Patent Description:
To meet the demand for wireless data traffic having increased since deployment of 4th generation (<NUM>) communication systems, efforts have been made to develop an improved 5th generation (<NUM>) or pre-<NUM> communication system. The <NUM> or pre-<NUM> communication system is also called a 'beyond <NUM> network' or a 'post long term evolution (LTE) system'. To decrease propagation loss of the radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large scale antenna techniques are discussed with respect to <NUM> communication systems. In the <NUM> system, hybrid frequency shift keying (FSK) and Feher's quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.

"<NPL> discloses procedures for supporting High Latency Communication.

"<NPL> discloses a paging strategy in the case of UE in CM-IDLE state or in the case of UE in CM-CONNECTED with RRC Inactive state.

The publication of <NPL>, is directed to a method of handling High Latency communication with extended buffering in CM-IDLE mode and in CM-CONNECTED with RRC Active/Inactive modes.

The publication of <NPL>, is directed to a solution for supporting High Latency Communication and Power Saving Function.

The embodiments of the present disclosure propose a method performed at a first node for transmitting data, comprising: receiving downlink data to be transmitted to a User Equipment (UE) in a non-connected state; and determining whether to buffer the downlink data. The method further comprises: when it is determined that the downlink data is to be buffered, if the first node is a first type of node, determining that a paging procedure is not to be initiated for the UE in the non-connected state, or if the first node is a second type of node, notifying the second node that the downlink data has been buffered, so that the second node determines that the paging procedure is not to be initiated for the UE in the non-connected state. There are further provided a method performed at a second node and corresponding devices and storage media.

The above and other features of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings, in which:.

In order to solve at least some of the above problems, the embodiments of the present disclosure provide a device and method for transmitting a signal.

According to a first aspect of the present disclosure, there is provided a method performed at a third node for transmitting data, the method comprising the steps disclosed in claim <NUM>.

According to a second aspect of the present disclosure, there is provided a method performed at a second node for transmitting data according to the disclosure of claim <NUM>.

In some embodiments, the method may further comprise: receiving, from the third node, a message comprising an information element indicating a forwarding data channel address of the first node.

In the claimed invention, the method further comprises transmitting, to another second node, a message comprising an information element indicating that the data is buffered by the first node, and optionally the message comprising the information element indicating the forwarding data channel address of the first node, so that the other second node forwards the message to another third node.

In some embodiments, the other second node may be a second node to which the UE is connected when the UE updates its registration area, and the message which is transmitted to the other second node and comprises the information element indicating that the data is buffered by the first node may be used to trigger the other second node to initiate a Packet Data Unit (PDU) session establishment procedure.

In the claimed invention, the first node is an User Plane Functional entity (UPF), the second node and the other second node are Access Mobility management Functional entities (AMF), and the third node and the other third node are Session Management Functional entities (SMF).

In some embodiments, the UE actively returning to a connected state may comprise the UE updating its registration area (for example, entering a new registration area). In this case, the method shown in <FIG> may further comprise: assisting in creation of a user plane session between the UE and the updated registration area, so that the buffered data may be transmitted using the created user plane session.

According to a third aspect of the present disclosure, there is provided a third node for transmitting data according to the disclosure of claim <NUM>. According to a fourth aspect of the present disclosure, there is provided a second node for transmitting data according to the disclosure of claim <NUM>.

According to the technical solutions of the embodiments of the present disclosure, it is determined by the first node, i.e. the UPF, itself whether to buffer the downlink data to be transmitted to the UE in the non-connected state, and in a case where the downlink data is to be buffered, paging for the UE may not be initiated, thereby enabling the UE to achieve saving of power consumption.

In order to make the purposes, technical solutions and advantages of the present application more clear and apparent, the present application will be further described in detail below in conjunction with the accompanying drawings. It should be illustrated that the description below is illustrated merely by way of example instead of limiting the present disclosure. In the following description, numerous specific details are set forth to provide a more thorough understanding of the present disclosure. However, it will be obvious to those skilled in the art that the present disclosure may be practiced without these specific details. In other instances, well-known circuits, materials or methods are not described in detail in order to avoid obscuring the present disclosure.

Reference throughout this specification to "an embodiment", "an embodiment", "one example" or "an example" means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least an embodiment of the present disclosure. Thus, the appearances of the phrase "in an embodiment", "in an embodiment", "one example" or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combination and/or sub-combination in one or more embodiments or examples. In addition, it should be understand by those skilled in the art that the accompanying drawings provided herein are for the purpose of illustration, and are not necessarily drawn to scale. A term "and/or" used herein comprises any or all combinations of one or more listed related items.

As a new generation of mobile communication systems, <NUM> communication systems include a variety of network elements. <FIG> illustrates a schematic diagram of system architecture in a <NUM> communication system. As shown in <FIG>, network elements in the <NUM> communication system may be classified into different types of elements, for example, User Equipments (UEs), Access Nodes (ANs), Access Mobility management Functional entities (AMF), Session Management Functional entities (SMF), and User Plane Functional entities (UPF) etc., according to tasks undertaken.

After a UE enters a CM-IDLE state, when a UPF receives downlink data for the UE, the UPF transmits a Downlink Data Notification (DDN) to an SMF, and expects the UE to reconstruct a user plane. The SMF then notifies the AMF, and the AMF initiates a paging procedure to an AN. After the UE receives paging signaling, the UE returns to a CM-CONNECTED state, and restores a user plane function with the UPF to receive data.

