DAS: Distributed antenna systems are a popular deployment strategy for increasing the coverage of mobile cellular as well as WLANs in large settings such as convention/exhibition centers, enterprises, stadiums, hospitals, etc. However, instead of simply using them as extended transmitters, these DAS systems can also be intelligently leveraged to perform a multitude of wireless transmission strategies, ranging from simple broadcast to more sophisticated network MIMO - the configuration of such strategies being orchestrated from a central controller. Such software-defined wireless access networks are critical to delivering enhanced user experience for mobile services and applications. In this project, we have designed and implemented a C-RAN system that can effectively cater to users with varying channel conditions (static and mobile users, network dynamics, etc.) by appropriately tailoring their transmission strategies, thereby resulting in a superior quality of mobile experience.

• “ToneTrack: Leveraging Frequency-agile Radios for Time-based Indoor Wireless Localization”, J. Xiong, K. Sundaresan, K. Jamieson, Proceedings of ACM International Conference on Mobile Computing and Networking (MOBICOM), Sept 2015.
• "MIDAS: Empowering 802.11ac Networks with Multiple-input Distributed Antenna Systems", J. Xiong, K. Sundaresan, K. Jamieson, M. Khojastepour, S. Rangarajan, Best Paper Award, ACM International Conference on emerging Networking EXperiments and Technologies (CONEXT), Dec 2014.

Cloud/Centralized Radio Access Networks: In a cloud-driven radio access network (C-RAN), the processing of all the cells is moved to a central processing entity (cloud), while the remote ends only serves as simple radio transmission/reception units. Interestingly, this creates a new "front-haul" network (between the central processor and remote radio units) that is uniqie to C-RANs. Unlike wired networks, where software-defined networking (SDN) is related to configuring routes on the fly, the notion of "software-defined, reconfigurable" front-hauls is even more powerful in C-RANs - the configurations directly map to different wireless transmission strategies on the access network, as well as also affect the usage of computing resources in the cloud. Given this duplex effect on both the access network and the cloud, we introduce the notion of a "reconfigurable" or "software-defined" front-haul (SDF) for C-RANs and show that adapting them to network traffic conditions and dynamics is critical to the success of the entire C-RAN, delivering both improved user performance as well as cost and energy reduction for operators.

• “AmorFi: Amorphous WiFi Networks for High Density Deployments”, R. Seshadri, M. Arslan, K. Sundaresan, S. Rangarajan, D. Koutsonikolas, ACM International Conference on emerging Networking EXperiments and Technologies (CONEXT), Dec 2016.
• “Trinity: Tailoring Wireless Transmission Strategies to User Profiles in Enterprise Wireless Networks”,S. Singh, K. Sundaresan, S. Krishnamurthy, X. Zhang, M. Khojastepour, IEEE/ACM Transactions on Networking, 2016.
• “Trinity: A Practical Transmitter Cooperation Framework to Handle Heterogeneous User Profiles in Wireless Networks”, S. Singh, K. Sundaresan, S. Krishnamurthy, X. Zhang, M. Khojastepour, S. Rangarajan, Proceedings of ACM International Conference on Mobile Ad Hoc Networking and Computing (MOBIHOC), July 2015.
• "FluidNet: A Flexible Cloud-based Radio Access Network of Small Cells", K. Sundaresan, M. Arslan, S. Singh, S. Rangarajan, S. Krishnamurthy, ACM MOBICOM 2013.
• "The Case for Re-configurable Backhaul for Cloud-RAN based Small cell Networks", C. Liu, K. Sundaresan, M. Jiang, S. Rangarajan, G.K. Chang, IEEE International Conference on Computer Communications (INFOCOM), Apr 2013.