WSN nodes resource constrained. In order to keep the size and the cost of the nodes down, the nodes have limited processing power, memory and radio range. However, the resource constraint which has the most significant impact on many WSNs is the constraint on energy. WSN nodes are battery operated. Many wireless sensor networks are deployed in locations where battery replacement is not feasible. A node has to be discarded when the battery depletes. Energy scavenging may alleviate this problem in some sensor networks. Most WSN protocols are very conscious of the limited supply of energy, and try to conserve energy.
If you discover that another academic has written a thesis on a topic similar to your own, don't stress out. Carefully read the material to gain an understanding of what it is that the prior thesis has accomplished and consider ways your thesis might further develop the topic or might approach the topic from a totally different perspective. You are likely to find that the former thesis is not the same as the one you are considering after all. To be sure, show the competing thesis to your advisor; he or she can give you indispensable advice. If you discover that another graduate student is writing a thesis on the same topic you've chosen, you could also consider contacting that author to get an even better idea of whether your ideas overlap. (Be careful not to give away too much of your own thinking on the topic as you conduct this discussion.)