In the embodiment of the invention, if the paging carrier is a secondary carrier, then when the UE resides on the secondary carrier, then the UE will listen to a system information update notification sent on the secondary carrier, and receive updated system information on the primary carrier upon reception of the notification. Optionally the UE selects a paging message based upon the latest system information after the system information is updated, where the UE can select a paging message as described above, so a repeated description thereof will be omitted here.

Particularly, when the UE resides on the secondary carrier, the UE receives the system information update notification by listening to a paging message or a Narrowband Physical Downlink Control Channel (NPDCCH).

Correspondingly, if there is be a UE to possibly reside on a secondary carrier in the system, then the eNB will send the NPDCCH or the paging message carrying the system information update notification on the secondary carrier supporting paging when the system information is updated.

In the embodiment of the invention, if the paging carrier is a secondary carrier, then the UE will compare a channel quality of the paging carrier with those of primary carriers in respective surrounding cells, and reselect a cell according to comparison results.

Based upon the same inventive idea, as illustrated in FIG. 2, an eNB can send a paging message according to an embodiment of the invention in the following flow.

In the step 201, the eNB broadcasts system information, where the system information carries information about carriers on which a paging message is allowed to be received.