A User Equipment, UE,, comprising: a processor; and a memory, wherein the memory stores instructions that cause the processor to: initiate transmission of a Radio Resource Control, RRC connection resume request message if the UE is resuming an RRC connection, wherein the UE uses a pre-configured uplink resource, PUR to transmit uplink data; derive security keys; and when the following conditions are fulfilled: a cell reselection occurs; timer T300 is running after the cell reselection; and the UE has transmitted the RRC connection resume request message and has not received the corresponding response message, perform the following actions: resetting a Medium Access Control, MAC; deleting the derived security key; suspending all Signaling Radio Bearer(s), SRB(s) and Data Radio Bearer(s), DRB(s) except the first SRB, SRBO; configuring lower layers to suspend integrity protection and encryption function; and informing upper layers about a failure to establish an RRC connection or a failure to resume an RRC connection with suspend indication. a processor; and a memory, wherein the memory stores instructions that cause the processor to: initiate transmission of a Radio Resource Control, RRC connection resume request message if the UE is resuming an RRC connection, wherein the UE uses a pre-configured uplink resource, PUR to transmit uplink data; derive security keys; and when the following conditions are fulfilled: a cell reselection occurs; timer T300 is running after the cell reselection; and the UE has transmitted the RRC connection resume request message and has not received the corresponding response message, perform the following actions: resetting a Medium Access Control, MAC; deleting the derived security key; suspending all Signaling Radio Bearer(s), SRB(s) and Data Radio Bearer(s), DRB(s) except the first SRB, SRBO; configuring lower layers to suspend integrity protection and encryption function; and informing upper layers about a failure to establish an RRC connection or a failure to resume an RRC connection with suspend indication. initiate transmission of a Radio Resource Control, RRC connection resume request message if the UE is resuming an RRC connection, wherein the UE uses a pre-configured uplink resource, PUR to transmit uplink data; derive security keys; and when the following conditions are fulfilled: a cell reselection occurs; timer T300 is running after the cell reselection; and the UE has transmitted the RRC connection resume request message and has not received the corresponding response message, perform the following actions: resetting a Medium Access Control, MAC; deleting the derived security key; suspending all Signaling Radio Bearer(s), SRB(s) and Data Radio Bearer(s), DRB(s) except the first SRB, SRBO; configuring lower layers to suspend integrity protection and encryption function; and informing upper layers about a failure to establish an RRC connection or a failure to resume an RRC connection with suspend indication. a cell reselection occurs; timer T300 is running after the cell reselection; and the UE has transmitted the RRC connection resume request message and has not received the corresponding response message, perform the following actions: resetting a Medium Access Control, MAC; deleting the derived security key; suspending all Signaling Radio Bearer(s), SRB(s) and Data Radio Bearer(s), DRB(s) except the first SRB, SRBO; configuring lower layers to suspend integrity protection and encryption function; and informing upper layers about a failure to establish an RRC connection or a failure to resume an RRC connection with suspend indication. resetting a Medium Access Control, MAC; deleting the derived security key; suspending all Signaling Radio Bearer(s), SRB(s) and Data Radio Bearer(s), DRB(s) except the first SRB, SRBO; configuring lower layers to suspend integrity protection and encryption function; and informing upper layers about a failure to establish an RRC connection or a failure to resume an RRC connection with suspend indication.