Full-Duplex: Full-duplex communication allows for simultaneous transmission and reception on the same spectral resource at a node. The key challenging in realizing a wireless full-duplex node is in addressing the self-interference posed by the transmission on the simultaneous reception at the node. Our focus is not just on realizing a full-duplex node but on addressing all the challenges facing its scalability and adoption on a network-wide scale, especially in the presence of MIMO and with half-duplex clients.
“Scaling Wireless Full-duplex to Multi-cell Networks”, M. Khojastepour, K. Sundaresan, S. Rangarajan, IEEE International Conference on Computer Communications (INFOCOM), Apr 2015.
"Full-duplex without Strings: Enabling Full-duplex with Half-duplex Clients", K. Sundaresan, M. Khojastepour, E. Chai, S. Rangarajan, Proceedings of ACM International Conference on Mobile Computing and Networking (MOBICOM), Sept 2014.
"Degrees of Freedom per Communication Node", M. Khojastepour, K. Sundaresan, M. Farajzadeh-Tehrani, S. Rangarajan, International Symposium on Modeling and Optimization in Mobile, Ad-hoc and Wireless Networks (WiOPT), May 2014.
"MIDU: Enabling MIMO Full Duplex." E. Aryafar, M. Khojastepour, K. Sundaresan, S. Rangarajan and M. Chiang, ACM MOBICOM, Aug 2012.
"Characterizing the Throughput Gain of Single Cell MIMO Wireless Systems with Full Duplex Radios." S. Barghi, M. Khojastepour, K. Sundaresan, S. Rangarajan, International Symposium of Modeling and Optimization of Mobile, Ad Hoc, and Wireless Networks (WIOPT), May 2012.
"The Case for Antenna Cancellation for Scalable Full Duplex Communications." A. Khojastepour, K. Sundaresan, S. Rangarajan, X. Zhang, S. Barghi, Proceedings of ACM Workshop on Hot Topics in Networks (HotNets), Cambridge, Nov 2011.
MIMO (multi-user, massive): Multiple element antenna arrays can be used to send multiple data streams (unlike beamforming) by leveraging the rich scattering multipath nature of the environment. Designing efficient network layer solutions and protocols to leverage MIMO's physical layer benefits forms our key focus here.
“Hekaton: Efficient and Practical Large-Scale MIMO”, X. Xie, E. Chai, X. Zhang, K. Sundaresan, M. Khojastepour, S. Rangarajan, Proceedings of ACM International Conference on Mobile Computing and Networking (MOBICOM), Sept 2015.
“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 2014.
"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.
"Synchronicity: Pushing the Envelope of Fine-grained Localization with Distributed MIMO", J. Xiong, K. Jamieson, K. Sundaresan, ACM Workshop on Hot Topics in Wireless, Sept 2014.
"Clustered Network MIMO for Wireless Networks", X. Zhang, K.Sundaresan, M. Khojasteour, S. Rangarajan, K. Shin, ACM MOBICOM 2013.
"Adaptive Feedback Compression in MIMO Networks", X. Xie, X. Zhang, K. Sunsdaresan, ACM MOBICOM 2013.
"Exploiting Interference Locality in Coordinated Multipoint Transmission Systems." X. Zhang, M. Khojastepour, K. Sundaresan, S. Rangarajan, K. Shin, IEEE International Conference on Communications (ICC), Jun 2012.
"Routing in Ad-Hoc Networks with MIMO Links." K. Sundaresan and R. Sivakumar, Best Paper Award, Proceedings of IEEE International Conference on Network Protocols (ICNP), Boston, Nov 2005.
"A Unified MAC Framework for Ad-hoc Networks with Smart Antennas." K. Sundaresan , and R. Sivakumar, Proceedings of ACM International Symposium on Mobile Ad Hoc Networking and Computing (MOBIHOC), Tokyo, Japan, May 2004.
