User equipment and method for sending preconfigured uplink resources executed by the same

Abstract

The present invention provides a user equipment and a method for sending preconfigured uplink resources executed by the user equipment. The method for sending preconfigured uplink resources executed by the user equipment comprises the following steps: when upper layer data arrives at the access layer of the user equipment UE, the radio resource control RRC layer triggers an RRC process to confirm whether the conditions for sending using the preconfigured uplink resources are met, if the conditions for sending using the preconfigured uplink resources are met, the RRC layer performs the operation of transmitting the preconfigured uplink resource data; when using the preconfigured uplink resource transmission mode, the media access control MAC layer verifies whether the preconfigured uplink resource can be used, if the MAC layer determines that the preconfigured uplink resource is not available, the UE performs a fallback to a data transmission mode that does not use the preconfigured uplink resource data transmission to send the uplink data.

Description

Technical Field

[0001] The present disclosure relates to the technical field of wireless communications, and more specifically, to a user equipment and a method for sending pre-configured uplink resources executed by the user equipment. Background Art

[0002] In June 2018, at the 3rd Generation Partnership Project (3GPP) RAN#80 plenary meeting, a new work item on NarrowBand Internet Of things (NB-IoT) Release 16 enhancement (see RP-181451: New WID on R16enhancement forNB-IoT) and a new work item on Machine Type Communication (MTC) Release 16 enhancement (see RP-181878, revised WID for additional MTC enhancement) were approved. One of the goals of this research project is to improve the efficiency of uplink transmission to reduce the energy consumption of user equipment (UE).

[0003] In the prior art, if a UE in an idle state wants to send uplink data, there are two ways: one way is to enter the RRC connection state through the Radio Resource Control (RRC) connection establishment / recovery process, that is, to send uplink data in the RRC connection state where a connection is established with the network side (this transmission method is referred to as a traditional transmission method or a traditional data transmission method in this disclosure); the other way is to use the Early Data Transmission (EDT) mechanism introduced in version 15, and send a small data packet to the base station together in the third message during the random access process. For small data packets, the use of the EDT method obviously saves more signaling overhead and consumes less UE energy than entering the RRC connection state and then sending uplink data. The above version 16 aims to further improve the efficiency of uplink transmission and reduce UE energy consumption. In the ongoing technical discussion on improving uplink transmission efficiency to reduce UE energy consumption, a feasible method is to pre-allocate available uplink resources for users in the RRC idle state. When uplink data arrives, if the UE's uplink is still in a synchronized state (i.e., there is a valid uplink time advance (TA)), the uplink transmission can be completed by using the pre-allocated uplink resources without having to perform uplink transmission through a random access process or enter a connected state through an RRC connection establishment / recovery process to transmit uplink data.

[0004] In the present disclosure, the method of sending uplink data by UE in RRC idle state through pre-configured resources is called pre-configured uplink resource sending. The present disclosure mainly proposes a solution to the problem of how to implement pre-configured uplink resource sending, and more specifically, proposes a solution to the problem of how to implement fallback from the pre-configured uplink resource sending method to the traditional uplink data sending method or the EDT method, and the problem of pre-configured uplink resource sending in the mobility scenario and the configuration problem of pre-configured uplink resources. Summary of the invention

[0005] The present disclosure is made in view of the above problems, and its purpose is to provide a user equipment and a method for sending pre-configured uplink resources executed by the user equipment, which can improve the efficiency of uplink transmission to reduce the energy consumption of the user equipment.

[0006] According to one aspect of the present invention, a method for sending pre-configured uplink resources performed by a user equipment is provided, comprising the following steps: when upper layer data arrives at an access layer of the user equipment UE, a radio resource control RRC layer triggers an RRC process to confirm whether a condition for sending using pre-configured uplink resources is met; if the condition for sending using pre-configured uplink resources is met, the RRC layer performs an operation for transmitting the pre-configured uplink resource data; when using the pre-configured uplink resource transmission method, a media access control MAC layer verifies whether the pre-configured uplink resources can be used; if the MAC layer determines that the pre-configured uplink resources are not available, the UE performs a fallback to a data transmission method that does not use the pre-configured uplink resource data transmission to send the uplink data.

[0007] In the above-mentioned method for sending pre-configured uplink resources executed by the user equipment, preferably, the fallback is executed at the MAC layer of the UE or determined by the RRC layer of the UE.

