Project Engineering

Venkatesh Rajendran

Jack Baskin School of Engineering

University of California

**** **** ******

Santa Cruz, CA 95064.

Home Phone: 831-***-****

Work Phone: 831-***-****

Email: ******@***.****.***

URL: http://www.soe.ucsc.edu/~venkat/

Professional Objective

To pursue a research career in wireless communication system design. Currently looking for summer internship/Co-op

position in wireless communications research.

Education

Ph.D in Computer Engineering, June 2005

University of California, Santa Cruz.

Overall GPA: 3.91 out of 4.00

Master's in Computer Engineering, June 2003

University of California, Santa Cruz.

Overall GPA: 3.89 out of 4.00

B.E in Electronics and Communication Engineering, June 2001

College of Engineering, Anna University, India.

Overall GPA: 8.9 out of 10.0

Master's Thesis: Reliable Multicasting in Ad Hoc Networks.

B.E. Thesis: Energy Allocation and Multiple Access for Multi-carrier communication.

Awards and Honors

Jack Baskin School of Engineering's Outstanding Teaching Assistant Award, 2002-2003.

Regents Fellowship, UC Santa Cruz, for the year 2001-2002.

Rotary Club Award for Project Work for the year 2000-2001, Alumni Association, College of Engineering,

Guindy, Anna University.

The Engineering College Co-Operative Society Common Good Fund Endowment Prize for the year 1998-1999.

Research Interests

Wireless communication system design, protocols and services for mobile ad hoc wireless networks, smart MAC

protocols for WLANs, IEEE WLAN standards, energy-aware media access control protocols for smart sensor networks,

reliable multicasting in MANETs, OFDM/multi-carrier communications for multiuser systems, digital signal processing,

adaptive modulation, and MIMO / smart antenna systems.

Computer Skills

Experience in Linux, FreeBSD, Windows XP/9x/NT, and Solaris. Experience in network programming in UNIX

environment using sockets and POSIX threads. Network administration experience in Linux and FreeBSD. Experience in

implementing network protocols in Qualnet (contributed protocols to the development team), Glomosim, CSIM and NS2.

Programming knowledge in C, C++, PERL scripting, assembly, and Matlab. Experience in programming TMS320C5x

series and ADSP21xx series fixed-point DSP and TMS320C3x series floating point DSP.

Employment History

Graduate Student Researcher

Internetworking Research Group (I-NRG) headed by Prof. Katia Obraczka

Spring 2002 Present

Design, implement and evaluate network protocols for wireless ad hoc networks, and maintain lab web pages.

Venkatesh Rajendran - R sum - page 1

Projects:

Flow-based Multi-channel Media Access Protocol for Sensor Networks

This project involves design and implementation of a flow-based multi-channel media access protocol for CC1000 radio

used in Mica2 Motes. CC1000 is a FSK-based radio with selectable power states and tunable channels. Current media

access protocols implemented for CC1000 radio does not take into advantage of the frequency diversity. We propose a

distributed, energy-aware, collision-free scheduling for electing flows to improve the channel utilization.

Traffic-Adaptive Medium Access Protocol (TRAMA)

Sensor networks are generally power-anemic and energy-efficient channel access is important to enhance the lifetime of

the network. The main sources of energy inefficiency are: idle listening, hidden-terminal collisions and transmissions to

sleeping node. We propose TRAMA, a novel distributed scheduling scheme to regulate channel access. Channel access

is time-slotted and neighborhood-aware contention resolution is used to schedule transmissions. Schedules are adapted

based on the traffic rate and an analytical model is developed to evaluate the performance and is verified using Qualnet

simulations. TRAMA significantly outperforms other contention-based channel access schemes. A simplified version of

TRAMA for MOTES platform is being implemented to test the real-world performance of TRAMA. This project is

under the supervision of Dr.Katia Obraczka and in collaboration with Dr.J.J.Garcia-Luna-Aceves.

