IP mobility . Macromobility , micromobility , quality of service and security

The current trend towards offering seamless connectivity no matter the place, time, application in use, or access technology served to coin the expression Always Best Connected (ABC) for describing such a framework. A key issue in accomplishing this goal is the provisioning of mobility to users and/or terminals. This paper overviews some of the solutions for offering mobility at the network layer as well as other relevant issues to solve towards this goal, namely quality of service and security. Both of them pose challenging research problems due to the variability of conditions found in mobile environments and their increased security threats.