A statement of the problem and why it should be solved.
Reference to and comments upon relevant work by others on the same or similar problems (this is more than just a bibliography). This does not have to be the complete "related works" section, but at least some pointers to work and summaries of what you hope to find. See ***
The candidate's ideas and insights for solving the problem and any preliminary results already obtained.
A statement or characterization of what kind of solution is being sought.
A plan of action for the remainder of the research including equipment, software, persons (such as advisors) necessary to support completion of the research.
A rough outline of the thesis to the level of major topics within chapters, including a list of appendices or other material that is anticipated.
An annotated bibliography
I would suggest that you immediately start searching for references on your topic. Not only should you look for references in technical journals and proceedings to see what research has been done in this area, but you should collect as much information as possible on competing platforms and protocols.
The process of collecting information, and understanding what others have done before you, is extremely time-consuming.
If one wants to "evaluate" aspects of a problem, such as the "architecture, core service features, and scalability", they should start compiling evaluation criteria. What aspects of the architecture, core service features, and scalability are important, and why? How does one rate the quality of the design? How can one compare this platform to others that exist or have been proposed?