Mobility in the IP multimedia subsystem: Network centric mobility vs. device centric mobility

Mobility is a key research area in next generation networks. With operators moving towards fixed mobile convergence where various access networks connect to a common IP centric core, users are being offered a plethora of ways in which to connect to this core. Although there has been a rise in the types of access technologies, we have not seen one access technology prove to be useful in all situations. Each access technology performs best when in a given paradigm. WLAN offers a high data rate and is relatively cheap to install. However it only offers coverage to a small geographical area. UMTS on the other hand offers coverage to a larger geographical area but is expensive to deploy and comparatively offers a lower data rate. One can easily see that a situation where both networks work in conjunction with one another would be most beneficial to the end user. With this in mind, this research paper aims to investigate a manner in which to offer users a seamless experience when performing mid-session handovers. In particular we aim to compare network centric mobility and device centric mobility.