BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a mobile communication system. More specifically, the present disclosure relates to a method to transmit and receive common control channel message with proper subheader.

2. Description of the Related Art

Mobile communication systems were developed to provide mobile users with communication services. With rapid technological advancements, the mobile communication systems have evolved to the level capable of providing high speed data communication service to support various QoS requirements.

In the mobile communication system called NR (Next Radio) which is being developed, to support various QoS requirement in various deployment scenarios, efficient way to perform various RRC procedures is required. Common control channel message is used in uplink and in downlink for various purpose like RRC connection setup, RRC connection reestablishment and RRC connection resumption. Common control channel message is transmitted during random access procedure where transmission resource is limited. Hence it is required to minimize the overhead in performing RRC procedures involving common control channel message exchange.

SUMMARY

Aspects of the present disclosure are to address at least the above mentioned problems. Accordingly, an aspect of the present disclosure is to provide a method and an apparatus to transmit and receive common control channel message with minimum overhead.

In accordance with an aspect of the present disclosure, a method to transmit and receive common control channel message is provided. In the method, UE applies a 1stmethod to generate MAC subPDU including CCCH SDU and applies 2ndmethod to process the received MAC subPDU including CCCH SDU. In the first method the length of CCCH SDU is indicated by LCID field and in the 2ndmethod the length of CCCH SDU is indicated by L field.

