A network node comprising: a communication interfacing unit configured for communicating with a communication device via a radio resource control, RRC, connection and at least one first radio bearer, RB, with a master cell group, MCG, bearer type; and a processor electrically connected with the communication interfacing unit, the processor operable to perform operations comprising: controlling the communication interfacing unit to establish at least one second RB with a secondary cell group, SCG, bearer type between the communication device and an auxiliary network node; controlling the communication unit to release the at least one second RB with a secondary cell group, SCG, bearer type between the communication device and the auxiliary network node; and releasing the RRC connection when the processor determines that a first condition is met and for a first time period, a second condition has been met, wherein the first condition is that no second RB with a secondary cell group, SCG, bearer type is configured between the communication device and an auxiliary network node, and the second condition is that all of downlink data in all of at least one downlink buffer corresponding to all of at least one first RB is successfully transmitted or all of the at least one downlink buffer corresponding to all of the at least one first RB is empty, and the network node does not receive any request for an uplink grant allocation from the communication device. a communication interfacing unit configured for communicating with a communication device via a radio resource control, RRC, connection and at least one first radio bearer, RB, with a master cell group, MCG, bearer type; and a processor electrically connected with the communication interfacing unit, the processor operable to perform operations comprising: controlling the communication interfacing unit to establish at least one second RB with a secondary cell group, SCG, bearer type between the communication device and an auxiliary network node; controlling the communication unit to release the at least one second RB with a secondary cell group, SCG, bearer type between the communication device and the auxiliary network node; and releasing the RRC connection when the processor determines that a first condition is met and for a first time period, a second condition has been met, wherein the first condition is that no second RB with a secondary cell group, SCG, bearer type is configured between the communication device and an auxiliary network node, and the second condition is that all of downlink data in all of at least one downlink buffer corresponding to all of at least one first RB is successfully transmitted or all of the at least one downlink buffer corresponding to all of the at least one first RB is empty, and the network node does not receive any request for an uplink grant allocation from the communication device. controlling the communication interfacing unit to establish at least one second RB with a secondary cell group, SCG, bearer type between the communication device and an auxiliary network node; controlling the communication unit to release the at least one second RB with a secondary cell group, SCG, bearer type between the communication device and the auxiliary network node; and releasing the RRC connection a first condition is met and for a first time period, a second condition has been met, wherein the first condition is that no second RB with a secondary cell group, SCG, bearer type is configured between the communication device and an auxiliary network node, and the second condition is that all of downlink data in all of at least one downlink buffer corresponding to all of at least one first RB is successfully transmitted or all of the at least one downlink buffer corresponding to all of the at least one first RB is empty, and wherein the first condition is that no second RB with a secondary cell group, SCG, bearer type is configured between the communication device and an auxiliary network node, and the second condition is that all of downlink data in all of at least one downlink buffer corresponding to all of at least one first RB is successfully transmitted or all of the at least one downlink buffer corresponding to all of the at least one first RB is empty, and all of downlink data in all of at least one downlink buffer corresponding to all of at least one first RB is successfully transmitted or all of the at least one downlink buffer corresponding to all of the at least one first RB is empty, and the network node does not receive any request for an uplink grant allocation from the communication device.