Fundamentals of Networking Lab







Code Contributions

Presentations and Documents  (Restricted Access)




Journal Publications


Ma, H; Zhu, J; Roy, S; Shin S;Joint Transmit Power and Physical Carrier Sensing Adaptation based on Loss Differentiation for High Density IEEE 802.11 WLAN , To appear in Elsevier Computer Networks, 2008




Ma, H; Zhu, J; Roy, S, On Loss Differentiation for CSMA-based Dense Wireless , IEEE Communications Letters, Nov. 2007

Ramachandran, I; Das, A; Roy, S, Analysis of the Contention Access Period of IEEE 802.15.4 MAC, ACM Trans. on Sensor Networks, Feb. 2007.




Ramachandran, I; Das, A; Roy, S, Clear Channel Assessment in Energy-constrained Wideband Wireless Networks, IEEE Wireless Comm. Mag., June 2007

Zhu, J.; Roy, S; Kim, J., Performance Modelling of TCP Enhancements in Terrestrial-Satellite Hybrid Networks, IEEE/ACM Transactions on Networking, Aug. 2006.

Ramachandran, I; Roy, S, On Acquisition of Wideband Direct-Sequence Spread Spectrum Signals, IEEE Transactions on Wireless Comm., Vol. 5, No. 6, pp. 1537-1546, Jun. 2006.



Shao L, Roy S, Rate-1 Space-Frequency Block Codes with Maximum Diversity for MIMO-OFDM, IEEE Trans. on Wireless Comm. Vol. 4, No. 4, Jul. 2005

Jing Zhu, Roy S, A 802.11 Based Dual-Channel Reservation MAC Protocol for In-Building Multihop Networks, Springer Mobile Networks and Applications, Volume 10, Number 5, Oct. 2005, Pages: 593-606

Yan H, Roy S, Parallel Interference Cancellation for Uplink Multirate Overlay Channels, IEEE Trans. on Comm, Volume 53, Issue 1, Jan. 2005, Pages: 152-161


Jing Zhu, Xingang Guo, L. Lily Yang, W. Steven Conner, Sumit Roy, Mousumi M. Hazra, Adapting physical carrier sensing to maximize spatial reuse in 802.11 mesh networks, Wireless Communications and Mobile Computing Volume 4, Issue 8, p 933-946, December 2004.

Mir, H.S.; Roy, S., Optimum transmitter/receiver design for a narrowband overlay in noncoordinated subscriber lines, Communications, IEEE Transactions on  ,Volume: 52 , Issue: 6 , June 2004, Pages:992 - 998

Jing Zhu; Roy, S., Improving link layer performance on satellite channels with shadowing via delayed two-copy selective repeat ARQ, Selected Areas in Communications, IEEE Journal on  ,Volume: 22 , Issue: 3 , April 2004, Pages:472 - 481

Roy, S.; Foerster, J.R.; Somayazulu, V.S.; Leeper, D.G., Ultrawideband radio design: the promise of high-speed, short-range wireless connectivity, Proceedings of the IEEE  ,Volume: 92 , Issue: 2 , Feb. 2004 , Pages:295 - 311


Jing Zhu; Roy, S., MAC for dedicated short range communications in intelligent transport system, Communications Magazine, IEEE  ,Volume: 41 , Issue: 12 , Dec. 2003, Pages:60 - 67

Smith, P.J.; Roy, S.; Shafi, M., Capacity of MIMO systems with semicorrelated flat fading, Information Theory, IEEE Transactions on , Volume: 49 , Issue: 10 , Oct. 2003, Pages:2781 - 2788

Abouzeid, A.A.; Roy, S.; Stochastic Modeling of TCP in Networks with Abrupt Delay Variations, Wireless Networks, Volume: 9, Sept. 2003, Pages: 509 - 524

Shah, R.C.; Roy, S.; Jain, S.; Brunette, W., Data MULEs: modeling a three-tier architecture for sparse sensor networks, Sensor Network Protocols and Applications, 2003. Proceedings of the First IEEE. 2003 IEEE International Workshop on , 11 May 2003, Pages:30 - 41

Abouzeid, A.A.; Roy, S.; Azizoglu, M., Comprehensive performance analysis of a TCP session over a wireless fading link with queueing, Wireless Communications, IEEE Transactions on , Volume: 2 , Issue: 2 , March 2003, Pages:344 - 356

Chengyang Li; Roy, S., Subspace-based blind channel estimation for OFDM by exploiting virtual carriers, Wireless Communications, IEEE Transactions on , Volume: 2 , Issue: 1 , Jan. 2003, Pages:141 - 150


Roy, S.; Chengyang Li, A subspace blind channel estimation method for OFDM systems without cyclic prefix, Wireless Communications, IEEE Transactions on , Volume: 1 , Issue: 4 , Oct. 2002, Pages:572 - 579

