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

Mobility management in a sliced 5G network introduces new and complex challenges. In a network-sliced environment, user mobility has to be managed not only among different base stations or access technologies, but also among different slices. This motivates the need for new mobility management solutions, which, by convention are required to be standards-compliant. This article, presented as a tutorial, focuses on the problem of inter-slice mobility from the perspective of 3GPP standards for 5G. A detailed overview of the relevant 3GPP standard principles is provided. Accordingly, the key technical gaps, challenges and the corresponding research directions are identified towards achieving seamless inter-slice mobility within the current 3GPP network slicing framework