The document discusses wireless sensor networks (WSNs) and energy efficient routing protocols. It provides background on the challenges of WSNs including limited energy. It describes that communication is the most energy expensive activity and multihop transmission can help. It then discusses the LEACH routing protocol, a hierarchical clustering protocol, including its phases and stochastic threshold algorithm for selecting cluster heads. It proposes adapting k-means clustering for LEACH to select cluster heads more efficiently and compares performance of random LEACH versus adaptive k-means LEACH.