A. Cloud Computing and Datacenters
The emergence of user-facing online services such as web search (e.g., Bing), social networks (e.g., Twitter), and advertising systems (e.g., Google AdWords) has led to the development of mega-scale datacenters. In addition, with the rise of cloud computing service providers like Amazon, Microsoft, and Google, datacenters have emerged as a primary platform for managing the computation, storage, and communication requirements of users. These datacenters have unique network and traffic characteristics (e.g., microsecond latencies, partition-aggregate structure of applications, and multi-rooted tree topologies) that give rise to interesting research questions such as: what topologies work best for datacenters? how can we design efficient load balancing schemes? how can we architect scalable cloud management frameworks? how can we come up with power efficient datacenter designs suited to the needs of the developing world?
[DRIBS, NSDI 2017]
[SAPS, INFOCOM 2017]
[RANS, HotNets 2016]
[eSDN, SIGCOMM 2015]
[MulBuff, SIGCOMM 2014]
[PASE, SIGCOMM 2014] (PASE ns2 simulation code, patch applies to ns-2.34)
[L2DCT, INFOCOM 2013] (L2DCT ns2 simulation code, patch applies to ns-2.35)
[Coexistence of Datacenter Transports, ICC 2014]
[Incast Congestion, Globecom 2015]
[RACS, ICC 2013]
B. Mobile/Wireless Networks
Wireless technologies (e.g., WiFi, Bluetooth, and 3G/4G) have become extremely pervasive in our lives. While technological advances have led to substantial improvements in these technologies, several research challenges arise as these technologies increase in diversity, scale (e.g., in terms of speeds), or are densely deployed. These trends lead to many interesting challenges such as (1) how can we use multiple wireless interfaces (e.g., WiFi, Bluetooth, and 4G) to better support different applications (e.g., AR/VR), (2) how can we achieve high throughput efficiency at Gigabits/sec WiFi speeds?, (3) how can we design a scalable packet core for next-generation cellular networks (e.g., 5G and beyond), and (4) how can we design extremely low cost WiFi that can achieve high speeds at 10s of kilometers of distances?
[SlickFi, CoNEXT 2016]
[BLMon, INFOCOM 2014, INFOCOM 2013]
[Rate Equilibria in WLANs, LCN 2013]
C. Internet Censorship
Internet censorship has become increasingly pervasive with nearly 70 countries restricting internet access in one way or another. The resulting impact on the user base is widespread and has drawn a lot of interest from researchers, activists, and citizens in recent years. Existing systems research on Internet censorship has focused on either measuring censorship (i.e., what is blocked, where it is blocked, how it is blocked, and when it is blocked?) or designing tools for resisting censorship (e.g., Tor). We are exploring several research themes in this space: How can we design scalable systems for gathering reliable and continuous censorship measurements? How can one improve the performance of anonymity tools? How can we analyze mechanism(s) used by a censor to block content in real-time? What are the ethical and effectiveness tradeoffs in measuring censorship?
[Ethics, NSDI 2018]
[Advention, HotNets 2017]
[C-Saw, SIGCOMM 2018, HotNets 2015]
D. ICT for Developing Regions
Despite marked improvements in Information and Communication Technologies (ICT) the world over, the common use of low-end devices with a slow Internet connection often leads to poor user experience in developing countries. This is due to a variety of reasons including lack of ICT infrastructure, lack of access to high-end mobile devices, and lack of focused policy and research towards addressing ICT challenges in the developing world. Our research aims to bridge this digital divide by building low cost network infrastructure that is aware of user device limitations and is able to meet the performance, security, and policy requirements of different stakeholders in the Internet ecosystem.
[Facebook Free Basics, SIGCOMM CCR 2017]
[Facebook Free Basics, SIGMETRICS 2017]
[Mobile Phone Characteristics in Developing Regions, IMC 2016]
[Long Distance WiFi, INFOCOM 2014]
E. Greening the Electrical Grid using Internet Concepts
The Electrical grid and the Internet share the same goal of interconnecting distributed suppliers to geographically dispersed consumers. The existing grid faces several challenges: it is centralized, with wasteful transmission and distribution technologies, carbon-intensive energy sources, limited energy storage, and minimal use of ICT. We think the future Electrical Grid will have architecture like the Internet and thus the lessons learnt from its design and evolution could play a key role towards the Next-Generation Grid (a.k.a Smart Grid).
[Models for Load Prediction, ICONIP 2012]