WO2024207457A1

WO2024207457A1 - Groupcast transmission method and device for handover enhancement

Info

Publication number: WO2024207457A1
Application number: PCT/CN2023/086971
Authority: WO
Inventors: Xin Zhang; Yincheng Zhang
Original assignee: Shenzhen TCL New Technology Co Ltd
Current assignee: Shenzhen TCL New Technology Co Ltd
Priority date: 2023-04-07
Filing date: 2023-04-07
Publication date: 2024-10-10
Anticipated expiration: 2025-10-07
Also published as: CN120391075A

Abstract

A groupcast transmission method for handover enhancement includes generating a group based radio network temporary identifier (G-RNTI) for groupcast transmission/reception in a handover procedure, wherein the G-RNTI is generated by both a user equipment (UE) and a network on their own, or the G-RNTI is generated by the network or the UE. A groupcast transmission device for handover enhancement includes a user equipment (UE) and/or a network configured to execute the above method.

Description

GROUPCAST TRANSMISSION METHOD AND DEVICE FOR HANDOVER ENHANCEMENT

BACKGROUND OF DISCLOSURE

1. Field of the Disclosure

The present disclosure relates to the field of wireless communication systems such as non-terrestrial network (NTN) systems, and more particularly, to groupcast transmission methods and devices for handover enhancement such as NTN-NTN handover.

2. Description of the Related Art

The current work considers existing methods from new radio (NR) terrestrial network (TN) as well as Rel-17 NR NTN work item (WI) outcome as baseline for NTN-TN mobility. The mobility related objective of this WI includes specifying NTN-TN and NTN-NTN measurement/mobility and service continuity enhancements and further includes specifying NTN-NTN handover enhancement for RRC_CONNECTED UEs in the quasi-earth-fixed cell and earth-moving cell to reduce the signaling overhead.

In non-geosynchronous orbit (NGSO) scenarios, satellites (especially low-earth orbits (LEO) satellites) are featured as high-speed moving. Considering some scenarios, the relative speed of LEO satellite with respect to the earth can be as high as 7.56 km per second (i.e., 27216 km/h) , which is in the level of 100x times compared to high-speed train. No matter whether UE is moving or stationary, this means that in the LEO scenario, almost all UEs in the same cell may encounter frequent handovers in very short period. If existing handover command is adopted, this would result in a lot of signaling overhead and especially these signalling may happen in a burst, since handover command is now carried in dedicated radio resource control (RRC) signaling in the form of RRCReconfiguration message.

Signaling burst raises challenges to the network since network may not have sufficient radio resources to transmit handover command for each concerned UE within short time. As a consequence, some UE’s handover commands may reach later than others and this may cause too late handover and even handover failures. Therefore, there is an open issue to reduce the handover (HO) command signaling load.

SUMMARY

An object of the present disclosure is to propose groupcast transmission methods and devices for handover enhancement, which can reduce a signaling load during a HO procedure such as NTN-NTN HO procedure.

In a first aspect of the present disclosure, a groupcast transmission method for handover enhancement includes generating a group based radio network temporary identifier (G-RNTI) for groupcast transmission/reception in a handover procedure, wherein the G-RNTI is generated by both a user equipment (UE) and a network on their own, or the G-RNTI is generated by the network or the UE.

In a second aspect of the present disclosure, a groupcast transmission device for handover enhancement includes a user equipment (UE) and/or a network configured to execute the above method.

In a third aspect of the present disclosure, a non-transitory machine-readable storage medium has stored thereon instructions that, when executed by a computer, cause the computer to perform the above method.

In a fourth aspect of the present disclosure, a chip includes a processor, configured to call and run a computer program stored in a memory, to cause a device in which the chip is installed to execute the above method.

In a fifth aspect of the present disclosure, a computer readable storage medium, in which a computer program is stored, causes a computer to execute the above method.

In a sixth aspect of the present disclosure, a computer program product includes a computer program, and the computer program causes a computer to execute the above method.

In a seventh aspect of the present disclosure, a computer program causes a computer to execute the above method.

BRIEF DESCRIPTION OF DRAWINGS

In order to illustrate the embodiments of the present disclosure or related art more clearly, the following figures will be described in the embodiments are briefly introduced. It is obvious that the drawings are merely some embodiments of the present disclosure, a person having ordinary skill in this field can obtain other figures according to these figures without paying the premise.

