The University has a document where the answer to this question is written up in detail. This is not it, the thoughts that follow are my personal reflections. So what is the MDes Design Communication, what does it mean?

A person who has an MDes is a designer who is self aware of their own design practice, its strong points, limits, context and scope.
When the course was set up it was envisaged as a course for people who were already working in design. They would return to study on a part time basis. The course would give them the opportunity to explore, develop and think about their design practice. In the early days of the course it was a very self directed course supported by close supervision. Essentially the course is about taking on a project (or two, three or four) and using it(them) to come to an understanding about your design practice, its strong points, limits, context and scope.Over the years we have gradually added more formal “taught” modules. This helps give the course more structure while not limiting students to develop their own practice. We also have broadened the course to support graduating students coming straight from degree courses.

One area where there is a “taught element” is in the project definition area.This gives rise to DES809 Design Research Proposal. This module helps you to figure out what your MDes project should be, how big it should be, why do it, etc.