What is the difference between Handover cancel and Handover failure procedures in Handover?

Question

Different patents talks about radio link failure ratio and handover failure ratio...
Can any one list the difference and scenario for this type of failure to occur?

Answer 1

There are two messages Handover Failure and Handover Cancel, defined for un-successful handover procedure.
Handover Failure : Target eNodeB to MME
Handover Cancel : Source eNodeB to MME.

I never seen any message named as " handover reject ".