FIG. 1 is a block diagram of one or more user equipments (UEs) and a network (e.g., gNB) of communication in a communication network system according to an embodiment of the present disclosure.

FIG. 2 is a flowchart illustrating a groupcast transmission method for handover enhancement according to an embodiment of the present disclosure.

FIG. 3 is a schematic diagram illustrating sub area index/ID according to an embodiment of the present disclosure.

FIG. 4 is a schematic diagram illustrating sub area index/ID according to an embodiment of the present disclosure.

FIG. 5 is a schematic diagram illustrating sub area index/ID according to an embodiment of the present disclosure.

FIG. 6 is a schematic diagram illustrating sub area index/ID according to an embodiment of the present disclosure.

FIG. 7 is a schematic diagram illustrating a mapping relationship between the parameters and G-RNTI according to an embodiment of the present disclosure.

FIG. 8 is a schematic diagram illustrating a mapping relationship between the parameters and G-RNTI according to an embodiment of the present disclosure.

FIG. 9 is a flowchart illustrating a groupcast transmission for NTN-NTN handover according to a first embodiment of the present disclosure.

FIG. 10 is a schematic diagram illustrating sub area index/ID and a mapping table according to a first embodiment of the present disclosure.

FIG. 11 is a flowchart illustrating a groupcast transmission for NTN-NTN handover according to a second embodiment of the present disclosure.

FIG. 12 is a schematic diagram illustrating a relationship between sub area index/ID and G-RNTI according to a second embodiment of the present disclosure.

FIG. 13 is a flowchart illustrating a groupcast transmission for NTN-NTN handover according to a third embodiment of the present disclosure.

FIG. 14 is a flowchart illustrating a groupcast transmission for NTN-NTN handover according to a fourth embodiment of the present disclosure.

FIG. 15 is a flowchart illustrating a groupcast transmission for NTN-NTN handover according to a fifth embodiment of the present disclosure.

FIG. 16 is a block diagram of a system for wireless communication according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure are described in detail with the technical matters, structural features, achieved objects, and effects with reference to the accompanying drawings as follows. Specifically, the terminologies in the embodiments of the present disclosure are merely for describing the purpose of the certain embodiment, but not to limit the disclosure.

In some embodiments of this disclosure, broadcast or groupcast signaling can be used for NTN HO procedure. In the case groupcast signaling is used, how to derive G-RNTI and how the UE acquires the G-RNTI are issues that need to be resolved.

The network refers to nodes in an NTN system including one of the following nodes, for example: 1. space-borne vehicle (such as satellite) , airborne vehicle, aerial vehicle (such as drone) , etc. 2. Base station. 3. Gateway. 4. Core Network. The NTN system includes nodes such as satellite, gateways, base station, and core network, etc. The network in some embodiments of this disclosure refers to any node in the NTN system. The “satellite” my be divided into many types, including space-borne vehicle (such as satellite) , airborne vehicle, aerial vehicle (such as drone) , etc.

FIG. 1 illustrates that, in some embodiments, one or more user equipments (UEs) 10 and a network (e.g., gNB) 20 for communication in a communication network system 40 according to an embodiment of the present disclosure are provided. The communication network system 40 includes the one or more UEs 10 and the network 20. The one or more UEs 10 may include a memory 12, a transceiver 13, and a processor 11 coupled to the memory 12 and the transceiver 13. The network 20 may include a memory 22, a transceiver 23, and a processor 21 coupled to the memory 22 and the transceiver 23. The processor 11 or 21 may be configured to implement proposed functions, procedures and/or methods described in this description. Layers of radio interface protocol may be implemented in the processor 11 or 21. The memory 12 or 22 is operatively coupled with the processor 11 or 21 and stores a variety of information to operate the processor 11 or 21. The transceiver 13 or 23 is operatively coupled with the processor 11 or 21, and the transceiver 13 or 23 transmits and/or receives a radio signal.

The processor 11 or 21 may include application-specific integrated circuit (ASIC) , other chipset, logic circuit and/or data processing device. The memory 12 or 22 may include read-only memory (ROM) , random access memory (RAM) , flash memory, memory card, storage medium and/or other storage device. The transceiver 13 or 23 may include baseband circuitry to process radio frequency signals. When the embodiments are implemented in software, the techniques described herein can be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The modules can be stored in the memory 12 or 22 and executed by the processor 11 or 21. The memory 12 or 22 can be implemented within the processor 11 or 21 or external to the processor 11 or 21 in which case those can be communicatively coupled to the processor 11 or 21 via various means as is known in the art. Further, in some embodiments, the processor 11 is configured to perform the following methods. Further, in some embodiments, the processor 21 is configured to perform the following methods.

