BACKGROUND

Mobile communications using wireless communication continue to evolve. A fifth generation may be referred to as 5G. A previous (legacy) generation of mobile communication may be, for example, fourth generation (4G) long term evolution (LTE).

SUMMARY

Systems, methods, and instrumentalities for resource pool sharing between network-scheduled wireless transmit/receive unit (WTRU) and autonomous-scheduled WTRU transmissions may be disclosed herein. A WTRU may be configured to operate in a first sidelink scheduling mode (e.g., a network-scheduled mode). For example, a network may select sidelink resources for sidelink transmissions by a WTRU operating in the first sidelink scheduling mode. A WTRU may be configured to operate in a second sidelink scheduling mode (e.g., an autonomous-scheduled mode). For example, a WTRU operating in the second sidelink scheduling mode may autonomously select sidelink resources for sidelink transmissions.

A WTRU may be configured to select a first resource from a resource pool. The WTRU may be operating in the second sidelink scheduling mode. The resource pool may be configured to be shared by WTRUs operating in the first sidelink scheduling mode and WTRUs operating in the second sidelink scheduling mode. The WTRU may transmit a first resource reservation message (e.g., via first SCI) indicating a forward booking of the first resource, for example after selecting the first resource. The WTRU may determine that the first resource is reserved for at least one sidelink transmission scheduled via the first sidelink scheduling mode. For example, the WTRU may determine that the first resource is reserved for at least one sidelink transmission scheduled via the first sidelink scheduling mode based on an indication (e.g., an explicit indication) received in SCI and/or by comparing the reference signal received power (RSRP) of the first resource to a threshold (e.g., a third threshold). For example, the WTRU may determine that the first resource is reserved for at least one sidelink transmission scheduled via the first sidelink scheduling mode if the RSRP of the first resource is higher than the threshold. The first resource may be reserved by, for example, another WTRU or the network. The WTRU may determine to reselect to a second resource in the resource pool.

The WTRU may evaluate the availability of resources in the resource pool based on determining that the first resource is reserved for the at least one sidelink transmission scheduled via the first sidelink scheduling mode. The WTRU may determine that a resource is available based on a measurement comparison to one or more thresholds. For example, there may be a first threshold for resources reserved by WTRUs operating using the first sidelink scheduling mode and a second threshold for resources reserved by WTRUs operating using the second sidelink scheduling mode. The measurement comparison may include comparing the RSRP of the resource to the first threshold or the second threshold. For example, the WTRU may determine that a resource reserved by a WTRU operating using the first sidelink scheduling mode is available if the RSRP of the resource is below the first threshold. The WTRU may determine that a resource reserved by a WTRU operating using the second sidelink scheduling mode is available if the RSRP of the resource is below the second threshold.

The WTRU may reselect to a second resource in the resource pool based on the evaluated resource availability. For example, there may be a set of available resources, and the WTRU may choose the second resource from the set of available resources. The WTRU may transmit a second resource reservation message (e.g., via second SCI) indicating a forward booking of the second resource, for example after selecting the second resource.

The first threshold may be determined based on the second threshold and an offset value. The second threshold and/or the offset value may be configured (e.g., preconfigured) in the WTRU and/or received from the network. The first threshold may be lower than the second threshold. For example, the offset value may be a negative value and may be added to the second threshold to generate the first threshold, or the offset value may be a non-negative value and may be subtracted from the second threshold to generate the first threshold.

A network scheduled wireless transmit/receive unit (WTRU) may report a sensing result to a network. The network scheduled WTRU may select the resource to perform sensing. An autonomously scheduled WTRU may perform resource selection and/or reselection based on a detection of network scheduled sidelink/V2X transmission. A WTRU may autonomously determine its scheduling mode (e.g., network vs. autonomous).

A network scheduled WTRU may prepare and/or send a periodic report and may prepare and/or send a difference report (e.g., delta) which may indicate the status of available resource from the last periodic report. The difference report may be event triggered. A network scheduled WTRU may perform reporting based on, for example, different selection of PPPP values. An autonomous scheduled WTRU may report its available resources based on sensing, for example after the WTRU performs resource selection.

A WTRU may evaluate a sensing result. For example, the WTRU may determine channel availability (e.g., the availability of one or more time and/or frequency resources) based on a sensing result. The WTRU may interpret results of a sensing event to determine whether a channel is available (e.g., able to be used for a transmission) or unavailable (e.g., unable to be used for a transmission). The WTRU may use a channel that it has determined to be available to transmit one or more scheduled packets. The WTRU may determine parameters for evaluating the sensing result, and may determine when to evaluate the sensing result. The WTRU may compare the result of a current sensing evaluation event with a result of a previous reporting event.