If the UE enters the CM-IDLE state, the SMF may instruct the UPF to temporarily buffer data on the UPF (without expecting the UE to reconstruct the plane) after receiving the DDN and not transmit the DDN to the SMF at the same time. The SMF may also determine how long the data is buffered or a number of data packets to be buffered.

After the UE enters a RRC-INACTIVE state, the AN initiates an RAN paging procedure after receiving the downlink data of the UE. After the UE receives the paging signaling, the UE returns to a RRC-CONNECTED state, and recovers a wireless link with the AN to receive the downlink data.

The above process may cause the UE which has entered a non-connected state (for example, the CM-IDLE state or the RRC-INACTIVE state) to be frequently woken up through paging signaling (for example, paging or RAN paging) to re-enter the connected state (for example, the CM-CONNECTED state or the RRC-CONNECTED state), thereby resulting in a large power consumption of the UE.

Therefore, there is a need for a solution which can reduce a number of times the UE is paged, so as to at least partially solve the above problems.

<FIG> illustrates a flowchart of a method performed at a first node for transmitting data according to an embodiment of the present disclosure. As shown in <FIG>, the method comprises step S210, in which downlink data to be transmitted to a User Equipment (UE) in a non-connected state is received.

The "non-connected state" described herein refers to a state in which a connection for signal transmission between the UE and a network device is not established, for example, an CM-IDLE state, a RRC-INACTIVE state, or any other similar states.

In operation S220, it is determined whether to buffer the downlink data.

In some examples, the determination may be made based on a priority of the downlink data. In this case, determining whether to buffer the downlink data may comprise: determining, based on a priority of the downlink data, whether to buffer the downlink data. Specifically, if the downlink data is data of a high priority, it is determined that the downlink data is to be transmitted immediately, rather than to be buffered, and if the downlink data is not data of a high priority, it is determined that the downlink data is to be buffered. Herein, the data may be prioritized using any method for dividing data into data of a high priority and data of a low priority in the related art, which will not be described in detail here.

For example, a network node such as the UPF etc. may determine the priority of the downlink data and add an Information Element (IE) of "Flow Priority" in a GTP-U data packet header of the downlink data. The UPF may use the IE to indicate how important the data carried by the data packet is for the UE. Therefore, the AN may decide whether to initiate a RAN Paging procedure immediately according to the IE. It should be illustrated that the technical solutions according to the embodiments of the present disclosure are not limited thereto, and it may be determined whether to buffer the downlink data according to any other feasible manner (for example, but not limited to, a buffer capacity, a data transmission scheduling policy, etc.).

In step S230, when it is determined that the downlink data is to be buffered, if the first node is a first type of node, it is determined that a paging procedure is not to be initiated for the UE in the non-connected state, or if the first node is a second type of node, the second node is notified that the downlink data has been buffered, so that the second node determines that the paging procedure is not to be initiated for the UE in the non-connected state.

The above notification to the second node may be IEs of a "Gateway buffered data indication", an "AN buffered data indication", or any message or information which may implement a similar function, and the present disclosure is not limited by a specific implementation.

Alternatively, the method shown in <FIG> may further comprise: determining, based on occurrence of a predefined event, that the buffered data is to be transmitted to the UE in the non-connected state. Here, the predefined event may comprise, but not limited to, at least one of: the UE actively returning to a connected state, occurrence of downlink data to be transmitted immediately (for example, data of a high priority for the UE), timeout of a predefined timer, and an event that a predefined upper limit of the buffered data has been reached.

In some examples, if the first node is the first type of node, after determining that the downlink data is to be buffered, the first node may further notify the second node that the downlink data has been buffered.

In some examples, a notification to the second node may carry an information element indicating that the data is buffered by the first node.

In some examples, notifying the second node that the downlink data has been buffered may comprise: transmitting, to a third node, a message carrying an information element indicating that the data is buffered by the first node, so that the third node notifies the second node that the data is buffered by the first node.

In some examples, the first type of node may be an Access Node (AN), the second type of node may be an User Plane Functional entity (UPF), the second node may be an Access Mobility management Functional entity (AMF), and the third node may be a Session Management Functional entity (SMF). However, the technical solutions according to the embodiments of the present disclosure are not limited thereto, and the first type of node, the second type of node, the second node, and the third node may also be corresponding nodes which have similar functions in an existing communication system or a future communication system, respectively, and should not be limited to the AN, the UPF, or the AMF.

In some examples, the UE actively returning to a connected state may comprise the UE updating its registration area (for example, entering a new registration area). In this case, the method shown in <FIG> may further comprise: assisting in creation of a user plane session between the UE and the updated registration area, so that the buffered data may be transmitted using the created user plane session.

<FIG> illustrates a flowchart of a method performed at a second node for transmitting data according to an embodiment of the present disclosure. As shown in <FIG>, the method comprises step S310, in which a notification indicating that downlink data to be transmitted to a User Equipment (UE) in a non-connected state has been buffered at a first node is received.

Alternatively, in step s320, it is determined, based on the notification, that a paging procedure is not to be initiated for the UE in the non-connected state.