FIG. 2 is a flowchart illustrating a groupcast transmission method 200 for handover enhancement according to an embodiment of the present disclosure. In some embodiments, the groupcast transmission method 200 includes: a step 202, generating a group based radio network temporary identifier (G-RNTI) for groupcast transmission/reception in a handover (HO) procedure, wherein the G-RNTI is generated by both a user equipment (UE) and a network on their own, or the G-RNTI is generated by the network or the UE.This can reduce a signaling load during a HO procedure such as NTN-NTN HO procedure.

In some embodiments, the G-RNTI is generated by the network, and the G-RNTI is delivered from the network to the UE via a broadcast and/or groupcast and/or unicast signaling. In some embodiments, if the G-RNTI is generated by one node, the G-RNTI is delivered from the node generating the G-RNTI to another node. In some embodiments, if the G-RNTI is generated by two nodes, a G-RNTI generating rule or generating parameter is the same for the two nodes. In some embodiments, the groupcast transmission method for handover enhancement further comprises generating the G-RNTI using at least one parameter and/or a G-RNTI derivation rule. In some embodiments, the at least one parameter comprises a reference signal received power (RSRP) , a reference signal received quality (RSPQ) , a distance between the UE and a reference location, a time measured at the UE, a public land mobile network (PLMN) , a UE location, a sub area index/ID, a slot information of an area/sub area, an orthogonal frequency division multiplexing (OFDM) information of the area/sub area, and/or a frequency information.

In some embodiments, the sub area index/ID is static and permeant, semi-static, or dynamic. In some embodiments, the sub area index/ID is allocated by a one-dimension format or a double/multiple-dimension format. In some embodiments, the sub area index/ID is global or regional. In some embodiments, the G-RNTI derivation rule comprises a mapping rule or a function rule. In some embodiments, the mapping rule defines a mapping relationship between the at least one parameter and the G-RNTI, and the mapping relationship comprises a multiple-to-one mapping or a one-to-one mapping. In some embodiments, the function rule defines a function relationship between the at least one parameter and the G-RNTI. In some embodiments, the at least one parameter and/or the G-RNTI derivation rule is maintained by both the UE and the network on their own, or the at least one parameter and/or the G-RNTI derivation rule is delivered from the UE to the network and/or from the network to the UE.

In some embodiments, the at least one parameter and/or the G-RNTI derivation rule is maintained by both the UE and the network on their own, the G-RNTI derivation rule is the mapping rule, and the G-RNTI is generated by both the UE and the network on their own. In some embodiments, the at least one parameter and/or the G-RNTI derivation rule is maintained by both the UE and the network on their own, the G-RNTI derivation rule is the function rule, and the G-RNTI is generated by both the UE and the network on their own. In some embodiments, the at least one parameter and/or the G-RNTI derivation rule is delivered from the UE to the network and/or from the network to the UE, the G-RNTI derivation rule is the mapping rule, and the G-RNTI is generated by both the UE and the network on their own. In some embodiments, the at least one parameter and/or the G-RNTI derivation rule is delivered from the UE to the network and/or from the network to the UE, the G-RNTI derivation rule is the function rule, and the G-RNTI is generated by both the UE and the network on their own.

In some embodiments, the G-RNTI is generated by the UE. In some embodiments, the G-RNTI is generated by the UE, and the G-RNTI is delivered from the UE to the network. In some examples, the UE is configured to generate the G-RNTI using at least one parameter and/or a G-RNTI derivation rule. Other examples are similar to the above embodiments, that is, generating the G-RNTI also requires the parameter and/or rule. The parameter and/or rule may be owned/derived/known/maintained by the UE itself, or may need to be sent to the UE by the network. In some examples, the at least one parameter and/or the G-RNTI derivation rule is maintained by both the UE and the network on their own, or the at least one parameter and/or the G-RNTI derivation rule is delivered from the UE to the network and/or from the network to the UE.

