Zero-Zero Mobility: Intra-Frequency Handovers with Zero Interruption and Zero Failures

Today's intra-frequency hard handovers in LTE suffer from interruption even if they are successful, and from a risk of failures. The next generation ?New Radio? will introduce more strict requirements which cannot be fulfilled with the traditional hard handover concept. Namely, a handover with 0ms interruption is mandated, and extreme reliability (URLLC services) will not tolerate any mobility failures. Consequently, softer handover concepts where the UE is multi-connected to source and one or more targets are already under discussion. This paper will investigate such a method using the well-known dual connectivity principle and evaluates the performance in terms of robustness/reliability and signaling costs.