IP Library › Granted Patent US 12,426,099
Granted Patent B2
US 12,426,099 · App. 18/019,888 · Granted Sep 23, 2025

Idle/inactive mobility for small data transmission

Inventors: Dylan Watts (Montreal, CA); Faris Alfarhan (Montreal, CA); Loic Canonne-Velasquez (Dorval, CA)
Assignee: InterDigital Patent Holdings, Inc.
H04W74/085H04W72/231H04W76/19
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Quick Facts
Patent No.
US 12,426,099
App. No.
18/019,888
Granted
Sep 23, 2025
Kind
B2
Abstract

A WTRU operating in an inactive state may be associated with a first cell. The WTRU may be configured to receive configuration information for a time period associated with small data transmission failure detection and a search space associated with small data transmission. The WTRU may be configured to send a first small data transmission and start the time period. The WTRU may be configured to monitor for a downlink transmission in the search space during the time period. If a condition for cell reselection is satisfied during the time period or the restarted time period, the WTRU may be configured to suspend a data radio bearer (DRB) associated with small data transmission, select a second cell, perform a random access procedure associated with the second cell, and send a small data transmission. The random access procedure may include sending a request to resume a radio resource control (RRC) connection.

Claims (40)

1. A wireless transmit-receive unit (WTRU) associated with a first cell, the WTRU comprising:

a processor configured to:

receive configuration information indicating a search space and a duration of a time period, wherein the time period is associated with small data transmission;

receive a first small data transmission and start tracking the time period;

monitor for a downlink transmission in the search space during the time period;

if the downlink transmission is received during the time period, receive a second small data transmission and restart the time period, wherein the downlink transmission comprises a downlink transmission grant; and

if a condition for cell reselection is satisfied during the time period or the restarted time period:

select a second cell, and

perform a random access procedure associated with the second cell, wherein the random access procedure is further associated with small data transmission and comprises sending a request to resume a radio resource control (RRC) connection.

2. The WTRU of claim 1 , wherein the processor is further configured to:

determine that the downlink transmission is not received during the time period, wherein the condition for cell reselection is satisfied based on the determination that the downlink transmission is not received during the time period.

3. The WTRU of claim 1 , wherein the processor is further configured to:

receive a small data transmission, wherein the small data transmission is a third small data transmission, a retransmission of the first small data transmission, or a retransmission of the second small data transmission.

4. The WTRU of claim 3 , wherein the small data transmission is received using resources associated with the second cell.

5. The WTRU of claim 1 , wherein the WTRU is operating in an inactive state.

6. The WTRU of claim 1 , wherein the processor is further configured to:

determine whether the downlink transmission is received during the time period; and

change, based on a determination that the downlink transmission is not received during the time period, a state from an inactive state to an idle state and receive a retransmission of the first small data transmission.

7. The WTRU of claim 6 , wherein the retransmission of the first small data transmission is received via an upper layer.

8. The WTRU of claim 1 , wherein if the condition for cell reselection is satisfied during the time period or the restarted time period, the processor is further configured to:

suspend a data radio bearer (DRB) associated with small data transmission.

9. A method associated with a first cell, the method comprising:

receiving configuration information indicating a search space and a duration of a time period, wherein the time period is associated with small data transmission;

receiving a first small data transmission and start tracking the time period;

monitoring for a downlink transmission in the search space during the time period;

if the downlink transmission is received during the time period, receiving a second small data transmission and restart the time period, wherein the downlink transmission comprises a downlink transmission grant; and

if a condition for cell reselection is satisfied during the time period or the restarted time period:

selecting a second cell, and

performing a random access procedure associated with the second cell, wherein the random access procedure is further associated with small data transmission and comprises sending a request to resume a radio resource control (RRC) connection.

10. The method of claim 9 , further comprising:

determining that the downlink transmission is not received during the time period, wherein the condition for cell reselection is satisfied based on the determination that the downlink transmission is not received during the time period.

11. The method of claim 9 , further comprising:

receiving a small data transmission, wherein the small data transmission is a third small data transmission, a retransmission of the first small data transmission, or a retransmission of the second small data transmission.

12. The method of claim 11 , wherein the small data transmission is received using resources associated with the second cell.

13. The method of claim 9 , further comprising:

determining whether the downlink transmission is received during the time period; and

changing, based on a determination that the downlink transmission is not received during the time period, a state from an inactive state to an idle state and receive a retransmission of the first small data transmission.

14. The method of claim 13 , wherein the retransmission of the first small data transmission is received via an upper layer.

15. The method of claim 9 , wherein if the condition for cell reselection is satisfied during the time period or the restarted time period, the method further comprises:

suspending a data radio bearer (DRB) associated with small data transmission.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 3, 2025
From: WATTS, DYLAN; ALFARHAN, FARIS; CANONNE-VELASQUEZ, LOIC
To: INTERDIGITAL PATENT HOLDINGS, INC.
Reel/Frame 071298/0363 →
Continuity (3)
Provisional Application 63061662 · Aug 5, 2020
Provisional Application 63093991 · Oct 20, 2020
Related Publication 20230284289A1 · Sep 7, 2023
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Cited By (2)
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