Reliable Broadcast/Multicast MAC Protocols for Wireless Ad hoc Networks

IEEE 802.11 DCF (CSMA/CA) has become a default standard for media-access in wireless ad hoc networks. For

broadcast/multicast transmissions the standard does not provide any reliability and is done by plain carrier-sensing.

Hence, the performance is severely affected due to hidden terminal collisions. The goal of this work is to develop a

novel approach to broadcasting/multicasting using two-hop neighborhood information. Unlike unicast transmissions,

broadcast and multicast transmissions have much larger contention region and hence, more susceptible to collisions. We

propose a hybrid contention resolution scheme based on collision avoidance and neighbor information. We are also

studying the impact of multicast reliability at MAC level on higher layer protocols.

Reliable Multicasting in MANETs

This work focuses on design and analysis of reliable multicast transport protocols for mobile ad-hoc networks. Unlike

wired environments, wireless environments have the inherent unreliability. Each of the members can experience

time-varying losses depending on its channel contention and link quality. We propose ReACT: Reliable, Adaptive,

Congestion-Controlled Ad hoc Multicast Transport Protocol (ReACT) aimed to improve reliability using local recovery

and source-based congestion control. ReACT classifies packet losses into local and global contention and generates

appropriate feedback to initiate recovery and congestion-control. Losses due to local factors like collision, link quality

etc., are recovered locally from nearest member, while losses due to congestion trigger source-based congestion control.

ReACT is designed work both on top of tree- and mesh-based multicast routing fabrics. ReACT improves the reliable

delivery ratio significantly when compared to plain UDP or Gossip-based approaches. This project is under supervision

of Dr. Katia Obraczka and in collaboration with Dr. Mario Gerla, UCLA, Dr. S.J. Lee, HP Research Labs and Dr.Ken

Tang, Scalable Networks.

Teaching Assistant

University of California

Teaching assistant for the following graduate and undergraduate level courses

CMPE252a Computer Networks, Fall 2003.

CMPE150 Introduction to Computer Networks, Spring 2003.

CMPE151 Network Administration, Winter 2003.

CMPE080N Introduction to Internet and Computer Networks, Winter 2002.

Summer Research Fellow

AU-KBC Research Center, India

1 June 2001 1 September 2001

Worked as a Summer Research Fellow at AU-KBC Research Center, India. Work involved developing an energy

allocation algorithm for multi-carrier communication and a patent has been filed for the algorithm developed.

Projects:

Multiple Access and Resource Allocation for Multi-carrier Communication

We propose a new Adaptive Allocation Algorithm for Multiuser OFDM (MOAAA), which outperforms existing

multiple access schemes like OFDM-TDMA and OFDM-FDMA. The experiments have been conducted with reference

to the powerline environment with multipath fading, exponential noise spectrum and narrow-band interference. We

have presented the results obtained by Monte-Carlo simulation using Matlab under different channel and noise

conditions. We have quantified the improvement in terms of overall transmit power and BER. Our new algorithm

achieves a significant gain of 3 to 5 dB in SNR over OFDM-FDMA and TDMA. Hence, the proposed algorithm can be

Venkatesh Rajendran - R sum - page 2

used for efficient multiple access for broadband multimedia communications over frequency selective fading

environments.

Industrial training in testing and servicing wireless equipments

Electronics Corporation of Tamil Nadu (ELCOT)

28 December 1998 4 January 1999

Patents

Multi-user Indoor Wireless Access Systems based on the OFDM Transmission Technique - under submission for Indian

Patent.

Other Selected Projects

Multihop Networking with Lego Mindstroms:Lego Mindstroms are tiny robots with an embedded micro-controller,

motion controllers, sensors and an IR port for downloading firm-wares. LegOS is an embedded operating system for the

Mindstroms based on Linux. This is an implementation project and a lightweight communication stack (MAC and routing

support) was implemented in the Linux kernel to enable multi-hop communication between the robots through the IR

port. To communicate with host PC, the stack was also implemented in host PC (as a daemon). Sample applications

involving multi-hop communication were demonstrated over the stack developed.