Aramvith, S.; Chia-Wen Lin; Roy, S.; Ming-Ting Sun, Wireless video transport using conditional retransmission and low-delay interleaving, Circuits and Systems for Video Technology, IEEE Transactions on , Volume: 12 , Issue: 6 , June 2002, Pages:558 - 565

Roy, S.; Hongbo Yan, Blind channel estimation in multi-rate CDMA systems, Communications, IEEE Transactions on , Volume: 50 , Issue: 6, June 2002, Pages:995 - 1004

Alhussein A. Abouzeid and Sumit Roy, Modeling random early detection in a differentiated services network  Computer Networks, Volume 40, Issue 4,15 November 2002, Pages 537-556


Conference Publications


Ma, H; Roy, S;   Contention Window and Transmission Opportunity Adaptation for Dense IEEE 802.11 WLAN Based on Loss Differentiation, Proc. IEEE ICC, Beijing, China, May 2008.

Luo, L; Roy, S;  A Two-stage Sensing Technique for Dynamic Spectrum Access , Proc. IEEE ICC, Beijing, China, May 2008.

Ye, F; Adams, M; Roy, S;  Vehicle-to-Vehicle Wireless Communication Protocol for Rear-End Collision Avoidance on Highways , VehiMobi'08,Vehicular Networking & Applications Workshop, Beijing, China, May 2008..




Gupta, Rohit; Shing, Tommy; Zhu, Jing ; Roy, S, Closed Loop RF Management Algorithm for Enterprise High Density WLANs, Globecom, Nov. 2007.

Ko, Y-C; Roy, S.; Smith, J. R.; Lee, H-W, and Cho, C-H, An Enhanced RFID Multiple Access Protocol for Fast Inventory, Globecom, Nov. 2007.

Neihart, N; Roy, S; and Allstot, D. J., A Parallel Multi-resolution Sensing Technique for Multiple Antenna Cognitive Radios, Proc. IEEE ISCAS, New Orleans, May 2007.

Ma, H; Shin, S-Y; and Roy, S;  Optimizing Throughput with Carrier Sensing Adaptation for IEEE 802.11 Mesh Networks Based on Loss Differentiation, Proc. IEEE ICC, Glasgow, Scotland, June 2007.

Shin, S-Y; Iyappan, R: Roy, S; and Kwon W. H; Cascaded Clear Channel Assessment: Enhanced Carrier Sensing for Cognitive Radios, IEEE Cognets Workshop, Glasgow, Scotland, June 2007.

Luo , L; and Roy, S;  Analysis of Search Schemes in Cognitive Radio, 2nd IEEE Workshop on Software Defined Radios, San Diego, June 2007.

Parrish N.; Roy S.; Fox W. L.; and Arabshahi P. Rate-Range for An FH-FSK Acoustic Modem, 2nd ACM Workshop on Underwater Networks, Montreal, Sep. 2007.




Henderson, T. R, Roy S., Floyd S. and Riley G., ns-3 Project Goals, Workshop on ns-2; the IP Simulator, Pisa, Italy, Oct. 2006.

Ramachandran, I; Roy S., On the Impact of Clear Channel Assessment on MAC Performance, Proc. IEEE Globecom, San Fransisco, Nov. 2006.

Ma, H. and Roy, S., Simple and Effective Carrier Sense Adaptation for Multi-rate Ad-Hoc MESH Networks, 1st Intl. Workshop Wireless MESH Networks and Applicns., Vancouver, BC, Oct. 2006.

 Das, A; Roy, S; and Vijaykumar, R, Static Channel Assignment in Multi-radio Multi-channel 802.11 Wireless Mesh Networks: Issues, Metrics and Algorithms, Proc. IEEE Globecom, San Fransisco, Nov. 2006.

Roy, S.; Arabshahi P.; Rouseff D.; and Fox W. L. Wide Area Ocean Networks: Architecture and System Design Considerations, 1st ACM Wkshp. Underwater Networks, Los Angeles, Sep. 2006.

Ma, H .;Alotaibi, E.; Roy, S., Analysis and Simulation Model of Physical Carrier Sensing in IEEE 802.11 Mesh Networks, OPNETWORK Conference 2006, Aug. 2006,Washington DC



Ramachandran, I; Roy, S; Analysis of Throughput and Energy Efficiency of p-persistent CSMA with Imperfect Carrier Sensing IEEE Globecom, St. Louis, Dec 2005.

Ma, H; Alazemi, H; Roy, S; A Stochastic model for Optimizing Physical Carrier Sensing and Spatial Reuse in Wireless Ad-hoc Networks IEEE MASS, Washington D.C, Nov. 2005

Roy, S; Das, A; Vijayakumar, R; Alazemi, H; Ma, H; Alotaibi, E; Capacity Scaling with Multiple Radios and Multiple Channels in Wireless Mesh Networks  IEEE WiMesh, Sept. 2005

Das, A; Alazemi, H; Vijayakumar, R; Roy, S; Optimization Models for Fixed Channel Assignment in Wireless Mesh Networks with Multiple Radios IEEE SECON, Santa Clara, Sept. 2005

Ramachandran, I; Roy, S; Acquisition of Direct-Sequence Ultra-Wideband Signals IEEE Wireless Communications and Networking Conference, New Orleans, March, 2005.

