I am a Ph.D. student in the
Department of Computer Science at Columbia University where I work in the Internet Real-Time Laboratory. My advisor is Prof. Henning Schulzrinne. Prior to Columbia, I was a researcher at Fraunhofer FOKUS in Berlin and later a co-founder and chief software architect at iptel.org, one of its spin-off companies ( acquired by Tekelec, now part of Oracle). I received my M.S. in Computer Science from the Czech Technical University in Prague in 2003.
Outside of work, I enjoy outdoor adventures, scuba diving, running, and cross-country skiing. I am also an avid reader with a soft spot for classic science fiction and
Karel Capek. Some of my favorite films have been made by Alexander Payne, Milos Forman, and Wes Anderson.
My primary research area is distributed network applications, with a focus on the Internet of Things (IoT), cyber-physical systems, and multi-media network services. My goal is to design and develop better programming abstractions for distributed and reliable IoT applications that are deployable across a heterogeneous network of devices. I am specificially interested in exploring the "computation follows data" approach to IoT application design, where the application gets deployed close to the origin of the data, as opposed to the more traditional "data follows computation" model leveraged by most existing cloud-based IoT services.
I also mentor and supervise student projects (undegraduate and graduate level). Our paper on the design of a wireless networking lab won the
Best Educational Paper Award at the Second GENI Educational and Research Workshop in 2013. I helped design the homework assigments for the Advanced Programming class at Columbia and supervised numerous student team projects.
An Analysis of Amazon Echo's Network Behavior, J. Janak, T. Tseng, A. Isaacs, H. Schulzrinne To appear in the proceedings of IEEE GlobeCom 2021, December 2021
Talking After Lights Out: An Ad Hoc Network for Electric Grid Recovery, J. Janak, D. Chee, H. Retty, A. Baloian, H. Schulzrinne In submission to IEEE SmartGridComm 2021, October 2021
Social Distancing and the Internet: What Can Network Performance Measurements Tell Us?, J. De Oliveira Moreira, A. Pasarkar, W. Chen, W. Hu, J. Janak, H. Schulzrinne, , December 2020 TPRC 48
Checkpointing and Migration of IoT Edge Functions, P. Karhula, J. Janak, H. Schulzrinne, EdgeSys '19, March 2019
Framework for Rapid Prototyping of Distributed IoT Applications Powered by WebRTC, J. Janak, H. Schulzrinne, IPTComm 2016, October 2016
Flexible Network Address Mapping for Container-based Clouds, K. Kim, J. Lee, M. Ben-Ami, H. Nam, J. Janak, H. Schulzrinne, NetSoft 2015, April 2015
NetServ: Active Networking 2.0, J. Lee, R. Francescangeli, Jan Janak, S. Srinivasan, S. Baset, H. Schulzrinne, Z. Despotovic, W. Kellerer, IEEE FutureNet IV (2011), June 2011
How Green is IP-Telephony?, S. Baset, J. Reich, J. Janak, P. Kasparek, H. Schulzrinne, V. Misra, D. Rubenstein, SIGCOMM Green Networking Workshop, August 2010
SIP Express Router (SER), A. Pelinescu-Onciul, J. Janak, J. Kuthan, IEEE Network Magazine, Vol. 17(4), pp. 9-9, July 2003
SIP Proxy Server Effectiveness, J. Janak, Master's Thesis, Czech Technical University, May 2003
NetServ Framework Design and Implementation 1.0, J. Lee, R. Francescangeli, W. Song, J. Janak, S. Srinivasan, M. Kester, S. Baset, E. Liu, Technical Report, cucs-016-11
Columbia University WiMAX Campus Deployment and Installation, S. Seo, J. Janak, H. Schulzrinne, Technical Report cucs-032-11
GRAND: Git Revisions As Named Data, J. Janak, J. Lee, H. Schulzrinne, Technical Report cucs-047-11
NetServ: Reviving Active Networks, J. Lee, R. Francescangeli, W. Song, E. Maccherani, J. Janak, S. Srinivasan, M. Kester, S. Baset, Technical Report cucs-001-12
Connecting the Physical World with Arduino in SECE, H. Nam, J. Janak, H. Schulzrinne, Technical Report cucs-013-13
Social Distancing and the Internet: What Can Performance Measurements Tell Us?, TPRC 48, Washington, D.C., February 2021
Prototyping Distributed IoT Applications With WebRTC, IPTComm 2016, Chicago, October 2016
Access Control for Smart Objects, IAB Workshop on Smart Object Security, Paris, March 2013
SIP Express Router, FOSDEM, Brussels, February 2006
autoprov: Auto-provisioning server for Yealink W52P phones
dns2avahi: A DNS to Avahi (multicast DNS) gateway
py-mjpeg: Python library for working with MJPEG streams
PulseAudio.js: PulseAudio client for NodeJS
AMBE: A library for working with DVSI's vocoder chips