CN113973297B

CN113973297B - Small data transmission method, equipment, device and storage medium

Info

Publication number: CN113973297B
Application number: CN202010726005.8A
Authority: CN
Inventors: 傅婧; 梁靖; 曾二林; 陈瑞卡
Original assignee: Datang Mobile Communications Equipment Co Ltd
Current assignee: Datang Mobile Communications Equipment Co Ltd
Priority date: 2020-07-24
Filing date: 2020-07-24
Publication date: 2022-12-13
Anticipated expiration: 2040-07-24
Also published as: CN113973297A

Abstract

The invention discloses a small data transmission method, equipment, a device and a storage medium, wherein the small data transmission method comprises the following steps: when the user equipment in the non-connection state before entering the radio resource control connection state transmits the small data packet to the radio access network side, distinguishing a bearer type and/or a used key type corresponding to the small data packet to be transmitted currently; the small data packet is processed according to the bearer type and/or the key type used. And the wireless access network side node decrypts and verifies the integrity of the received small data packet according to the stored or obtained user equipment context. By adopting the method and the device, the processing of small data transmission under the multi-air-interface-double-connection scene is solved, and the applicable scene of small data transmission is expanded.

Description

Small data transmission method, equipment, device and storage medium

Technical Field

The present invention relates to the field of wireless communications technologies, and in particular, to a small data transmission method, device, apparatus, and storage medium.

Background

The NR (5G New air interface, new Radio) system designs 3 RRC (Radio Resource Control) states: an IDLE state (RRC _ IDLE), a CONNECTED state (RRC _ CONNECTED), and an INACTIVE state (RRC _ INACTIVE). When RRC connection exists between the terminal and the network, the terminal is in a connected state or an inactivated state, otherwise, the terminal is in an idle state. Fig. 1 is a diagram illustrating an RRC state transition model, and the RRC state transition is shown. At one time, the terminal can only be in one RRC state.

For small data transmission, currently, it is mainly studied that inactive UE (UE) can directly send small data to the network side before entering RRC connected state, so as to avoid that UE frequently enters RRC connected state, and reduce signaling overhead.

The prior art is not sufficient in that the current inactive state UE does not have a technical scheme for sending small data to the network side before entering the RRC connected state.

Disclosure of Invention

The invention provides a small data transmission method, equipment, a device and a storage medium, which are used for solving the problem that small data are not sent to a network side before an inactive state UE does not enter an RRC (radio resource control) connection state.

The invention provides the following technical scheme:

a small data transmission method, comprising:

when the non-connected UE which does not enter the RRC connected state transmits the small data packet to the RAN side, distinguishing a bearer type and/or a used key type corresponding to the small data packet to be transmitted currently;

the small data packet is processed according to the bearer type and/or the key type used.

In implementation, the non-connected UE does not transmit the small data packet to the RAN side in one or a combination of the following situations:

the corresponding bearing of the small data packet is SN terminated bearing;

the bearer corresponding to the small data packet is an SN terminated MCG bearer;

the bearer corresponding to the small data packet is an SN terminated SCG bearer;

the bearer corresponding to the small data packet is an MN terminated SCG bearer;

the bearer corresponding to the small data packet uses a secondary key;

the bearer corresponding to the small data packet uses the MCG bearer of the secondary key;

the bearer corresponding to the small data packet uses the SCG bearer of the secondary key;

the bearer corresponding to the small data packet uses a secondary key, but the secondary key is not updated;

the bearer corresponding to the small data packet is an SCG bearer;

the bearer corresponding to the small data packet is not an MN terminated MCG bearer;

the bearing corresponding to the small data packet does not use master key;

the bearing corresponding to the small data packet does not use a master key and is not MCG bearing;

the currently suspended configuration includes the MR-DC configuration therein;

the corresponding bearing of the small data packet is split bearing;

the corresponding load of the small data packet is split load, and the main path is SCG;

the bearer corresponding to the small data packet is a split bearer, and the bearer is an SN terminated bearer or a bearer using a secondary key;

the corresponding load of the small data packet is a split load, and the main path is MCG but uses a secondary key;

the corresponding bearer of the small data packet is a split bearer, and the main path is SCG but master key is used.

In implementation, the condition that the non-connected UE does not transmit the small data packet to the RAN side is configured by the network side.

In implementation, the UE side learns one or a combination of the following bearer configurations for transmitting small data packets:

configuring the SN terminated bearer for transmitting the small data packets corresponds to one or a combination of the following bearer configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

configuring the SN terminated MCG bearer for transmitting small data packets corresponding to one or a combination of the following bearer configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

configuring the SN terminated SCG bearer for transmitting small data packets corresponds to one or a combination of the following bearer configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

configuring the MN terminated SCG bearer for transmitting small data packets corresponding to one or a combination of the following bearer configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

configuring one or a combination of the following bearer configurations corresponding to the bearer of the second key for transmitting the small data packet: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration.

In implementation, the configuration is sent from the RAN side or the protocol is predefined.

In implementation, if the small data packet is not an MN terminated MCG bearer or not a bearer corresponding to a master key, and the UE determines, according to the obtained bearer configuration, that the DRB identifier and/or the corresponding bearer type corresponding to the small data packet are included in the bearer configuration, the non-connected UE transmits the small data packet to the RAN side; otherwise, the unconnected UE does not transmit the small data packet to the RAN side.

In implementation, the UE applies the configuration in the acquired bearer configuration corresponding to the to-be-transmitted small data packet.

In the implementation, the method further comprises one or the combination of the following processes:

the UE updates the second key based on the sk-Counter obtained from the network side and applies the updated second key to the SN terminated or small data packet corresponding to the second key transmitted to the RAN side; or the like, or a combination thereof,

the UE applies the updated master key and/or the encryption and integrity protection algorithm corresponding to the master key to the small data packet corresponding to the SN terminated or secondary key transmitted to the RAN side; or,

and the UE applies the old secondary key to all SN terminated or secondary key corresponding small data packets transmitted to the RAN side.

In an implementation, when the UE in a non-connected state transmits a small data packet to the RAN side, the UE further instructs the RAN side to obtain one or a combination of the following auxiliary information:

indicating whether the bearer is an SCG bearer or an MCG bearer;

indicating whether the bearer is an MN terminated bearer or an SN terminated bearer;

indicating that the bearer is a non-MN terminated MCG bearer;

indicating whether the bearer uses a master key or a secondary key;

indicating whether the bearer is a split bearer.

In implementation, under the condition of split bearing, when the unconnected UE transmits a small data packet to the RAN side, RLC bearing configuration corresponding to a main path is adopted; or,

and when the non-connected UE transmits the small data packet to the RAN side, the RLC bearer configuration corresponding to the same CG is adopted as the PDCP layer borne by the split.

A small data transmission method, comprising:

receiving a small data packet transmitted by non-connected UE before entering an RRC (radio resource control) connected state by a RAN (radio access network) side node;

and the RAN side node decrypts and verifies the integrity of the received small data packet according to the stored or obtained UE context.

In an implementation, the method further comprises the following steps:

and configuring the condition that the non-connected UE does not transmit the small data packet to the RAN side.

In implementation, the non-connected UE is configured not to transmit a small data packet to the RAN side in one or a combination of the following situations:

the corresponding bearing of the small data packet is SN terminated bearing;

the bearer corresponding to the small data packet uses a secondary key;

the bearer corresponding to the small data packet is an SCG bearer;

the bearing corresponding to the small data packet does not use a master key;

the current suspended configuration includes the MR-DC configuration;

the corresponding bearing of the small data packet is split bearing;

the corresponding load of the small data packet is split load, and the main path is MCG but uses secondary key;

In an implementation, the method further comprises the following steps:

the RAN side node sends configuration to the UE, and the UE in a non-connection state before the configuration enters the RRC connection state transmits a small data packet to the RAN side under one of the following conditions or the combination of the following conditions:

configuring the SN terminated bearer for transmitting the small data packet corresponds to one or a combination of the following configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

the SN terminated MCG configured for transmitting small data packets carries a corresponding one or combination of the following configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

the SN terminated SCG configured for transmitting small data packets carries a corresponding one or combination of the following configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

the MN terminated SCG configured for transmitting small data packets carries a corresponding one or combination of the following configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

In implementation, the RAN side node determines the bearer type or the corresponding key type corresponding to the received small data packet based on a configuration in the configuration sent by the RAN side node to the UE or a protocol predefined configuration.

In implementation, the RAN-side node determines, based on a configuration in the configuration sent by the RAN-side node to the UE, or a protocol predefined configuration, a DRB identifier corresponding to the received small data packet;

and the RAN side node determines corresponding configuration based on the identification of the small data packet, and decrypts and/or verifies the integrity of the small data packet according to the configuration.

In implementation, the RAN-side node is a current RAN-side serving node of the UE; or,

the RAN side node is a service main node before the UE enters a non-connection state; or,

the RAN side node is the serving SN node before the UE enters the unconnected state.

