Abstract: This study evaluates the Network Life Time (NLT) of Wireless Sensor Networks. The Wireless Sensor Network uses a new Routing Algorithm proposed by the researchers. This algorithm is called Hierarchical Energy Tree based Routing Algorithm (HETRA). The aim is to have a routing algorithm with proper congestion control. An exponential congestion control is proposed. This combination is designed to improve the energy efficiency of the WSN and there by increase the NLT. The routing algorithm uses a Hierarchical Energy Tree (HET), which is constructed using the available energy in each node of the network. This HET is used to establish either a bidirectional link or unidirectional link with each node based on the remaining energy. This Algorithm also attempts to solve the data consistency problem due to dynamic nature of the sensor networks. With the proposed algorithm specific distribution patterns of sensor nodes are also assumed in this study for finding out the Routing Protocol along with the Congestion Control Algorithm that could improve the NLT of Wireless Sensor Networks. The analysis is performed by the simulation of wireless sensor networks with HETRA and the three routing protocols used in mobile ad hoc networks-AODV, DSDV and DSR. The Protocol assumed in the Transmission layer is TCP. Five variants of TCP congestion control are considered. They are TCP/Exp, MIMD-Poly, PIPD-Poly, TCP/Tahoe (simply called as TCP) and TCP/Reno. The Network is simulated using ns2. Five different node distribution patterns are assumed. Their performances are compared based on NLT, energy efficiency and a new parameter called Data Packets-ANLT (DANLT) product. The results show that if the sensor nodes are distributed as a CROSS pattern implemented with HETRA Routing protocol and TCP/Exp congestion control algorithm increases the DANLT product.