Indoor Location Estimation based on Wireless Signal Strength:Relative location information is needed for developing

location-aware application. In this project, a location estimation system that estimates the location of a mobile user

relative to the location servers was implemented and demonstrated. The main advantage of the system is it is developed

with off the shelf components: laptops and 802.11 based wireless cards. The location servers are laptops fixed in known

locations and a user roams around with a laptop. All the laptops are equipped with wireless cards and the distances of the

mobile user to the location servers are measured using the signal strength of the packet received from the servers. A

triangulation algorithm is used to find the exact location based on the distance information. This was done in Linux

platform. An adaptive learning algorithm is used reduce the estimation errors caused due to the highly varying signal

strength in indoor environment.

Dynamic Power Management Schemes for Sensor Networks:In this project various system level power management

schemes are analyzed. The power management model was developed in CSIM and analyzed extensively by simulation.

Survey of interconnection networks for M-SIMD architecture and its applications.

Publications

Venkatesh Rajendran, Katia Obraczka, J.J. Garcia-Luna-Aceves. "Energy-Efficient, Collision-Free Medium Access

Control for Wireless Sensor Networks". ACM/Kluwer Wireless Networks (WINET). 2004.

Venkatesh Rajendran, Katia Obraczka, Yunjung Yi, Sung-Ju Lee, Ken Tang, Mario Gerla. "Combining Source- and

Localized Recovery to Achieve Reliable Multicast in Multi-Hop Ad Hoc Networks". Proceedings of the Networking'

04. May 2004.

Venkatesh Rajendran, Katia Obraczka, J.J. Garcia-Luna-Aceves. "Energy-Efficient, Collision-Free Medium Access

Control for Wireless Sensor Networks ". ACM SenSys 03. November 2003. .

Venkatesh Rajendran, J.J. Garcia-Luna-Aceves, Katia Obraczka. "An Energy-Efficient Channel Access Scheduling for

Sensor Networks ". Proc. The Fifth International Symposium on Wireless Personal Multimedia Communication

(WPMC). October 2002.

Venkatesh Rajendran, Yunjung Yi, Katia Obraczka, Sung-Ju Lee, Ken Tang, Mario Gerla. "Reliable, Adaptive,

Congestion-Controlled Ad hoc Multicast Transport Protocol: Combining Source-based and Local Recovery". UCSC

Technical Report. 2003.

Venkatesh Rajendran, Karthikeyan Sundaresan, Srikanth Subramanian. "Performance of an OFDM based downlink

multiple access system for indoor wireless communications ". Wireless Personal Communications. April 2003.

Venkatesh Rajendran, Karthikeyan Sundaresan, Srikanth Subramanian. "A Power-Efficient Resource Allocation

Scheme for Multiuser OFDM ". International Conference on Personal Wireless Communications(ICPWC). December

2002.

Arun Pachai, Venkatesh Rajendran, Karthikeyan Sundaresan, Srikanth Subramanian. "Multiple Access Schemes for

OFDM based Indoor Wireless Systems ". Proc. The 8th National Conference on Communications (NCC). 2002.

Related Course Work

Wireless and Mobile Networks, Advanced Wireless Communications, Computer Networks, Software Engineering,

Advanced Operating Systems, Computer Architecture and Computer Performance Evaluation.

Other Activities

Venkatesh Rajendran - R sum - page 3

Reviewed Papers for MONET Journal, WCNC 2004, and IEEE Consumer Communications and Networking 2004.

Student Volunteer for IPSN 2003, and Infocom 2003.

Judge for Santa Cruz County Science Fair 2003.

Guest Lecture on Debugging Techniques in C for SWE ANSI-C workshop 2003.

References

J.J. Garcia-Luna-Aceves

Jack Baskin Professor, UC Santa Cruz

Phone: 831-***-****

Email: **@***.****.***

Katia Obraczka

Assistant Professor, UC Santa Cruz

Phone: 831-***-****

Email: *****@***.****.***

Last modified Feb 2004.

Venkatesh Rajendran - R sum - page 4

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