In some examples, the notification is received from the first node via a third node, and the method shown in <FIG> may further comprise: receiving, from the third node, a message comprising an information element indicating a forwarding data channel address of the first node.

In some examples, the method shown in <FIG> may further comprise: transmitting, to another second node, a message comprising an information element indicating that the data is buffered by the first node and/or the message comprising the information element indicating the forwarding data channel address of the first node, so that the other second node forwards the message to another third node.

In some examples, the other second node is a second node to which the UE connects when the UE updates its registration area, and the message which is transmitted to the other second node and comprises the information element indicating that the data is buffered by the first node is used to trigger the other second node to initiate a Packet Data Unit (PDU) session establishment procedure.

The first node is an User Plane Functional entity (UPF), the second node and the other second node are Access Mobility management Functional entities (AMF), and the third node and the other third node are Session Management Functional entities (SMF). However, technical solutions according to other embodiments which are not part of the present disclosure are not limited thereto, and the first node, the second node, and the third node may also be corresponding nodes which have similar functions in an existing communication system or a future communication system, respectively, and should not be limited to the UPF, the AMF, or the SMF.

In some examples, the UE actively returning to a connected state may comprise the UE updating its registration area (for example, entering a new registration area). In this case, the method shown in <FIG> may further comprise: assisting in creation of a user plane session between the UE and the updated registration area, so that the buffered data may be transmitted to the UE using the created user plane session.

<FIG> illustrates a schematic block diagram of a first node for transmitting data according to an embodiment of the present disclosure. As shown in <FIG>, the first node may comprise a receiving module <NUM>, a data buffer determination module <NUM> and a paging initiation determination module <NUM>.

The receiving module <NUM> is configured to receive downlink data to be transmitted to a User Equipment (UE) in a non-connected state.

The data buffer determination module <NUM> is configured to determine whether to buffer the downlink data.

For example, a network node such as the UPF etc. may determine the priority of the downlink data and may add an IE of "Flow Priority" in a GTP-U data packet header of the downlink data. The UPF may use the IE to indicate how important the data carried by the data packet is for the UE. Therefore, the AN may decide whether to initiate a RAN Paging procedure immediately according to the IE. It should be illustrated that the technical solutions according to the embodiments of the present disclosure are not limited thereto, and it may be determined whether to buffer the downlink data according to any other feasible manner (for example, but not limited to, a buffer capacity, a data transmission scheduling policy, etc.).

The paging initiation determination module <NUM> is configured to, when it is determined that the downlink data is to be buffered, if the first node is a first type of node, determine that a paging procedure is not to be initiated for the UE in the non-connected state, or if the first node is a second type of node, notify the second node that the downlink data has been buffered, so that the second node determines that the paging procedure is not to be initiated for the UE in the non-connected state.

Alternatively, the paging initiation determination module <NUM> may further be configured to: determine, based on occurrence of a predefined event, that the buffered data is to be transmitted to the UE in the non-connected state. Here, the predefined event may comprise, but not limited to, at least one of: the UE actively returning to a connected state, occurrence of downlink data to be transmitted immediately (for example, data of a high priority for the UE), timeout of a predefined timer, and an event that a predefined upper limit of the buffered data has been reached.

In some examples, if the first node is the first type of node, after determining that the downlink data is to be buffered, the second node may further be notified through a transmission module <NUM> that the downlink data has been buffered.

In some examples, the transmission module <NUM> may be configured to transmit, to a third node, a message carrying an information element indicating that the data is buffered by the first node, so that the third node notifies the second node that the data is buffered by the first node.

In some examples, the UE actively returning to a connected state may comprise the UE updating its registration area (for example, entering a new registration area). In this case, the device shown in <FIG> may further comprise a session creation assist module <NUM> configured to assist in creation of a user plane session between the UE and the updated registration area, so that the buffered data may be transmitted using the created user plane session.

The first node illustrated in <FIG> may correspond to the first node <NUM> illustrated in <FIG>. The transceiver <NUM> of the first node <NUM> may comprise the receiving module <NUM> and the transmission module <NUM>, or perform the operations performed by the receiving module <NUM> and the transmission module <NUM>. The processor <NUM> of the first node <NUM> may comprise the data buffer determination module <NUM>, the paging initiation determination module <NUM>, and the session creation assist module <NUM>, or perform the operations performed by the data buffer determination module <NUM>, the paging initiation determination module <NUM>, and the session creation assist module <NUM>.

<FIG> illustrates a schematic block diagram of a second node for transmitting data according to an embodiment of the present disclosure.

As shown in <FIG>, the second node comprises a notification receiving module <NUM>. The notification receiving module <NUM> is configured to receive a notification indicating that downlink data to be transmitted to a User Equipment (UE) in a non-connected state has been buffered at a first node.

Alternatively, the second node may comprise a paging initiation determination module <NUM>. The paging initiation determination module <NUM> is configured to determine, based on the notification, that a paging procedure is not to be initiated for the UE in the non-connected state.

Alternatively, the paging initiation determination module <NUM> may further be configured to determine, based on occurrence of a predefined event, that the buffered data is to be transmitted to the UE in the non-connected state. Here, the predefined event may comprise, but not limited to, at least one of: the UE actively returning to a connected state, occurrence of downlink data to be transmitted immediately (for example, data of a high priority for the UE), timeout of a predefined timer, and an event that a predefined upper limit of the buffered data has been reached.

