Inter-Slice Mobility Management in 5G: Motivations, Standard Principles, Challenges, and Research Directions.

Mobility management in a sliced 5G network introduces new and complexchallenges. In a network-sliced environment, user mobility has to be managedamong not only different base stations or access technologies but alsodifferent slices. Managing user mobility among slices, or inter-slice mobility,motivates the need for new solutions. This article, presented as a tutorial,focuses on the problem of inter-slice mobility from the perspective of 3GPPstandards for 5G. It provides a detailed overview of the relevant 3GPP standardprinciples. Accordingly, key technical gaps, challenges, and correspondingresearch directions are identified towards achieving seamless inter-slicemobility within the current 3GPP network slicing framework.