This paper proposes the Shape Shifting Traffic scheme, aimed at guarantee QoS in IEEE 802.11n.
In my view, this paper gives to much emphasis on the previous work of the authors . As a matter of fact only the 13 lines of the paragraph "Shape Shifting Traffic Scheme" at the end of the paper are aimed to describe the novelty proposed in this work. The content of  was summarized in a way that makes the paper hard to read, in the sense that there is not a seamless integration between the sections of the paper, and a number of concepts and symbols were not introduced.
Moreover, a number of inaccuracies can be found, for instance when you describe Algorithm 1 you refer to (lines 2-6) and (lines 7-17) which are the lines of the algorithm as reported in . In the plot of Fig. 4 the caption does not refer to the quantities reported in the plot.
I think, it is important to introduce the concepts of QoS as reported in IEEE 802.11e, how reported results are obtained (simulation or real setup), and especially increase the space dedicated to the main argument of the paper ("Shape Shifting Traffic Scheme"), starting from the title.
 L. Charfi, E. Fourati and L. Kamoun, "Qos support of voice/video services under ieee 802.11n wlans," in 9th International Symposium on Communication Systems, Networks & Digital Sign, 2014. CSNDSP 2014, 2014.
The paper presents a dynamic rate adaptation scheme, the Shape Shifting Traffic, to be used in IEEE 802.11n industrial networks in video services.
The paper language is bad and needs a big proofing effort. For this reason, the paper is difficult to read.
The paper could be better organised, for example Table 1 and Figures 1 and 2 can be removed, as they do not add any contributions to the paper. Instead, the paper lacks a better description of its main contribution, which is, currently, rather superficial.
The paper contribution is based on the IEEE 802.11 standard, which is not a recent standard, as mentioned in the paper.
Captions of Figures 4 and 5 are incorrect.
The paper proposes rate adaption techniques over WLAn for video services in industries.
The main novelty of the paper is supposed to be Shape shifting algorithm , which is an enhancement to the existing work.
However, the results shown in this paper are from an algorithm which has already been published. I would advise the conference chairs to not include this paper in the proceedings.
In order to accept this paper, following needs to be done in my opinion:
1) Over view section should be shortened
2) Figures 1 and 2 add nothing to the paper. Same goes for table 1. If the need to add figure 2 is strong, then it should be well motivated and the figure legends should be distinguishable even in Black and White
3)Shape shifting algorithm must be explained in more detail, and outline the enhancements to your existing work.
4) Existing work should not be a summary of the work done in this field. It should be used to compare and show what are the shortcomings of those works, and how is your work better.
5) Some immediate results should be shown from the new algorithm (shape shifting in this case) and not from existing work.
6) Explain please how figure 4 is obtained. If its from a simulation, then briefly describe simulation scenario. Similar elaboration will be required if the curves are obtained from hardware setup.
7) Remove Figure 5
8) language of the paper, English tenses, grammar, everything needs to be reworked. Best seek help from a native english speaker to correct the paper.
The paper contains very little novelty, in particular the main idea to prioritise video packets over audio packets is fairly straightforward (plus, harmful to lip synchronisation and other synchronisation concerns). Furthermore, it is not clear whether the results (in particular those in Fig. 4) are statistically significant. The paper also needs proofreading, there are several odd sentences.
Another comment: You should say right from the beginning that you consider multicast video. Without that information several statements in the introduction do not make sense (e.g. you say the transmitter does not know whether data is received correctly or not. But 802.11 has acknowledgements and retransmissions. You also claim link data rate is fixed. It is not, it can be adapted.).