publications/research

My current research focuses on dependable wireless ad hoc networks and related issues, including fundamental communication primitives such as reliable broadcasting. Lately however, I’ve been very interested in heterogeneous networks, consumer mesh networks and related problems.

2010:

  1. OLIVEIRA, Talmai and AGRAWAL, D. P. Stochastic Approximate Dynamic Programming with Link Estimation for High Quality Path Selection in Wireless Mesh Networks. Accepted for publication at the IEEE Globecom 2010 Workshop on Complex and Communication Networks. 2010.
  2. WSN in Computer Music and DanceHELMUTH, M., et. al. WIRELESS SENSOR NETWORKS AND COMPUTER MUSIC, DANCE AND INSTALLATION IMPLEMENTATIONS, In Proceedings of 2010 International Computer Music Conference, New York, NY. 2010.
  3. LOUHA, K.; JUN, J.; OLIVEIRA, Talmai and AGRAWAL, D. P. Exploring Load Balancing in Heterogeneous Networks by Rate Distribution. International Journal of Autonomous and Adaptive Communications Systems (IJAACS). Vol. 3, No. 3, pp 284-307, 2010.

2009:

  1. Time-Synch Tech. ReportOLIVEIRA, Talmai Brandão de ; Chi, Y.. Time Synchronization Algorithms for Randomly Deployed Ad-hoc Sensor Networks, Technical Report No. 001.06.2009, 2009.
  2. LOUHA, K.; JUN, J.; OLIVEIRA, Talmai and AGRAWAL, D. P. Exploring Load Balancing in Heterogeneous Networks by Rate Distribution. International Journal of Autonomous and Adaptive Communications Systems (IJAACS). 1st place in the 4th Annual ECE & CS Poster Competition.
  3. 2009 University of Cincinnati Graduate School Report. “Technology in Tune with Art: a Computer and Music partnership for UC makes for a Sound education” Cover story.

2007:

  1. Master ThesisOLIVEIRA, Talmai Brandão de ; COSTA, V. F. ; GREVE, F. G. P. . On the Behavior of Broadcasting Protocols for MANETs Under Omission Faults Scenarios. Lecture Notes in Computer Science, v. 4746, p. 142-159, 2007.
  2. Master ThesisOLIVEIRA, Talmai Brandão de ; GREVE, F. G. P. . Boosting the Reliability of Deterministic Broadcasting Protocols for MANETs. In: Workshop on Dependable Application Support for Self-Organizing Networks (DASSON 2007) in conjunction with the 37th Annual IEEE/IFIP International Conference on Dependable Systems and Networks, 2007, Edinburgh, UK. Supplemental Volume of the Proceedings of the 37th Annual IEEE/IFIP International Conference on Dependable Systems and Networks, 2007. v. 1. p. 7-12.
  3. Master ThesisOLIVEIRA, Talmai Brandão de ; GREVE, F. G. P. . The Node Reliability Approach to Broadcasting in Manets: Raising Reliability With Low End-to-End Delay. In: The Fourth IEEE International Conference on Mobile Ad-hoc and Sensor Systems (MASS 2007), 2007, Pisa, Italy. Proceedings of the Fourth IEEE International Conference on Mobile Ad-hoc and Sensor Systems, 2007.

2006:

  1. Master ThesisOLIVEIRA, Talmai Brandão de ; COSTA, V. F. ; GREVE, F. G. P. ; SCHNITMAN, L. . Evaluating the Impact of Faults on Broadcasting Protocols for MANETs. In: WTF 2006 VII Workshop de Testes e Tolerância a Falhas, 2006, Curitiba, Paraná. VII Workshop de Testes e Tolerância a Falhas, em conjunto com 24o Simpósio Brasileiro de Redes de Computadores. Porto Alegre : SBC – Sociedade Brasileira de Computação, 2006. v. 1. p. 49-60.
  2. Master ThesisOLIVEIRA, Talmai Brandão de ; GREVE, F. G. P. . On Augmenting the Reliability of Broadcasting Protocols for Scalable MANETs. In: 5th International Information and Telecommunication Technologies Symposium (I2TS 2006), 2006, Cuiabá, Mato Grosso. Proceedings of the 5th International Information and Telecommunication Technologies Symposium (I2TS 2006), 2006. v. 1. p. 22-29.

Master’s Dissertation:

  • Abstract: A mobile ad-hoc network (MANET) consists of a group of mobile devices (also called nodes) that are capable of communication restricted to their wireless transmission range. Ad-hoc networks are making a new set mobile applications possible by combining computing power, wireless communication capabilities and specialized actuators and sensors. Broadcasting refers to the process by which one node sends messages to all other nodes in the network. It is an essential operation, since it may be used to collect global information, to support addressing algorithms and to help routing protocols. Ensuring reliable communication between nodes, however, is still a major challenge in MANETs due to a large number of problems such as node failures and transient network partitions. But in spite of the importance of the broadcasting primitive, not so much attention has been devoted to reliability requirements beyond best-effort.This work studies the broadcasting problem in MANETs. Existing solutions are able to deal with mobility, congestion and even collisions, but only when under a fail-stop failure model. Unfortunately this model does not adequately represent real scenarios of faults such as link failures, temporary network partitions, topology changes and momentary node failures. Therefore in this work we evaluate — through the aid of simulation experiments — how well broadcasting protocols behave under a more realistic failure model characterized by omission faults. The study conducted here shows that most protocols are highly impacted by failures and are not capable of maintaining high delivery rates. Some even exhibit coverage levels that are unreasonable to expect from broadcasting protocols when placed in such a scenario. As a result of the study conducted, a new mechanism that helps to enhance the capability of broadcasting algorithms to deal with these kinds of faults is proposed. By relying on the mechanism, nodes are able to identify neighboring links that are more reliable prior to transmission. The proposed solution is capable of ensuring good delivery rates, in spite of failures, while maintaining relatively low end-to-end delays. Simulation results demonstrate its efficacy.
University of Cincinnati GAUDI - Grupo de Algoritmos e Computação Distribuída DCC-UFBa

Comments are closed.