In an implementation, when the RAN-side node is a current RAN-side serving node of the UE, the method further includes:

and the current RAN side service node of the UE sends the received small data packet to a service main node before the UE enters a non-connection state or a service SN node before the UE enters the non-connection state.

In an implementation, when the RAN-side node is a serving master node before the UE enters the non-connected state, the method further includes:

and the service main node before the UE enters the non-connection state sends the received small data packet to the service SN node before the UE enters the non-connection state.

In implementation, the RAN-side node sends MAC PDUs or PDCP PDUs corresponding to small packets.

In an implementation, the RAN-side node receives UE-indicated one or a combination of the following assistance information:

indicating whether the bearer is an SCG bearer or an MCG bearer;

indicating that the bearer is a non-MN terminated MCG bearer;

indicating whether the bearer uses a master key or a secondary key;

indicating whether the bearer is a split bearer.

In an implementation, the method further comprises the following steps:

and the RAN side node determines the bearer type or the corresponding key type corresponding to the received small data packet based on the auxiliary information.

In an implementation, the method further comprises the following steps:

judging whether to attempt to decode the received small data packet or to forward the received small data packet to a corresponding node based on the bearing type of the small data packet or the corresponding key type; or, judging whether the UE context at the SN side needs to be obtained.

In implementation, the service master node before the UE enters the non-connected state determines whether to perform UE context relocation according to whether to store MR-DC configuration or a bearer type corresponding to a small data packet or a key type corresponding to small data.

A UE, comprising:

a processor for reading the program in the memory, performing the following processes:

when the UE in the non-connection state before entering the RRC connection state transmits the small data packet to the RAN side, distinguishing a bearer type and/or a used key type corresponding to the small data packet to be transmitted currently;

processing the small data packet according to the bearer type and/or the used key type;

a transceiver for receiving and transmitting data under the control of the processor.

the corresponding bearing of the small data packet is SN terminated bearing;

the bearer corresponding to the small data packet uses a secondary key;

the bearer corresponding to the small data packet is an SCG bearer;

the bearing corresponding to the small data packet does not use a master key;

the current suspended configuration includes the MR-DC configuration;

the corresponding bearing of the small data packet is split bearing;

In implementation, one or a combination of the following bearer configurations for transmitting small data packets is known:

configuring the SN terminated bearer for transmitting the small data packets corresponding to one or a combination of the following bearer configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

configuring the SN terminated SCG bearer for transmitting small data packets corresponding to one or a combination of the following bearer configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

configuring the MN terminated SCG bearer for transmitting small data packets corresponds to one or a combination of the following bearer configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

In implementation, if the small data packet is not the MN terminated MCG bearer or not the bearer corresponding to the master key, and the UE determines, according to the obtained bearer configuration, that the DRB identifier and/or the corresponding bearer type corresponding to the small data packet are included in the bearer configuration, the non-connected UE transmits the small data packet to the RAN side; otherwise, the unconnected UE does not transmit the small data packet to the RAN side.

In implementation, the configuration in the acquired bearer configuration corresponding to the small data package to be transmitted is applied to the small data package to be transmitted.

updating the second key based on the sk-Counter obtained from the network side, and applying the updated second key to the SN terminated or small data packet corresponding to the second key transmitted to the RAN side; or,

applying the updated master key and/or the encryption and integrity protection algorithm corresponding to the master key to a small data packet corresponding to the SN terminated or second key transmitted to the RAN side; or,

and applying the old secondary key to all small data packets corresponding to the SN terminated or secondary key transmitted to the RAN side.

In implementation, when the UE in a non-connected state transmits a small packet to the RAN side, the RAN side is further instructed to send one or a combination of the following auxiliary information:

indicating whether the bearer is an SCG bearer or an MCG bearer;

indicating that the bearer is a non-MN terminated MCG bearer;

indicating whether the bearer uses a master key or a secondary key;

indicating whether the bearer is a split bearer.

In implementation, when the unconnected UE transmits a small data packet to the RAN side under the split bearer condition, RLC bearer configuration corresponding to the main path is adopted; or,

A RAN-side node, comprising:

receiving a small data packet transmitted by a non-connected UE before entering an RRC connected state;

decrypting and integrity verifying the received small data packet according to the stored or obtained UE context;

In an implementation, the method further comprises the following steps:

the corresponding bearing of the small data packet is SN terminated bearing;

the bearer corresponding to the small data packet uses a secondary key;

the bearer corresponding to the small data packet is an SCG bearer;

the bearing corresponding to the small data packet does not use a master key;

the current suspended configuration includes the MR-DC configuration;

the corresponding bearing of the small data packet is split bearing;

the corresponding bearer for the small packet is a split bearer, and the main path is SCG but using master key.

In an implementation, the method further comprises the following steps:

sending configuration to the UE, and transmitting the small data packet to the RAN side by the UE in the non-connection state before the configuration enters the RRC connection state under one or a combination of the following conditions:

the MN terminated SCG configured for transmitting small data packets carries one or a combination of the following configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

In implementation, the RAN-side node determines the bearer type or the key type corresponding to the received small data packet based on a configuration in the configuration sent by the RAN-side node to the UE or a protocol predefined configuration.

and determining corresponding configuration based on the identification of the small data packet, and decrypting and/or verifying the integrity of the small data packet according to the configuration.

In implementation, the MAC PDU or PDCP PDU corresponding to the small data packet is sent.

In implementation, one or a combination of the following assistance information indicated by the UE is received:

indicating whether the bearer is an SCG bearer or an MCG bearer;

indicating that the bearer is a non-MN terminated MCG bearer;

indicating whether the bearer uses a master key or a secondary key;

indicating whether the bearer is a split bearer.

In an implementation, the method further comprises the following steps:

and determining the bearer type corresponding to the received small data packet or the key type corresponding to the small data packet based on the auxiliary information.

In an implementation, the method further comprises the following steps:

judging whether to attempt to decode the received small data packet or to forward the received small data packet to a corresponding node based on the bearing type or the corresponding key type of the small data packet; or, judging whether the UE context at the SN side needs to be obtained.

In implementation, the service master node before the UE enters the non-connected state determines whether to perform UE context relocation according to whether to store MR-DC configuration or a bearer type corresponding to a small data packet or a key type corresponding to a small data packet.

A small data transmission apparatus comprising:

the terminal distinguishing module is used for distinguishing the bearer type and/or the used key type corresponding to the current small data packet to be transmitted when the small data packet is transmitted to the RAN side by the non-connection state UE before the RRC connection state is entered;

and the terminal processing module is used for processing the small data packet according to the bearer type and/or the used key type.

A small data transmission apparatus comprising:

the RAN receiving module is used for receiving a small data packet transmitted by the UE in the non-connection state before the UE enters the RRC connection state;

and the RAN processing module is used for decrypting and verifying the integrity of the received small data packet according to the stored or obtained UE context.

A computer-readable storage medium storing a computer program for executing the above-described small data transmission method.

The invention has the following beneficial effects:

the technical scheme provided by the embodiment of the invention provides a small data transmission scheme under double link, and when the UE in a non-connection state before entering an RRC connection state transmits a small data packet to an RAN side, the bearing type and/or the used key type corresponding to the small data packet to be transmitted currently are distinguished, and the transmission is carried out according to the bearing type and/or the used key type; and for the RAN side, decrypting and integrity checking the received small data packet according to the stored or obtained UE context. Therefore, the scheme solves the processing of small data transmission in an MR-DC scene, and expands the applicable scene of small data transmission.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a diagram illustrating a state transition model of RRC in the background art;

fig. 2 is a schematic flow chart of an implementation of a small data transmission method on a UE side in an embodiment of the present invention;

fig. 3 is a schematic flow chart of an implementation of a small data transmission method on the RAN side in an embodiment of the present invention;

fig. 4 is a schematic view of an implementation flow of an inter-node process in embodiment 4 of the present invention;

fig. 5 is a schematic view of an implementation flow of an inter-node process in embodiment 5 of the present invention;

fig. 6 is a schematic view of an implementation flow of an inter-node process according to embodiment 6 of the present invention;

FIG. 7 is a diagram illustrating a UE structure according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a small data transmission apparatus on the UE side in an embodiment of the present invention;

fig. 9 is a schematic view of a RAN-side node structure according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a small data transmission apparatus on a RAN-side node according to an embodiment of the present invention.

Detailed Description

The inventor notices in the process of invention that:

for MR-DC (Multi-Radio Dual Connectivity), when a UE (User Equipment) is configured as MR-DC, the UE may simultaneously utilize resources of two nodes connected by a non-ideal link. In the current MR-DC definition, one node is a node providing NR Access, and the other node is a node providing E-UTRA (evolved Universal Radio Access Network) or NR Access.