[0008] In the above-mentioned method for sending pre-configured uplink resources performed by the user equipment, preferably, when the fallback is performed at the MAC layer of the UE, the MAC layer triggers a random access process, and the random access process is a random access process that does not use early data transmission EDT.

[0009] In the above-mentioned method for sending pre-configured uplink resources performed by the user equipment, preferably, when the fallback is executed at the MAC layer of the UE, the process of the MAC layer triggering a random access process is as follows: if the size of the potential MAC protocol data unit is not larger than the EDT transmission block size configuration corresponding to the selected coverage enhancement level received in the system information for EDT, the MAC layer initiates a random access process for EDT, otherwise, the MAC layer initiates a random access process without using EDT.

[0010] In the above-mentioned method for sending pre-configured uplink resources executed by the user equipment, preferably, when the fallback is determined by the RRC layer of the UE, it includes the following steps: if the MAC layer determines that the pre-configured uplink resources are unavailable, the MAC layer sends a pre-configured uplink resource transmission cancellation indication to the RRC layer to inform that the pre-configured uplink resources are unavailable; when receiving the pre-configured uplink resource transmission cancellation indication from the MAC layer, the RRC layer determines whether the EDT conditions are met, and if so, the RRC layer configures the bottom layer to use EDT, otherwise, the RRC layer performs the operation of falling back to the traditional transmission mode.

[0011] In the above-mentioned method for sending pre-configured uplink resources executed by the user equipment, preferably, if the MAC layer initiates a random access process for EDT, the MAC layer sends an indication information to the upper layer for informing the upper layer that the EDT mode is currently being used.

[0012] In the above-mentioned method for sending pre-configured uplink resources executed by the user equipment, preferably, the MAC layer determines that the pre-configured uplink resources are unavailable in any one of the following situations: the MAC layer determines that there are no pre-configured uplink resources corresponding to the current coverage enhancement level; the MAC layer determines that the size of the potential MAC protocol data unit is larger than the transmission block size corresponding to the allocated pre-configured uplink resources; the timer used to determine the idle time advance TA times out; the idle TA determined based on the reference signal received power RSRP is invalid; the uplink data sent on the pre-configured uplink resources fails to send; the number of failures to send uplink data on the pre-configured uplink resources exceeds a configured threshold value.

[0013] In the above-mentioned method for sending pre-configured uplink resources performed by the user equipment, it is preferred that the RRC layer performs an operation of falling back to the traditional transmission mode, including one or more of the following operations: if the fallback operation corresponds to an RRC early data request message, initiating the sending of an RRC connection request message; if the fallback operation corresponds to an RRC connection recovery request message, reconstructing the radio link control RLC layer corresponding to the data radio bearer DRB and / or the signaling radio bearer SRB; if the fallback operation corresponds to an RRC connection recovery request message, reconstructing the packet data convergence protocol PDCP layer corresponding to the data radio bearer DRB and / or the signaling radio bearer SRB; if the fallback operation corresponds to an RRC connection recovery request message, deleting the security key derived in the RRC process; if the fallback operation corresponds to an RRC connection recovery request message, suspending all SRBs and DRBs; if the fallback operation corresponds to an RRC connection recovery request message, configuring the lower layer to suspend integrity protection and encryption functions; initiating the sending of an RRC connection recovery request message, and the RRC connection recovery request message is not used for EDT.

[0014] In the above-mentioned method for sending pre-configured uplink resources executed by the user equipment, it is preferred that the traditional transmission mode is to enter the RRC connection state through the RRC connection establishment / recovery process, that is, to send uplink data in the RRC connection state in which a connection is established with the network side.

[0015] According to another aspect of the present invention, a user equipment is provided, comprising: a processor; and a memory, wherein the memory stores instructions; when the instructions are executed by the processor, the user equipment executes the pre-configured uplink resource sending method described above.

[0016] According to the user equipment involved in the present disclosure and the pre-configured uplink resource sending method executed by it, it is possible to implement fallback from the pre-configured uplink resource sending mode to the traditional uplink data sending mode or the EDT mode, and can solve the problems of pre-configured uplink resource sending in mobility scenarios and the configuration problems of pre-configured uplink resources, thereby improving the efficiency of uplink transmission to reduce the energy consumption of the user equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other features of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0018] Figure 1 This is a flowchart of sending pre-configured uplink resources on a UE involved in Embodiment 1 of the present disclosure.

