Method for base station to obtain radio capability information of user equipment in long term evolution system

#The invention relates to a technology of obtaining information in long term evolution (LTE) system of mobile communications in the 3rd Generation Partnership Project (3GPP), especially to a method for a base station to obtain radio capability information of a User Equipment (UE) in LTE system.

#In the LTE system, because there is only packet switching (PS) domain, voice services are carried by the Internet Protocol (IP), which is strict in requirement for time delay. The time for the UE to transit from idle state to active state cannot be more than 100 milliseconds, thereby making a strict requirement for design of the whole LTE system. In the LTE system, the process that the base station, i.e., Evolution Node B (eNB) obtains UE radio capability information is one of the important processes in the process that the UE transits from idle state to active state, so the time delay of the process of obtaining the radio capability information of UE is also one of the important influence factors of the time delay of the whole afore-mentioned process.

#FIG. 1 illustrates a diagram of interface relationship among UE, eNB and Mobility Management Entity (MME) in the LTE system; as shown in FIG. 1, the interface between the UE and the eNB is UU interface which is a radio interface; the interface between the eNB and the MME is S1 interface which is a wire interface; the MME is an entity of the Core Network (CN).

#FIG. 1 illustrates a diagram of interface relationship among UE, eNB and MME;

#FIG. 2 illustrates a flowchart of a method for eNB to obtain radio capability information of a UE in the present invention.

#The main idea of the present invention is that: when the eNB sends a query message to a UE to obtain the UE radio capability information, if the initial context setup request message sent by an MME includes the IE of forbidden inter radio access technologies, the eNB only writes radio access technology types, which are not included in the IE of forbidden inter radio access technologies, in the query message, and sends the query message to the UE; according to the radio access technology types included in the query message, the UE sends the eNB the UE radio capability information of radio access technologies supported by the UE itself. Compared with the query message in the prior art which includes all the radio access technology types supported by protocol, the eNB in the present invention has pertinence when obtaining the UE radio capability information, which reduces the overhead of air interface, thereby shortens the connection delay of the UE.

#The UE in the present invention may be a mobile phone, a Wireless Local Area Network (WLAN) card, a vehicle-mounted radio station, etc.

#FIG. 2 illustrates a flowchart of the method for eNB to obtain radio capability information of the UE, as shown in FIG. 2, the method comprises the following steps.