MN terminated (terminated MN) bearer: under the MR-DC, the PDCP corresponding to the bearer is located in the MN (Master Node).

SN terminated (terminated at SN) bearer: under MR-DC, the PDCP corresponding to the bearer is located at SN (Secondary Node).

MCG (Master Cell Group) bearer: under the MR-DC, RLC (Radio Link Control) corresponding to the bearer is only located in the MCG.

SCG (Secondary Cell Group) bearer: under MR-DC, the RLC corresponding to the bearer is only located at SCG.

Split bearing: under MR-DC, the RLC corresponding to the bearer exists on the MCG side and the SCG side.

For small data transmission, inactive UE (UE in non-connected state) can directly send small data to the network side before entering RRC connected state, so that UE is prevented from frequently entering RRC connected state, and signaling overhead can be reduced. For example, the inactive UE (non-connected UE) may place the small data packet in the DTCH channel and send the small data packet to the network side together with the CCCH channel (including the RRC message), or the inactive UE (non-connected UE) directly sends the small data packet to the network side without establishing or recovering the RRC connection. At this time, the UE is still in the non-connected state when transmitting small data. This approach is described in the following description as "direct transfer of small packets".

If the direct small data transmission is allowed when the UE is in the RRC INACTIVE state (RRC _ INACTIVE), the UE is prevented from frequently entering the RRC connected state, and the signaling overhead can be reduced. However, at this time, the bearer corresponding to the small data to be sent may be an SN terminated bearer or an MN terminated SCG bearer, and at this time, how to process the small data is not currently provided with a corresponding scheme.

That is, if the UE suspends the MR-DC bearer at this time, the bearer corresponding to the small data to be sent may be an SN terminated bearer or an MN terminated SCG bearer, and how this is to be handled at this time, a corresponding scheme will be provided in this embodiment of the present invention.

The following describes embodiments of the present invention with reference to the drawings.

In the description process, the implementation of the UE and the RAN (Radio Access Network) side will be described separately, and then an example of the implementation of the UE and the RAN in cooperation with each other will be given to better understand the implementation of the scheme provided in the embodiment of the present invention. Such a description does not mean that the two must be implemented together or separately, and actually, when the UE and the RAN are implemented separately, the UE and the RAN respectively solve the problems at the UE side and the RAN side, and when the UE and the RAN are used in combination, a better technical effect is obtained.

Fig. 2 is a schematic flow chart of an implementation process of a small data transmission method on a UE side, as shown in the figure, the implementation process may include:

step 201, when the non-connected UE before entering the RRC connected state transmits a small data packet to the RAN side, distinguishing a bearer type and/or a key type used by the small data packet to be transmitted;

step 202, transmission is carried out according to the bearer type and/or the used key type.

Specifically, when the small data is directly transmitted by the non-connected UE in a small data mode, the bearer type and/or the key type corresponding to the small data packet to be currently transmitted are distinguished.

In implementation, the non-connected UE does not transmit the small data packet to the RAN side in one or a combination of the following situations: that is, the UE does not transmit the small packet in a "direct transmission small packet" manner if one or more of the following conditions are satisfied:

the corresponding bearing of the small data packet is SN terminated bearing;

the bearer corresponding to the small data packet uses a secondary key;

the load corresponding to the small data packet uses SCG load of secondary key;

the load corresponding to the small data packet is SCG load;

the bearing corresponding to the small data packet does not use master key;

the bearer corresponding to the small data packet does not use master key and is not MCG bearer;

the currently suspended configuration includes the MR-DC configuration therein;

the corresponding bearing of the small data packet is split bearing;

In an implementation, the case that the non-connected UE does not transmit the small data packet to the RAN side may be configured by the network side. That is, the UE side may not adopt the operation of "directly transmitting small data packets" based on the received configuration of the network side.

In implementation, the UE side learns one or a combination of the following bearer configurations for transmitting the small data packets, that is, the UE side learns the bearer configuration for "directly transmitting the small data packets" in advance, where the bearer configuration includes one or more of the following:

In an implementation, the configuration is sent by RAN side or protocol predefined, that is, the configuration may be sent by RAN side or protocol predefined.

In implementation, if the small data packet is not the MN terminated MCG bearer or not the bearer corresponding to the master key, and the UE determines, according to the obtained bearer configuration, that the DRB identifier and/or the corresponding bearer type corresponding to the small data packet are included in the bearer configuration, the non-connected UE transmits the small data packet to the RAN side; otherwise, the unconnected-state UE does not transmit the small data packet to the RAN side, that is, if the small data packet is not an MN-terminated MCG bearer or is not a bearer corresponding to a master key, and the UE determines, according to the configuration in the configuration, that the DRB identifier and/or the corresponding bearer type corresponding to the small data packet are included in the configuration, the UE transmits the small data packet in a "directly transmit small data packet" manner; otherwise, the UE does not adopt the mode of directly transmitting the small data packet to send the small data packet.

In implementation, the UE applies the known configuration in the bearer configuration corresponding to the to-be-transmitted small data packet, that is, the UE applies the configuration in the above configuration corresponding to the to-be-transmitted small data packet.

the UE updates the second key based on the sk-Counter obtained from the network side before, and applies the updated second key to the SN terminated or the small data packet corresponding to the second key transmitted to the RAN side; that is, the UE updates the second key based on the sk-Counter obtained from the network side, and applies the updated second key to the SN terminated or the small packet corresponding to the second key when the mode of directly transmitting the small packet is adopted;

the UE applies the updated master key and/or the encryption and integrity protection algorithm corresponding to the master key to the small data packet corresponding to the SN terminated or secondary key transmitted to the RAN side; that is, the UE applies the updated master key and/or the encryption and integrity protection algorithm corresponding to the master key to all the small data packets corresponding to the SN terminated or second key when the "direct transmission small data packet" mode is adopted;

the UE applies the old secondary key to all the SN terminated or small packets corresponding to the secondary key when transmitting to the RAN side, that is, the UE applies the old secondary key to all the SN terminated or small packets corresponding to the secondary key when adopting the "direct transmission small packets" mode.

In implementation, when the UE in the non-connected state transmits a small data packet to the RAN side, the UE further indicates one or a combination of the following auxiliary information at the RAN side, that is, when the UE transmits a small data packet in a "direct transmission small data packet" manner, the UE further indicates one or more of the following information:

indicating whether the bearer is an SCG bearer or an MCG bearer;

indicating that the bearer is a non-MN terminated MCG bearer;

indicating whether the bearer uses a master key or a secondary key;

indicating whether the bearer is a split bearer.

Specifically, for the case of a plit bearer, when the UE side sends small data, the following operation is performed:

adopting RLC bearing configuration corresponding to the main path;

and adopting the RLC bearing configuration corresponding to the same CG as the PDCP layer borne by the split.

Fig. 3 is a schematic flow chart of an implementation of a small data transmission method on the RAN side, as shown in the figure, the implementation may include:

301, receiving, by a RAN-side node, a small data packet transmitted by a non-connected UE before entering an RRC connected state;

step 302, the RAN-side node decrypts and integrity-verifies the received small data packet according to the stored or obtained UE context.

Specifically, the RAN side node decrypts and integrity-verifies the received small packet according to the stored or obtained UE context.

In an implementation, the method further comprises the following steps:

the bearer corresponding to the small data packet is an SN terminated bearer;

the bearer corresponding to the small data packet uses a secondary key;

the bearer corresponding to the small data packet is an SCG bearer;

the bearing corresponding to the small data packet does not use a master key;

the current suspended configuration includes the MR-DC configuration;

the corresponding bearing of the small data packet is split bearing;

In an implementation, the method further comprises the following steps:

the RAN side node sends a configuration to the UE, and the UE in a non-connected state before the configuration enters the RRC connected state transmits a small data packet to the RAN side when one of the following conditions or a combination thereof is configured, that is, the RAN side node sends the configuration to the UE, and the configuration is used for bearer configuration of "directly transmitting a small data packet", and includes one or more of the following conditions:

That is, the RAN-side node sends the configuration to the UE, and configures the UE in which case it may use the "direct transmission of small data packets".

That is, the RAN-side node determines the corresponding configuration (including RLC configuration, PDCP configuration, SDAP configuration, corresponding UPF address, etc.) based on the identifier of the small data packet, and decrypts and/or verifies the integrity of the small data packet according to the configuration.

That is, the RAN-side node may be: and the current RAN side service node is a service main node before the UE enters a non-connection state, or a service SN node before the UE enters the non-connection state.

In an implementation, when the RAN-side node is a current RAN-side serving node of the UE, the method further includes: and the current RAN side service node of the UE sends the received small data packet to a service main node before the UE enters a non-connection state or a service SN node before the UE enters the non-connection state. That is, the current RAN-side service node sends the received small data packet to the service master node before the UE enters the non-connected state or the service SN node before the UE enters the non-connected state.

and the service main node before the UE enters the non-connection state sends the received small data packet to the service SN node before the UE enters the non-connection state. That is, the serving primary node before the UE enters the unconnected state sends the received small packet to the serving SN node before the UE enters the unconnected state.