[0019] Figure 2 This is a flowchart of sending pre-configured uplink resources on a UE involved in Embodiment 2 of the present disclosure.

[0020] Figure 3 This is a flowchart of sending pre-configured uplink resources on a UE involved in Embodiment 3 of the present disclosure.

[0021] Figure 4 It is a simplified structural block diagram of the user equipment involved in the present disclosure. DETAILED DESCRIPTION

[0022] Other aspects, advantages and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description of exemplary embodiments of the disclosure taken in conjunction with the accompanying drawings.

[0023] In this disclosure, the terms "include" and "including" and their derivatives mean inclusion rather than limitation; the term "or" is inclusive, meaning and / or.

[0024] In this specification, the various embodiments described below for describing the principles of the present disclosure are merely illustrative and should not be interpreted in any way as limiting the scope of the disclosure. The following description with reference to the accompanying drawings is used to help fully understand the exemplary embodiments of the present disclosure as defined by the claims and their equivalents. The following description includes a variety of specific details to aid understanding, but these details should be considered merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. In addition, for the sake of clarity and brevity, descriptions of well-known functions and structures are omitted. In addition, throughout the accompanying drawings, the same reference numerals are used for similar functions and operations.

[0025] The following uses NB-IoT in the Long Term Evolution (LTE) mobile communication system and its subsequent evolution versions as an example application environment to specifically describe multiple implementations of the present disclosure. However, it should be noted that the present disclosure is not limited to the following implementations, but can be applied to more other wireless communication systems, such as machine type communication (MTC) systems, and can also be used in 5G next generation wireless communication systems (NewRadio, NR).

[0026] The base station in the present disclosure may be any type of base station, including Node B, enhanced base station eNB, or 5G communication system base station gNB, or micro base station, micro-micro base station, macro base station, home base station, etc.; the cell in the present disclosure may also be a cell under any of the above types of base stations. In the present disclosure, unless otherwise specified, the coverage enhancement level (CoverageEnhancement level) is equivalent to the enhanced coverage level (Enhanced Coverage level), or it may also be called the repetition level (Repetition Level). The idle state (RRC Idle) of the UE may also be the inactive state (RRC Inactive) of the UE in the NR system.

[0027] Different embodiments may also work in combination.

[0028] The following first describes some concepts involved in the present disclosure. It should be noted that some of the names in the following description are only illustrative and not restrictive, and other names may also be used.

[0029] Message 3: uplink data transmitted on the uplink resources corresponding to the uplink grant carried in the random access response during the random access process, or physical uplink shared channel (Physical Uplink Shared CHannal, PUSCH) transmission scheduled by the random access response.

[0030] Early Data Transmission (EDT):

[0031] The small data transmission optimization scheme in R15 has made further optimizations for the characteristics of small data transmission from the control plane and the user plane. For uplink data transmission, the optimization content is mainly to transmit small data together with message 3 during the random access process. Because this optimization method can complete data transmission at an earlier time than the traditional data transmission method, it is called early data transmission. In this disclosure, small data (small data or small packet) can be equivalent to early data. In EDT, it is allowed to send an uplink data transmission during the random access process, and optionally, a downlink data transmission can follow. When uplink data is received, the network side and the UE side will establish or restore the S1 connection, and the S1 connection may be released or suspended along with the transmission of the above-mentioned downlink data.

[0032] Enhanced Coverage level:

[0033] In enhanced coverage technology, the degree of enhanced coverage required is divided into multiple enhanced coverage levels. For example, in NB-IoT, three enhanced coverage levels are defined. In MTC, four enhanced coverage levels are defined. In some enhanced coverage methods, each enhanced coverage level can correspond to a different set of wireless parameter configurations, such as random access configurations (such as PRACH (Physical Random Access Channel) resources). When initiating random access, the UE's medium access control (MAC) layer will determine the UE's enhanced coverage level based on the measured reference signal received power (RSRP) and the RSRP threshold value received in the system information for determining the enhanced coverage level, and select the corresponding random access resources (such as preamble) and parameters (such as random access response window size) according to the determined enhanced coverage level to initiate the random access process.

[0034] Control plane optimization solution: The full name is Control plane Cellular IoT Evolved Packet System (EPS) optimisation. It refers to a method to effectively transmit user data in the control plane through the mobility management entity without triggering the establishment of data radio bearers (DRBs).

