A method performed by a serving gateway control plane function to manage a plurality of serving gateway user plane functions , comprising: connecting (S201) with the plurality of serving gateway user plane functions ; storing (S202) serving area information of the plurality of serving gateway user plane functions ; selecting (S203) a first serving gateway user plane function among the plurality of serving gateway user plane functions for a user equipment , according to location of the user equipment and the serving area information of the plurality of serving gateway user plane functions ; sending (S204) serving area information of the first serving gateway user plane function to a mobility management entity ; receiving (S601), from the mobility management entity , a request for changing the first serving gateway user plane function ; reselecting (S602) a second serving gateway user plane function from the plurality of serving gateway user plane functions ; sending (S603) serving area information of the second serving gateway user plane function to the mobility management entity; and deleting (S604) a session with the first serving gateway user plane function ; and any one out of: receiving, in response to that the reselection of the second serving gateway user plane function happens during a preparation phase of a handover procedure, an indication of not to notify a packet data network gateway from the mobility management entity , or receiving, in response to that the reselection of the second serving gateway user plane function happens during an idle mode mobility procedure, or during a completion phase of a handover procedure, an indication of to notify a packet data network gateway from the mobility management entity . connecting (S201) with the plurality of serving gateway user plane functions ; storing (S202) serving area information of the plurality of serving gateway user plane functions ; selecting (S203) a first serving gateway user plane function among the plurality of serving gateway user plane functions for a user equipment , according to location of the user equipment and the serving area information of the plurality of serving gateway user plane functions ; sending (S204) serving area information of the first serving gateway user plane function to a mobility management entity ; receiving (S601), from the mobility management entity , a request for changing the first serving gateway user plane function ; reselecting (S602) a second serving gateway user plane function from the plurality of serving gateway user plane functions ; sending (S603) serving area information of the second serving gateway user plane function to the mobility management entity; and deleting (S604) a session with the first serving gateway user plane function ; and any one out of: receiving, in response to that the reselection of the second serving gateway user plane function happens during a preparation phase of a handover procedure, an indication of not to notify a packet data network gateway from the mobility management entity , or receiving, in response to that the reselection of the second serving gateway user plane function happens during an idle mode mobility procedure, or during a completion phase of a handover procedure, an indication of to notify a packet data network gateway from the mobility management entity . receiving, in response to that the reselection of the second serving gateway user plane function happens during a preparation phase of a handover procedure, an indication of not to notify a packet data network gateway from the mobility management entity , or receiving, in response to that the reselection of the second serving gateway user plane function happens during an idle mode mobility procedure, or during a completion phase of a handover procedure, an indication of to notify a packet data network gateway from the mobility management entity . <EOS>