METHOD AND APPARATUS FOR PERFORMING RANDOM ACCESS PROCEDURE
A communication method and system for converging a fifth generation (5G) communication system for supporting higher data rates beyond a fourth generation (4G) system with a technology for internet of things (IoT) are provided. The communication method and system may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A method of a terminal for performing a random access procedure is provided. The method includes transmitting a random access preamble associated with a random access procedure to a base station, receiving a random access response including information on a backoff parameter value from the base station, identifying a scaling factor for backoff based on a priority of the random access procedure or an event which triggers the random access procedure, determining a random backoff time based on the scaling factor and the backoff parameter value, and transmitting a subsequent random access preamble after the random backoff time to the base station.
1 . A method of a terminal for performing a random access procedure, the method comprising:
transmitting, to a base station, a random access preamble associated with a random access procedure;
receiving, from the base station, a random access response including information on a backoff parameter value;
identifying a scaling factor for backoff based on a priority of the random access procedure or an event which triggers the random access procedure;
determining a random backoff time based on the scaling factor and the backoff parameter value; and
transmitting, to the base station, a subsequent random access preamble after the random backoff time.
2 . The method of claim 1 , wherein the random access has one of a high access priority or a normal access priority.
3 . The method of claim 2 , wherein, if the random access is for a handover or a beam failure recovery, the random access is determined as the high access priority.
4 . The method of claim 1 , further comprising:
receiving, from the base station, information on the scaling factor.
5 . The method of claim 1 , wherein, if the terminal fails to receive a random access response from the base station in response to transmitting the random access preamble, the method further comprises:
determining a power ramping step parameter based on the priority of the random access; and
retransmitting, to the base station, the random access preamble using the power ramping step.
6 . A method of a base station for performing a random access procedure, the method comprising:
receiving, from a terminal, a random access preamble associated with a random access procedure;
transmitting, to the terminal, a random access response including information on a backoff parameter value; and
receiving, from the terminal, a subsequent random access preamble after a random backoff time,
wherein the random backoff time is determined based on a scaling factor for backoff and the backoff parameter value, and the scaling factor is determined based on a priority of the random access procedure or an event which triggers the random access procedure.
7 . The method of claim 6 , wherein the random access has one of a high access priority or a normal access priority.
8 . The method of claim 7 , wherein, if the random access is for a handover or a beam failure recovery, the random access is determined as the high access priority.
9 . The method of claim 6 , further comprising:
transmitting, to the terminal, information on the scaling factor.
10 . A terminal comprising:
a transceiver configured to:
receive signals from a base station, and
transmit signals to the base station; and
a processor coupled with the transceiver and configured to:
control the transceiver to transmit, to the base station, a random access preamble associated with a random access procedure,
control the transceiver to receive, from the base station, a random access response including information on a backoff parameter value,
identify a scaling factor for backoff based on a priority of the random access procedure or an event which triggers the random access procedure,
determine a random backoff time based on the scaling factor and the backoff parameter value, and
control the transceiver to transmitting, to the base station, a subsequent random access preamble after the random backoff time.
11 . The terminal of claim 10 , wherein the random access has one of a high access priority or a normal access priority.
12 . The terminal of claim 11 , wherein the processor is further configured to determine the random access as the high access priority if the random access is for a handover or a beam failure recovery.
13 . The terminal of claim 10 , wherein the processor is further configured to control the transceiver to receive information on the scaling factor from the base station.
14 . The terminal of claim 10 , wherein the processor is further configured to:
determine a power ramping step parameter based on the priority of the random access, and
control to the transceiver to retransmit the random access preamble using the power ramping step to the base station if the terminal fails to receive a random access response from the base station in response to transmitting the random access preamble.
15 . A base station comprising:
a transceiver configured to:
receive signals from a terminal, and
transmit signals to the terminal; and
a processor coupled with the transceiver and configured to:
control the transceiver to receive, from the terminal, a random access preamble associated with a random access procedure,
control the transceiver to transmit, to the terminal, a random access response including information on a backoff parameter value, and
control the transceiver to receive, from the terminal, a subsequent random
access preamble after a random backoff time,
wherein the random backoff time is determined based on a scaling factor for backoff and the backoff parameter value, and the scaling factor is determined based on a priority of the random access procedure or an event which triggers the random access procedure.
16 . The base station of claim 15 , wherein the random access has one of a high access priority or a normal access priority.
17 . The base station of claim 16 , wherein if the random access is for a handover or a beam failure recovery, the random access is determined as the high access priority.
18 . The base station of claim 15 , wherein the processor is further configured to control the transceiver to transmit information on the scaling factor from the terminal.