In some examples, the notification is received by the notification receiving module <NUM> from the first node via a third node, and the notification receiving module <NUM> may further be configured to receive, from the third node, a message comprising an information element indicating a forwarding data channel address of the first node.

In some examples, the device shown in <FIG> may further comprise a transmission module <NUM>, configured to transmit, to another second node, a message comprising an information element indicating that the data is buffered by the first node and/or the message comprising the information element indicating the forwarding data channel address of the first node, so that the other second node forwards the message to another third node.

The first node is an User Plane Functional entity (UPF), the second node and the other second node are Access Mobility management Functional entities (AMF), and the third node and the other third node are Session Management Functional entities (SMF). However, the technical solutions according to the embodiments which are not part of the present disclosure are not limited thereto, and the first node, the second node, and the third node may also be corresponding nodes which have similar functions in an existing communication system or a future communication system, respectively, and should not be limited to the UPF, the AMF, or the SMF.

In some examples, the UE actively returning to a connected state may comprise the UE updating its registration area (for example, entering a new registration area). In this case, the device shown in <FIG> may further comprise a session creation assist module <NUM>, configured to assist in creation of a user plane session between the UE and the updated registration area, so that the buffered data may be transmitted using the created user plane session.

The second node illustrated in <FIG> may correspond to the second node <NUM> illustrated in <FIG>. The transceiver <NUM> of the second node <NUM> may comprise the notification receiving module <NUM> and the transmission module <NUM>, or perform the operations performed by the notification receiving module <NUM> and the transmission module <NUM>. The processor <NUM> of the second node <NUM> may comprise the paging initiation determination module <NUM> and the session creation assist module <NUM>, or perform the operations performed by the paging initiation determination module <NUM> and the session creation assist module <NUM>.

The technical solutions according to the embodiments of the present disclosure are separately described below as two cases, i.e., a case where the first node is a UPF and a case where the first node is an AN. It is to be illustrated that the following description is just a specific example for implementing the embodiments of the present disclosure, and should not be construed as limiting the protection scope of the present disclosure. In addition, in the following description, although a specific message/message name is taken as an example to illustrate a specific implementation of the embodiments of the present disclosure, it should be appreciated that in other implementations, an existing message having a different name from that of the message or even a new message may also be used to implement the technical solutions according to the embodiments of the present disclosure, and the scope of the present disclosure is not limited by the specific message/message name.

After the UE enters a CM-IDLE state and then the UPF receives downlink data for the UE, the UPF may not require an indication of an SMF, and may decide whether to temporarily buffer the data on the UPF by itself (in a case where the UE is not expected to re-create a plane). However, the UPF still needs to transmit a DDN to the SMF to notify the SMF that there is data buffered on the UPF. The SMF also needs to notify the AMF that there is data buffered on the UPF. At that time, the AMF may not start a Paging procedure. In this case, the downlink data is buffered on the UPF while the UE is still maintained in the CM-IDLE state.

After the UE enters a RRC-INACTIVE state and then the AN receives the downlink data for the UE, the AN may decide to buffer the data in the AN without initiating a RAN Paging procedure. In this case, the downlink data is buffered in the AN while the UE is still maintained in the RRC-INACTIVE state.

The UE is maintained in the non-connected state (for example, the CM-IDLE state or the RRC-INACTIVE state) in the above manner, which reduces a number of times the UE is woken up through paging signaling after the UE enters the CM-IDLE state to re-enter a CM-CONNECTED state, and/or reduces a number of times the UE is woken up by a RAN Paging procedure after the UE enters the RRC-INACTIVE state to re-enter a RRC-CONNECTED state, thereby achieving energy saving at the UE.

The method according to the embodiments of the present application may comprise one or more of the following operations.

The above operations are just specific examples provided for explaining the technical solutions according to the embodiments of the present disclosure, and should not be construed as limiting the protection scope of the present disclosure. For example, when there is no switching between the AMF and the SMF in the communication system, the above operations <NUM>, <NUM>, <NUM>, etc. may not be included. For example, in some specific implementations, the above operations <NUM>, <NUM>, etc. may also be omitted. For example, the operations <NUM>-<NUM> and the operations <NUM>-<NUM> may be performed in any relative order according to specific conditions.

After the AN and the UPF buffer the data and the AN or the AMF decides not to transmit the paging message, as described above, the buffered data may be transmitted to the UE when some predefined events occur. As an example of the UE actively returning to the connected state, the UE may enter a new registration area and update the registration area. A specific process of transmitting the buffered data to the UE will be described below by taking the case where the UE updates the registration area as an example. It is to be illustrated that the following embodiments are merely illustrative of specific examples of the technical solutions according to the present disclosure, and should not be construed as limiting the protection scope of the present disclosure.

In a first embodiment, a case where after the UPF receives the downlink data but the AMF decides not to start the paging procedure when the UE is in the CM-IDLE state, the UE enters a new registration area is described. In this embodiment, it is assumed that the UE is allocated to a new AMF, a new SMF, and a new UPF, and the original SMF may communicate with the new SMF.

