Distinct Research questions in Phd research proposal? I am writing my PhD research proposal. In "Research Aims / Questions" section, I have proposed two distinct research questions which are from the same sub-field but divert from each other a little bit. 

Here is an example in my discipline, Computer Science, and subfield, Communications. The first research question involves analysis of router throughput with some specific algorithm.  The second question involves a compression mechanism a router, and the compression mechanism is not related to its throughput.

Question: Can I be successful having two not-closely-related research questions? or should I write two separate research proposals?

Any help would be appreciated.
It sounds like your proposal is for a PhD in technology of some kind, as such I can't tell you if the specific questions that you asked would work. However, I can share my own experiences so far. As a general rule, the easier your PhD questions are to research and answer, the better. For that reason, many people stick to one question. If there is more than one question in the proposal, they should be highly related. For example; in my own dissertation I am sampling approximately 30 schools across the country to determine if an anomaly that I discovered last year is universal, or if it is localized to that specific school (or possibly if it occurs in some areas but not others). Then, depending on the findings of that analysis, a secondary question becomes: what predictive factors determine those outcomes? In my case that will be easy to answer because I will have already taken those variables into account in order to control for them during the data collection phase. I'm not sure how much that helps, but in short I would avoid two questions unless they are directly related to each other.