1. Rating
   Rate the paper in the following categories (For each category,
   choose a one numeric rating)
       
   Overall grade (overall, how do you rate this summary paper?)
      4: Very good
      
   Language (how fluent is the language, did you understand what this 
   paper is saying?)
      4: Very good
      
   Technical quality
      5: Contents are completely correct. There are no errors. It corresponds
         information on the source material. 
      
   Editorial quality
      4: Mostly understandable, some improvements identified below
      
   Confidence (how confident are you about this review?)
      2: I have some general knowledge of this subject
      

2. Detailed comments

   1 - General Comments:
	The paper is a really very good work, Its main advantages are the smooth description
	of the protocols and supporting the text using the figures. REALLY V. GOOD

   2 - On page 1, In the introduction:
	The author wrote:
		“One class of these protocols is the flat and the hierarchical protocols”
	The comment:
		Should it be, “One class of these protocols is the flat protocols and
		the other is the hierarchical protocols” ?!

   3 - On page 1, line 7 from the bottom:
	The author wrote:
		“Here, every cluster has its leader which is elected through different algorithms”
	The comment:
		For a single protocol, such election algorithm should be a single well defined one. Is not it?

4 - On page 1, The last 3 lines + The third paragraph on page 2:
	The author wrote:
		“However, besides physical clustering, HSR defines also the concept of logical clustering.
		 Here the links between the nodes are not physical. The links are based on certain relations”
	The comment:
		The term logical clustering is not mentioned or more detailed later in the text, however it seems
		a main one. This leaves the reader with the guessing, does it mean the link at higher levels? 
		Specially with the afterwards mentioning of the statement “The links are based on certain relations”
		
		However on page 2, the third paragraph mentions the term “virtual link”. It is what was meant by 
		“logical link” on page 1?

5 - On page 2, line 3 from the bottom:
	The author wrote:
		“the process of exchanging information concerned …”
	The comment:
		Should it be ”concerns” instead of “concerned” ?!


6 - On page 3, line 7:
	The author wrote:
		“information received …”
	The comment:
		Should it be ”the received information” instead?!
 
7 - On page 3, line 12:
	The author wrote:
		“a set of nodes who can reach …”
	The comment:
		Should it be “which” instead of “who”.