System, method, and product for selecting timing information based on subcarrier spacing
User equipment performs autonomous time adjustment that includes selecting a Timing Error Limit (i.e. T e_NR ) and Maximum Autonomous Time Adjustment Step (i.e. T q_NR ) based on bandwidth (BW) and subcarrier spacing (SCS). In one embodiment, given a certain downlink BW, if the SCS=x(kHz) and the T e_NR of this SCS is N, then the T e_NR of SCS=x/2(kHz) is 2*N. Given a certain downlink BW, if the SCS=x(kHz) and the T e_NR of this SCS is N, then the T e_NR of SCS=2*x(kHz) is N/2. For example, given BW=10 MHz, if the T e_NR of SCS=30kHz is n*T s_NR (T S_NR is the basic timing unit for NR system), then the T e_NR of SCS=60 kHz is N/2*T s_NR , and the T e_NR of SCS=15 kHz is 2*N*T s_NR .
1. An apparatus for a user equipment (UE), comprising:
a wireless interface configured to communicate with a radio access network (RAN) node; and
a processor coupled to the wireless interface, the processor configured to:
determine a reconfiguration event has occurred, the reconfiguration event corresponding to a first transmission after a random access channel (RACH)-less inter-radio access network (RAN) node handover; and
in response to the reconfiguration event:
determine a bandwidth (BW) and a subcarrier spacing (SCS); and
select a Timing Error Limit (T e_NR ) associated with a value N based on the BW, the SCS associated with a value x, and a system basic timing unit.
2. The apparatus of claim 1 , wherein:
the T e_NR =N+L when the SCS is x, wherein L is 0 or a fixed margin;
the T e_NR ≥2·N when the SCS is
x
2
;
and
the
T
e
_
NR
≥
N
2
when the SCS is 2·x.
3. The apparatus of claim 1 , wherein the
T
e_NR
=
N
2
+
L
when the SCS is 2·x, where L is a fixed margin.
4. The apparatus of claim 1 , wherein the T e_NR =2·N+L when the SCS is
x
2
,
where L is a fixed margin.
5. The apparatus of claim 1 , wherein the
T
e_NR
=
N
2
+
L
2
when the SCS is 2 ·x, where L is a fixed margin.
6. The apparatus of claim 1 , wherein the T e_NR =2·N+2·L when the SCS is
x
2
,
where L is a fixed margin.
7. The apparatus of claim 1 , wherein the processor is a baseband processor.
8. A user equipment (UE) for determining a Maximum Autonomous Time Adjustment Step (T q_NR ), the UE comprising:
storage for the T q_NR ; and
a processor configured to:
determine a reconfiguration event has occurred, the reconfiguration event corresponding to a first transmission after a random access channel (RACH)-less handover inter-radio access network (RAN) node; and
in response to the reconfiguration event:
determine a bandwidth (BW) and a subcarrier spacing (SCS); and
select the T q_NR associated with a value N based on the BW, the SCS associated with a value x, and a system basic timing unit.
9. The UE of claim 8 , wherein:
the T q_NR =N+L when the SCS is x, wherein L is 0 or a fixed margin;
the T q_NR ≥2·N when the SCS is
x
2
;
and
the
T
q
_
NR
≥
N
2
when the SCS is 2·x.
10. The UE of claim 8 , wherein the
T
q_NR
≥
N
2
+
L
when the SCS is 2·x, where L is a fixed margin.
11. The UE of claim 8 , wherein the T q_NR =2·N+L when the SCS is
x
2
,
where L is a fixed margin.
12. The UE of claim 8 , wherein the
T
q_NR
=
N
2
+
L
2
when the SCS is 2·x, where L is a fixed margin.
13. The UE of claim 8 , wherein the T q_NR =2·N+2·L when the SCS is
x
2
,
where L is a fixed margin.
14. The UE of claim 8 , wherein the processor is a baseband processor.
15. A computer program product comprising a non-transitory computer-readable storage medium that stores instructions for execution by a processor to perform operations of a user equipment (UE), the operations, when executed by the processor, to perform a method, the method comprising:
determining a reconfiguration event has occurred, the reconfiguration event corresponding to a first transmission after a random access channel (RACH)-less inter-radio access network (RAN) node handover; and
in response to the reconfiguration event:
determining a bandwidth (BW) and a subcarrier spacing (SCS); and
selecting a Timing Error Limit (T e_NR ) based on the BW associated with a value N, the SCS associated with a value x, and a system basic timing unit T S_NR .
16. The computer program product of claim 15 , wherein selecting the comprises selecting the T e_NR from a table based on the BW and the SCS being between two values or equal to one of the two values.
17. The computer program product of claim 15 , wherein the
T
e_NR
=
(
N
2
+
L
)
·
T
S_NR
when the SCS is 2·x, and where L is a fixed margin.
18. The computer program product of claim 15 , wherein the
T
e_NR
=
(
N
2
+
L
2
)
·
T
S_NR
when the SCS is 2·x, and where L is a fixed margin.