The present invention discloses a method and an apparatus for synchronization in a communication
system, the method includes: detecting whether a
user equipment is in an uplink out-of-synchronization state; triggering, by a
downlink scheduling entity, an uplink enhanced
random access synchronization process, if the
user equipment is in the uplink out-of-synchronization state; and obtaining, by an
uplink scheduling entity, a
user equipment identifier sent by the user equipment on which the uplink enhanced
random access synchronization process is triggered, and informing the
downlink scheduling entity via an interaction with the
downlink scheduling entity that uplink synchronization of the user equipment is restored. By employing the method and the apparatus of the invention, the uplink synchronization is accomplished by using the existing enhanced
random access technology of the current
system and via the interaction between the uplink and downlink scheduling entities, the
delay of the synchronization may be shortened effectively, the
data transmission efficiency and the
system resource utilization are improved, and the normal sending and transmitting of the downlink data may be guaranteed.