"A Mobile Ad-hoc wireless NETwork (MANET) is a self-configuring infrastructure-less network of mobile devices connected by wireless. Each device in a MANET is free to move independently in any direction, and will therefore change its links to other devices frequently. Mobility causes a number of issues in mobile ad hoc networks. To overcome this problem, the authors have taken overview of different mechanisms proposed by different authors for the enhancement of most commonly used Ad-hoc On-demand Distance Vector routing protocol (AODV). In this paper, they provide review of piggyback mechanism and weighted neighbor stability algorithm to achieve better route cost and smaller delay respectively."