Homepage of Ahmad Rahmati, احمد رحمتی

Ahmad Rahmati

Wireless Technologies,
Apple Inc.

1 Infinite Loop, MS 60-1IOS
Cupertino, CA 95014

ahmad [at] rahmati . com
arahmati [at] apple . com


Ahmad Rahmati


Throughout my professional career and graduate studies, I have become an expert in designing and building complete systems, platforms, and prototypes, followed by lab and field evaluations. In particular, I have worked on the following:

  • Mobile, embedded, and wireless system design, applications, and productization
  • 3GPP/LTE, WiFi, and Bluetooth selection, interworking, and coexistence
  • Context-aware computing through sensing and statistical learning on large data
  • System power measurement, analysis, and battery optimization
  • Human factors, user studies, and Human-Computer Interaction
  • Pervasive health and biomedical applications

I received my Ph.D. and M.Sc. from the Department of Electrical and Computer Engineering at Rice University, in 2012 and 2008. I worked with Professor Lin Zhong in the Rice Efficient Computing Group. I received my B.Sc. in Computer Engineering from Sharif University of Technology in 2004.

Before joining Apple in 2014, I was a Senior Staff Scientist at Broadcom's Mobile and Wireless Group from 2012. I have been a research intern with Deutsche Telekom R&D Lab USA, Motorola Labs and AT&T Labs Research in Spring 2010, Summer 2008, and Summer 2006. At Rice, I led the design and implementation of the Rice Orbit Platform, an open source Bluetooth body area research platform for mobile computing and health applications.

My interests fall within the area of human-centered wireless and mobile computing. In particular, system solutions for energy efficient, usable, and context-aware mobile devices, services, and applications.



Patents

  • Ahmad Rahmati et. al., "System and methods for anonymous crowdsourcing of network condition measurements", US Patent US2014/0211648, January 29, 2014

  • Ahmad Rahmati et. al., "Systems and methods for network discovery and selection using contextual information", US Patent US2014/0192643, January 7, 2014

  • Ahmad Rahmati et. al., "A System for Heterogeneous Network Access on Devices with One or Multiple Network Interfaces", US Patent US2012/0071141, July 7, 2011

  • Ahmad Rahmati et. al., "Sensor-Assisted Motion Estimation For Efficient Video Encoding", US Patent US2010/0079605, September 28, 2009

  • Several Provisional Patents related to mobile and wireless systems including 3GPP LTE / WLAN interworking.

Publications (800+ citations)
  • Ahmad Rahmati, Clayton Shepard, Chad Tossell, Lin Zhong, and Phillip Kortum, "Practical Context Awareness: Measuring and Utilizing the Context Dependency of Mobile Usage", to appear in IEEE Transactions on Mobile Computing. [pdf]; prior technical report: [arxiv]

  • Ahmad Rahmati, Clayton Shepard, Chad Tossell, Lin Zhong, Phillip Kortum, Angela Nicoara, and Jatinder Singh, "Seamless Flow Migration on Smartphones without Network Support", to appear in IEEE Transactions on Mobile Computing. [pdf]; prior technical report: [arXiv]

  • Chad Tossell, Phillip Kortum, Clayton Shepard, Ahmad Rahmati, and Lin Zhong, "You can lead a horse to water but you cannot make him learn: Smartphone use in higher education", to appear in British Journal of Educational Technology (BJET). [pdf]

  • Ahmad Rahmati and Lin Zhong, "Studying smartphone usage: lessons from a four-month field study", in IEEE Transactions on Mobile Computing, vol. 12, no. 7, July 2013. (field study of 12 Windows Mobile phones) [pdf]

  • Chad Tossell, Phillip Kortum, Clayton Shepard, Ahmad Rahmati, and Lin Zhong, "An Empirical Analysis of Smartphone Personalization: Measurement and User Variability", in Behavior & Information Technology, vol. 31, no.10, October 2012. (measuring phone personalization and exploring its user differences) [pdf]