In implementation, the RAN-side node sends MAC PDUs or PDCP PDUs corresponding to small packets. That is, the MAC (Media Access Control) PDU (Protocol Data Unit) or PDCP (Packet Data Convergence Protocol) PDU corresponding to the forwarded small Packet.

In an implementation, the RAN-side node receives one or a combination of the following assistance information indicated by the UE, that is, the RAN-side node receives the assistance information, which includes one or more of the following information:

indicating whether the bearer is an SCG bearer or an MCG bearer;

indicating that the bearer is a non-MN terminated MCG bearer;

indicating whether the bearer uses a master key or a secondary key;

indicating whether the bearer is a split bearer.

In the implementation, the method can further comprise the following steps:

the RAN side node judges whether to try to decode the received small data packet or to forward the received small data packet to a corresponding node based on the auxiliary information; or,

the RAN side node judges whether UE context of the SN side needs to be obtained or not based on the auxiliary information;

That is, the RAN-side node may determine whether to attempt to decode the received small data packet or to forward the received small data packet to the corresponding node based on the auxiliary information; or may determine whether the UE context on the SN side needs to be obtained.

In an implementation, the serving master node before the UE enters the non-connected state may determine whether to perform UE context relocation (reconfiguration) according to whether to store the MR-DC configuration or the bearer type corresponding to the small data packet or the corresponding key type.

The following is an example.

Example 1:

in this example, for some bearers, the non-connected UE does not use "direct transmission of small packets".

The unconnected state may be an RRC inactive state or an RRC idle state, and is not limited herein.

1. The non-connected UE has a small data packet to be transmitted. When the UE needs to determine whether to transmit the small data packet by using the "direct transmission small data packet" method, if one or more of the following conditions are satisfied, the UE does not transmit the small data packet by using the "direct transmission small data packet" method:

the corresponding bearing of the small data packet is SN terminated bearing;

the bearer corresponding to the small data packet uses a secondary key;

the bearer corresponding to the small data packet is an SCG bearer;

the bearing corresponding to the small data packet does not use a master key;

the current suspended configuration includes the MR-DC configuration;

the corresponding load of the small data packet is split load;

Optionally, the UE does not transmit the small data packet in a "direct transmission small data packet" manner, and is configured based on the network side, where the network side may configure:

whether the SN terminated bearer is allowed to be sent in a mode of directly transmitting small data packets;

whether the SN terminated MCG bearer is allowed to be sent in a mode of directly transmitting small data packets;

whether the SN terminated SCG bearing is allowed to be sent in a mode of directly transmitting small data packets;

whether the MN terminated SCG bearer is allowed to be sent in a mode of directly transmitting small data packets;

whether the bearer corresponding to the secondary key is allowed to be sent and used in a mode of directly transmitting small data packets;

whether the MCG bearing using the secondary key is allowed to be sent in a mode of directly transmitting small data packets;

whether the SCG bearer using the secondary key is allowed to be sent in a mode of directly transmitting small data packets;

whether the bearer corresponding to the updated second key is allowed to be sent in a mode of directly transmitting small data packets;

whether the SCG bearer is allowed to be sent in a mode of directly transmitting small data packets;

whether the data which is not borne by the MN terminated MCG is allowed to be sent in a mode of directly transmitting small data packets;

whether the mode of directly transmitting small data packets is allowed to be adopted for sending the bearer which does not use the master key or not is allowed;

whether the data which does not use the master key and is not borne by the MCG is allowed to be sent in a mode of directly transmitting small data packets;

if the current suspended configuration is the MR-DC configuration, whether a mode of directly transmitting small data packets is allowed;

whether the split bearer is allowed to be sent in a mode of directly transmitting small data packets or not;

whether the transmission is allowed to be carried by split bearing in a mode of directly transmitting small data packets or not, and the main path is carried by SCG;

whether the mode of directly transmitting small data packets is allowed to be adopted to send the small data packets as SN terminated bearing or split bearing using secondary key;

whether to allow the mode of directly transmitting the small data packet to transmit the main path as MCG but using the split bearer of the secondary key;

whether the mode of directly transmitting small data packets is allowed to be adopted to send the SCG as the main path but the split bearer of the master key is used.

Example 2:

in this example, the non-connected UE sends the SN terminated MCG bearer in a "direct packet transfer" manner.

The implementation can be divided into the case of using a new key and the case of using a previous old key when the mode of directly transmitting small data packets is adopted.

Example 2-1:

and a new key is used when a mode of directly transmitting small data packets is adopted.

In this case, the new key is used, and the method is divided into two modes, namely, the updated secondary key and the updated master key.

Example 2-1a:

the updated second key is used.

1. When the network side lets the UE enter RRC inactive, besides configuring NCC (Next hop chain Counter) for updating KgNB key (gNB root key) for the UE, providing sk-Counter (Secondary key Counter) for the UE to subsequently update secondary key;

2. the UE enters an RRC inactive state.

3. And the UE determines to adopt a mode of directly transmitting the small data packet to transmit the small data to be transmitted.

The UE updates the KgNB key by using the NCC obtained before; further, according to the previously obtained sk-Counter, an updated second key is obtained, and a KUPenc key (key for data encryption) and a kuplint key (key for data integrity protection) associated with the second key are further derived.

And if the UE finds that the small data packet to be transmitted is an SN terminated MCG bearer, the UE uses a KUPenc key and a KUPint key related to the second key to carry out encryption and integrity protection.

The UE sends the small data packet to be transmitted on a first UL-SCH (uplink Shared Channel) transport Channel (which may also include other messages, such as an RRC recovery message).

4. The RAN side receives the small data packet and optionally other information. And the RAN side finds the UE context according to other information and verifies the UE context. After the verification is passed, the RAN side node updates the KgNB key and the secondary key according to the UE context. And decrypts and/or verifies the integrity of the received small Data packet according to the context information of the UE (e.g., DRB id (DRB identifier; DRB: data Radio Bearer), encryption algorithm and integrity protection algorithm corresponding to the second key, etc. corresponding to the small Data packet. See examples 4, 5, and 6 for processes involving inter-node context fetch and data forwarding.

The RAN side sends the small data after decryption and integrity check (if any) to the corresponding UPF (User Plane Function).

Examples 2 to 1b

In this example, an updated master key is used.

1. When the network side lets the UE enter RRC inactive, NCC (for updating KgNB key) is configured.

2. The UE enters an RRC inactive state.

The UE updates the KgNB key by using the NCC obtained before; and further derives a KUPenc key (key for data encryption use) and a kuplint key (key for data integrity protection use) associated with the master key.

The UE finds that the small data packet to be transmitted is the SN terminated MCG bearer, but the UE wants to send the small data to be transmitted by adopting a mode of directly transmitting the small data packet, and the UE side automatically changes the key corresponding to the SN terminated MCG bearer into a master key; optionally, the corresponding security algorithm (including encryption algorithm/integrity protection algorithm) is also automatically updated to the algorithm corresponding to the master key.

The UE encrypts and integrity protects the small data packet using the KUPenc key and kuplint key associated with the master key.

The UE sends the small data packet to be transmitted on the first UL-SCH transmission channel (which may also include other messages, such as RRC recovery messages).

4. The RAN side receives the small data packet and optionally other information. And the RAN side finds the UE context according to other information and verifies the UE context. And after the verification is passed, the RAN side node updates the KgNB key according to the UE context. And according to the UE context information (such as the DRB id corresponding to the small data packet, the encryption algorithm and integrity protection algorithm corresponding to the master key, etc.), the received small data packet is decrypted and/or integrity verified. See examples 4, 5, and 6 when referring to inter-node context fetch and data forwarding processes.

And the RAN side sends the small data after decryption and/or integrity verification (if any) to the corresponding UPF.

Example 2-2:

this example is a scenario where old key is used when the "direct transmission of small data packets" mode is adopted.

The network side makes the UE enter an RRC unconnected state (which may be an RRC inactive state or an RRC idle);

the UE enters a corresponding RRC non-connected state;

and the UE determines to adopt a mode of directly transmitting the small data packet to transmit the small data to be transmitted.

And if the UE finds that the small data packet to be transmitted is carried by the SN terminated MCG, the UE uses the KUPENC key and the KUPINT key related to the second key to carry out encryption and integrity protection. (in implementation, the key here is the key before entering into the RRC unconnected state).

The UE sends the small data packet to be transmitted on the first UL-SCH transmission channel (which may also include other information, such as UE identity).

4. The RAN side receives the small data packet and optionally other information. And the RAN side finds the context of the UE according to other information and decrypts and/or protects the integrity of the received small data packet according to the context information of the UE. (in implementation, after receiving a small data packet sent by the UE, the current serving cell on the RAN side needs to forward the small data packet to the SN node before the UE enters the non-connected state according to the UE context.