[0035] User plane optimization solution: full name User plane Cellular IoT Evolved Packet System optimisation solution. It refers to supporting the change from EPS mobility management idle state to EPS mobility management connected state without using the service request process.

[0036] There are two ways to preconfigure uplink resources. One is dedicated preconfigured uplink resources, that is, pre-allocating dedicated uplink resources for a UE, so that uplink data transmission will not cause collision conflicts. The other is shared preconfigured uplink resources, that is, the allocated uplink resources are shared by multiple UEs, which can be a shared resource pool. In this way, multiple UEs may use one resource to send uplink data, so there is potential competition to cause conflicts and lead to transmission failure. At present, the conclusion reached at the 3GPP meeting is to support the allocation of dedicated preconfigured uplink resources to UEs through RRC dedicated signaling, but whether to support shared preconfigured uplink resources has not yet been determined. Preconfigured uplink resources are uplink resources pre-allocated to UEs for use through RRC messages. The preconfigured uplink resources can be allocated in the RRC connected state for uplink data transmission when the UE is in the RRC idle state and / or for the RRC connected state. This method is usually used for dedicated preconfigured uplink resources; it can also be notified to the UE through system information for uplink data transmission in the RRC idle state. This method is usually used for shared preconfigured uplink resources. Unless otherwise specified, in the present disclosure, the pre-configured uplink resources may refer to either dedicated pre-configured uplink resources or shared pre-configured uplink resources.

[0037] For the dedicated preconfigured uplink resources, the dedicated preconfigured uplink resources may be configured by the base station through RRC dedicated signaling when the UE was previously in the RRC connection state, such as RRC connection release message, RRC connection reconfiguration information, RRC connection establishment message, RRC connection recovery message, etc. When a UE in the RRC idle state uses preconfigured uplink resources to send uplink data, if it is determined that the allocated preconfigured uplink resources are unavailable, for example, the transmission on the preconfigured uplink resources fails or the number of transmission failures exceeds a certain threshold value, the UE will fall back to the traditional data transmission mode or EDT mode, that is, not using the preconfigured uplink resource transmission mode to send data. In this case, how to implement the fallback to the traditional transmission mode or EDT mode becomes a problem of concern in the present disclosure.

[0038] Considering that a UE using pre-configured uplink resources may have a certain degree of mobility, when the UE is in the process of using the pre-configured uplink resources for data transmission, if a cell reselection occurs at this time, how the UE handles the current data transmission also becomes an issue of concern in the present disclosure.

[0039] In addition, the 105th RAN2 meeting reached the following consensus: UE can send pre-configured uplink resource request information to the base station to request the base station to allocate pre-configured uplink resources for it and can provide some auxiliary information to the base station for reference when the base station allocates pre-configured uplink resources. The auxiliary information may include the transmission block size, pre-configured uplink resource period, channel quality status, etc. In the pre-configured uplink resource mechanism based on UE request, consider a situation: due to mobility or network load balancing, the UE's serving base station triggers the handover preparation process with the target by sending a handover request message. If the UE sends pre-configured uplink resource request information to its serving base station at this time and the UE subsequently receives a handover command and a handover occurs, the target base station cannot obtain the UE's latest pre-configured uplink resource request information. The following embodiments also propose solutions based on this problem.

[0040] In the following embodiments of the present disclosure, indication (indicate / indication) and notification (notify / notification) or inform / information (inform / information) can be interchangeable. UE can refer to NB-IoT UE, Bandwidth reduced Low complexity (BL) UE, or UE in enhanced coverage (enhanced coverage), or other UE such as 5G NR UE. In the present disclosure, Physical Random Access CHannal (PRACH), Narrowband Physical Random Access CHannal (NPRACH) and Random Access CHannal (RACH) can be replaced. Physical Downlink Control Channel (PDCCH) and Narrowband Physical Downlink Control Channel (NPDCCH) or MTC Physical Downlink Control Channel (MPDCCH) are equivalent. In the present disclosure, the pre-configured uplink resource may also be referred to as a pre-configured uplink grant or a pre-allocated uplink resource or a pre-allocated uplink grant or an idle state semi-static scheduling grant, etc. The pre-configured uplink resource request information may also be referred to as pre-configured uplink resource auxiliary information or a pre-configured uplink resource request or pre-configured uplink resource information. When describing a protocol stack, a lower layer may also be referred to as a bottom layer, and an upper layer may also be referred to as a high layer. The initiation may also be referred to as initialization.

