8.9.07 WARP team completes OFDMA prototype
In collaboration with Xilinx, the WARP team has completed a prototype for a fully scheduled Orthogonal Frequency Division Multiple Access (OFDMA) system. The system mimics the topology of next-generation wide area networks like WiMAX by using a single WARP node as a base station and two WARP nodes as subscribers to the network. Beyond serving as a demonstration of an OFDMA system for WARP, the prototype was designed to serve as a WiMAX testbed. This prototype will allow the WARP team to experiment with techniques for scheduling, power control, subcarrier allocation, synchronization issues, and other problems that need to be addressed in future WiMAX applications.
The video below shows the potential performance degradation in these systems if the classic problem of power control is not properly addressed.
7.14.07 WARP team builds first cooperative communications link
Rice CMC graduate student Patrick Murphy has developed a real-time amplify-and-forward cooperative communications system using WARP nodes. Cooperative communications is a new communication paradigm which was invented at Rice by Prof. Behnaam Aazhang and his students. Now the same group has delivered another first by actually implementing the scheme, demonstrating the feasibility of cooperation by distributed nodes at the very short timescales required for physical layer processing.
Patrick, co-advised by Ashutosh Sabharwal and Behnaam Aazhang, has submitted a journal paper which details the design and experiments for world's first true, three node cooperative communications network. With a peak power constrained system, which mimics how real wireless devices work, gains upto 5.5dB are possible. When the total network power is constrained, gains in excess of 2dB are possible. The group has already identified many enhancements for exceeding these initial gains, and expect to deliver these improvements in the coming months. A key aspect of the current design is that the receiving node is agnostic to whether transmitter is MIMO (like WiMax or 802.11n) or cooperating with another. Thus, a single receiver design works in both transmission conditions, making the new system design backwards compatible with current standards which do not explicitly incorporate cooperative nodes.
In continuing WARP's open-access approach to wireless research, all the FPGA designs for the cooperative system will be made freely available via the WARP repository.
5.01.07 WARP team demonstrates MIMO OFDM link
The WARP team is pleased to demonstrate a 2x2 MIMO OFDM link. This link utilizes two WARP FPGA boards, four radio boards, two clock boards and one analog board. The physical layer implements a 2-antenna OFDM transmitter utilizing Alamouti's space-time block code. The 2-antenna receiver uses switching diversity.
The video below shows this link being used to transmit video in real-time between two PCs. You can download a higher quality version of this video here (13MB QuickTime 6.0 movie).
1.27.07CMC is looking for Undergraduate Summer Interns
Center for Multimedia Communications is a $2+ Million/year multi-disciplinary
center focused on research in wireless systems. With five core faculty and several
associated faculty, the research spans the full spectrum of theory, algorithms and
architectures for high-performance wireless networks.
CMC has a strong tradition of undergraduate research. In last 5 years, more than 40
Rice and international students have worked in CMC Labs. Many of our students continue
to work for multiple semesters in CMC Labs, perform their senior projects in wireless design,
present papers in peer-reviewed technical conferences, and conduct domestic & international
CMC-organized workshops. For example, CMC conducted four workshops in 2006 (2 at Rice,
one in Taiwan and one in India), where CMC undergraduate students helped design
and teach the workshops. The workshop participants were professors and students from
universities all over the world, who were learning how to use the technologies developed at CMC.
The CMC summer internship is being considerably expanded starting Summer 2007. The main
areas of interest are :
1) Communication Systems Hardware: One of the major projects at CMC is the
Wireless Open-Access Research Platform (WARP), to conduct
high-performance wireless networking research at all layers - PHY, MAC, Routing.
The platform is now completely operational and being adopted by several universities
and company research centers. Many key pieces of WARP were developed by undergraduate
students from ground-up and in fact, the next generation WARP hardware is being developed completely
by undergraduate students. Interested students can design enhanced hardware peripherals,
embedded code for network protocols, field-test and characterize the performance of
current designs and perform measurement studies.
2) Applications in High-performance Networking: Rice Networks Group (RNG)
operates one of its kind community network in one of
most under-resourced Houston neighbourhood, Pecan Park. Built and run in collaboration
with non-profit Technology For All (TFA), the TFA-Rice network
now serves 2000 (real) users over a 3 square-kilometers. With the aim to do clean-slate
design of mesh networks, we are building a highly optimized, deployable system for
the next upgrade of TFA-Rice network using WARP platform. Interested students will
design, build, and thrash-test different aspects of deployed mesh networks, giving them a unique
system level view of real networks.
3) Digital Health Sensor Networks: The Rice Orbit platform consists of an Internet-capable
mobile phone and its wireless body-area peripherals, including sensors and auxiliary user
interfaces. It is intended to be an open-source (both hardware and software) research platform
for mobile and embedded computing. Interested students will work in developing innovative
hardware and embedded software for emerging digital health applications.
The WARP team invites you to submit questions about the project and join them in discussion about the possibilities WARP presents, by creating an account on the WARP Forums. More information is available on the WARP Support page
9.05.06 WARP Team Receives NSF MRI
The WARP team has been awarded $800K 4-year grant from NSF to develop an
open-access platform which will be used to build experimental deployable networks. This complements
the $1.5 million NSF CRI award to develop WARP, which forms the basis for the new project called WARPnet.
The project WARPnet will design new FPGA-based
hardware, software support packages and remote monitoring software to
enable deployed networks which are completely programmable at all network layers.
