Selecting Resources for Mobile Terminated Small Data Transmission (MT-SDT) in a Wireless Network

A method comprising:

• receiving a Mobile Terminated Small Data Transmission (MT SDT) paging message from a base station of a wireless network;
• determining a resource for transmitting an uplink (UL) response message to the base station, based on at least one of:
• a Configured Grant resource specific to Small Data Transmission (CG-SDT),
• a legacy Random Access Channel (RACH) resource, or
• a Random Access Small Data Transmission (RA-SDT) resource;
• and
• transmitting the UL response message to the base station using the determined resource.

A non-transitory computer storage medium encoded with instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• transmitting a MT SDT paging message to a user equipment (UE);
• receiving, from the UE, an uplink (UL) response message using a resource, wherein the resource is determined based on at least one of:
• a Configured Grant resource specific to Small Data Transmission (CG-SDT),
• a legacy Random Access Channel (RACH) resource, or
• a Random Access Small Data Transmission (RA-SDT) resource;
• and
• transmitting data to the UE based on the UL response message.

An apparatus comprising one or more processors and one or more storage devices on which are stored instructions that are operable, when executed by the one or more processors, to cause the one or more processors to perform operations comprising:

• receiving, from a base station of a wireless network, configuration information for selecting a resource for transmitting an uplink (UL) response message to the base station;
• receiving, in an RRC_INACTIVE state, a Mobile Terminated Small Data Transmission (MT-SDT) paging message from the base station;
• determining whether the MT-SDT paging message includes an indication of at least one of a first resource or a first resource type for transmitting the UL response message;
• and
• performing at least one of:
• (i) upon determining that the MT-SDT paging message includes the indication and that one or more conditions have been satisfied, transmitting the UL response message to the base station using at least one of the first resource or the first resource type,
• (ii) upon determining that the MT-SDT paging message includes the indication and that one or more conditions for using the first resource have not been satisfied, transmitting the UL response message to the base station using a second resource that is selected based on configuration information, or
• (iii) upon determining that the MT-SDT paging message does not include the indication, transmitting the UL response message to the base station using the second resource selected based on the configuration information.