Random access resource configuration in different bandwidth parts for two-step random access
Techniques are provided to enable use of more than two preamble group Bs during random access (RA) for connected UEs. This flexibility is achieved by configuring the active BWP to overlap with the 2-step RA resources on the initial BWP, configuring different sizes of preamble group B in the initial BWP and the active BWP, a allowing connected UEs in the active BWP to use the MsgA PRACH and MsgA PUSCH resources in the initial BWP without switching active BWP.
1. A method implemented by a user equipment (UE) in a wireless communication network, said method comprising:
configuring first 2-step random access resources in an inactive bandwidth part (BWP) to use in both connected and idle/inactive modes:
configuring second 2-step random access resources in an active BWP overlapping the inactive BWP and configured for the UE to use in connected mode;
initiating a 2-step random access procedure while in a connected mode in the active bandwidth part BWP; and
transmitting a random access message to an access node on the first 2-step random access resources configured for the inactive BWP without changing the active BWP.
2. The method of claim 1 , further comprising monitoring a search space in the active BWP, a search space for the inactive BWP, or a common search space for both the active BWP and inactive BWP for a random access response from the access node.
3. The method of claim 1 , further comprising monitoring a common search space for the inactive BWP and the active BWP for a random access response from the access node.
4. The method of claim 1 , wherein a periodicity of Physical Uplink Shared Channel (PUSCH) occasions for the active BWP and inactive BWP are different.
5. The method of claim 1 , wherein the inactive BWP comprises an initial BWP configured for the UE or a default BWP configured for the UE.
6. The method of claim 1 , further comprising selecting the first 2-step random access resources for the transmission of the ransom access message depending on at least one of:
a size of the random access message;
a priority of the random access message; and
a path loss between the UE and the access node.
7. A user equipment in a wireless communication network, said user equipment comprising:
communication circuitry configured for communication with an access node;
processing circuitry configured to:
configure first 2-step random access resources in an inactive bandwidth part (BWP) to use in both connected and idle/inactive modes;
configure second 2-step random access resources in an active BWP overlapping the inactive BWP and configured for the UE to use in connected mode;
initiate a 2-step random access procedure while in a connected mode in the active BWP;
transmit a random access message to an access node on the first 2-step random access resources configured for the inactive BWP without changing the active BWP.
8. The user equipment of claim 7 being further configured to:
select the first 2-step random access resources for the transmission of the random access message depending on at least one of:
a size of the random access message;
a priority of the random access message; and
a path loss between the UE and the access node.
9. The method of claim 8 further comprising:
receiving, from a connected mode UE, a random access message transmitted on 2-step random access resources in an inactive bandwidth part (BWP) configured for the UE; and
transmitting, responsive to the random access message, a random access response.
10. A method implemented by a network node in a wireless communication network of supporting random access, said method comprising:
configuring 2-step random access resources for random access by the UE in connected mode including first 2-step random access resources in an inactive bandwidth part (BWP) for use in both connected and idle/inactive modes and second 2-step random access resources in an active BWP overlapping the inactive BWP configured for the UE to use in a connected model; and
sending an indication whether UEs are allowed to use the random access resources of the inactive BWP to the access node.
11. The method of claim 10 , wherein the indication specifies one or more purposes for which the 2-step resources in the inactive BWP can be used.
12. The method of claim 10 , wherein the inactive BWP comprises an initial BWP or default BWP.
13. The method of claim 10 , wherein the 2-step random access resources for the active BWP are within the non-overlapping portion of the active BWP.
14. The method of claim 10 , wherein a periodicity of Physical Uplink Shared Channel (PUSCH) occasions for the active BWP and inactive BWP are different.
15. A network node in a wireless communication network, said network node comprising:
communication circuitry configured for communication with user equipment and/or other network nodes;
processing circuitry configured to:
configure 2-step random access resources for random access by the UE in connected mode including first 2-step random access resources in an inactive bandwidth part (BWP) for use in both connected and idle/inactive modes and second 2-step random access resources in an active BWP overlapping the inactive BWP configured for the UE to use in a connected mode; and
sending an indication whether UEs are allowed to use the random access resources of the inactive BWP to the access node.
16. The network node of claim 15 , wherein the processing circuitry is further configured to:
receive, from a connected mode UE, a random access message transmitted on 2-step random access resources in an inactive BWP configured for the UE; and
transmit, responsive to the random access message, a random access response.