For examples, in some embodiments, the at least one parameter comprises a reference signal received power (RSRP) , a reference signal received quality (RSPQ) , a distance between the UE and a reference location, a time measured at the UE, a public land mobile network (PLMN) , a UE location, a sub area index/ID, a slot information of an area/sub area, an orthogonal frequency division multiplexing (OFDM) information of the area/sub area, and/or a frequency information. In some embodiments, the sub area index/ID is static and permeant, semi-static, or dynamic. In some embodiments, the sub area index/ID is allocated by a one-dimension format or a double/multiple-dimension format. In some embodiments, the sub area index/ID is global or regional. In some embodiments, the G-RNTI derivation rule comprises a mapping rule or a function rule. In some embodiments, the mapping rule defines a mapping relationship between the at least one parameter and the G-RNTI, and the mapping relationship comprises a multiple-to-one mapping or a one-to-one mapping. In some embodiments, the function rule defines a function relationship between the at least one parameter and the G-RNTI. In some embodiments, the at least one parameter and/or the G-RNTI derivation rule is maintained by both the UE and the network on their own, or the at least one parameter and/or the G-RNTI derivation rule is delivered from the UE to the network and/or from the network to the UE.

G-RNTI derivation

This issue is regarding who can determine the G-RNTI. Two ways are considered. One way is that a network (NW) is responding for generating (in this disclosure, we refer “generate” as “allocate/calculate/maintain or any other way to derive the G-RNTI) the G-RNTI for each group and the NW sends the G-RNTIs to the UEs belonging to each group in a NTN cell. In this way, the NW can group the UEs in a NTN cell first, generate the G-RNTI for each group, then send the G-RNTI (s) to the UEs (in this disclosure we refer this way as “NW generation” ) .

The other way is both UE and NW can generate the G-RNTI on their own and there is no need for the NW to send G-RNTI. In this way, the NW can send signaling directly to the UEs belonging to the same group scrambled with the same G-RNTI, and the UEs may monitor the G-RNTI, also C-RNTI, and other RNTIs that are needed to be monitored due to some other procedures UEs are performing, and the UE can receive the groupcast signaling/data (in this disclosure we refer this way as “local generation” ) .

Parameter for G-RNTI derivation

At least one parameter for G-RNTI derivation comprises a reference signal received power (RSRP) , a reference signal received quality (RSPQ) , a distance between the UE and a reference location, a time measured at the UE, a public land mobile network (PLMN) , a UE location, a sub area index/ID, a slot information of an area/sub area, an orthogonal frequency division multiplexing (OFDM) information of the area/sub area, a frequency information, and/or some other parameters.

In some embodiments, a new parameter is defined which is called sub area index/ID. An NTN cell/coverage is divided into several sub area, and each sub area is allocated/assigned an index. The index could be with the following three situations. The first situation is that the index could be static and permeant. For example, the earth surface would be divided into several sub areas according to such as country, land attributes, (desert, maritime area, or forest) etc. In this way, the index of each sub area could be static and permeant. The second situation is that the index could be semi-static which implies that the index could be stay the same during a relative long period and however could be changed by NW. For example, in case one area is originally covered by one satellite, therefore is divided in to one sub area and allocated one index. However, later one, this area is covered by five satellites, then it might be necessary to divided it into more sub areas to provide more accurate geographic information. The third situation is that the sub area division and index allocation can be changed/modified by NW dynamically. In the above some embodiments, the sub area index/ID is static and permeant, semi-static, or dynamic.

In some embodiments, the sub area index/ID is allocated by a one-dimension format, i.e., single layer: each sub area owns a unique index. FIG. 3 illustrates that, in an example, the area of three countries is divided into 8 sub areas, and each area is with a unique index which is with a one dimension format.

In some embodiments, the sub area index/ID is allocated by a double/multiple-dimension format, i.e., double/Multiple layer: the index can be with double/multiple dimension format. FIG. 4 illustrates that, in an example, the area of three countries is divided into 8 sub areas, and each area is with a unique index which is with a two dimensions format which can be a vector. The first value of the vector can represent the country information, and the second value of the vector can represent the ID within this country.

In some embodiments, the sub area index/ID is global or regional. FIG. 5 illustrates that, in an example, all the indices are global and unique. FIG. 6 illustrates that, in an example, the index can be reused between different sub areas such as Country 1 and Country 3 areas in this example.

