Evaluation of cross-layer reliability mechanisms for satellite digital multimedia broadcast

This paper presents a study of some reliability mechanisms which may be put at work in the context of Satellite Digital Multimedia Broadcasting (SDMB) to mobile devices such as handheld phones. These mechanisms include error correcting codes, interleaving at the physical layer, erasure codes at intermediate layers and error concealment on the video decoder. The evaluation is made on a realistic satellite channel and takes into account practical constraints such as the maximum zapping time and the user mobility at several speeds. The evaluation is done by simulating different scenarii with complete protocol stacks. The simulations indicate that, under the assumptions taken here, the scenario using highly compressed video protected by erasure codes at intermediate layers seems to be the best solution on this kind of channel

Collecting and using student feedback Date: A guide to good practice

The purpose of this Guide is to help higher education institutions make the best use of their student feedback. This guide is based on a HEFCE funded project undertaken by the Centre for Higher Education Research and Information (CHERI). The purpose of this Guide is to help higher education institutions make the best use of their student feedback. All institutions collect feedback from their students and in many different forms. They use it to improve the quality of the education they provide. In recent years, there has been a shift in the balance between informal and formal types of student feedback with a greater emphasis on the latter. Now, new devolved forms of national quality assurance promise to give an important role to students and there is also an expectation that information from student feedback will be used to inform the choices of students when applying to higher education. Thus, as the importance attached to student feedback increases, ensuring that feedback is collected effectively and used wisely becomes an increasing priority for higher education institutions. This Guide draws on the experiences of the sector to highlight some of the good practices that exist as well as some of the problems that institutions are experiencing in using student feedback. Its focus is upon the use of student feedback for the purpose of enhancing the quality of teaching and learning. Other purposes are acknowledged but are not the main emphasis of this publication