  This paper elaborates on Conditional Handover (CHO) - a mobility feature
designed in Release 16 of 3rd Generation Partnership Project (3GPP), aimed at
improving the reliability of handover in cellular networks. CHO has turned out
to be a successful feature and attracted several other areas of mobile
networks, where increased reliability is also desirable (e.g. Non-Terrestrial
Networks or Integrated Access Backhaul). This paper explains the principles of
CHO, describes its future use in vertical areas and provides performance
results showing the gains CHO may offer to 5G systems at higher frequency
bands. Our simulative analysis was focused on the handover in Frequency Range 2
(FR2) and CHO recovery procedure. Results have shown that also at higher
frequencies CHO can substantially reduce the mobility failures compared to
baseline handover of Release 15. Moreover, it has been verified that CHO
recovery can be a useful means to allow faster reconnection to the network
after a failure. In certain scenarios CHO Recovery usage ratio was found to
exceed 80%. The paper also outlines the future research and standardization
directions in the area of CHO which appears to be a solid candidate for further
development in 3GPP Release 18 and beyond.