After decryption and/or integrity protection (if any) is successful, the SN sends the small data packet to the corresponding UPF.

Example 3:

in this example, the non-connected UE sends the bearer corresponding to the secondary key, or an SN terminated SCG bearer, or an MN terminated SCG bearer, or a split bearer in a "direct packet transmission" manner.

Similar to embodiment 2, when the bearer corresponding to the small data packet to be transmitted is a bearer corresponding to the secondary key or an SN terminated SCG bearer, the case of using the new key and the case of using the old key can be also divided. And the use of a new key is divided into two sub-cases of using an updated secondary key and an updated master key. However, the difference from the embodiment 2 is that when the UE sends the small data packet in the "direct transmission small data packet" manner, the UE further indicates one or more of the following information:

indicating whether the bearer is an SCG bearer or an MCG bearer;

indicating that the bearer is a non-MN terminated MCG bearer;

indicating whether the bearer uses a master key or a secondary key;

indicating whether the bearer is a split bearer;

how to carry and send the indication information to the RAN-side node is not limited.

Optionally, under the split bearer, when the UE side sends small data, one of the following operations is performed:

using RLC bearer configuration corresponding to the main path (for example, if the split bearer main path is a path whose LCID (Logical Channel identifier) under SCG is 3, when the UE side sends small data, the RLC bearer configuration is the configuration corresponding to LCID under SCG being 3); or,

and adopting RLC bearer configuration corresponding to the same CG (Cell Group) as the PDCP layer carried by the split (for example, if the PDCP layer carried by the split is in SCG, the main path carried by the split is a path with LCID of 2 under MCG, and the other path is a path with LCID of 3 under SCG, then when the UE sends small data, adopting configuration corresponding to the path with LCID of 3 under SCG).

The RAN side node finds the UE context, determines the type of the bearer or the key corresponding to the bearer according to the received small data packet and by combining the received auxiliary information, executes related inter-node operation, and decrypts and/or integrally verifies the small data packet. And after the decryption and/or the integrity verification are successful, sending the small data packet to the corresponding UPF.

Example 4

In this example, an embodiment of an inter-node procedure is described, and in the example, a serving master node before entering an inactive state is the same as a serving node when sending a small packet.

Because the service master node before entering the inactive state is the same node as the service node when sending the small data packet, the UE context acquisition process is not needed. Fig. 4 is a schematic flowchart of an implementation process of the inter-node process in embodiment 4, and as shown in the figure, the following may be implemented:

1. the RAN side service node receives the small data packet sent by the UE and optional other information. The RAN side node determines that the serving master node before entering the inactive state is the same node as the serving node when sending the small data packet according to other information received from the UE (this determination may continue with the existing process), and finds the stored UE context according to other information.

2. The RAN side service node executes the following steps:

mode 1: based on the stored UE context and the LCID corresponding to the small data packet, the RAN-side serving node finds the DRB id corresponding to the small data packet (for example, the LCID corresponding to the small data packet is 5, and the stored UE context has information such as the DRB id and the LCID corresponding to the DRB, and based on this, the RAN-side node may determine that the DRB id with the LCID of 5 is 3), and tries to decrypt and/or integrity check the received small data packet (at this time, the security key (key) and algorithm used in the decryption and/or integrity check process are consistent with the UE side, that is, if the UE side uses the update key, the RAN-side also uses the update key when decrypting and/or integrity check, and if the UE-side uses the old key to perform integrity protection and encryption on the small data packet, the RAN-side also uses the old key when decrypting and/or verifying);

optionally, in this process, the RAN-side serving node may request a previous service SN of the UE to obtain a UE context stored by the previous service SN, so as to obtain a DRB id corresponding to the small data packet (for example, knowing that a DRB id with an LCID of 5 is 3 according to the UE context stored by the previous service SN);

optionally, in this process, the RAN-side service node attempts to decrypt and/or integrity check the small data packet by using a secondary key in addition to attempting to decrypt and/or integrity check the small data packet by using a master key;

optionally, if the RAN-side serving node cannot successfully decrypt and/or integrity check the small data packet, the RAN-side serving node forwards data including the small data packet to a serving SN node before the UE, where the forwarded data may be a MAC PDU or PDCP PDU corresponding to the small data packet. Upon receipt, the service SN attempts to decrypt and/or integrity validate the small data packet, depending on the stored UE context.

Mode 2: the RAN side service node determines how to process the received small data according to the bearer type or the corresponding key corresponding to the received small data packet, including:

if the bearer is the MN terminated bearer or the bearer corresponding to the master key, the RAN-side serving node attempts to decrypt and/or integrity check the received small data packet according to the stored UE context. Optionally, in this process, the RAN-side service node may request, from the previous service SN of the UE, the UE context stored in the previous service SN, so as to obtain the DRB id corresponding to the small data packet (for example, when knowing that the LCID carried by the MN terminated SCG is 5, the corresponding DRB id is 3 according to the UE context stored in the previous service SN);

if the bearer is an SN terminated bearer or a bearer corresponding to a secondary key, the RAN-side serving node forwards data including the small data packet to a serving SN node before the UE, where the forwarded data may be a MAC PDU or PDCP PDU corresponding to the small data packet. After the previous service SN receives it, it tries to decrypt and/or integrity check the small data packet according to the stored UE context (SN may determine the relation between LCID and DRB id, determine the key used, security algorithm, etc. in combination with its own stored UE context). Optionally, the RAN-side service node sends the configuration corresponding to the SN terminated MCG bearer to the previous service SN, and the SN may determine the relationship between the LCID and the DRB id borne by the SN terminated MCG by combining the UE context stored in the SN terminated MCG and the configuration corresponding to the SN terminated MCG bearer, so as to determine the bearer identifier corresponding to the received small data packet (when the small data packet is decrypted and/or integrity-verified, the bearer identifier is an input).

After decryption and/or integrity verification is successful, the MN or SN sends the small data packet to the corresponding UPF.

If decryption and/or integrity verification is unsuccessful, one or more of the following processes may be performed:

the RAN-side serving node may inform the UE that the current small packet decryption and/or integrity validation was not successful.

RAN side services may send RRC connection setup messages to the UE;

the UE may retransmit the small data packet based on this feedback; or the UE initiates a normal RRC establishment or RRC recovery process (not carrying the small data to be transmitted) based on the feedback and converts to the RRC connection state.

Example 5

In this example, an implementation of an inter-node process is described, in the example, a serving node before entering an inactive state and a serving node when sending a small data packet are not the same node, and UE context relocation needs to be performed), fig. 5 is a schematic flowchart of an implementation of the inter-node process in embodiment 5, and as shown in the figure, the following may be performed:

1. the RAN side service node receives the small data packet sent by the UE and optional other information. The RAN side node determines that a service master node before the UE enters the inactive state is not the same as a service node when the small data packet is sent according to other information received from the UE (the judgment can continue the existing process), and the RAN side service node sends a request for obtaining the UE context to the service master node before the UE enters the inactive state; optionally, the RAN-side service node forwards the bearer type corresponding to the small data packet to the service master node before the UE enters the inactive state;

2. before the UE enters an inactive state, a service master node finds the context of the UE, verifies that the UE is legal (existing process), and provides the stored UE context for a RAN side service node; optionally, in this process, the node may request the UE from the previous service SN to obtain the UE context stored by the previous service SN;

3. based on the received UE context, the RAN-side serving node optionally finds, in combination with the bearer type or key type auxiliary information reported by the UE and the LCID corresponding to the small data packet, information such as the DRB id corresponding to the received small data packet, and a used security algorithm. The RAN-side serving node attempts to decrypt and/or integrity validate the received small data packet. At this time, the security key and algorithm used in the decryption and/or integrity validation process are consistent with those of the UE side, that is, if the UE side uses the updated master key, the RAN side also uses the updated master key in the decryption and/or integrity validation, and if the UE side uses the old second key to perform integrity protection and encryption on the small data packet, the RAN side also uses the old second key in the decryption and/or integrity validation.

4. The RAN side service node performs a path switch procedure with the AMF (existing procedures may be adopted).

5. And if the decryption and/or the integrity verification are successful, the RAN side node sends the small data packet to the corresponding UPF.

If decryption and/or integrity verification is unsuccessful, the subsequent procedure is similar to that in example 4.

In step 2, the service master node before the UE enters the inactive state may determine whether to perform UE context relocation according to whether to store MR-DC configuration or a bearer type corresponding to the small data packet or a key type (master key or secondary key) corresponding to the small data packet. For example, if the service master node before the UE enters the inactive state finds that the MR-DC configuration related to the UE is stored, the UE context relocation procedure and the steps related to embodiment 5 are executed; in other cases, it is possible to choose to perform the relevant steps after step 2 in example 6. Or the service master node before the UE enters the inactive state finds that the bearer corresponding to the small data packet is a non-MCG terminated MCG bearer or a bearer using a non-master key, then the relevant steps after step 2 in embodiment 5 are executed.