  • Ahmad Rahmati, Chad Tossell, Clayton Shepard, Phillip Kortum, and Lin Zhong, "Exploring iPhone Usage: The Influence of Socioeconomic Differences on Smartphone Adoption, Usage and Usability", in Proc. ACM Int. Conf. Human Computer Interaction with Mobile Devices and Services (MobileHCI), September 2012. [pdf]

  • Chad Tossell, Phillip Kortum, Clayton Shepard, Ahmad Rahmati, and Lin Zhong, "Getting real: A naturalistic methodology for using smartphones to collect mediated communications", in Advances in Human-Computer Interaction, vol. 2012, art. 815972, June 2012. [pdf]

  • Chad Tossell, Phillip Kortum, Ahmad Rahmati, Clayton Shepard, and Lin Zhong, "Characterizing web use on smartphones", in ACM SIGCHI Conf. Human Factors in Computing Systems (CHI), May 2012. [pdf]

  • Chad Tossell, Phillip Kortum, Clayton Shepard, Laura Barg-Walkow, Ahmad Rahmati, and Lin Zhong, "A Longitudinal Study of Emoticon Use in Text Messaging from Smartphones", in Computers in Human Behavior, vol. 28, no. 2, March 2012. [pdf]

  • Hang Yu, Ahmad Rahmati, Ardalan Amiri Sani, Lin Zhong, Jehan Wickramasuriya, and Venu Vasudevan, "Data broadcasting using mobile FM radio: design, realization and application", in ACM Int. Conf. Ubiquitous Computing (UbiComp), September 2011. [pdf]

  • Chad Tossell, Jo Jardina, Phillip Kortum, Camille Peres, Clayton Shepard, Ahmad Rahmati, and Lin Zhong, "Effects of Socioeconomic diversity on iPod Touch Device Use in Real-World Environments", in Proc. Human Factors and Ergonomics Society Annual Meeting (HFES), September 2011. [pdf]

  • Ahmad Rahmati, Clayton Shepard, Chad Tossell, Mian Dong, Zhen Wang, Lin Zhong, and Phillip Kortum, "Tales of 34 iPhone Users: How they change and why they are different", Rice University Technical Report TR-2011-0624. [pdf] [arXiv]

  • Xiaoming Chen, Zhendong Zhao, Ahmad Rahmati, Ye Wang, and Lin Zhong, "Sensor-Assisted Video Encoding for Mobile Devices in Real-World Environments", in Proc. IEEE Trans. Circuits and Systems for Video Technology (TCSVT), vol. 21, no. 3, March 2011. [pdf]

  • Ahmad Rahmati and Lin Zhong, "Context-based network estimation for energy-efficient ubiquitous wireless connectivity", in IEEE Transactions on Mobile Computing, vol. 10, no.1, January 2011. (January issue's Spotlight Paper, with substantial new results on network condition prediction) [pdf] [link]

  • Clayton Shepard, Ahmad Rahmati, Chad Tossell, Lin Zhong, and Phillip Kortum, "LiveLab: Measuring Wireless Networks and Smartphone Users in the Field", in ACM SIGMETRICS Performance Evaluation Review (PER), vol. 38, no. 3, December 2010. [pdf]

  • Yunxin Liu, Ahmad Rahmati, Yuanhe Huang, Hyukjae Jang, Lin Zhong, Yongguang Zhang, and Shensheng Zhang, "Design, realization, and evaluation of xShare for impromptu sharing of mobile phones", in IEEE Transactions on Mobile Computing, vol. 9, no. 12, December 2010. (December issue's Spotlight Paper) [pdf] [link]

  • Xiaozhu Lin, Ahmad Rahmati, and Lin Zhong, "Dandelion: A framework for transparently programming phone-centered wireless body sensor applications for health", in ACM Wireless Health, October 2010. [pdf]

  • Chad Tossell, Phillip Kortum, Clayton Shepard, Ahmad Rahmati, and Lin Zhong, "Assessing the Performance of Common Tasks on Handheld Mobile Computers", in Proc. Human Factors and Ergonomics Society (HFES), September 2010. [pdf]

