Wireless technologies have experienced an explosive growth in recent years. This trend is clear from the emergence of various wireless devices such as Personal Digital Assistants (PDAs), wireless computer, and cellular phones. Wireless networks have also been proliferating at a rapid pace in our society and are increasingly being used as extensions to the wired Internet infrastructure to allow ubiquitous service access, anywhere, anytime. These networking developments have also been paving the way for a plethora of applications (such as those involving audio and video) many of which have stringent Quality of Service (QoS) requirements (bandwidth, delay, loss) that must be satisfied. However, there still remains a significant challenge to provide QoS solutions that operate seamlessly over wired-wireless domains and maintain end-to-end QoS with user mobility. The advent of MPLS technology promises to address some of these QoS challenges. We present and discuss various MPLS-based approaches that have recently been proposed for the support of QoS over wired networks connected to wireless networks (as the last hop). We highlight and discuss the effectiveness and benefits of each of the approaches in minimizing end-to-end QoS degradations (for example, due to large handover delays) when deployed over wired-wireless domains for mobile users. Additionally, we present the limitations associated with each of the MPLS-based approaches proposed.