Example 6

In this example, an embodiment of an inter-node procedure is described, in which a serving node before entering an inactive state is not the same node as a serving node when sending a small packet, but does not perform UE context relocation. Fig. 6 is a schematic flowchart of an implementation procedure between nodes in embodiment 6, and as shown in the figure, the following may be implemented:

1. the RAN side service node receives the small data packet sent by the UE and optional other information. The RAN side node determines that a service master node before the UE enters the inactive state is not the same as a service node when the small data packet is sent according to other information received from the UE (the judgment can continue the existing process), and the RAN side service node sends a request for obtaining the UE context to the service master node before the UE enters the inactive state; meanwhile, the data including the small data packet is forwarded to the service master node before the UE enters the inactive state, where the forwarded data may be a MAC PDU or PDCP PDU corresponding to the small data packet (if the data is a PDCP PDU, the RAN-side service node may optionally send an LCID corresponding to the small data packet).

2. A service master node (denoted as RAN node 2) before the UE enters the inactive state finds the context of the UE, and after verifying that the UE is a valid UE (which can be processed according to the existing process), performs a certain step as follows:

1) The RAN node 2 finds the DRB id corresponding to the small data according to the stored UE context and the LCID corresponding to the small data packet (for example, the LCID corresponding to the small data packet is 5, and the stored UE context has information such as the DRB id and the LCID corresponding to the DRB, based on which, the RAN node 2 may determine that the DRB id with the LCID of 5 is 3), try to decrypt and/or integrity check the received small data packet (at this time, the security key (key) and algorithm used in the decryption and/or integrity check process are consistent with the UE side, that is, if the UE side uses the update key, the RAN side also uses the update key during decryption and/or integrity check, if the UE side uses the old key to perform integrity protection and encryption on the small data packet, the RAN side also uses the old key during decryption and/or integrity check);

optionally, in this process, RAN node 2 may initiate a request to a previous service SN (denoted as RAN node 3) of the UE, and obtain a UE context stored by the previous service SN, so as to obtain a DRB id corresponding to the small data packet (for example, according to the UE context stored by the previous service SN, it is known that the DRB id with LCID 5 is 3);

optionally, in this process, the RAN node 2 attempts to decrypt and/or integrity-check the small packet using the secondary key in addition to attempting to decrypt and/or integrity-check the small packet using the master key;

optionally, if the RAN node 2 cannot successfully decrypt and/or integrity check the small data packet, the RAN node 2 forwards the data including the small data packet to the serving SN node (RAN node 3) before the UE, where the forwarded data may be a MAC PDU or PDCP PDU corresponding to the small data packet. Upon receipt, the serving SN (RAN node 3) attempts to decrypt and/or integrity validate the small data packet, depending on the stored UE context.

2) The RAN node 2 determines how to process the received small data according to the bearer type or the key type corresponding to the received small data packet, including:

in case of MN terminated bearers or bearers using master key, the RAN node 2 tries to decrypt and/or integrity check the received small data packets according to the stored UE context. Optionally, in this process, RAN node 2 may request from a previous service SN (RAN node 3) of the UE to obtain a UE context stored by the previous service SN, so as to obtain a DRB id corresponding to the small data packet (for example, when knowing that LCID carried by MN terminated SCG is 5, its corresponding DRB id is 3 according to the UE context stored by the previous service SN);

in case of SN terminated bearer or bearer not using master key, RAN node 2 forwards the data comprising the small data packet to the serving SN node (RAN node 3) before the UE, where the forwarded data may be MAC PDU or PDCP PDU corresponding to the small data packet. After receiving the packet, RAN node 3 attempts to decrypt and/or integrity check the small data packet according to the stored UE context (SN may determine the relationship between LCID and DRB id, determine the key used, security algorithm, etc. in combination with the UE context stored by itself). Optionally, the RAN node 2 sends the configuration corresponding to the SN terminated MCG bearer to the previous serving SN (RAN node 3), and the SN may determine the relationship between the LCID and the DRB id borne by the SN terminated MCG in combination with the UE context stored by itself and the configuration corresponding to the SN terminated MCG bearer, so as to determine the bearer identifier corresponding to the received small data packet (when the small data packet is decrypted and/or integrity-verified, the bearer identifier is an input).

After decryption and/or integrity verification is successful, the RAN node 2 or the RAN node 3 sends the small data packet to the corresponding UPF.

the RAN-side serving node or RAN node 2 may inform the UE that the current small packet decryption and/or integrity validation was not successful.

RAN node 2 informs RAN side service node that UE context acquisition fails; the RAN side service node informs the UE of the failure;

RAN node 2 informs RAN side service node that UE context acquisition fails; RAN side services may send RRC connection setup messages to the UE;

the UE may retransmit the small data packet based on the feedback; or the UE initiates a normal RRC establishment or RRC recovery process (not carrying the small data to be transmitted) based on the feedback and converts to the RRC connection state.

Example 7

In this example, the network side configures bearer configuration for "direct transmission of small packets".

1: when the UE is configured as MR-DC, the bearer configuration configured on the network side for "directly transmitting small data packets" may include one or more of the following:

the SN terminated bearer configured for "direct transmission of small data packets" corresponds to one or a combination of the following configurations: DRB (Data Radio Bearer) identifier, LCID, RLC configuration, PDCP configuration, and SDAP (Service Data attachment Protocol) configuration; for example, configuring SN terminated bearer of "directly transmitting small data packet" with corresponding DRB identifier =3, LCID =3, RLC configuration, PDCP configuration, and SDAP configuration;

the SN terminated MCG configured for "direct transmission of small data packets" carries a corresponding one or combination of the following configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration; for example, SN terminated MCG configured to directly transmit small data packets "carries corresponding DRB identifier =4, LCID =4, RLC configuration, PDCP configuration, and SDAP configuration;

the SN terminated SCG configured for "direct transmission of small data packets" carries one or a combination of the following configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration; for example, configuring SN terminated SCG of "direct transmission small data packet" to carry corresponding DRB identifier =4, LCID =4, RLC configuration, PDCP configuration, and SDAP configuration;

the MN terminated SCG configured for "direct transmission of small data packets" carries one or a combination of the corresponding following configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration; for example, the MN terminated SCG configured with "directly transmitting small data packet" carries corresponding DRB identifier =5, LCID =5, RLC configuration, PDCP configuration, and SDAP configuration;

configuring one or a combination of the following bearer configurations corresponding to the bearer of the second key for transmitting the small data packet: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration; for example, MN terminated SCG configured with "directly transmitting small data packet" carries corresponding DRB identification =6, LCID =8, RLC configuration, PDCP configuration, and SDAP configuration.

In implementation, the configuration may be sent to the UE by the MN or the SN, and in addition, the network-side node MN and the SN may need to interact with the configuration sent to the UE. The network node also stores the configuration information as part of the UE context.

2: when the unconnected state UE directly transmits small data in a small data mode, if the small data packet is not an MN terminated MCG bearer or not a bearer corresponding to a master key, the UE determines that the configuration comprises a DRB identifier and/or a corresponding bearer type corresponding to the small data packet according to the configuration in received 1, the UE transmits the small data packet in a mode of directly transmitting the small data packet, and applies the configuration of the DRB identifier received in 1 to the small data packet; otherwise, the UE does not adopt the mode of directly transmitting the small data packet to send the small data packet.

In addition, what key is used when the small data packet is transmitted by adopting the mode of directly transmitting the small data packet can be according to the configuration in 1, or:

1) When the small data packet corresponds to an SN terminated bearer, using one of the updated secondary key, updated master key, or old secondary key in embodiment 2;

2) When the small data packet corresponds to the MN terminated bearer, the updated master key or old master key is used.

3: the RAN side receives the data packet sent in a mode of directly transmitting small data packets.

The following cases can be specifically classified:

the first condition is as follows: when the serving master node before entering the inactive state is the same node as the serving node when sending the small data packet (it is determined as in the foregoing embodiment), the RAN-side serving node determines the bearer type or the key type or the DRB identifier corresponding to the small data packet according to the stored UE context and the LCID corresponding to the small data packet (for example, when the RAN-side node receives the small data packet with LCID =3, it knows that the corresponding bearer type is an SN terminated bearer according to the stored information (including the configuration information sent to the UE in step 1), or uses a secondary key or the DRB identifier = 3).

