Thanks for stopping by! I am an applied researcher working on topics that will hopefully achieve the trinity of production deployments, top-tier conference papers and open-source contributions. My interests span the following areas (in no particular order):

• Software-defined network control of both the core and RAN
• Application verticals like video, augmented reality, drones etc, that can leverage fine-grained control of the 5G/LTE RAN
• Large-scale distributed systems and storage

In a prohibitively long 😴, but enjoyable Ph.D. (2005-2012) at UT Austin under Vijay Garg, I focused on coding-theoretic fault-tolerance in distributed systems. Following this, I worked as a Postdoc at Princeton University with Mung Chiang (2012-2014). Since then, I have been at ATT Labs Research.

My wife, Mini, writes and edits children’s books. If you want something slightly 😬 more fun than my pulpy papers, do swing by missmini.home.blog.

New!

• Nokia press release on the live trial of the 5G/LTE RAN Intelligent controller (RIC) that was intitated by ATT and Nokia. I was part of the team that built this controller and performed the trial. This controller has been open-sourced through the O-RAN alliance.
• Work on multi-site state management (MUSIC) released as part of the Open-network Automation Platform (ONAP) and accepted at VLDB and ICDCS 2020.
• Measurement study of augmented reality on cellular networks selected as a best paper finalist at IEEE SECON 2020.

Recent Work

Currently (2018-Present), my focus is on the software-defined control of the RAN. Specifically, I work on the following aspects of a 5G/LTE RAN Intelligent controller (RIC) that was initiated by ATT and Nokia and is now open-sourced through the O-RAN alliance:

• As product owner of the RIC, I identify key software deliverables across various teams in ATT and Nokia, coordinate live trials of the software and associated use-cases on our network and lead a team that performs the end-to-end testing and validation of the RIC.
• As use-case manager for the RIC, work with various business-units to prioritize use-cases of the RIC and perform financial modeling to convert technical gains (e.g. % throughput improvement) into actual dollars saved.
• Collaborate with universities on forward-looking applications of the RIC in diverse areas such as augmented reality (Secon 2020), localization (Lanman 2020), drones (HotNets 2020), and video analytics.

Prior to this (2014-2018) my main focus was on the state management of ATT’s network automation platform:

• Conceived and built the first version of a multi-site key-value store (MUSIC) to address ATT’s geo-distribution needs.
• Worked with production teams to identify clients for this tool, successfully deploy this tool in our network and transition the code-base. MUSIC has been running in production for over 3 years now.
• Served as the Project Technical Lead for MUSIC in the open source network automation platform (ONAP) where I worked to evangelize the tool and solicited code contributions from several companies (Intel, IBM) and universities (GeorgiaTech, University of Toronto).
• Collaborated with GeorgiaTech, University of Toronto, US Naval Academy and Princeton University to enhance the code-base, formally verify MUSIC and publish it in conferences (VLDB, ICDCS 2020).

Recent Publications

[VLDB 2020] A Drop-in Middleware for Serializable DB Clustering across Geo-distributed Sites

Enrique Saurez, Bharath Balasubramanian, Richard Schlichting, Brendan Tschaen, Shankaranarayanan Puzhavakath Narayanan, Zhe Huang and Umakishore Ramachandran

[SECON 2020] Characterization of Multi-User Augmented Reality over Cellular Networks

Kittipat Apicharttrisorn, Bharath Balasubramanian, Jiasi Chen, Rajarajan Sivaraj, Yi-Zhen Tsai , Rittwik Jana , Srikanth Krishnamurthy, Tuyen Tran and Yu Zhou
Best Paper Finalist!

[ICDCS 2020] MUSIC: Multi-Site Critical Sections over Geo-Distributed State

Bharath Balasubramanian, Pamela Zave, Richard Schlichting, Mohammad Salehe, Shankaranarayanan Puzhavakath Narayanan, Seyed Hossein Mortazavi, Eyal De Lara, Matti Hiltunen, Kaustubh Joshi and Gueyoung Jung

[HotMobile 2020] Live and let Live: Flying UAVs Without affecting Terrestrial UEs

Lorenzo Bertizzolo, Tuyen X. Tran, Brian Amento, Bharath Balasubramanian, Rittwik Jana, K. Hal Purdy, Yu Zhou, Tommaso Melodia

[LANMAN 2020] A Study of Network-Side 5G User Localization Using Angle-Based Fingerprints

Jiayi Meng, Abhigyan Sharma, Tuyen X. Tran, Bharath Balasubramanian, Gueyoung Jung, Matti A. Hiltunen, Y. Charlie Hu

[ICFEC 2020] SessionStore: A Session-Aware Datastore for the Edge.

Seyed Hossein Mortazavi, Mohammad Salehe, Bharath Balasubramanian, Eyal de Lara, Shankaranarayanan PuzhavakathNarayanan

For my older papers, please refer to DBLP.

Students

One of the biggest privileges of this job is that it provides me with many opportunities to work with students.

If you are a student interested in working on any of the topics mentioned above, please do get in touch with me! It could either be through an internship or simply a no-cost colloboration where we work together on topics of common interest.

I have worked closely with these Ph.D. students and am grateful for their role in the papers and works listed above:

• Yi-Zhen (Angela) Tsai, UC Riverside, 2019-current
• Kittipat Apicharttrisorn (Patrick), UC Riverside, 2019-present
• Lorenzo Bertizzolo, Northeastern University, 2019-present
• Jiayi Meng, Purdue University, 2019-2020
• Enrique Saurez, Georgia Tech, 2017-present
• Azzam Alsudais, UC Bolder, 2017-present
• Muhammad Wajahat, SUNY Stony Brook, 2017-2020
• Shijing Li, George Washgington University, 2017-2020
• Mohammad Salehe, University of Toronto, 2017-2020
• Seyed Hossein Mortazavi, University of Toronto, 2017-2020
• Tariq Mahmood, Purdue University, 2015-2017
• Shankaranarayanan Puzhavakath Narayanan (Shankar), Purdue University, 2015-2016
• Michael Wang, Princeton University, 2013-2014

Service

Program Committees: ICDCS, SEC, IEEE Cloud, SRDS

Invited Reviews: Journal of Operations Research, TPDS, JPDC, ICDCS, OPODIS, DISC, SSS