[0041] Example 1

[0042] Next, use Figure 1 A process of sending pre-configured uplink resources on a UE is described as follows:

[0043] 1. When the upper layer data reaches the access stratum (AS) layer of the UE (step S101), the RRC layer triggers an RRC process, such as an RRC connection establishment process. In this process, the UE RRC layer determines whether the conditions for using pre-configured uplink resources for transmission are met (step S102). If the conditions for using pre-configured uplink resources for transmission are met, the RRC layer performs the operation of pre-configured uplink resource PUR data transmission (step S103), and optionally, also includes indicating to the downlink to use the pre-configured uplink resource transmission mode, or describing to configure the lower layer to use the pre-configured uplink resource transmission.

[0044] The conditions for using the preconfigured uplink resource transmission may be one or more of the following: the UE has a saved preconfigured uplink resource configuration, the service cell where the UE currently resides is the same as the service cell when the preconfigured uplink resource configuration was previously received, that is, the service cell for which the preconfigured uplink resource is configured and the service cell to which the preconfigured uplink resource transmission is currently to be initiated are the same cell, the establishment or recovery request is for mobile originating calls (mobile originating calls) and the establishment reason is mobile originating data (MO-data) or mobile originating exception data (mo-exception data) or delay tolerant access (delay tolerant Access). The RRC layer performs the operation of preconfigured uplink resource data transmission, including one or more of the following operations: if the UE is initiating a control plane mode (called control plane preconfigured uplink resource transmission), the UE initiates the transmission of an RRC connection establishment request message or an RRC early data request; if the UE is initiating a user plane mode (called user plane preconfigured uplink resource transmission), that is, an RRC connection is being restored, the UE initiates the transmission of an RRC connection recovery request message. The sending of the initiation of the RRC connection establishment request message or the RRC early data request message includes including the data / information received from the upper layer in the RRC connection establishment request or the RRC early data request message, and further, in the dedicatedInfoNAS information element. The sending of the initiation of the RRC connection recovery request message is the same as the operation of initiating the RRC connection recovery request message for early data transmission in the existing mechanism (see Section 5.3.3.3a of Protocol Specification 36.331), including restoring the Packet Data Convergence Protocol (PDCP) state, reestablishing the PDCP entities corresponding to all signaling radio bearers (SRBs) and data radio bearers (DRBs), instructing the lower layer to use the saved UE access layer context, restoring all SRBs and DRBs, deriving new keys, and restoring security.

[0045] 2. When using the pre-configured uplink resource transmission method, the UE MAC layer verifies whether the pre-configured uplink resources are available (step S104). If the MAC layer determines that the pre-configured uplink resources are not available, the UE executes a fallback to the traditional data transmission method that does not use the pre-configured uplink resource data transmission method (step S105) to send uplink data (step S106).

[0046] In this embodiment, the fallback is performed at the MAC layer of the UE. That is, if the MAC layer determines that the pre-configured uplink resources are unavailable, the UE MAC layer triggers a random access process, and the random access process is a traditional random access process, that is, a random access process that does not use EDT. The MAC layer determines that the pre-configured uplink resources are unavailable in any of the following situations:

[0047] Case 1: The UE MAC layer determines that there is no preconfigured uplink resource corresponding to the current coverage enhancement level. In this case, the configuration of the preconfigured uplink resource is differentiated by coverage enhancement level, that is, different preconfigured uplink resources can be configured for different coverage enhancement levels. The UE determines the current coverage enhancement level based on the measured RSRP. The RSRP threshold value used by the UE to determine the coverage enhancement level can be obtained in the preconfigured uplink resource configuration information.

[0048] Case 2: The UE MAC layer determines that the size of the potential MAC protocol data unit is larger than the transport block size corresponding to the allocated pre-configured uplink resources. Preferably, case 2 is applicable when the control plane optimization solution is used.

[0049] Case 3: The TAT timer used to determine the idle state time advance (TA) times out, that is, the TAT timer corresponding to the pre-configured uplink resource times out.

[0050] Case 4: The idle TA determined based on the Reference Signal Received Power (RSRP) is invalid.

