BASE STATION AND USER EQUIPMENT FOR EARLY-DATA TRANSMISSION IN A RANDOM ACCESS PROCEDURE

1 . A base station for performing a random access procedure with a user equipment, comprising:

a processor, being configured to generate a contention-free early-data transmission indication, and the contention-free early-data transmission indication comprises a contention-free resource; and

a transceiver, being electrically connected with the processor and configured to:

transmit a paging message including the contention-free early-data transmission indication to the user equipment;

receive a random access request message which the user equipment transmits on the contention-free resource, after transmitting the paging message; and

transmit a random access response message carrying early downlink data to the user equipment in response to the random access request message.

2 . The base station of claim 1 , wherein the contention-free resource comprises a dedicated preamble and a dedicated narrowband internet of things (NB-IoT) physical random access channel (NPRACH).

3 . The base station of claim 1 , wherein:

the transceiver is further configured to receive a scheduling request message from the user equipment after transmitting the random access response message to the user equipment;

the processor is further configured to generate downlink control information with an uplink grant for the scheduling request message; and

the transceiver is further configured to transmit the downlink control information to the user equipment so that the user equipment transmits uplink data corresponding to the early downlink data to the base station using the uplink grant.

4 . The base station of claim 3 , wherein the scheduling request message carries a hybrid automatic repeat request (HARQ) acknowledgement for the early downlink data.

5 . A base station for performing a random access procedure with a user equipment, comprising:

a processor, being configured to generate a contention-based early-data transmission indication; and

a transceiver, being electrically connected with the processor and configured to:

transmit a paging message including the contention-based early-data transmission indication to the user equipment;

receive a random access request message which the user equipment transmits on a contention-based resource related to the random access procedure, after transmitting the paging message;

transmit a random access response message to the user equipment in response to the random access request message;

receive a radio resource control (RRC) request message from the user equipment after transmitting the random access response message; and

transmit an RRC response message carrying early downlink data in response to the RRC request message.

6 . The base station of claim 5 , wherein the RRC request message is an RRC connection request message or an RRC early-data request message.

7 . The base station of claim 5 , wherein the RRC request message is an RRC connection resume request message, and the RRC response message is an RRC connection resume message or an RRC connection release message.

8 . The base station of claim 5 , wherein the processor is further configured to blindly decode the RRC request message according to a plurality of transport block sizes after the transceiver receives the RRC request message.

9 . The base station of claim 5 , wherein:

the transceiver is further configured to receive a scheduling request message from the user equipment after transmitting the RRC response message to the user equipment;

the processor is further configured to generate downlink control information with an uplink grant for the scheduling request message; and

the transceiver is further configured to transmit the downlink control information to the user equipment so that the user equipment transmits uplink data corresponding to the early downlink data to the base station using the uplink grant.

10 . The base station of claim 9 , wherein the scheduling request message carries a hybrid automatic repeat request (HARQ) acknowledgement for the early downlink data.

11 . A user equipment for performing a random access procedure with a base station, comprising:

a processor, being configured to generate a scheduling request message in response to early downlink data transmitted by the base station in the random access procedure; and

a transceiver, being electrically connected with the processor and configured to:

receive the early downlink data in the random access procedure;

transmit the scheduling request message to the base station after receiving the early downlink data;

receive an uplink grant from the base station after transmitting the scheduling request message to the base station; and

transmit uplink data corresponding to the early downlink data to the base station according to the uplink grant.

12 . The user equipment of claim 11 , wherein the transceiver is further configured to:

receive a paging message including a contention-free early-data transmission indication from the base station, wherein the contention-free early-data transmission indication comprises a contention-free resource;

transmit a random access request message to the base station on the contention-free resource; and

receive a random access response message carrying the early downlink data from the base station after transmitting the random access request message.

13 . The user equipment of claim 12 , wherein the transceiver transmits the uplink data corresponding to the early downlink data to the base station via an RRC early-data request message or an RRC connection resume request message.

14 . The user equipment of claim 12 , wherein the contention-free resource comprises a dedicated preamble and a dedicated narrowband internet of things (NB-IoT) physical random access channel (NPRACH).

15 . The user equipment of claim 11 , wherein the transceiver is further configured to:

receive a paging message including a contention-based early-data transmission indication from the base station;

transmit a random access request message to the base station on a contention-based resource related to the random access procedure;

receive a random access response message from the base station after transmitting the random access request message;

transmit a radio resource control (RRC) request message to the base station after receiving the random access response message; and

receive an RRC response message carrying the early downlink data from the base station after transmitting the RRC request message.

16 . The user equipment of claim 15 , wherein the RRC request message is an RRC connection request message or an RRC early-data request message.

17 . The user equipment of claim 15 , wherein the RRC request message is an RRC connection resume request message, and the RRC response message is an RRC connection resume message or an RRC connection release message.

18 . The user equipment of claim 15 , wherein the processor is further configured to determine a number of repetition of the RRC request message according to a transport block size limitation configured by the random access response message.

19 . The user equipment of claim 11 , wherein the scheduling request message transmitted to the base station carries a hybrid automatic repeat request (HARQ) acknowledgement for the early downlink data.