<FIG> and <FIG> illustrate schematic flowcharts of one specific implementation of a method for transmitting data according to an embodiment of the present disclosure in this case. As shown in <FIG> and <FIG>, the specific implementation comprises the following steps.

In step <NUM>, after the UE enters the CM-IDLE state, the original UPF receives downlink data. The original UPF decides to buffer the downlink data. The original UPF transmits a Data Notification to the original SMF, wherein the message carries a relevant session ID and a gateway buffered data indication, but is not limited to these contents.

In step <NUM>, the original SMF transmits a Data Notification Ack to the original UPF.

In step <NUM>, the original SMF transmits a Namf_Communication_N1N2MessageTransfer to the original AMF. The message should carry the relevant session ID and the gateway buffered data indication, but is not limited to these contents.

In step <NUM>, the original AMF transmits a Namf_Communication_N1N2MessageTransfer Response to the original SMF.

In step <NUM>, the UE moves to a new registration area in the CM-IDLE state. The UE transmits a registration request to the new AMF through the AN.

In step <NUM>, the new AMF transmits a Namf_Communication_UEContextTransfer to the original AMF. The message should carry the above registration request, but is not limited to these contents.

In step <NUM>, the original AMF transmits a Namf_Communication_UEContextTransfer Response to the new AMF. The message should carry a mobility management context and SMF information, but is not limited to these contents. The SMF information should carry the relevant session ID and the gateway buffered data indication, but is not limited to these contents.

In step <NUM>, the UE completes identification, authentication, security, UDM-related procedures, PCF-related procedures etc. It can be illustrated here that an arrow on the right of step <NUM> does not point to a particular network entity. Such an indication manner herein means that there may also be network entities which are not shown in the figure and are involved in this step.

In step <NUM>, the new AMF transmits a Registration Accept to the UE through the AN.

In step <NUM>, the UE transmits a Registration Complete to the new AMF through the AN.

In step <NUM>, the new AMF transmits a Nsmf_PDUSession_CreateSMContext Request to the new SMF. The creation request is transmitted based on, for example, the gateway buffered data indication received by the new AMF from the original AMF, and thereby a PDU session establishment procedure is initiated.

In step <NUM>, the new SMF transmits a Nsmf_PDUSession_CreateSMContext Response to the new AMF.

In step <NUM>, the new SMF transmits a N4 Session Establishment Request to the new UPF.

In step <NUM>, the new UPF transmits a N4 Session Establishment Response to the new SMF. The message should carry CN channel information, but is not limited to these contents. The CN channel information is allocated by the new UPF.

In step <NUM>, the new SMF transmits a Nsmf_PDUSession_Update to the original SMF. The message should carry the above CN channel information, but is not limited to these contents.

In step <NUM>, the original SMF transmits a N4 Session Modification Request to the original UPF. The message should carry the above CN channel information, but is not limited to these contents.

In step <NUM>, the original UPF transmits a N4 Session Modification Response to the original SMF. The message should carry the CN channel information, but is not limited to these contents. The CN channel information is allocated by the original UPF.

In step <NUM>, the original SMF transmits a Nsmf_PDUSession_Update Response to the new SMF. The message should carry the CN channel information allocated by the original UPF, but is not limited to these contents.

In step <NUM>, the new SMF transmits the N4 Session Modification Request to the new UPF. The message should carry the CN channel information allocated by the original UPF, but is not limited to these contents.

In step <NUM>, the new UPF transmits the N4 Session Modification Response to the new SMF.

In step <NUM>, the new SMF transmits Namf_Communication_N1N2MessageTransfer to the new AMF.

In step <NUM>, the new AMF transmits an Namf_Communication_N1N2MessageTransfer Response to the new SMF.

In step <NUM>, the new AMF transmits a N2 PDU Session Resource Setup Request to the AN.

In step <NUM>, the UE completes an RRC connection reconfiguration procedure with the AN.

In step <NUM>, the AN transmits a N2 PDU Session Resource Setup Response to the new AMF.

In step <NUM>, the new AMF transmits a Nsmf_PDUSession_ UpdateSMContext Request to the new SMF.

In step <NUM>, the new SMF transmits the N4 Session Modification Request to the new UPF.

In step <NUM>, the new SMF transmits a Nsmf_PDUSession_ UpdateSMContext Response to the new AMF. At that time, the downlink data buffered by the original UPF may be transmitted to the UE through the new UPF and the AN.

In a second embodiment, a case where after the UPF receives the downlink data but the AMF decides not to start the paging procedure when the UE is in the CM-IDLE state, the UE enters a new registration area is described. In this embodiment, it is assumed that the UE is allocated to a new AMF, a new SMF, and a new UPF, and the original SMF cannot communicate with the new SMF. <FIG> and <FIG> illustrate schematic flowcharts of another specific implementation of a method for transmitting data according to an embodiment of the present disclosure in this case. As shown in <FIG> and <FIG>, the specific implementation comprises the following steps.

In step <NUM>, after the UE enters the CM-IDLE state, the original UPF receives downlink data. The original UPF decides to buffer the downlink data. The original UPF transmits a Data Notification to the original SMF, wherein the message should carry a relevant session ID and a gateway buffered data indication, but is not limited to these contents.

In step <NUM>, the new AMF transmits A Namf_Communication_UEContextTransfer to the original AMF. The message should carry the above registration request, but is not limited to these contents.

