A method and system for adjusting uplink transmission timing when sending
an initial transmission to a target cell/Node-B of an evolved universal
terrestrial radio access network (E-UTRAN) immediately after handover
from a source cell/Node-B of the E-UTRAN. In one embodiment, a user
equipment (UE) autonomously computes and applies a timing advance (TA)
value based on the current source cell/Node-B timing value, cell/Node-B
beacon channel reference signal measurements and knowledge of the
relative time difference, (if any), between the source and target
cells/Node-Bs. In another embodiment, the UE sends a scheduling request
message or real data packets with the computed TA value applied to the
uplink transmission timing to the E-UTRAN via pre-allocated
non-contention based uplink radio resources. In an alternate embodiment,
the UE sends a scheduling request message with the new computed TA value
applied to the UL transmission timing to an E-UTRAN via a synchronous
random access channel (RACH).