This research presents a survey of energy efficient routing protocols in sensor network by categorizing into a main classification as architecture based routing. Architecture based routing is further classified into two main areas: flat or location based routing protocol, and hierarchical based routing protocols. Flat based routing is more suitable when a huge number of sensor nodes are deployed, and location based routing is employed when nodes are aware of their location. Hierarchical routing look into alternative approach by placing intermediate nodes in terms of cluster heads, gateway nodes, or mobile entities for efficient handling of energy. The survey is presented in order to highlight the advantage of hierarchical based routing, mainly the deployment of mobility routing. As not many surveys have been conducted in mobility based routing, this chapter can be helpful for looking into a new perspective and paradigm of energy efficient routing protocols. © 2012, IGI Global.