In step <NUM>, the UE completes identification, authentication, security, UDM-related procedures, PCF-related procedures etc..

In step <NUM>, the new AMF transmits a Nsmf_PDUSession_CreateSMContext Request to the new SMF.

In step <NUM>, the new SMF transmits a Nsmf_PDUSession_CreateSMContext Response to the new AMF. The message should carry the CN channel information allocated by the new UPF, but is not limited to these contents.

In step <NUM>, the new AMF transmits the a Namf_Communication_UEContextTransfer to the original AMF. The message should carry the CN channel information allocated by the new UPF, but is not limited to these contents.

In step <NUM>, the original AMF transmits a Nsmf_PDUSession_UpdateSMContext Request to the original SMF. The message should carry the CN channel information allocated by the new UPF, but is not limited to these contents.

In step <NUM>, the original SMF transmits a N4 Session Modification Request to the original UPF. The message should carry the CN channel information allocated by the new UPF, but is not limited to these contents.

In step <NUM>, the original SMF transmits a Nsmf_PDUSession_UpdateSMContext Response to the original AMF. The message should carry the CN channel information allocated by the original UPF, but is not limited to these contents.

In step <NUM>, the original AMF transmits the Namf_Communication_UEContextTransfer Response to the new AMF. The message should carry the CN channel information allocated by the original UPF, but is not limited to these contents.

In step <NUM>, the new AMF transmits the Nsmf_PDUSession_ UpdateSMContext Request to the new SMF. The message should carry CN channel information allocated by the original UPF, but is not limited to these contents.

In step <NUM>, the new SMF transmits the Nsmf_PDUSession_UpdateSMContext Response to the new AMF.

In step <NUM>, the new SMF transmits a Namf_Communication_N1N2MessageTransfer to the new AMF.

In step <NUM>, the new AMF transmits a Namf_Communication_N1N2MessageTransfer Response to the new SMF.

In step <NUM>, the new AMF transmits the Nsmf_PDUSession_ UpdateSMContext Request to the new SMF.

In step <NUM>, the new SMF transmits the Nsmf_PDUSession_UpdateSMContext Response to the new AMF. At that time, the downlink data buffered by the original UPF may be transmitted to the UE through the new UPF and the AN.

In a third embodiment, a case where after the AN receives the downlink data but the AN decides not to start the RAN paging procedure when the UE is in the RRC-INACTIVE state, the UE enters a new registration area is described. In this embodiment, it is assumed that the UE is connected to a new AN, and is allocated to a new AMF, a new SMF, and a new UPF. <FIG> and <FIG> illustrate schematic flowcharts of another specific implementation of a method for transmitting data according to an embodiment of the present disclosure in this case. As shown in <FIG> and <FIG>, the specific implementation comprises the following steps.

In step <NUM>, the UE is in the RRC-INACTIVE state, the AN receives downlink data, but the AN decides not to start the RAN Paging procedure. The AN buffers the downlink data.

In step <NUM>, the UE enters a new registration area in the RRC-INACTIVE state. The UE transmits a registration request to the new AMF through the AN.

In step <NUM>, the original AMF transmits a N2 message to the original AN. The N2 message may be a UE State Transition Notification Request.

In step <NUM>, the original AN transmits a N2 message to the original AMF. The N2 message may be a UE notification. The message should carry an AN buffered data indication, but is not limited to these contents.

In step <NUM>, the original AMF transmits a Namf_Communication_UEContextTransfer Response to the new AMF. The message should carry a mobility management context and SMF information, but is not limited to these contents. The SMF information should carry the relevant session ID and the AN buffered data indication, but is not limited to these contents.

In step <NUM>, after step <NUM>, the original AMF may transmit a Nsmf_PDUSession_ UpdateSMContext Request to the original SMF.

In step <NUM>, the original SMF transmits a N4 Session Modification Request to the original UPF.

In step <NUM>, the original UPF transmits a N4 Session Modification Response to the original SMF. The message should carry N3 interface orientated data channel information allocated by the original UPF, but is not limited to these contents.

In step <NUM>, the original SMF transmits a Nsmf_PDUSession_ UpdateSMContext Response to the original AMF. The message should carry the N3 interface orientated data channel information allocated by the original UPF, but is not limited to these contents.

In step <NUM>, the original AMF transmits a N2 message to the original AN. The message may be a PDU session resource modification request on the N2 interface. The message should carry the N3 interface orientated data channel information allocated by the original UPF, but is not limited to these contents.

In step <NUM>, the original AN transmits a N2 message to the original AMF. The message may be a PDU session resource modification response on the N2 interface. At that time, the original AN may transmit the buffered downlink data to the original UPF.

In step <NUM>, after step <NUM>, the new AMF transmits a Nsmf_PDUSession_CreateSMContext Request to the new SMF.

In step <NUM>, the new UPF transmits a N4 Session Establishment Response to the new SMF. The message should carry the N3 interface orientated data channel information and CN channel information, but is not limited to these contents. The N3 interface orientated data channel information and the CN channel information are allocated by the new UPF.

In step <NUM>, the new SMF transmits a Nsmf_PDUSession_Update to the original SMF. The message should carry the CN channel information allocated by the new UPF, but is not limited to these contents.

