# A Survey on an Energy-Efficient and Energy-Balanced Routing Protocol for Wireless Sensor Networks
## 2 Related Work
The authors summarised the seventeen surveyed routing techniques based on these categories, stating their strengths and weaknesses. Furthermore, the paper explains the areas of application of the surveyed routing protocols and concluded with open research directions on energy consumption issues with WSNs. The authors in [4] classified these routing protocols based on the topology, communication model, network structure, and reliable routing schemes. Their work also discuss the pros and cons of different energy-efficient routing protocols whereby they presented a comparison among these routing techniques using some measures such as mobility, scalability, power usage, etc. On the other hand, this paper focuses on both energy-efficient and energy-balanced routing protocols. Accordingly, the taxonomy introduced in this paper covers both energy-efficient routing protocols and energy-balanced routing protocols, where we grouped the studied routing protocols based on their mode of communication towards the BS. We also attempt to classify these routing protocols based on the decision variables (hop-distance, residual energy, average network energy) used in achieving optimal energy consumption. Furthermore, this paper grouped the surveyed routing protocols based on the solution types or algorithms in order to enable researchers to make decisions based on their network applications and scenarios. The survey in [10] gives a general overview of WSNs, stating the areas of application and challenges of WSNs. The authors reviewed the prime research work and testbeds, standards and platforms, and the techniques and principles of WSNs. Besides, they outlined the current happenings in WSN research that considers the possible interaction between WSNs and other technologies such as mobile robots, micro-blog, sensorcloud, etc. The authors explained how this synergy will assist WSNs to realise the right potential. Their survey is concluded with open research directions for interested researchers. Nevertheless, we narrowed down our survey to energy consumption issues with WSNs. We surveyed literature that attempts to proffer a solution to energy consumption issues with SNsduring the network data transmission phase. With this in mind, we introduced a taxonomy to classify these energy-efficient and energy-balanced routing protocols for WSNs. Additionally, we classified these routing protocols based on the solution types or algorithms, and the design input decision variables. Also, we presented noteworthy areas for possible research directions. An extensive survey on clustering routing protocols for WSNs is presented in [12; 13; 14; 15; 38; 39]. In [12], the authors emphasised the challenges and logic in developing a clustering algorithm for WSNs. Also, the authors discussed the problems that face the practical design of clustering routing techniques in WSN applications. The nine surveyed papers in [12] are subsequently classified based on the clustering routing objectives and design principles. The authors in [13] introduced a taxonomy to classify clustering routing protocol; pinpointing the design complexity, objectives and principles. The authors [13] discussed the strengths and weaknesses of these clustering routing algorithms whereby they presented a comparison among these clustering techniques using some measures such as cluster stability, location-awareness, convergence rate. In [38], the authors focused only on energy-efficient hierarchical cluster-based routing protocols for WSNs. They discussed and compared different energy-efficient hierarchical cluster-based routing protocols for WSNs. The paper in [14] provides a survey on energy-efficient clustering routing protocols for heterogeneous WSNs. The authors compared fifteen heterogeneous energy-efficient routing protocols based on some factors such as clustering method, clustering attributes, location-awareness, and heterogeneity level.