigating storage energy in Android smartphones

Smartphones have now become a dominant computing device for a wide variety of mobile applications. For such a device, the main challenge is to provide the best performance, while utilizing energy efficiently. Hence, it is important to study the trade-off between performance and energy. In this work, we provide a detailed analysis and evaluation of storage energy consumption on Android devices. We have evaluated the energy consumption of sequential and random I/O and SQLite operations on two filesystems supported by Android -- Ext4 and Flash Friendly File System (F2FS). Our experiments reveal that the energy consumed by random writes in F2FS is 40\% less, whereas it is 20\% higher for random reads as compared to ext4. We also present a brief study on benchmarking SQLite in Android devices.

Based on our findings, we have determined that storage consumes significant amount of energy in Android smart phones. Currently investigating on techniques to dynamically alter the power consumed by storage for android applications, which helps in efficient usage of battery.

Mobile Data Offloading

Recently, there has been a tremendous growth in mobile network traffic that is requiring novel solutions in network design. Network providers are looking for techniques that selectively offload mobile data traffic onto WiFi (IEEE 802.11) networks to improve network performance. We have proposed a novel architecture called Seamless Inter-network Flow Mobility (SIFM) to support selective and seamless flow-mobility between LTE and WiFi networks. The SIFM architecture has been implemented on the NS-3 simulator. The performance studies validate that selective flow-mobility improves network performance.

A proof-of-concept prototype of the SIFM architecture is also implemented on an experimental testbed. The LTE network is emulated by integrating USRP B210x with the OpenLTE eNodeB and OpenLTE EPC. WiFi network is emulated using hostapd and dnsmasq daemons running on ubuntu 12.04. An off-the-shelf LG G2 mobile phone running Android 4.2.2 is used for the mobile node.