Hi Rajan!
Speed sensitive waork in this way, in Siemens System, there is a time(penalty timer) that is started when handover condition is detected and the target cell has been created as microcell. If the timer is set for example 40 seconds, the call will only be handed to microcell after 40 seconds has expired. It is assumed that if you are driving fast after 40 seconds you will have passed the microcell coverage area. You can still handover to microcell even when you are not stationary if you are driving slow and after 40 seconds you are still in micro cell coverage. I hope this helps