The RAN-side serving node determines how to process the received small data according to the bearer type, which may specifically refer to mode 2 in embodiment 4;

the RAN side service node determines corresponding configuration (including RLC configuration, PDCP configuration, SDAP configuration, corresponding UPF address and the like) according to the DRB identifier, and decrypts and/or verifies the integrity of the small data packet according to the configuration;

case two: the service master node before entering the inactive state is not the same node as the service node when sending the small data packet, and needs to perform UE context relocation, and the RAN side service node determines the bearing type or key type or DRB identifier corresponding to the small data packet, the used safety algorithm and other information based on the received UE context and the LCID corresponding to the small data packet. The RAN side service node attempts to decrypt and/or integrity verify the received small data packet. See step 3 in example 5;

case three: the service master node before the inactive state is not the same as the service node when the small data packet is sent, but when the UE context relocation is not carried out, the RAN side service node sends a request for obtaining the UE context to the service master node before the inactive state is entered by the UE; meanwhile, the data including the small data packet is forwarded to the service master node before the UE enters the inactive state, where the forwarded data may be a MAC PDU or a PDCP PDU corresponding to the small data packet (if the data is a PDCP PDU, the RAN-side service node may optionally send an LCID corresponding to the small data packet). And a service main node (RAN node 2) before the UE enters an inactive state finds out the UE context, and determines the bearing type or the key type or the DRB identifier corresponding to the small data packet according to the stored UE context and the LCID corresponding to the small data packet.

The RAN node 2 determines how to process the received small data according to the bearer type or the key type corresponding to the received small data packet, which may specifically refer to 2 in embodiment 6);

after decryption and/or integrity verification is successful, the RAN node 2 or the RAN node 3 sends the small data packet to the corresponding UPF. If the decryption and/or integrity verification is not successful, the execution can be similar to the above embodiments 4, 5 and 6.

In the implementation, the configuration in 1 may not be configured in advance on the network side, but the protocol may predefine the relevant configuration.

Based on the same inventive concept, the embodiment of the present invention further provides a RAN side node, a user equipment, a small data transmission apparatus, and a computer storage medium, and because the principle of solving the problem of these apparatuses is similar to that of the small data transmission method, the implementation of these apparatuses can refer to the implementation of the method, and repeated details are not repeated.

When the technical scheme provided by the embodiment of the invention is implemented, the implementation can be carried out as follows.

Fig. 7 is a schematic structural diagram of a UE, and as shown in the figure, the UE includes:

the processor 700, which is used to read the program in the memory 720, executes the following processes:

processing the small data packet according to the bearing type and/or the used key type;

a transceiver 710 for receiving and transmitting data under the control of the processor 700.

the corresponding bearing of the small data packet is SN terminated bearing;

the bearer corresponding to the small data packet uses a secondary key;

the bearer corresponding to the small data packet is an SCG bearer;

the bearing corresponding to the small data packet does not use master key;

the currently suspended configuration includes the MR-DC configuration therein;

the corresponding bearing of the small data packet is split bearing;

configuring the SN terminated MCG bearer for transmitting small data packets corresponds to one or a combination of the following bearer configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

based on the sk-Counter obtained from the network side, updating the second key, and applying the updated second key to the SN terminated or the small data packet corresponding to the second key transmitted to the RAN side; or,

applying the updated master key and/or the encryption and integrity protection algorithm corresponding to the master key to a small data packet corresponding to the SN terminated or second key transmitted to the RAN side; or the like, or a combination thereof,

indicating whether the bearer is an SCG bearer or an MCG bearer;

indicating that the bearer is a non-MN terminated MCG bearer;

indicating whether the bearer uses a master key or a secondary key;

indicating whether the bearer is a split bearer.

Where in fig. 7, the bus architecture may include any number of interconnected buses and bridges, with various circuits being linked together, particularly one or more processors represented by processor 700 and memory represented by memory 720. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 710 may be a number of elements including a transmitter and a receiver that provide a means for communicating with various other apparatus over a transmission medium. The user interface 730 may also be an interface capable of interfacing with a desired device for different user devices, including but not limited to a keypad, display, speaker, microphone, joystick, etc.

The processor 700 is responsible for managing the bus architecture and general processing, and the memory 720 may store data used by the processor 700 in performing operations.

Fig. 8 is a schematic structural diagram of a small data transmission apparatus on the UE side, as shown in the figure, the small data transmission apparatus may include:

a terminal distinguishing module 801, configured to distinguish, when a non-connected UE before entering an RRC connected state transmits a small data packet to a RAN side, a bearer type and/or a used key type corresponding to the small data packet to be currently transmitted;

and a terminal processing module 802, configured to process the small data packet according to the bearer type and/or the used key type.

The specific implementation may refer to implementation of the small data transmission method on the UE side.

For convenience of description, each part of the above-described apparatus is separately described as being functionally divided into various modules or units. Of course, the functionality of the various modules or units may be implemented in the same one or more pieces of software or hardware in practicing the invention.

Fig. 9 is a schematic structural diagram of a RAN-side node, and as shown in the figure, the node includes:

a processor 900 for reading the program in the memory 920, executing the following processes:

decrypting and integrity-verifying the received small data packet according to the stored or obtained UE context;

a transceiver 910 for receiving and transmitting data under the control of the processor 900.

In an implementation, the method further comprises the following steps:

the corresponding bearing of the small data packet is SN terminated bearing;

the bearer corresponding to the small data packet uses a secondary key;

the bearer corresponding to the small data packet is an SCG bearer;

the bearing corresponding to the small data packet does not use a master key;

the current suspended configuration includes the MR-DC configuration;

the corresponding bearing of the small data packet is split bearing;

In an implementation, the method further comprises the following steps:

In implementation, the RAN-side node determines the bearer type corresponding to the received small data packet based on a configuration in the configuration sent by the RAN-side node to the UE, or a protocol predefined configuration.

indicating whether the bearer is an SCG bearer or an MCG bearer;

indicating that the bearer is a non-MN terminated MCG bearer;

indicating whether the bearer uses a master key or a secondary key;

indicating whether the bearer is a split bearer.

In an implementation, the method further comprises the following steps:

and determining the bearer type or the key type corresponding to the received small data packet based on the auxiliary information.

In an implementation, the method further comprises the following steps:

judging whether to attempt to decode the received small data packet or to forward the received small data packet to a corresponding node based on the bearing type or the key type of the small data packet; or, judging whether the UE context at the SN side needs to be obtained.

In fig. 9, among other things, the bus architecture may include any number of interconnected buses and bridges, with one or more processors, represented by processor 900, and various circuits, represented by memory 920, being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 910 may be a number of elements including a transmitter and a receiver that provide a means for communicating with various other apparatus over a transmission medium. The processor 900 is responsible for managing the bus architecture and general processing, and the memory 920 may store data used by the processor 900 in performing operations.

Fig. 10 is a schematic structural diagram of a small data transmission apparatus on a RAN-side node, which may include:

an RAN receiving module 1001, configured to receive a small data packet transmitted by a non-connected UE before entering an RRC connected state;

RAN processing module 1002, configured to decrypt and integrity check the received small data packet according to the stored or obtained UE context.

The specific implementation can be seen in the implementation of the small data transmission method on the RAN-side node.

In specific implementation, refer to implementation of a small data transmission method on a UE side node and/or a RAN side node.

In summary, the technical solution provided by the embodiment of the present invention provides a small data transmission scheme under dual link, which solves the problem of processing small data transmission under MR-DC scenario and expands the applicable scenario of small data transmission.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A small data transmission method, comprising:

when User Equipment (UE) in a non-connection state before entering a Radio Resource Control (RRC) connection state transmits a small data packet to a Radio Access Network (RAN), distinguishing a bearer type and/or a used key type corresponding to the small data packet to be transmitted currently;

the method further comprises one or a combination of the following processes:

the UE obtains an updated secondary key based on the secondary key Counter sk-Counter obtained from the network side before, and applies the updated secondary key to an SN terminated or small data packet corresponding to the secondary key transmitted to the RAN side; or,

the UE applies the old secondary key to all SN terminated or secondary key corresponding small packets transmitted to the RAN side.

2. The method of claim 1, wherein a non-connected UE does not transmit small packets to the RAN side when one or a combination of the following situations:

the bearer corresponding to the small data packet is a secondary node SN terminated bearer;

the corresponding bearing of the small data packet is a bearing terminated at a secondary node master cell group SN terminated MCG;

the corresponding load bearing of the small data packet is a SN terminated SCG load bearing which is terminated in a secondary node secondary cell group;

the corresponding load bearing of the small data packet is a load bearing terminated at a primary node secondary cell group MN terminated SCG;

the bearer corresponding to the small data packet uses a secondary key;

the bearer corresponding to the small data packet uses a master cell group MCG bearer of a secondary key;

the load corresponding to the small data packet is loaded by using a secondary cell group SCG of the secondary key;

the bearer corresponding to the small data packet is an SCG bearer;

the bearer corresponding to the small data packet is not terminated in a main node main cell group MN terminated MCG bearer;

the load corresponding to the small data packet does not use a master key;

the current suspended configuration comprises a multi-air interface-double connection MR-DC configuration;

the corresponding load of the small data packet is split load;

3. The method of claim 2, wherein a condition that a non-connected UE does not transmit small data packets to the RAN side is configured by the network side.

