Base station, radio terminal, and methods therein

A method for a base station, the method comprising:

• broadcasting system information, the system information including a first value of a ra-ResponseWindowSize and at least one multiplier factor corresponding to a coverage enhancement level;
• receiving a Random Access (RA) preamble from a User Equipment (UE) in the coverage enhancement level, the UE performing radio communication according to Narrow Band-Internet of Things (NB-IoT);
• and
• in response to the received RA preamble, transmitting a RA Response (RAR) to the UE,
• wherein the RAR is received within a RA Response Window whose length is indicated by a second value of the ra-ResponseWindowSize,
• wherein the second value of the ra-ResponseWindowSize is derived by multiplying the first value of the ra-ResponseWindowSize with the at least one multiplier factor corresponding to the coverage enhancement level, and
• wherein the at least one multiplier factor is also configured as a value corresponding to a number of repetitions for the RAR of a random access procedure.

A User Equipment (UE) comprising:

• a memory;
• and
• at least one processor coupled to the memory, wherein the at least one processor is configured to:
• receive system information from a base station, the system information including a first value of a ra-ResponseWindowSize and at least one multiplier factor corresponding to a coverage enhancement level;
• transmit a Random Access (RA) preamble to the base station in the coverage enhancement level, the UE performing radio communication according to Narrow Band-Internet of Things (NB-IoT);
• and
• receive a RA Response (RAR) from the base station, in response to the transmitting the RA preamble, within a RA Response Window whose length is indicated by a second value of the ra-ResponseWindowSize,
• wherein the second value of the ra-ResponseWindowSize is derived by multiplying the first value of the ra-ResponseWindowSize with the at least one multiplier factor corresponding to the coverage enhancement level, and
• wherein the at least one multiplier factor is also configured as a value corresponding to a number of repetitions for the RAR of a random access procedure.

A method for a User Equipment (UE), the method comprising:

• receiving system information from a base station, the system information including a first value of a ra-ResponseWindowSize and at least one multiplier factor corresponding to a coverage enhancement level;
• transmitting a Random Access (RA) preamble to the base station in the coverage enhancement level, the UE performing radio communication according to Narrow Band-Internet of Things (NB-IoT);
• and
• receiving a RA Response (RAR) from the base station, in response to the transmitting the RA preamble, within a RA Response Window whose length is indicated by a second value of the ra-ResponseWindowSize,
• wherein the second value of the ra-ResponseWindowSize is derived by multiplying the first value of the ra-ResponseWindowSize with the at least one multiplier factor corresponding to the coverage enhancement level, and
• wherein the at least one multiplier factor is also configured as a value corresponding to a number of repetitions for the RAR of a random access procedure.