The project of Long Term Evolution (LTE) is an evolution of the Third Generation Wireless Communication (3G), and it improves and enhances the air access technology of 3G, and it takes Orthogonal Frequency Division Multiplexing (OFDM) and Multiple-Input Multiple-Output (MIMO) as the unique standard for the wireless network evolution thereof.
In the LTE system, services based on location information are proposed, such as legal interception, emergency calls. Here, a Mobility Management Entity (MME) needs to know an ID of the serving cell accessed by a UE, or the location information of the UE. When it is required to know the location information of the UE, the MME will send a location information command to the evolved Node B (eNB) to request it to report information of the UE.
Nowadays, the prior art has already proposed a dedicated location reporting procedure, in which the MME requests the eNB to report information about the cell where the UE is located. As seen in FIG. 1, it shows the flow chart of the dedicated location reporting procedure in the prior art during which the MME requests the eNB to report the current location information of the UE, and the following steps are included:                Step S101: The MME sends a location reporting control message to the eNB to query the current location information of the UE. The location reporting control message contains an information element (IE), such as the location information required to be reported and report types. The location information required to be reported comprises the Global Cell Identifier (GCI) of the cell where the UE is located, or geographic location information, etc.; the report types mean that this location reporting control message initiates only one message reporting the GCI of the current cell, or the eNB is required to return a report message as long as the cell of the UE is changed.        Step S102: The eNB returns a location reporting message to the MME; the message carries the location information of the UE, such as the GCI and a geographic location message.        Step S103: The MME sends a cancel location reporting message to the eNB for requiring to terminate the function of location reporting of the UE. It should be indicated that this message is required only when the MME requests a periodic report of location information.        
The disadvantage of the prior art is: in the above procedure, although the MME enables the UE to report location information when the UE is handed over to another cell by setting report types, in fact, the target eNB does not receive the location reporting control message from the MME, thereby the target eNB could hardly know whether it is necessary to report location information of the UE, which results in achieving no report of location information after a handover of the UE occurs. Therefore, the flow of reporting the location information in the prior art is still not perfect and has the defect that it is impossible for the target eNB to report location information of the UE after the UE is handed over to another serving cell.
USPTO Backgrounds
USPTO Backgrounds