4. The method of claim 1, wherein the UE side learns one or a combination of the following bearer configurations for transmitting small data packets:

configuring the SN terminated bearer for transmitting the small data packets corresponds to one or a combination of the following bearer configurations: a Data Radio Bearer (DRB) identifier, a Logical Channel Identifier (LCID), radio Link Control (RLC) configuration, packet Data Convergence Protocol (PDCP) configuration and Service Data Adaptation Protocol (SDAP) configuration;

5. The method of claim 4, wherein the configuration is sent on a RAN side or a protocol is predefined.

6. The method of claim 4, wherein if the small data packet is not an MN terminated MCG bearer or not a bearer corresponding to a master key, and the UE determines that the DRB identifier and/or the corresponding bearer type corresponding to the small data packet are included in the bearer configuration according to the learned bearer configuration, the UE in the non-connected state transmits the small data packet to the RAN side; otherwise, the unconnected UE does not transmit the small data packet to the RAN side.

7. The method of claim 4, wherein the UE applies the learned configuration of the bearer configuration corresponding to the to-be-transmitted mini-packet.

8. The method of claim 1, wherein when the non-connected UE transmits a small packet to the RAN side, the UE further indicates one or a combination of the following assistance information at the RAN side:

indicating whether the bearer is an SCG bearer or an MCG bearer;

indicating that the bearer is a non-MN terminated MCG bearer;

indicating whether the bearer uses a master key or a secondary key;

indicating whether the bearer is a split bearer.

9. The method of claim 1, wherein for a split bearer, when a UE in a non-connected state transmits a small packet to the RAN side, the RLC bearer configuration corresponding to the main path is adopted; or,

and when the non-connected UE transmits the small data packet to the RAN side, the PDCP layer carried by the split is adopted as the RLC carrying configuration corresponding to the same cell group CG.

10. A method for small data transmission, comprising:

the RAN side node receives a small data packet transmitted by the UE in the non-connection state before entering the RRC connection state;

the RAN side node decrypts and verifies the integrity of the received small data packet according to the stored or obtained UE context;

the decrypting and integrity verifying of the received small data packet includes one or a combination of the following:

decrypting and integrity checking an SN terminated transmitted to the RAN side or a small data packet corresponding to the secondary key according to an updated secondary key, wherein the updated secondary key is obtained based on sk-Counter in the stored UE context;

decrypting and integrity verifying the small data packet corresponding to the SN terminated or secondary key at the RAN side according to the updated master key and/or the encryption and integrity protection algorithm corresponding to the master key;

and decrypting and integrity verifying the SN terminated at the RAN side or the small data packet corresponding to the second secondary key according to the old secondary key.

11. The method of claim 10, further comprising:

12. The method of claim 11, wherein the non-connected UE is configured not to transmit small data packets to the RAN side when one or a combination of the following situations:

the corresponding bearing of the small data packet is SN terminated bearing;

the bearer corresponding to the small data packet uses a secondary key;

the bearer corresponding to the small data packet is an SCG bearer;

the bearing corresponding to the small data packet does not use a master key;

the current suspended configuration includes the MR-DC configuration;

the corresponding bearing of the small data packet is split bearing;

13. The method of claim 10, further comprising:

the RAN side node sends configuration to the UE, and the non-connection state UE before the configuration enters the RRC connection state transmits a small data packet to the RAN side under one of the following conditions or the combination of the following conditions:

14. The method of claim 13, wherein the RAN-side node determines the bearer type or the corresponding key type corresponding to the received small data packet based on a configuration of the configurations sent by the RAN-side node to the UE or a protocol predefined configuration.

15. The method of claim 13, wherein the RAN-side node determines the DRB identity corresponding to the received small data packet based on a configuration of the configurations sent by the RAN-side node to the UE, or a protocol predefined configuration;

16. The method of claim 10, wherein the RAN-side node is a UE current RAN-side serving node; or,

17. The method of claim 16, wherein when the RAN-side node is a UE current RAN-side serving node, further comprising:

18. The method of claim 16, wherein when the RAN-side node is a serving master node before the UE enters the non-connected state, further comprising:

19. The method according to claim 17 or 18, wherein the RAN-side node sends MAC PDUs or PDCP PDUs corresponding to small data packets.

20. The method according to claim 10, 17 or 18, characterized in that the RAN-side node receives UE-indicated one or a combination of the following assistance information:

indicating whether the bearer corresponding to the small data packet is an SCG bearer or an MCG bearer;

indicating whether the bearer corresponding to the small data packet is an MN terminated bearer or an SN terminated bearer;

indicating that the bearer corresponding to the small data packet is a non-MN terminated MCG bearer;

indicating whether the bearer corresponding to the small data packet uses a master key or a secondary key;

indicating whether the bearer corresponding to the small data packet is a split bearer.

21. The method of claim 20, further comprising:

22. The method of claim 14 or 21, further comprising:

judging whether to attempt to decode the received small data packet or to forward the received small data packet to a corresponding node based on the bearing type of the small data packet; or, judging whether the UE context at the SN side needs to be obtained.

23. The method of claim 10, wherein a serving master node before the UE enters the non-connected state determines whether to perform UE context relocation according to whether to store the MR-DC configuration or a bearer type corresponding to the small data packet or a key type corresponding to the small data.

24. A UE, comprising:

a transceiver for receiving and transmitting data under the control of the processor;

the processor is further configured to process one or a combination of the following:

based on the sk-Counter obtained from the network side, obtaining an updated second key, and applying the updated second key to the SN terminated transmitted to the RAN side or a small data packet corresponding to the second key; or,

applying the updated master key and/or the encryption and integrity protection algorithm corresponding to the master key to a small data packet corresponding to the SN terminated or secondary key transmitted to the RAN side; or,

25. The UE of claim 24, wherein a non-connected UE does not transmit small packets to the RAN side when one or a combination of the following:

the corresponding bearing of the small data packet is SN terminated bearing;

the bearer corresponding to the small data packet uses a secondary key;

the bearer corresponding to the small data packet is an SCG bearer;

the bearing corresponding to the small data packet does not use a master key;

the currently suspended configuration includes the MR-DC configuration therein;

the corresponding bearing of the small data packet is split bearing;

26. The UE of claim 24, wherein one or a combination of the following bearer configurations for transmitting small data packets are learned:

27. The UE of claim 24, wherein the UE in a non-connected state further instructs the RAN side to perform one or a combination of the following auxiliary information when transmitting a small packet to the RAN side:

indicating whether the bearer is an SCG bearer or an MCG bearer;

indicating that the bearer is a non-MN terminated MCG bearer;

indicating whether the bearer uses a master key or a secondary key;

indicating whether the bearer is a split bearer.

28. A RAN-side node, comprising:

and decrypting and integrity checking the SN terminated or small data packet corresponding to the second secondary key at the RAN side according to the old secondary key.

29. The node of claim 28, further comprising:

30. The node of claim 29, wherein the non-connected UE is configured not to transmit small packets to the RAN side when one or a combination of the following situations:

the corresponding bearing of the small data packet is SN terminated bearing;

the bearer corresponding to the small data packet uses a secondary key;

the bearer corresponding to the small data packet is an SCG bearer;

the bearer corresponding to the small data packet is not a MN terminated MCG bearer;

the bearing corresponding to the small data packet does not use a master key;

the currently suspended configuration includes the MR-DC configuration therein;

the corresponding load of the small data packet is split load;

31. The node of claim 28, further comprising:

sending configuration to the UE, and transmitting a small data packet to the RAN side by the UE in a non-connection state before the UE enters the RRC connection state under one or a combination of the following conditions:

the SN terminated bearer configured for transmitting the small data packets corresponds to one or a combination of the following configurations: DRB identification, LCID, RLC configuration, PDCP configuration and SDAP configuration;

32. The node according to claim 28, wherein one or a combination of the following assistance information is received as indicated by the UE:

33. A small data transmission apparatus, comprising:

the terminal processing module is used for processing the small data packet according to the bearing type and/or the used key type;

the terminal processing module is further used for one or a combination of the following processes:

the UE obtains an updated second key based on the sk-Counter obtained from the network side, and applies the updated second key to an SN terminated or small data packet corresponding to the second key transmitted to the RAN side; or,

and the UE applies the old secondary key to all SN terminated or small data packets corresponding to the secondary key when the old secondary key is transmitted to the RAN side.

34. A small data transmission apparatus, comprising:

the RAN processing module is used for decrypting and verifying the integrity of the received small data packet according to the stored or obtained UE context;

decrypting and integrity-verifying the SN terminated or small data packet corresponding to the secondary key transmitted to the RAN side according to the updated secondary key, wherein the updated secondary key is obtained based on the sk-Counter in the stored UE context;

35. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program for executing the method of any one of claims 1 to 23.