==== 5th Semester: Wireless Data Transmission - Using Informative Feedback ==== **Semester Topic:** Communication Technology\\ **Group Members:** Rasmus Krigslund, Brian Ank Mertz, Janus Heide Møller, Simon Just Kjeldgaard Pedersen, and Jesper Hemming Sørensen.\\ **Abstract:** \\ This report concerns the development of a communication protocol using informative feedback. Fundamental theory within the field og communication networks is studied, and the IrDA protocol stack is chosen as a reference. The initial analysis results in a set of guidelines, by which a scheme is proposed. The idea of the proposed scheme is to limit the amount of retransmitted data in case of errors, by using more comprehensive feedback than the widely used binary feedback. The performance of the proposed scheme and the IrDA protocol is estimated and compared, and it is concluded that informative feedback can improve performance. Software that realizes the proposed scheme is designed and implemented, and tests are performed in order to verify the made estimations. The tests show a significant performance increase, but the measured goodput deviate from the estimated at low error rates. This deviation is explained by a type of error, the scheme is not designed to handle. These errors occur at a rate that dominates the artificially introduced errors, for BER between 10^−6 and 10^−4. Based on the tests and the following discussion of the results it is concluded, that informative feedback in communication protocols has a noticeable potential. **Additional Info:** This project was rewritten to a paper which was accepted at the AISPC 2008 IEEE Student Paper Conference. @ARTICLE{4460539, title={Communication beyond (N)acks: wireless transmission with informative feedback}, author={Mertz, B.A. and Heide, J. and Sorensen, J.H. and Krigslund, R. and Pedersen, S.J.K.}, journal={Student Paper, 2008 Annual IEEE Conference}, year={15-26 Feb. 2008}, volume={}, number={}, pages={1-4}, doi={10.1109/AISPC.2008.4460539}, ISSN={}, }