  • Bo Han, Ahmad Rahmati, and Bhojan Anand, "Report of HotMobile 2010", in IEEE Pervasive Computing, July 2010. (invited article) [pdf]

  • Clayton Shepard, Ahmad Rahmati, Chad Tossell, Lin Zhong, and Phillip Kortum, "LiveLab: Measuring Wireless Networks and Smartphone Users in the Field", in Proc. Wrkshp. Hot Topics in Measurement & Modeling of Computer Systems (HotMetrics), June 2010. [pdf]

  • Ahmad Rahmati, Lin Zhong, Venu Vasudevan, Jehan Wickramasuriya, and Daniel Stewart, "Enabling Pervasive Mobile Applications with the FM Radio Broadcast Data System", in Proc. 10th ACM/SIG Int. Wrkshp. Mobile Computing Systems and Applications (HotMobile), February 2010. [pdf]

  • Xiaoming Chen, Zhendong Zhao, Ahmad Rahmati, Ye Wang, and Lin Zhong, "SaVE: sensor-assisted motion estimation for efficient H.264/AVC video encoding", in Proc. ACM Multimedia, October 2009. [pdf]

  • Ahmad Rahmati and Lin Zhong, "Human-battery interaction on mobile phones", in Pervasive and Mobile Computing Journal, vol 5, no. 5, October 2009. [pdf] [link]

  • Ahmad Rahmati and Lin Zhong, "A longitudinal study of non-voice mobile phone usage by teens from an underserved urban community", Technical Report 0515-09, Rice University, May 2009. [pdf] [arXiv]

  • Yunxin Liu, Ahmad Rahmati, Yuanhe Huang, Hyukjae Jang, and Lin Zhong, "xShare: Supporting Impromptu Sharing of Mobile Phones", in Proc. ACM/USENIX Int. Conf. Mobile Systems, Applications, and Services (MobiSys), June 2009. [pdf]

  • Ahmad Rahmati, Clayton Shepard, and Lin Zhong, "NoShake: Content Stabilization for Shaking Screens of Mobile Devices", in Proc. IEEE Int. Conf. Pervasive Computing and Communication (PerCom), March 2009. [pdf]

  • Guang-ming Hong, Ahmad Rahmati, Ye Wang, and Lin Zhong, "SenseCoding: Accelerometer-assisted motion estimation for efficient video encoding", in Proc. ACM Multimedia, October 2008. [pdf]

  • Nilanjan Banerjee, Ahmad Rahmati, Mark Corner, Sami Rollins, and Lin Zhong, "Users and Batteries: Interactions and Adaptive Energy Management in Mobile Systems", in Proc. Int. Conf. Ubiquitous Computing (UbiComp), September 2007. [pdf]

  • Ahmad Rahmati and Lin Zhong, "Usability evaluation of a commercial Pocket PC phone: A pilot study", in Proc. ACM Int. Conf. Mobile Technology, Applications and Systems (Mobility), September 2007. [pdf]

  • Ahmad Rahmati, Angela Qian, and Lin Zhong, "Understanding Human-Battery Interaction on Mobile Phones", in Proc. ACM Int. Conf. Human Computer Interaction with Mobile Devices and Services (MobileHCI), September 2007. (MobileHCI Best Paper Award) [pdf]

  • Ahmad Rahmati, Lin Zhong, Matti Hiltunen, and Rittwik Jana, "Reliability techniques for RFID-based object tracking applications", in Proc. IEEE/IFIP Int. Conf. Dependable Systems and Networks (DSN), June 2007. [pdf]

  • Ahmad Rahmati and Lin Zhong, "Context-for-Wireless: Context-Sensitive Energy-Efficient Wireless Data Transfer", in Proc. ACM/USENIX Int. Conf. Mobile Systems, Applications, and Services (MobiSys), June 2007. [pdf] [slides]


Last updated April 2014