Date of Graduation


Document Type


Degree Name

Bachelor of Science in Industrial Engineering

Degree Level



Industrial Engineering


Dr. Kelly M. Sullivan

Committee Member/Reader

Dr. Chase E. Rainwater


A wireless sensor network (WSN) is a group of sensors deployed over an area, which monitor changes in the environment, collects them as data and forwards it between sensors through wireless links. Data is routed, either in a single-hop or multi-hop manner, with the goal of getting this collected data to the sink nodes, which have higher computational capabilities and connects the network with a user interface. Studies have determined that multi-hop WSNs that integrate relay nodes, which function is to only receive and forward data, can maximize lifetime network. A linear programming model, created by Chang and Tassiulas in 1999, aims to maximize network lifetime by routing data from each sensor node to the sink node. This model can be adapted to incorporate the energy consumed and data transmitted by relay nodes.

This thesis contributes to the research done on WSNs with a numerical study done on the modified lifetime maximization model. The numerical study is based on sensitivity analyses that observe how changing network parameters affects relay node locations, having WSN as a performance measure. The results for this study show that relay nodes follow a ring structure around the sink node and might slightly change when parameter values are changed. This ring structure can be explained by the energy hole problem, that describes that sensor nodes around the sink nodes will fail first because of the great amount of energy spent in sensing and transmitting data. Therefore, relay nodes are placed near where sensor nodes will first run out of battery.


Industrial Engineering, Operations Research, Wireless Sensor Network, Lifetime Maximization Linear Programming Model