[0051] Case 5: The uplink data sent on the pre-configured uplink resources fails to be sent, such as no response is received from the base station, or no confirmation information is received from the base station to confirm that the base station has correctly received the uplink data. In other words, the Hybrid Automatic Repeat Request (HARQ) transmission of the uplink transmission sent on the pre-configured uplink resources has reached the maximum number of retransmissions.

[0052] Case 6: The number of failures in sending uplink data on the pre-configured uplink resources exceeds a configured threshold.

[0053] Example 2

[0054] Next, use Figure 2 Another process of sending pre-configured uplink resources on a UE is described below.

[0055] In this embodiment, steps S101 to 104 and 106 are the same as those in embodiment 1, and the only difference is step S205. Therefore, only step S205 will be described below.

[0056] In this embodiment, the fallback is executed at the MAC layer of the UE (S205). The difference from Embodiment 1 is that if the MAC layer determines that the pre-configured uplink resources are not available, the process of the UE MAC layer triggering a random access process is as follows: If the size of the potential MAC protocol data unit is not greater than the EDT transport block size configuration (edt-TBS information element) corresponding to the selected coverage enhancement level received in the system information for EDT, the MAC layer initiates a random access process for EDT, and optionally, the MAC layer sends an indication information to the upper layer to inform the upper layer (such as the RRC layer) that the EDT mode is being used. Otherwise, the MAC layer initiates a traditional random access process, that is, initiates a non-EDT random access process.

[0057] The MAC layer determining that the pre-configured uplink resources are unavailable may be any of the following situations:

[0058] Case 1: The UE MAC layer determines that there is no preconfigured uplink resource corresponding to the current coverage enhancement level. In this case, the configuration of the preconfigured uplink resource is differentiated by coverage enhancement level, that is, different preconfigured uplink resources can be configured for different coverage enhancement levels. The UE determines the current coverage enhancement level based on the measured RSRP. The RSRP threshold value used by the UE to determine the coverage enhancement level can be obtained in the preconfigured uplink resource configuration information.

[0059] Case 2: The UE MAC layer determines that the size of the potential MAC protocol data unit is larger than the transport block size corresponding to the allocated pre-configured uplink resources. Preferably, case 2 is applicable when the control plane optimization solution is used.

[0060] Case 3: The TAT timeout used to determine the idle TA is the TAT timeout corresponding to the pre-configured uplink resources.

[0061] Case 4: The idle state TA determined based on RSRP is invalid.

[0062] Case 5: The uplink data sent on the pre-configured uplink resources fails to be sent, such as no response from the base station or no confirmation information from the base station confirming that the base station has correctly received the uplink data. In other words, the HARQ transmission of the uplink transmission sent on the pre-configured uplink resources has reached the maximum number of retransmissions.

[0063] Case 6: The number of failures in sending uplink data on the pre-configured uplink resources exceeds a configured threshold.

[0064] Example 3

[0065] Next, use Figure 3 Another process of sending pre-configured uplink resources on a UE is described below.

[0066] In this embodiment, steps S101 to 104 and 106 are the same as those in embodiment 1, and the only difference is step S305. Therefore, only step S305 will be described below.

[0067] In this embodiment, the fallback is determined by the RRC layer (step S305).

[0068] 1. If the MAC layer determines that the pre-configured uplink resources are unavailable, the UE MAC layer sends an indication message to the upper layer to inform the upper layer (such as the RRC layer) that the pre-configured uplink resources are unavailable. The indication message may also be referred to as a pre-configured uplink resource transmission cancellation indication.

[0069] Optionally, the indication information is the reason why the pre-configured uplink resources are unavailable, such as transmission failure on the pre-configured uplink resources, or transmission on the pre-configured uplink resources reaching the maximum number of retransmissions, or TA is invalid, or the size of the MAC protocol data unit is larger than the transmission block size allowed by the pre-configured uplink resources, etc.

[0070] 2. When receiving a pre-configured uplink resource transmission cancellation indication from a lower layer (such as a MAC layer), the RRC layer determines whether the EDT conditions are met. If so, the RRC layer configures the lower layer to use EDT; otherwise, the RRC layer performs an operation of falling back to the traditional transmission mode.

[0071] The conditions for determining whether the EDT is satisfied include the following:

[0072] Condition 1: The establishment or resumption request is for a mobile originating call and the establishment reason is mobile originated data (MO-data) or mobile originated exception data (mo-exception data) or delay tolerant access (delay tolerant Access).

