My general research interest lies in wireless, mobile networks (i.e., includes mobile ad hoc networks and wireless sensor networks) and I have led projects called INSIGNIA, HMP and SOFA. First two projects produced a number of publications. Some of softwares and testbed codes used to produce the results are available.

In-band Signaling Support for Adaptive Services in MANETs

(a) Part I: Adaptive QOS Framework & Adaptive QoS signaling
My first project is called INSIGNIA.  INSIGNIA stands for In-band Signaling Support for QOS in Ad Hoc Networks. First part of the INSIGNIA project identified "the need for QOS support in mobile ad hoc networks" and we proposed an adaptive QOS framework that suits the mobile ad hoc networks. Detailed INSIGNIA Framework and INSIGNIA's benefits were evaluated through OPNET, NS-2, and actual testbed demos. INSIGNIA was first built on Temporally Ordered Routing Algorithm (TORA) using OPNET and it was later rebuilt to work with Dynamic Source Routing (DSR), Ad-hoc On deamnd Distance Vector (AODV) and TORA using NS2.  INSIGNIA is, in principle, totally distributed and transparent to any underlying mechanisms. Therefore, it operates on any routing protocols and MACs.
Please refer to INSIGNIA project website more detail.

(b) Part II: Performance Benefits on TCP/IP and UDP flows
In the second phase of the project, we conducted a detailed and focused study on its performance benefits, especially its impact on TCP/IP and UDP traffic in diverse network environments.  Detailed performance evaluation results are published in Networking 2000 and IEEE Communication Magazine in June 2001.

(c) INSIGNIA Code Release
INSIGNIA testbed was DEMONSTRATED (on-site) for 2 days at MOBICOM 2000, Boston.
INSIGNIA was demo'ed numerous occasions for Industry Sponsors and Academic Visitors
Test bed codes used in the demo (now with some updates) are available at :  www.comet.columbia.edu/insignia/testbed.html. 
Simulation codes are also available at :  www.comet.columbia.edu/insignia/ns_source_code.html

Hotspot Mitigation Protocol for MANETs

My next project is called HMP. It stands for Hotspot Mitigation Protocol for ad hoc networks. It was one of the first paper that addressed hotspot (flash congestion) conditions in wireless networks and in that project, I have identified that hotspot conditions observed in all wireless network is mainly due to CONTENTION and provided a simple solution. It is published in the IWQOS 2003 and also in the Premiere Issue (Vol. 1, No.1) of Ad Hoc Networks Journal by Elsevier. To learn more about HMP please refer to www.comet.columbia.edu/HMP/

Solicitation-based Forwarding for Sensor Networks

This represents my latest piece of work. This work is on wireless sensor networks. Solicitation-based Forwarding Algorithm (SOFA) aims to provide an agile forwarding mechanism to support improved fidelity in highly unpredictable sensor networks. This work is a part of the Armstrong Project SOFA project includes extensive experimental testbed studies using 40 Mica2 sensor motes running TinyOS. The result of this work is published in IEEE SECON 2006. Current version of the work is available here The project is still in progress and it will be updated soon. Please visit the "work in progress" project website for future updates.