Bach's homepage
My name is Bach Duy Bui (Vietnamese order: Bui Duy Bach).
PhD Candidate @ Real-time Systems Lab, Computer Science Department, University of Illinois at Urbana Champaign
Email: 
Research | Publications
| Patents | CV | Contact Information
Real-time Scheduling for
Concurrent Transactions on Network-On-Chip
Time Predictable Execution in
Computer Systems with Cache and DMA-enable Devices
Real-time
Wireless Communication for Embedded Systems
In these
researches, we are interested in designing and implementing communication
real-time services for multi-hop sensor networks which include MAC and Routing
protocols. Because of the lossy nature of wireless
communication, providing timing guarantee services is hard problem. It is even
harder in a distributed settings of a multi-hop
network. Since our goal is to provide a practical and implementable protocol,
our design choices must be grounded on physical realities and standardized
platform.
1. Mac protocol
We introduce real-time chain, a new prioritized MAC protocol to support real-time flow communication in wireless sensor networks. By avoiding packet collisions and limiting the effect of priority inversions, real-time chain is able to provide significant delay and bandwidth guarantees. Furthermore, the use of multiple channels enable high spatial reuse and transmission rates. Finally, we can achieve compatibility with IEEE 802.15.4 after minor modifications. The protocol has been fully implemented on Crossbow MICAz hardware and its performance has been validated with a large set of both indoor and outdoor experiments.
2. Routing protocol
We propose a hard real-time routing protocol which guarantees the end-to-end deadlines of multiple data flows running on a network. To do so, we first analyzed explicitly the souces of packet delay in wireless network. Second, by using the understanding of the packet delay sources and the Stage Delay Theorem (a new real-time theory), we cast the real-time routing problem into an optimization problem where one of the constraints is the end-to-end deadline of each flow and the objective is to maximize network lifetime. The optimization problem is calculated offline with the output is a set of routes such that all packets meet their deadline. The correctness of the algorithm is verified by simulations on Ns2. We have found that our proposed solution can guarantee hard real-time constraints whereas shortest path routing and RAP protocol would have failed. Apart form the offline technique, an online rediscovery real-time path algorithm in case of node failure is also proposed. We provide analytical proofs for the correctness of the offline algorithm as well as simulation results to show its effectiveness and communication overhead.
Other Projects
A
Smart Home Infrastructure:this is my CS424 class project in
which we created a software architecture for a smart home. The architecture was
implemented and had a very cool demo at Room SC 2111.
Previous Researches
My master thesis investigates on localization protocol for wireless sensor networks which can works even in adversary environment. The designed protocol can be used on many location-aware applications. The protocol was also implemented as a service of the 802.15.4 MAC (IEEE standard) running on H2 sensor node platform.
1.
Bach
D. Bui, Rodolfo Pellizzoni, Marco Caccamo, Real-time
Scheduling of Concurrent Transactions in Multi-domain Ring Buses, to appear in IEEE
Transaction of Computer, 2011.
2.
Bach D.
Bui, Rodolfo Pellizzoni, Marco Caccamo, A Slot-based
Real-time Scheduling Algorithm for Concurrent Transactions in NoC, in the Proceedings of the 17th IEEE
International Conference on Embedded and Real-Time Computing Systems and
Applications (RTCSA), 2011. (full
version)
3.
Bach D. Bui, Rodolfo Pellizzoni,
Deepti K. Chivukula and
Marco Caccamo, Real-time Communication for Multicore Systems with Multi-domain Ring Buses, in
the Proceedings of the 16th IEEE International Conference on Embedded and Real-Time
Computing Systems and Applications (RTCSA), Macau, China, 2010.
4.
Bach D. Bui, Marco Caccamo,
Lui Sha, Joseph Martinez, Design
and Evaluation of a Cache Partitioned Environment for Real-Time Embedded Systems,
in the Proceedings of the 14th IEEE International Conference on Embedded and
Real-Time Computing Systems and Applications (RTCSA), KaoHsiung,
Taiwan, 2008. (Best paper award)
5.
Rodolfo Pellizzoni, Bach
D. Bui, Marco Caccamo, Coscheduling
of CPU and I/O Transactions in COTS-based Embedded Systems, in the
Proceedings of The 29th IEEE Real-Time Systems Symposium (RTSS), Barcelona,
Spain, 2008.
6.
Vartika Bhandari, Vivek Raghunathan, Bach D. Bui, Marco Caccamo,
Impact of multiple transmission rates on real-time scheduling in wireless
systems (extended abstract), ACM Mobicom 2007.
7.
Bach D. Bui, Rodolfo Pellizzoni,
Marco Caccamo, Chin F. Cheah,
Andrew Tzakis, Soft Real-Time Chains for Multi-hop
Wireless Ad-Hoc Networks, in the Proceedings of the IEEE Real-Time and
Embedded Technology and Applications Symposium (RTAS), Bellevue, WA, United
States, 2007.
8.
B.
D. Bach, D.
Kim, A Localization Algorithm with Parametric Learning-based Distance, in
the Proceedings of the 14th International Conference on Computer Communication
and Networks (ICCCN '05)
9.
B.
D. Bach, D.
Kim, J. Yang , Y. Doh , A Hybrid Approach for
Wireless Sensor Network Localization, in the Proceedings of The 15th
Joint Conference on Communications and Information (JCCI '05).
(Best paper award)
10.
B.
D. Bach, D.
Kim, A Localization Algorithm Extension for
The Evolvable Sensor Network, in the Proceedings of the International
Conference on Parallel and Distributed Computing and Systems (PDCS '04).
- B.
D. Bach, D. Kim, U.S. Patent: System,
medium, and method for estimating distance in communication system having
nodes.
- B. D. Bach, D. Kim, Korean Patent: An Adaptive Method
for Localization in Wireless Ad-hoc Sensor Network.
Bach Bui
305 N Lincoln Ave, Apt 301
Urbana, Illinois 61801
U.S.A.