Headed by Ashu Sabharwal, the WARP team PIs include Behnaam Aazhang,
Joe Cavallaro, Ed Knightly and Patrick Frantz.
8.27.06 WARP provides undergraduate research opportunities
Recognizing the importance of research opportunities for undergraduate students, The Center for Multimedia Communication actively looks for motivated students, involving them in the research activities of the lab. During the school year, undergraduates may work as part of a senior design project, or independent research program, Or, the CMC employs them during the summer months as full-time research staff. In fact, the CMC employed seven undergraduates during the summer of 2006, including five Rice ECE students, and two international exchange students from India.
Students worked as a team on a variety of practical and theoretical problems including algorithm development and implementation for the CMC's development of the Wireless Open-Access Research Platform (WARP). WARP is a hardware and software suite designed to allow rapid prototyping of virtually any conceivable wireless system.
Austin Bratton, Elliot Ng, Andrea Trevino, and Warren Scott, developed and refined methods for designing projects for WARP. Mission-critical projects like this help improve the productivity of higher-level research-centric projects and provide invaluable real-world experience to the students.
Austin Bratton was responsible for writing an EEPROM driver that equips each WARP node with unique factory-default settings ranging from calibration values for individual radios to unique MAC addresses for maximum ethernet compatibility. Elliot Ng authored a script that allows seamless integration between two development suites provided by Xilinx. Andrea Trevino produced a built-in-self-test for radio hardware that allows rapid verification of equipment received from the PCB assembler. Warren Scott developed a framework to allow for easy communication between WARP nodes and PCs via Ethernet. This framework allows experimental data and control information to pass between WARP nodes. Also, it allows for arbitrary scaling of the experiment, making a test of 10s to 100s of nodes as easy as a test between a mere few.
The remaining students used WARP at a research application level, displaying the wide range of tasks well suited for the platform. Justin Chen used the tools provided by the other students to create a spectrum analyzer. Leveraging the significant graphing capabilities of Matlab on the front end, Justin was able to display real-time spectrum information about the test environment in which we operated. Varun Nayyar, a visiting student from IIT Delhi, used an existing MAC development framework to rapidly prototype a new medium access protocol. In just a few months, the project matured from a pen-and-paper state machine to an operational medium access layer that capable of empirical testing. Visiting student, Nandini Dikshit, developed proof-of-concept video processing techniques for a Xilinx University Program FPGA board. Much of the work is platform independent, allowing for rapid porting to WARP. This, in turn, demonstrates the feasibility of true application-layer projects that are on top of a custom wireless link.
Undergraduate research at CMC is a powerful, mutually beneficial experience. "For an international intern student, CMC simply offers a great work atmosphere which is totally flexible and informal and at the same time an unforgettable learning experience," says Varun Nayyar about his stay. Another area in which CMC excels is in carving individual student projects out of the overall research thrust. "Not only was I exposed to the cutting edge research in communication," says Elliot Ng, "but I also get to see where my contribution fits in the overall scope of the project."
8.24.06 WARP tests clean-slate multi-hop TAP framework in labs
Using the framework designed by graduate student Chris Hunter to implement any random access based network protocol stack, first true multi-hop
link with three WARP nodes was tested in the labs. Chris used the multi-hop
link to carry out a voice chat using Skype, thereby testing every
part of the WARP infrastructure - ethernet connectivity, custom MAC layer,
custom PHY and radios. The portability of the WARP nodes will be used to test
the new protocols developed as part of TAPs project will be then used
for actual deployed nodes.
8.17.06 WARP Team Completes First Wireless Link
A custom wireless link spanning two layers of the OSI protocol stack - Physical, and Data Link have been
successfully tested on the WARP platform. The custom physical layer is OFDM-based, much like all the emerging
standards, while medium access control layer, is an acknowledgment- based protocol similar to ALOHA.
Fully bi-directional, the point-to-point link can be used as a hop in any wireless network - multi-hop
or otherwise. The demo (setup shown in figure below)
shows a two-hop system, where the first hop is a commercial IEEE 802.11b based link
and the second hop is the WARP link. The setup completes the key first step towards clean slate design
of wireless backhaul networks like TAPs. The result of significant teamwork, the major
contributors to-date are Patrick Murphy (team leader, hardware architect, OFDM PHY), Chris Hunter (Network Protocols framework), Gareth Middleton (PHY front-end) and
Siddharth Gupta (Radio controller). Internet performce over WARP demo
8.8.06 Second Rice-Xilinx Workshop Announced
October 5 & 6, 2006 at IIT Delhi Event Details
7.5.06 ECE’s Center for Multimedia Communication Welcomes new Project Manager
As the new Project Manager for the CMC, Charles Camp is a welcome addition
to the team. With 15 years of industry experience in high-speed circuit design, FPGA-based signal processing, high-performance I/O and signal processing hardware design, and the development of Verilog and VHDL code for
FPGA-based signal processing and data acquisition systems, his experience complements the current and future research efforts of the CMC. Charles earned a BSEE degree from the University of Texas at Austin (1990) and an
MEE degree from Rice University (2000).
5.4.06 First revision of WARP hardware tested in CMC labs
First revision of WARP FPGA board and WARP MIMO radios have been successfully tested in the CMC Labs. Furthermore, a video daughter-card has also been designed and tested.
4.12.06 Rice WARP wins NSF CRI
Rice team, led by Dr. Ashu Sabharwal, receives a $1.5 Million support for unique open-access platform for wireless research, cross-cutting multiple communities.