[0073] Condition 2: For control plane EDT, the upper layer requests to establish an RRC connection, the UE supports control plane EDT, and the system information contains the cp-EDT information element. Or, for user plane EDT, the upper layer requests RRC connection recovery, the UE supports user plane EDT, the system information 2 contains the up-EDT information element, and the UE has a saved next hop chaining count value (nextHopChainingCount) provided in the RRC connection release message with suspension indication received during the humble suspension process.

[0074] Condition 3: The system information contains EDT parameter configuration (ie, edt-parameters information element).

[0075] Condition 4: The size of the formed MAC protocol data unit is less than or equal to the transport block size configured in the edt-TBS information element. The size of the MAC protocol data unit includes all uplink data. The edt-TBS information element is used to include the maximum transport block size of message 3 corresponding to one PRACH resource when the UE performs EDT transmission.

[0076] The RRC layer performs operations to fall back to the traditional transmission mode (see Section 5.3.3.3c of the protocol specification TS36.331), including one or more of the following operations:

[0077] Operation 1: If the fallback operation corresponds to the control plane optimization solution, that is, corresponds to the RRC early data request message, the sending of the RRC connection request message is initiated.

[0078] Operation 2: If the fallback operation corresponds to the user plane optimization solution, that is, corresponds to the RRC connection recovery request message, rebuild the radio link control (Radio Link Control, RLC) layer corresponding to the data radio bearer (Data Radio Bearer, DRB) and / or the signaling radio bearer (SignallingRadio Bearer, SRB).

[0079] Operation 3: If the fallback operation corresponds to the user plane optimization solution, that is, corresponds to the RRC connection recovery request message, rebuild the packet data convergence protocol (PDCP) layer corresponding to the data radio bearer (DRB) and / or the signaling radio bearer (SRB).

[0080] Operation 4: If the fallback operation corresponds to the user plane optimization solution, that is, corresponds to the RRC connection recovery request message, delete the security key derived in the RRC process.

[0081] Operation 5: If the fallback operation corresponds to the user plane optimization solution, that is, corresponds to the RRC connection recovery request message, suspend all SRBs and DRBs, excluding the first SRB, that is, SRB0.

[0082] Operation 6: If the fallback operation corresponds to the user plane optimization solution, that is, corresponds to the RRC connection recovery request message, configure the lower layer to suspend integrity protection and encryption functions.

[0083] Operation 7: Initiate sending of an RRC connection recovery request message, where the RRC connection recovery request message is not used for EDT.

[0084] Example 4

[0085] This embodiment also proposes a method for pre-configured uplink resource transmission to fall back to a traditional transmission mode or an EDT mode. This embodiment is different from the assumptions made in embodiments 1 to 3 regarding the transmission of pre-configured uplink resources. In embodiments 1 to 3, the user plane data will always trigger the RRC connection establishment / recovery process and will be sent on the pre-configured uplink resources along with an RRC request message (such as an RRC connection establishment request, an RRC early data request, an RRC connection recovery request message). In embodiment 4, the assumption is that only user plane data is sent on pre-configured uplink resources without additional RRC request messages.

[0086] In this embodiment, the fallback is determined by the RRC layer.

[0087] Step 1: If the MAC layer determines that the pre-configured uplink resources are unavailable, the UE MAC layer sends an indication message to the upper layer to inform the upper layer (such as the RRC layer) that the pre-configured uplink resources are unavailable. The indication message may also be referred to as a pre-configured uplink resource transmission cancellation indication.

[0088] Optionally, the indication information is the reason why the pre-configured uplink resources are unavailable, such as transmission failure on the pre-configured uplink resources, or transmission on the pre-configured uplink resources reaching the maximum number of retransmissions, or TA is invalid, or the size of the MAC protocol data unit is larger than the transmission block size allowed by the pre-configured uplink resources, etc.

[0089] Step 2: When receiving the pre-configured uplink resource transmission cancellation indication from the lower layer, the RRC layer determines whether the EDT condition is met. If so, the RRC layer performs the following operation of falling back to EDT; otherwise, the RRC layer performs the operation of falling back to the traditional transmission mode.

