Method, device, computer-readable storage and carrier for random access
The present disclosure provides a method a user equipment (UE) to perform random access to a radio network comprising an uplink physical resource configuration (UL) and supplementary physical resource configuration (SUL). A random access request containing a preamble may be transmitted from the UE to the radio network on a physical random access channel (PRACH) of one of the uplink physical resource configuration or the supplementary uplink physical resource configuration. A random access response for the UE indicating the physical resource configuration on whose PRACH the random access request was sent may be received at the UE, wherein the indication is made by a Random Access Radio Network Temporary Identifier (RA-RNTI) used to identify the random access response. The radio network may be accessed by the UE based on information in the random access response.
1. A method for a user equipment, UE, to perform random access to a radio network comprising two or more uplinks, comprising:
transmitting, from the UE, a random access request containing a preamble to the radio network on a physical random access channel, PRACH, of one of the uplinks;
receiving, at the UE, a random access response for the UE indicating the uplink on whose PRACH the random access request was sent; and
accessing, by the UE, the radio network based on information in the random access response.
2. The method of claim 1 , wherein the uplink on whose PRACH the random access request was sent is indicated by a parameter in Downlink Control Information, DCI, in the random access response.
3. The method of claim 2 , wherein the parameter is an index indicating the uplink on whose PRACH the random access response was sent.
4. The method of claim 2 , wherein the uplink on whose PRACH the random access response was sent is indicated in a Physical Resource Block, PRB, region in the DCI.
5. The method of claim 1 , wherein the random access response comprises at least two grant fields dedicated for the two or more respective uplinks, to indicate grants of random access for the UE that sends random access requests on PRACHs of the two or more respective uplinks.
6. The method of claim 1 , wherein the uplink whose PRACH the random access request was sent is indicated by a Random Access Radio Network Temporary Identifier, RA-RNTI, in the random access response.
7. The method of claim 6 , wherein the RA-RNTI is calculated as a function of an index of the uplink.
8. The method of claim 6 , wherein the RA-RNTI is calculated as follows:
RA-RNTI=1+ t _ id+X*f _ id+X*Y*C _ id,
wherein t_id refers to an index of slot where the preamble transmission starts, f_id refers to an index of the PRACH within the slot, X is the maximum number of slots per radio frame of different uplinks, Y is the maximum number of PRACHs in frequency domain of different uplinks, 0≤t_id<X, 0≤f_id<Y, and C_id is the index of the uplink on whose PRACH the random access request was sent.
9. The method of claim 6 , wherein the RA-RNTI is calculated as follows:
RA-RNTI=1+t_id+max(X1, X2)*f_id+max(X1, X2)*max(Y1, Y2)*C_id
wherein t_id refers to an index of slot where the preamble starts, f_id refers to an index of the PRACH within the slot, X1 is the number of slots per radio frame in a first uplink, X2 is the number of slots per radio frame in a second uplink, Y1 is the number of PRACHs in frequency domain in the first uplink, Y2 is the number of PRACHs in frequency domain in the second uplink, 0<_id<max(X1,X2), 0>f_id<max(Y1,Y2), and C_id is the index of the uplink physical resource configuration on whose PRACH the random access request was sent, which is either the first uplink or the second uplink.
10. The method of claim 1 , wherein the information comprises an indication of the uplink on whose PRACH the random access request was sent.
11. The method of claim 1 , wherein the uplink is a uplink physical resource configuration.
12. The method of claim 1 , wherein one of the two or more uplinks is a supplementary physical resource configuration.
13. A method for a network device to control random access of one or more User Equipments, UEs, to a radio network comprising two or more uplinks, comprising:
receiving, from a UE, a random access request containing a preamble on a physical random access channel, PRACH, of one of the uplinks;
determining parameters for a random access response for the UE; and
transmitting, by the network device, the random access response indicating the uplink on whose PRACH the random access request was received from the UE.
14. The method of claim 13 , wherein the uplink on whose PRACH the random access request was sent is indicated by a parameter in Downlink Control Information, DCI, in the random access response.
15. The method of claim 14 , wherein the parameter is an index indicating the uplink on whose PRACH the random access response was sent.
16. The method of claim 14 , wherein the uplink on whose PRACH the random access response was sent is indicated in a Physical Resource Block, PRB, region in the DCI.
17. The method of claim 13 , wherein the random access response comprises at least two grant fields dedicated for the two or more respective uplinks, to indicate grants of random access for the UE that sends random access requests on PRACHs of the two or more respective uplinks.
18. The method of claim 13 , wherein the uplink on whose PRACH the random access request was sent is indicated by a Random Access Radio Network Temporary Identifier, RA-RNTI, in the random access response.
19. The method of claim 18 , wherein the RA-RNTI is calculated as a function of an index of the uplink.
20. The method of claim 18 , wherein the RA-RNTI is calculated as follows:
RA-RNTI=1+ t _ id+X*f _ id+X*Y*C _ id,
wherein t_id refers to an index of slot where the preamble transmission starts, f_id refers to an index of the PRACH within the slot, X is the maximum number of slots per radio frame of different uplinks, Y is the maximum number of PRACHs in frequency domain of different uplinks, 0≤t_id<X, 0≤f_id<Y, and C_id is the index of the uplink on whose PRACH the random access request was sent.
21. The method of claim 18 , wherein the RA-RNTI is calculated as follows:
RA-RNTI=1+ t _ id +max( X 1, X 2)* f _ id +max( X 1, X 2)*max( Y 1, Y 2)* C _ id
wherein t_id refers to an index of slot where the preamble starts, f_id refers to an index of the PRACH within the slot, X1 is the number of slots per radio frame in a first uplink, X2 is the number of slots per radio frame in a second uplink, Y1 is the number of PRACHs in frequency domain in the first uplink, Y2 is the number of PRACHs in frequency domain in the second uplink, 0<_id<max(X1,X2), 0>f_id<max(Y1,Y2), and C_id is the index of the uplink on whose PRACH the random access request was sent, which is either the first uplink or the second uplink.
22. A user equipment, UE, operative in a radio network having two or more uplinks to perform random access to the radio network, comprising:
a transmitter configured to transmit a random access request containing a preamble to the radio network on a physical random access channel, PRACH, of one of the uplinks;
a receiver configured to receive a random access response for the UE indicating the uplink on whose PRACH the random access request was sent; and
a processor configured to enable the UE to access the radio network based on information in the random access response.
23. A network device, operative in a radio network, to control random access of one or more User Equipment, UEs, to the radio network having two or more uplinks, comprising:
a receiver configured to receive, from a UE, a random access request containing a preamble on a physical random access channel, PRACH, of one of the uplinks;
a processor configured to determine parameters for a random access response for the UE; and
a transmitter configured to transmit the random access response.