"A Fair Medium Access Control Protocol for Ad-hoc Networks with MIMO Links." K. Sundaresan , R. Sivakumar, and M. A. Ingram, Proceedings of IEEE International Conference on Computer Communications (INFOCOM), Honk Kong, Mar 2004
Switched Beamforming: Fixed beam patterns are employed and directionality is leveraged in line of sight environments to project signal energy in desired directions. We have prototyped several switched beamforming solutions both for indoor and outdoor networks including unicast and multicast applications.
"Design and Implementation of an Integrated Beamformer and Uplink Scheduler for OFDMA Femtocells." M. Arslan, K. Sundaresan, S. Krishnamurthy, S. Rangarajan, ACM MOBIHOC 2012.
"Wireless Data Multicasting with Switched Beamforming Antennas." H. Zhang, Y. Jiang, K. Sundaresan, and S. Rangarajan, Proceedings of IEEE International Conference on Computer Communications (INFOCOM), Mini-Conf, Shanghai, China, April 2011.
"Optimal Beam Scheduling for Multicasting in Wireless Networks." K. Sundaresan, K. Ramachandran, and S. Rangarajan, Proceedings of ACM International Conference on Mobile Computing and Networking (MOBICOM), Beijing, China, Sept 2009.
"R2D2: Regulating Beam Shape and Rate as Directionality meets Diversity." K. Ramachandran, R. Kokku, K. Sundaresan, M. Gruteser and S. Rangarajan, Proceedings of ACM International Conference on Mobile Systems, Applications and Services (MOBISYS), Krakow, Poland, June 2009.
"On the Effectiveness of Switched Beam Antennas in Indoor Wireless Environments." M. Blanco, R. Kokku, K. Ramachandran, S. Rangarajan, and K. Sundaresan, Proceedings of Passive and Active Measurement Conference (PAM), Cleveland OH, USA, Apr 2008.
Adaptive Beamforming: Adaptive beam patterns are formed on the fly using channel state information from clients and can be optimized for multipath environments. We have worked on several algorithmic as well as prototypes of adaptive beamforming solutions, mainly for indoor multipath environments, including both unicast and multicast applications.
"ADAM: An Adaptive Beamforming System for Multicasting in Wireless LANs", E. Aryafar, A. Khojastepour, K. Sundaresan, E. Knightly, S. Rangarajan, in IEEE/ACM Transactions on Networking 2013.
"ADAM: An Adaptive Beamforming System for Multicasting in Wireless LANs", E. Aryafar, A. Khojastepour, K. Sundaresan, E. Knightly, S. Rangarajan, IEEE INFOCOM 2012.
"Adaptive Beamforming Algorithms for Wireless Link Layer Multicasting." M. Khojastepour, A. Khajehnejad, K. Sundaresan, S. Rangarajan, Proceedings of IEEE Personal Indoor Mobile Radio Communications (PIMRC), Toronto, Sept 2011.
"Practical Beamforming based on RSSI Measurements using Off-the-Shelf Wireless Clients." S. Lakshmanan, K. Sundaresan, S. Rangarajan and R. Sivakumar, Proceedings of ACM SIGCOMM Internet Measurement Conference (IMC), Chicago, Nov 2009.
"Towards Adaptive Beamforming in Indoor Wireless Networks: An Experimental Approach." S. Lakshmanan, K. Sundaresan, R. Kokku, M. Khojastepour and S. Rangarajan, Proceedings of IEEE International Conference on Computer Communications (INFOCOM), Mini-Conf, Rio De Janeiro, Brazil, April 2009.
"Cooperating with Smartness: Using Heterogeneous Smart Antennas in Ad-Hoc Networks." K. Sundaresan, and R. Sivakumar, Proceedings of IEEE International Conference on Computer Communications (INFOCOM), Anchorage, Alaska, May 2007.
"Algorithmic Aspects of Communication in Ad-hoc Networks with Smart Antennas." K. Sundaresan, W. Wang and S. Eidenbenz, Proceedings of ACM International Symposium on Mobile Ad Hoc Networking and Computing (MOBIHOC), Florence, Italy, May 2006.