Shao, L; Roy, S; Downlink Multicell MIMO-OFDM: An Architecture for Next Generation Wireless Networks Wireless Communications and Networking Conference, New Orleans, March, 2005.

Jing Zhu, and Sumit Roy, 802.11 Mesh Networks with Two-Radio Access Points, ICC 2005, May 2005, Seoul, Korea.


Fishkin,K; Jiang, B; Roy, S, I Sense a Disturbance in the Force: Unobstrusive Detection of Interactions with RFID-tagged Objects, Ubicomp, Nottingham, England, Sept. 2004

Lei Shao; Sumit Roy; Sandhu, S; Ho, M, High-rate Space-frequency Block-code Designs for Next-generation 802.11 WLANs, ICC, 2004, June 2004, Paris, France.


Lei Shao; Sumit Roy; Sandhu, S; Ho, M, Rate-one Space-Frequency Block-codes with Maximum Diversity Gain for MIMO-OFDM, Globecom 2003, Dec 2003, San Francisco, CA.

Jing Zhu, and Sumit Roy, Improving TCP Performance in TDMA-based Satellite Access Networks, ICC, 2003, May 2003, Anchorage AL.

Jing Zhu, and Sumit Roy, Modeling TCP over Selective Repeat ARQ in Wireless Networks with Non-negligible Propagation Delay, ICC, 2003, May 2003, Anchorage AL.

Jing Zhu, and Sumit Roy, Satellite Link-Layer Performance Using Two-copy ARQ and its Impact on TCP Traffic, Int. Conf. on Information Networks, 2005, Feb 2003, Jeju, Korea.


Ho, M.; Somayazulu, V.S.; Foerster, J.; Roy, S.; A differential detector for an ultra-wideband communications system Vehicular Technology Conference, 2002. VTC Spring 2002. IEEE 55th , Volume: 4 , 6-9 May 2002 Pages:1896 - 1900 vol.4

Jing Zhu; Roy, S.; An adaptive two-copy delayed SR-ARQ for satellite channels with shadowingVehicular Technology Conference, 2002. Proceedings. VTC 2002-Fall. 2002 IEEE 56th , Volume: 2 , 24-28 Sept. 2002 Pages:849 - 853 vol.2

Somayazulu, V.S.; Foerster, J.R.; Roy, S.; Design challenges for very high data rate UWB systemsSignals, Systems and Computers, 2002. Conference Record of the Thirty-Sixth Asilomar Conference on , Volume: 1 , 3-6 Nov. 2002 Pages:717 - 721 vol.1

Lei Shao; Roy, S.; A rate-one non-orthogonal space-time coded OFDM system with estimation for frequency selective channels Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE , Volume: 1 , 17-21 Nov. 2002 Pages:676 - 680 vol.1

Chengyang Li; Man-On Pun; Roy, S.; Low complexity blind frequency-offset estimator for OFDM systems over ISI channelsGlobal Telecommunications Conference, 2002. GLOBECOM '02. IEEE , Volume: 1 , 17-21 Nov. 2002 Pages:249 - 253 vol.1

Jing Zhu; Roy, S.; Performance of land mobile satellite communication (LMSC) channel with hybrid FEC/ARQGlobal Telecommunications Conference, 2002. GLOBECOM '02. IEEE , Volume: 3 , 17-21 Nov. 2002 Pages:2851 - 2854 vol.3


Contributed Articles

J. Zhu; S. Roy; X. Guo and W. S. Conner, ` `Maximizing Aggregate Throughput in 802.11 Mesh Networks with Physical Carrier Sensing and Two-radio Multichannel Clustering,'' Proc. NSF-RPI Workshop on Pervasive Computing and Networking, Apr. 2004, Kluwer Acad. (to appear).

Roy, S.; Ramachandran, I.; "Channel Estimation for High Rate Ultra-Wideband Systems" in "UWB Communication Systems - A Comprehensive Overview", T. Kaiser (ed.), EURASIP Publishing (to appear).


Technical Reports

J. Zhu, S. Roy, Jae Kim, Performance Modelling of TCP Enhancements in Terrestrial-Satellite Hybrid Networks, UW/EE Technical Report, 2005

Ramachandran I, Das A, Roy S Analysis of Contention Access Period of IEEE 802.15.4 MAC UWEE Technical Report, UWEETR-2006-0003, 2006

Purushothaman I, Roy S Infrastructure mode support for IEEE 802.11 implementation in NS-2

For 802.11 infrastructure mode patch for ns2, Click Here.