User equipments, base stations and methods

A base station comprising:

• Radio resource control (RRC) layer processing circuitry configured to send an RRC message in system information (SIB), and
• Medium Access Control (MAC) layer processing circuitry configured to receive a MAC Protocol Data Unit (PDU) from a UE, wherein:
• the RRC message is a configuration of repetition for Msg4 Hybrid Automatic Repeat request ACKnowledgement (HARQ-ACK);
• the MAC PDU includes a MAC sub-header and MAC Service Data Unit (SDU) SUD containing UL Common Control Channel (CCCH);
• the MAC sub-header consist of 1 bit for the first reserved field, 1 bit for a field X, and 6 bits for a Logical Channel Identifier (LCID) field;
• and
• the field X is used for indicating whether or not the UE is capable of repetition of Msg4 HARQ-ACK.

A method for a user equipment (UE), the method comprising:

• acquiring a first Radio resource control (RRC) message in system information (SIB), and
• sending a Medium Access Control (MAC) Protocol Data Unit (PDU), wherein:
• the RRC message is a configuration of repetition for Msg4 Hybrid Automatic Repeat request ACKnowledgement (HARQ-ACK);
• the MAC PDU includes a MAC sub-header and MAC Service Data Unit (SDU) containing UL Common Control Channel (CCCH);
• in a case that the RRC message is not acquired, the MAC sub-header consists of 1 bit for a first reserved field, 1 bit for a second reserved field, and 6 bits for a Logical Channel Identifier (LCID) field;
• in a case that the RRC message is acquired, the MAC sub-header consists of 1 bit for the first reserved field, 1 bit for a field X, and 6 bits for the LCID field;
• and
• the field X is used for indicating whether or not the UE is capable of repetition of Msg4 HARQ-ACK.