A method of reference cell maintenance by a mobile device in a wireless communication system, the method comprising: being configured with a plurality of secondary cells, where one of the plurality of secondary cells is a reference cell for information reference for another secondary cell; and keeping the reference cell activated when the reference cell is used by the another secondary cell for information reference; said method being characterized in that keeping the reference cell activated when the reference cell is used by another secondary cell for information reference comprises: starting or restarting a first deactivation timer for the reference cell when the reference cell is used by said another secondary cell for information reference and a second deactivation timer for the another secondary cell is started or restarted, wherein the first and the second deactivation timer is used for providing a period of time for secondary cell activation; or starting or restarting an extension timer for the reference cell when the reference cell is used by said another secondary cell for information reference and a deactivation timer for the another secondary cell is started or restarted, wherein the deactivation timer is used for providing a period of time for secondary cell activation, and the extension timer is a specific timer used for providing a period of time for reference cell activation; or starting or restarting a deactivation timer for the reference cell when the reference cell is used by said another secondary cell for information reference and an uplink grant is allocated for the another secondary cell, wherein the deactivation timer is used for providing a period of time for reference cell activation; or starting or restarting an extension timer for the reference cell when the reference cell is used by said another secondary cell for information reference and an uplink grant is allocated for the another secondary cell, wherein the extension timer is a specific timer used for providing a of period time for reference cell activation. being configured with a plurality of secondary cells, where one of the plurality of secondary cells is a reference cell for information reference for another secondary cell; and keeping the reference cell activated when the reference cell is used by the another secondary cell for information reference; said method being characterized in that keeping the reference cell activated when the reference cell is used by another secondary cell for information reference comprises: starting or restarting a first deactivation timer for the reference cell when the reference cell is used by said another secondary cell for information reference and a second deactivation timer for the another secondary cell is started or restarted, wherein the first and the second deactivation timer is used for providing a period of time for secondary cell activation; or starting or restarting an extension timer for the reference cell when the reference cell is used by said another secondary cell for information reference and a deactivation timer for the another secondary cell is started or restarted, wherein the deactivation timer is used for providing a period of time for secondary cell activation, and the extension timer is a specific timer used for providing a period of time for reference cell activation; or starting or restarting a deactivation timer for the reference cell when the reference cell is used by said another secondary cell for information reference and an uplink grant is allocated for the another secondary cell, wherein the deactivation timer is used for providing a period of time for reference cell activation; or starting or restarting an extension timer for the reference cell when the reference cell is used by said another secondary cell for information reference and an uplink grant is allocated for the another secondary cell, wherein the extension timer is a specific timer used for providing a of period time for reference cell activation. starting or restarting a first deactivation timer for the reference cell when the reference cell is used by said another secondary cell for information reference and a second deactivation timer for the another secondary cell is started or restarted, wherein the first and the second deactivation timer is used for providing a period of time for secondary cell activation; or starting or restarting an extension timer for the reference cell when the reference cell is used by said another secondary cell for information reference and a deactivation timer for the another secondary cell is started or restarted, wherein the deactivation timer is used for providing a period of time for secondary cell activation, and the extension timer is a specific timer used for providing a period of time for reference cell activation; or starting or restarting a deactivation timer for the reference cell when the reference cell is used by said another secondary cell for information reference and an uplink grant is allocated for the another secondary cell, wherein the deactivation timer is used for providing a period of time for reference cell activation; or starting or restarting an extension timer for the reference cell when the reference cell is used by said another secondary cell for information reference and an uplink grant is allocated for the another secondary cell, wherein the extension timer is a specific timer used for providing a of period time for reference cell activation.