Method and apparatus for performing random access procedure in NB-IoT carrier in wireless communication system
A method and apparatus for performing a random access procedure in a narrowband internet-of-things (NB-IoT) carrier in a wireless communication system is provided. A user equipment (UE) transmits a random access preamble to a network, receives a random access response from the network, determines resources of scheduled uplink (UL) transmission, and performs the scheduled UL transmission to the network. A number of repetitions and a number of tones for the scheduled UL transmission are determined by the random access preamble.
1. A method for performing a random access procedure in a narrowband internet-of-things (NB-IoT) carrier in a wireless communication system, the method comprising:
transmitting a random access preamble to a network;
receiving a random access response from the network, wherein the random access response includes information on available tones and starting subframe of a scheduled uplink (UL) transmission;
determining a plurality of tones of the scheduled UL transmission within the available tones, based on an index of the random access preamble; and
performing the scheduled UL transmission to the network from the starting subframe on the plurality of tones,
wherein a number of the plurality of tones is determined based on coverage level of the UE,
wherein resources of the scheduled UL transmission include a time resource of the scheduled UL transmission, and
wherein the time resource of the scheduled UL transmission is determined based on a gap value (g) and the index of the random access response (i), where the scheduled UL transmission is calculated by (g*i)+4.
2. The method of claim 1 , wherein the number of tones for the scheduled UL transmission is one.
3. The method of claim 1 , wherein the time resource of the scheduled UL transmission is indicated by the random access response.
4. The method of claim 1 , wherein a frequency resource of the scheduled UL transmission is determined based on an index of the random access response.
5. A user equipment (UE) in a wireless communication system, the UE comprising:
a memory;
a transceiver; and
a processor, coupled to the memory and the transceiver, that:
controls the transceiver to transmit a random access preamble to a network,
controls the transceiver to receive a random access response from the network, wherein the random access response includes information on available tones and starting subframe of a scheduled uplink (UL) transmission,
determines a plurality of tones of the scheduled UL transmission within the available tones, based on an index of the random access preamble, and
controls the transceiver to perform the scheduled UL transmission to the network from the starting subframe on the plurality of tones,
wherein a number of the plurality of tones is determined based on coverage level of the UE,
wherein resources of the scheduled UL transmission include a time resource of the scheduled UL transmission, and
wherein the time resource of the scheduled UL transmission is determined based on a gap value (g) and the index of the random access response (i), where the scheduled UL transmission is calculated by (g*i)+4.