ectivity, which may not always be available, for example, when 5G is only using one band in a given location or the UE itself has limitations (for example, lack of support for the band combination necessary in the current situation). RACH-less handover. For the reliability improvements, the following items are under study: Conditional handover, which would make handover preparations early when the serv- ing cell is still strong, and the handover is actually performed only when necessary (the serving cell getting weaker). This is illustrated in Figure 15.8. If the serving cell stays strong until the connection ends, then handover does not happen at all. The approach allows signaling (including measurement report and actual handover com- mand delivery) to be done when the signal quality (and reliability) is still at the desired level. When the handover is finally performed, then the UE can move to the target cell very fast since all the preparations and signaling are already in place. Fast handover failure recovery. Giving the UE more responsibility to determine handover actions (based on the boundaries configured for the UE). Some of the solutions have been included in the LTE side either in Release 14 and 15 to improve the LTE performance. With 5G, it is important to continue improvements of the Figure 15.8 Conditional handover principle. 1. Measure & report target cell 2. Conditional Target Handover preparations 3. Handover performed only Source when source below threshold 15 5G Phase 2 and Beyond mobility side, especially when taking up the need for higher reliability services covered in the IIoT study and work item. An improvement in reliability needs to be reflected also in the performance with mobility cases. The work is expected to be finalized by March 2020. 15.2.6 MIMO Enhancements Release 15 already describes MIMO features in detail, and includes support for two or four MIMO streams as mandatory requirements for the UE, as discussed in Chapter 6. In Release 16, the work is on enhancing MIMO partly based 