G-RNTI derivation rule

In some embodiments, the G-RNTI derivation rule comprises a mapping rule or a function rule. In some embodiments, the mapping rule defines a mapping relationship between the at least one parameter and the G-RNTI, and the mapping relationship comprises a multiple-to-one mapping or a one-to-one mapping. In details, in some examples, the parameters and rule can be mapping relationship, which can be N to one mapping or one to one mapping (in some embodiments of this disclosure, we refer this rule as “mapping rule” ) . Further, the parameters can be one or any combination of the parameter sets. The relationship could be in a table format as illustrated in FIG. 7 (one-to-one mapping example) and FIG. 8 (multiple-to-one mapping example) , or any other types of formats that could imply the relationship between the parameters and G-RNTI.

In some embodiments, the function rule defines a function relationship between the at least one parameter and the G-RNTI. In details, in some examples, the G-RNTI can be calculated by a function and the variables of the function are the parameters. The format is as the following (in some embodiments of this disclosure, we refer this rule as “function rule” ) .

G-RNTI=Function (Parameter 1)

G-RNTI=Function (Parameter 1, Parameter 2, …, Parameter M)

The rule can be static and permeant, or it can be modified or configured by NW and transmitted the UEs in an NTN cell when modified/updated. The transmission could be in a broadcast way, such as system information.

Parameters and rule maintenance

In some embodiments, the at least one parameter and/or the G-RNTI derivation rule is maintained by both the UE and the network on their own, or the at least one parameter and/or the G-RNTI derivation rule is delivered from the UE to the network and/or from the network to the UE.

In details, in some examples, the first option is that the parameters and rule can be maintained by both UE and NW, and there is no need to transfer any parameter or rule from NW to UE or vice versa. Both UE and NW can generate the G-RNTI based on the parameters and rule (in some examples of this disclosure, we refer this way as “Local Maintenance” ) .

In some examples, the second option is either NW or UE is not aware of one/some of the parameters or rule and is received from the other side (in some embodiments of this disclosure, we refer this way as “NW Delivery” ) . In an example, NW maintains all the parameters and rule, and UE doesn’t maintain any of them or some of them, then NW delivers the parameter (s) or rule to the UE, and vice versa. In an example, UE maintains all the parameters and rule, and NW doesn’ t maintain any of them or some of them, then UE delivers the parameter (s) or rule to the NW. The delivery from NW to UE could be in a broadcast way such as a system information.

Embodiment 1: “Local Maintenance” , “Mapping Rule” , and “Local Generation”

In some embodiments, the at least one parameter and/or the G-RNTI derivation rule is maintained by both the UE and the network on their own, the G-RNTI derivation rule is the mapping rule, and the G-RNTI is generated by both the UE and the network on their own.

FIG. 9 illustrates that, in some examples, a groupcast transmission for NTN-NTN handover includes the following steps:

In step 0: UEs and a source cell can perform measurement control and reports. In step 1: the source cell can perform HO decision. In step 2: The source cell sends the group common HO signaling scrambled with G-RNTI to the UEs belonging the same group in an NTN cell, and UEs may receive the signaling via monitoring G-RNTI. In step 3: The source cell sends a UE-specific HO signaling to UEs via a dedicated signaling. Further, regards UE monitoring G-RNTI, use “Local Maintenance” , “Mapping Rule” , and “Local Generation” . Both UE and NW pre-store/maintain the mapping table and parameters such as Sub area ID. Both UE and NW can generate the G-RNTI on their own. UE also monitors C-RNTI and any other RNTI which is necessary for other procedures UE needs to perform simultaneously. In step 4: UEs, the source cell, and a target cell can execute HO.

In summary, both UE and NW are aware of/maintain the parameters and/or rule and can generate the G-RNTI on their own, and there is no need to change/send any related signaling. In some examples, the rule is a mapping relationship between parameters and G-RNTI. The mapping could be N to one or one to one. The format of the mapping could be a table. N is a positive integer greater than 1. In some examples, the rule can be static or dynamic which can be configured by NW. FIG. 10 illustrates an example of the mapping table. NW may send HO signaling/data or any other necessary signaling/data scrambled with the G-RNTI to UEs in the same group in a NTN cell. Further, the UEs may monitor G-RNTI to receive the possible groupcast HO signaling/data or any other signaling/data, and meanwhile also monitor C-RNTI and any other RNTI which is necessary for other procedures UE needs to perform simultaneously.

Embodiment 2: “Local Maintenance” , “Function Rule” , and “Local Generation”

In some embodiments, the at least one parameter and/or the G-RNTI derivation rule is maintained by both the UE and the network on their own, the G-RNTI derivation rule is the function rule, and the G-RNTI is generated by both the UE and the network on their own.

