Currently, there is a need to provide communication services at anytime, anywhere with the low cost and the best quality. Moreover, deployment of WLAN network aiming to offer services in a hot-spot region, such as airports, hotels, railway stations, etc. tend towards the need to provide the integrated architecture of UMTS and WLAN. The integration of UMTS and WLAN is beneficial for both user and service provider. Many research proposals have been proposed to provide solutions to tackle problems concerning mobility and handover management in an integrated network environment. This paper gives an overview of the most recent research efforts made regarding mobility and handover management in heterogeneous network environment. The paper mainly focuses on the various coupling approaches used for the integration of UMTS and WLAN. © 2011 IEEE.