In step <NUM>, the original SMF transmits the N4 Session Modification Request to the original UPF. The message should carry the CN channel information allocated by the new UPF, but is not limited to these contents.

In step <NUM>, the original UPF transmits the N4 Session Modification Response to the original SMF. The message should carry the CN channel information, but is not limited to these contents. The CN channel information is allocated by the original UPF.

In step <NUM>, the new UPF transmits the N4 Session Modification Response to the new SMF. At that time, the original UPF may forward the buffered data to the new UPF.

In step <NUM>, the new SMF transmits a Namf_Communication_N1N2MessageTransfer to the new AMF. The message should carry the N3 interface orientated data channel information allocated by the new UPF, but is not limited to these contents.

In step <NUM>, the new AMF transmits a N2 PDU Session Resource Setup Request to the new AN. The message should carry the N3 interface orientated data channel information allocated by the new UPF, but is not limited to these contents.

In step <NUM>, the new AN transmits a N2 PDU Session Resource Setup Response to the new AMF. The message should carry the N3 interface orientated data channel information allocated by the new AN, but is not limited to these contents.

In step <NUM>, the new AMF may transmit a Nsmf_PDUSession_ UpdateSMContext Request to the new SMF. The message should carry the N3 interface orientated data channel information allocated by the new AN, but is not limited to these contents.

In step <NUM>, the new SMF transmits the N4 Session Modification Request to the new UPF. The message should carry the N3 interface orientated data channel information allocated by the new AN, but is not limited to these contents.

In step <NUM>, the new UPF transmits the N4 Session Modification Response to the new SMF. At that time, the data buffered by the new UPF may be transmitted to the UE through the new AN.

In step <NUM>, the new SMF transmits the Nsmf_PDUSession_ UpdateSMContext Response to the new AMF.

In step <NUM>, after a predefined event occurs, the original AN may transmit a N2 UE Context Release Request to the original AMF. The predefined event may be completion of forwarding of the data buffered on the original AN by the original AN, or timeout of a predefined timer.

In step <NUM>, the original AMF may transmit a N2 UE Context Release Command to the original AN.

In step <NUM>, the original AN may transmit a N2 UE Context Release Complete to the original AMF.

In step <NUM>, the original AMF may transmit a Nsmf_PDUSession_ UpdateSMContext Request to the original SMF.

In step <NUM>, the original SMF transmits the N4 Session Modification Request to the original UPF.

In step <NUM>, the original UPF transmits the N4 Session Modification Response to the original SMF.

In step <NUM>, the original SMF transmits the Nsmf_PDUSession_ UpdateSMContext Response to the original AMF.

<FIG> schematically illustrates a block diagram of a device <NUM> according to an embodiment of the present disclosure. The device <NUM> comprises a processor <NUM>, for example, a Digital Signal Processor (DSP). The processor <NUM> may be a single apparatus or multiple apparatuses for performing different actions according to the embodiments of the present disclosure. The device <NUM> may further comprise an Input/Output (I/O) apparatus <NUM> configured to receive signals from other entities or transmit signals to other entities.

In addition, the device <NUM> comprises a memory <NUM> which may be in a form of nonvolatile or volatile memory, for example, an Electrically Erasable Programmable Read Only Memory (EEPROM), a flash memory, etc. The memory <NUM> has computer readable instructions stored thereon, which when executed by the processor <NUM>, cause the processor to perform the method according to the embodiments of the present disclosure.

The device illustrated in <FIG> may correspond to the device <NUM> illustrated in <FIG>. The transceiver <NUM> of the device <NUM> may comprise the Input/Output (I/O) apparatus <NUM> or perform the operations performed by the Input/Output (I/O) apparatus <NUM>. The processor <NUM> of the device <NUM> may comprise the processor <NUM> or perform the operations performed by the processor <NUM>. The memory <NUM> of the device <NUM> may comprise the memory <NUM> or perform the operations performed by the memory <NUM>.

<FIG> schematically illustrates a block diagram of a first node <NUM> according to an embodiment of the present disclosure.

The first nodes described above may correspond to the first node <NUM>. For example, the first nodex illustrated in <FIG> may correspond to the first node <NUM>.

Referring to the <FIG>, the first node <NUM> may include a processor <NUM>, a transceiver <NUM> and a memory <NUM>. However, all of the illustrated components are not essential. The first node <NUM> may be implemented by more or less components than those illustrated in <FIG>. In addition, the processor <NUM> and the transceiver <NUM> and the memory <NUM> may be implemented as a single chip according to another embodiment.

The processor <NUM> may include one or more processors or other processing devices that control the proposed function, process, and/or method. Operation of the first node <NUM> may be implemented by the processor <NUM>.

The processor <NUM> may detect a PDCCH on a configured control resource set. The processor <NUM> determines a method for dividing CBs and a method for rate matching of a PDSCH according to the PDCCH. The processor <NUM> may control the transceiver <NUM> to receive the PDSCH according to the PDCCH. The processor <NUM> may generate HARQ-ACK information according to the PDSCH. The processor <NUM> may control the transceiver <NUM> to transmit the HARQ-ACK information.