The difference between this embodiment and the embodiment 1 is the rule is a function rule.

FIG. 11 illustrates that, in some examples, a groupcast transmission for NTN-NTN handover includes the following steps:

In step 0: UEs and a source cell can perform measurement control and reports. In step 1: the source cell can perform HO decision. In step 2: The source cell sends the group common HO signaling scrambled with G-RNTI to the UEs belonging the same group in an NTN cell, and UEs may receive the signaling via monitoring G-RNTI. In step 3: The source cell sends a UE-specific HO signaling to UEs via a dedicated signaling. Further, regards UE monitoring G-RNTI, use “Local Maintenance” , “Function Rule” , and “Local Generation” . Both UE and NW pre-store/maintain the mapping table and parameters such as Sub area ID. Both UE and NW can generate the G-RNTI on their own. UE also monitors C-RNTI and any other RNTI which is necessary for other procedures UE needs to perform simultaneously. In step 4: UEs, the source cell, and a target cell can execute HO.

Both UE and NW are aware of/maintain the parameters and/or rule and can generate the G-RNTI on their own, and there is no need to change/send any related signaling.

NW may send HO signaling/data or any other necessary signaling/data scrambled with the G-RNTI to UEs in the same group in a NTN cell. Further, the UEs may monitor G-RNTI to receive the possible groupcast HO signaling/data or any other signaling/data, and meanwhile also monitor C-RNTI and any other RNTI which is necessary for other procedures UE needs to perform simultaneously.

FIG. 12 illustrates some examples of the function rule. In details, some examples of the function rule are given in the following.

G-RNTI=Function 1 (sub area ID)

G-RNTI=Function 2 (sub area ID, PLMN)

G-RNTI=Function 1 (sub area ID, frequency information)

G-RNTI=Function 3 (sub area ID, PLMN, UE location)

G-RNTI=Function 4 (Parameter 1, Parameter 2, …, Parameter N)

G-RNTI=Function 1 (Slot information of area/sub area, frequency information of area/sub area) and so on.

More specially, in some examples, the function could be the following.

G-RNTI=N+sub area ID+ A× t_id + B × f_id

G-RNTI=N+ s_id + A× t_id + B × f_id + D × carrier_id

s_id/t_id/f_id: any related paremeter

carrier_id: frequency information (DL/UL)

“Area” here represents any area related to G-RNTI generation.

Embodiment 3: “NW Delivery” , “Mapping Rule” , and “Local Generation”

In some embodiments, the at least one parameter and/or the G-RNTI derivation rule is delivered from the UE to the network and/or from the network to the UE, the G-RNTI derivation rule is the mapping rule, and the G-RNTI is generated by both the UE and the network on their own.

The difference between this embodiment and embodiment 1 is that parameter (s) and/or rule is delivered from NW to UE or vice versa (from UE to NW) .

FIG. 13 illustrates an example that parameter (s) and/or rule needed to be delivered from NW to UE in the following steps.

The following steps may include: Source cell sends the parameter (s) and/or mapping table used for G-RNTI generation to UEs. The transmission could be in a broadcast way. The UE and the source cell can perform measurement control and reports. The source cell can perform HO decision. The source Cell sends the group common HO signaling scrambled with G-RNTI to UEs belonging the same group in an NTN cell, and UEs may receive the signaling via monitoring G-RNTI. The source cell sends UE-specific HO signaling to UEs via a dedicated signaling. UEs, the source cell, and a target cell can execute HO. Further, regards UE monitoring G-RNTI, use “NW Delivery” , “Mapping Rule” , and “Local Generation” . Both UE and NW and can generate the G-RNTI on their own. UE also monitors C-RNTI and any other RNTI which is necessary for other procedures UE needs to perform simultaneously.

In some examples, both UE and NW can generate the G-RNTI on their own, however the parameter (s) and/or rule used for G-RNTI generation is not kept by UE originally and is delivered by NW. In some examples, both UE and NW can generate the G-RNTI on their own, however the parameter (s) and/or rule used for G-RNTI generation is not kept by NW originally and is delivered by UE. The rule is a “mapping rule” in this embodiment.