The memory <NUM> may store the control information or the data included in a signal obtained by the first node <NUM>. The memory <NUM> may be connected to the processor <NUM> and store at least one instruction or a protocol or a parameter for the proposed function, process, and/or method. The memory <NUM> may include read-only memory (ROM) and/or random access memory (RAM) and/or hard disk and/or CD-ROM and/or DVD and/or other storage devices.

<FIG> schematically illustrates a block diagram of a second node <NUM> according to an embodiment of the present disclosure.

The second nodes described above may correspond to the second node <NUM>. For example, the second node illustrated in <FIG> may correspond to the second node <NUM>.

Referring to the <FIG>, the second node <NUM> may include a processor <NUM>, a transceiver <NUM> and a memory <NUM>. However, all of the illustrated components are not essential. The second node <NUM> may be implemented by more or less components than those illustrated in <FIG>. In addition, the processor <NUM> and the transceiver <NUM> and the memory <NUM> may be implemented as a single chip according to another embodiment.

The processor <NUM> may include one or more processors or other processing devices that control the proposed function, process, and/or method. Operation of the second node <NUM> may be implemented by the processor <NUM>.

The memory <NUM> may store the control information or the data included in a signal obtained by the second node <NUM>. The memory <NUM> may be connected to the processor <NUM> and store at least one instruction or a protocol or a parameter for the proposed function, process, and/or method. The memory <NUM> may include read-only memory (ROM) and/or random access memory (RAM) and/or hard disk and/or CD-ROM and/or DVD and/or other storage devices.

<FIG> schematically illustrates a block diagram of a device <NUM> according to an embodiment of the present disclosure.

The devices or UEs described above may correspond to the device <NUM>. For example, the device illustrated in <FIG> may correspond to the device <NUM>.

Referring to the <FIG>, the device <NUM> may include a processor <NUM>, a transceiver <NUM> and a memory <NUM>. However, all of the illustrated components are not essential. The device <NUM> may be implemented by more or less components than those illustrated in <FIG>. In addition, the processor <NUM> and the transceiver <NUM> and the memory <NUM> may be implemented as a single chip according to another embodiment.

The processor <NUM> may include one or more processors or other processing devices that control the proposed function, process, and/or method. Operation of the device <NUM> may be implemented by the processor <NUM>.

The memory <NUM> may store the control information or the data included in a signal obtained by the device <NUM>. The memory <NUM> may be connected to the processor <NUM> and store at least one instruction or a protocol or a parameter for the proposed function, process, and/or method. The memory <NUM> may include read-only memory (ROM) and/or random access memory (RAM) and/or hard disk and/or CD-ROM and/or DVD and/or other storage devices. It can be understood by those skilled in the art that the methods described above are merely exemplary. The method according to the present disclosure is not limited to the steps and sequences described above. The device described above may comprise more modules, for example, may further comprise modules which have been developed or will be developed in the future for base stations or UEs, etc. Various identifications described above are merely exemplary and not restrictive, and the present disclosure is not limited to specific cells as examples of such identifications. Many variations and modifications can be made by those skilled in the art in light of the teachings of the illustrated embodiments.

It should be understood that the embodiments of the present disclosure described above may be implemented by software, hardware, or a combination thereof. For example, various components within the device in the embodiments described above may be implemented by various devices including, but not limited to, analog circuit devices, digital circuit devices, Digital Signal Processing (DSP) circuits, programmable processors, Application-Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), Programmable Logic Devices (CPLDs), etc..

In the present application, "base station" refers to a mobile communication data and control switching center having a large transmission power and a relatively large coverage area, which has functions such as resource allocation scheduling, data reception and transmission, etc. "User Equipment" refers to a user mobile terminal, for example, a terminal device which comprises a mobile phone, a notebook, etc., and may communicate wirelessly with a base station or a micro-base station.

Further, the embodiments of the present disclosure disclosed here may be implemented on a computer program product. More specifically, the computer program product is a product having a computer readable medium encoded with a computer program logic which, when executed on a computing device, provides related operations to implement the technical solutions of the present disclosure. When executed on at least one processor of a computing system, the computer program logic causes the processor to perform the operations (methods) described in the embodiments of the present disclosure. Such an arrangement according to the present disclosure is typically provided as software, codes and/or other data structures, disposed or encoded on a computer readable medium such as an optical medium (for example, CD-ROM), a floppy disk, or a hard disk etc., firmware or other media for micro-codes on one or more ROM or RAM or PROM chips, or downloadable software images, shared databases, etc. in one or more modules. The software or firmware or such a configuration may be installed on the computing device, so that one or more processors in the computing device perform the technical solutions described in the embodiments of the present disclosure.

Claim 1:
A method performed at a third network entity for transmitting data, comprising:
receiving, from a first network entity (<NUM>), a notification indicating that downlink data to be transmitted to a User Equipment, UE, (<NUM>) in a non-connected state is buffered on the first network entity (<NUM>); and
transmitting, to a second network entity (<NUM>), a message comprising an indication regarding a buffering of the downlink data by the first network entity (<NUM>,
wherein a paging procedure for the UE (<NUM>) is not initiated by the second network entity (<NUM>) based on the message, if the UE (<NUM>) is in the non-connected state, and
wherein:
the first network (<NUM>) entity is a User Plane Functional, UPF, entity,
the second network entity (<NUM>) is an Access Mobility management Functional, AMF, entity, and
the third network entity is a Session Management Functional, SMF, entity.