Embodiment 4: “NW Delivery” , “Function Rule” , and “Local Generation”

The difference between this embodiment and embodiment 2 is that parameter (s) and/or rule is delivered from NW to UE or vice versa (from UE to NW) . The difference between this embodiment and the embodiment 3 is that the rule is a function rule. The function rule is the same as the description in embodiment 2.

FIG. 14 illustrates an example that parameter (s) and/or rule needed to be delivered from NW to UE in the following.

The following steps may include: Source cell sends the parameter (s) and/or rule used for G-RNTI generation to UEs. The transmission could be in a broadcast way. The UE and the source cell can perform measurement control and reports. The source cell can perform HO decision. The source Cell sends the group common HO signaling scrambled with G-RNTI to UEs belonging the same group in an NTN cell, and UEs may receive the signaling via monitoring G-RNTI. The source cell sends UE-specific HO signaling to UEs via a dedicated signaling. UEs, the source cell, and a target cell can execute HO. Further, regards UE monitoring G-RNTI, use “NW Delivery” , “Function Rule” , and “Local Generation” . Both UE and NW and can generate the G-RNTI on their own. UE also monitors C-RNTI and any other RNTI which is necessary for other procedures UE needs to perform simultaneously.

In some examples, both UE and NW can generate the G-RNTI on their own, however the parameter (s) and/or rule used for G-RNTI generation is not kept by UE originally and is delivered by NW. In some examples, both UE and NW can generate the G-RNTI on their own, however the parameter (s) and/or rule used for G-RNTI generation is not kept by NW originally and is delivered by UE. The rule is a “function rule” in this embodiment.

Embodiment 5: NW Generation

In some embodiments, the at least one parameter and/or the G-RNTI derivation rule is delivered from the UE to the network and/or from the network to the UE, the G-RNTI derivation rule can be the function rule or the mapping rule.

The difference between this embodiment and the embodiments 1 to 4 is that the G-RNTI is generated by NW and delivered to UE. UEs are not able to generate the G-RNTI on their own.

FIG. 15 illustrates that, in some examples, a groupcast transmission for NTN-NTN handover includes the following steps:

The following steps may include: UE and the source cell can perform information reports. The source cell can perform decision. The source Cell sends the group common HO signaling scrambled with G-RNTI to UEs belonging the same group in an NTN cell, and UEs may receive the signaling via monitoring G-RNTI. The source cell sends UE-specific HO signaling to UEs via a dedicated signaling. UEs, the source cell, and a target cell can execute HO. Further, regards UE monitoring G-RNTI, use “NW Generation” . UE also monitors C-RNTI and any other RNTI which is necessary for other procedures UE needs to perform simultaneously.

In the example, UEs can’ t generate the G-RNTI, and the G-RNTI is generated and delivered by NW.

Embodiment 6: UE Generation

In some embodiments, the at least one parameter and/or the G-RNTI derivation rule is delivered from the UE to the network and/or from the network to the UE, and the G-RNTI derivation rule can be the function rule or the mapping rule.

The difference between this embodiment and the embodiments 1 to 4 is that the G-RNTI is generated by UE and delivered to NW.

The steps may include: UE and the source cell can perform information reports. The source cell can perform decision. The source Cell sends the group common HO signaling scrambled with G-RNTI to UEs belonging the same group in an NTN cell, and UEs may receive the signaling via monitoring G-RNTI. The source cell sends UE-specific HO signaling to UEs via a dedicated signaling. UEs, the source cell, and a target cell can execute HO. Further, regards UE monitoring G-RNTI, use “UE Generation” . UE also monitors C-RNTI and any other RNTI which is necessary for other procedures UE needs to perform simultaneously.

In the example, the G-RNTI is generated and delivered by UE.

Further, in the above embodiments, for example, if the G-RNTI is generated by one node of the NTN system, the G-RNTI is delivered from the node generating the G-RNTI to another node of the NTN system. In some examples, if the G-RNTI is generated by two nodes of the NTN system, a G-RNTI generating rule or generating parameter is the same for the two nodes.

FIG. 16 is a block diagram of an example system 700 for wireless communication according to an embodiment of the present disclosure. Embodiments described herein may be implemented into the system using any suitably configured hardware and/or software. FIG. 16 illustrates the system 700 including a radio frequency (RF) circuitry 710, a baseband circuitry 720, an application circuitry 730, a memory/storage 740, a display 750, a camera 760, a sensor 770, and an input/output (I/O) interface 780, coupled with each other at least as illustrated. The application circuitry 730 may include a circuitry such as, but not limited to, one or more single-core or multi-core processors. The processors may include any combination of general-purpose processors and dedicated processors, such as graphics processors, application processors. The processors may be coupled with the memory/storage and configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems running on the system.

While the present disclosure has been described in connection with what is considered the most practical and preferred embodiments, it is understood that the present disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.

Claims

A groupcast transmission method for handover enhancement, comprising:

generating a group based radio network temporary identifier (G-RNTI) for groupcast transmission/reception in a handover procedure, wherein the G-RNTI is generated by both a user equipment (UE) and a network on their own, or the G-RNTI is generated by the network or the UE.
The groupcast transmission method for handover enhancement according to claim 1, wherein the G-RNTI is generated by the network, and the G-RNTI is delivered from the network to the UE via a broadcast and/or and/groupcast and/or unicast signaling; or the G-RNTI is generated by the UE, and the G-RNTI is delivered from the UE to the network.
The groupcast transmission method for handover enhancement according to claim 1, wherein if the G-RNTI is generated by one node, the G-RNTI is delivered from the node generating the G-RNTI to another node.
The groupcast transmission method for handover enhancement according to claim 1, wherein if the G-RNTI is generated by two nodes, a G-RNTI generating rule or generating parameter is the same for the two nodes.
The groupcast transmission method for handover enhancement according to any one of claims 1 to 4, further comprises generating the G-RNTI using at least one parameter and/or a G-RNTI derivation rule.
The groupcast transmission method for handover enhancement according to claim 5, wherein the at least one parameter comprises a reference signal received power (RSRP) , a reference signal received quality (RSPQ) , a distance between the UE and a reference location, a time measured at the UE, a public land mobile network (PLMN) , a UE location, a sub area index/ID, a slot information of an area/sub area, an orthogonal frequency division multiplexing (OFDM) information of the area/sub area, and/or a frequency information.
The groupcast transmission method for handover enhancement according to claim 6, wherein the sub area index/ID is static and permeant, semi-static, or dynamic.
The groupcast transmission method for handover enhancement according to claim 6 or 7, wherein the sub area index/ID is allocated by a one-dimension format or a double/multiple-dimension format.
The groupcast transmission method for handover enhancement according to any one of claims 6 to 8, wherein the sub area index/ID is global or regional.
The groupcast transmission method for handover enhancement according to any one of claims5 to 9, wherein the G-RNTI derivation rule comprises a mapping rule or a function rule.
The groupcast transmission method for handover enhancement according to claim 10, wherein the mapping rule defines a mapping relationship between the at least one parameter and the G-RNTI, wherein the mapping relationship comprises a multiple-to-one mapping or a one-to-one mapping.
The groupcast transmission method for handover enhancement according to claim 10, wherein the function rule defines a function relationship between the at least one parameter and the G-RNTI.
The groupcast transmission method for handover enhancement according to any one of claims 5 to 12, wherein the at least one parameter and/or the G-RNTI derivation rule is maintained by both the UE and the network on their own, or the at least one parameter and/or the G-RNTI derivation rule is delivered from the UE to the network and/or from the network to the UE.
The groupcast transmission method for handover enhancement according to claim 13, wherein the at least one parameter and/or the G-RNTI derivation rule is maintained by both the UE and the network on their own, the G-RNTI derivation rule is the mapping rule, and the G-RNTI is generated by both the UE and the network on their own.
The groupcast transmission method for handover enhancement according to claim 13, wherein the at least one parameter and/or the G-RNTI derivation rule is maintained by both the UE and the network on their own, the G-RNTI derivation rule is the function rule, and the G-RNTI is generated by both the UE and the network on their own.
The groupcast transmission method for handover enhancement according to claim 13, wherein the at least one parameter and/or the G-RNTI derivation rule is delivered from the UE to the network and/or from the network to the UE, the G-RNTI derivation rule is the mapping rule, and the G-RNTI is generated by both the UE and the network on their own.
The groupcast transmission method for handover enhancement according to claim 13, wherein the at least one parameter and/or the G-RNTI derivation rule is delivered from the UE to the network and/or from the network to the UE, the G-RNTI derivation rule is the function rule, and the G-RNTI is generated by both the UE and the network on their own.
A groupcast transmission device for handover enhancement, comprising:

a user equipment (UE) and/or a network configured to execute the method of any one of claims 1 to 17.