[0090] Optionally, before the RRC layer determines whether the EDT condition is met, the RRC layer also includes triggering an RRC connection establishment process (an RRC process for initially establishing or restoring an RRC connection).

[0091] The conditions for determining whether the EDT is satisfied are the same as those in the previous embodiment and are not described in detail here.

[0092] The RRC performs the operation of falling back to EDT including one or more of the following operations:

[0093] Operation 1: For the control plane optimization solution (or control plane EDT), the RLC corresponding to the SRB is rebuilt. Preferably, the SRB is SRB0.

[0094] Operation 2: For the user plane optimization scheme (or user plane EDT), the RRC connection recovery request message is sent. The operation 2 is performed under the condition that SRB1 has been restored (resumed). If SRB1 has not been restored, operation 2 also includes restoring SRB1. The execution of sending the RRC connection recovery request message refers to constructing an RRC connection recovery request message and submitting it to the lower layer for sending. The construction of an RRC connection recovery request message includes the following: setting the resumeID field to the saved resumption identifier (resumeIdentity); setting the resumecause field to the information received from the upper layer; setting the shortensumeMAC-I field to the lowest 16 bits of the calculated MAC-I.

[0095] The RRC performs an operation of falling back to the traditional transmission mode (see Section 5.3.3.3c of the protocol specification TS36.331), including one or more of the following operations:

[0096] Operation 1: If the fallback operation corresponds to the control plane optimization solution, that is, corresponds to the RRC early data request message, the sending of the RRC connection request message is initiated.

[0097] Operation 2: If the fallback operation corresponds to the user plane optimization solution, that is, corresponds to the RRC connection recovery request message, rebuild the radio link control (Radio Link Control, RLC) layer corresponding to the data radio bearer (Data Radio Bearer, DRB) and / or the signaling radio bearer (SignallingRadio Bearer, SRB).

[0098] Operation 3: If the fallback operation corresponds to the user plane optimization solution, that is, corresponds to the RRC connection recovery request message, rebuild the packet data convergence protocol (PDCP) layer corresponding to the data radio bearer (DRB) and / or the signaling radio bearer (SRB).

[0099] Operation 4: If the fallback operation corresponds to the user plane optimization solution, that is, corresponds to the RRC connection recovery request message, delete the security key derived in the RRC process.

[0100] Operation 5: If the fallback operation corresponds to the user plane optimization solution, that is, corresponds to the RRC connection recovery request message, suspend all SRBs and DRBs, excluding SRB0.

[0101] Operation 6: If the fallback operation corresponds to the user plane optimization solution, that is, corresponds to the RRC connection recovery request message, configure the lower layer to suspend integrity protection and encryption functions.

[0102] Operation 7: Initiate sending of an RRC connection recovery request message, where the RRC connection recovery request message is not used for EDT.

[0103] Operation 8: Initiate an RRC connection establishment process.

[0104] Example 5

[0105] This embodiment provides a method for a UE to process ongoing transmission of pre-configured uplink resources when cell reselection occurs.

[0106] Step 1: The UE uses the stored pre-configured uplink resources to send uplink data, that is, the UE is performing an uplink transmission process based on the pre-configured uplink resources.

[0107] In this step, as described above, the UE RRC layer triggers the RRC connection establishment or RRC connection recovery process, and determines to use the pre-configured uplink resource transmission mode to send uplink data.

[0108] Step 2: UE performs cell reselection, or cell reselection occurs.

[0109] Step 3: The UE performs one or more of the following operations:

[0110] Action 1: Reset MAC.

[0111] Operation 2: Reestablish the RLC entity corresponding to the SRB and / or DRB.

[0112] Operation 3: Inform the upper layer of the failure to establish the RRC connection or the failure to resume the RRC connection with the suspend indication. Preferably, operation 3 is performed after all other operations.

[0113] Operation 4: Release the saved or used pre-configured uplink resource configuration.

[0114] The above operations 1 / 2 / 3 may be performed under the condition that the UE has sent an RRC connection recovery request message and has not received a corresponding response message, or may be performed under other conditions.

[0115] If the UE has sent an RRC Connection Recovery Request message and has not received a corresponding response message, such as an RRC Connection Recovery message, then

[0116] Action 5: Delete the security key derived in step 1.

[0117] Operation 6: Suspend all SRBs and / or DRBs. Preferably, the SRBs do not include SRB0.

[0118] Action 7: Configure the lower layer to suspend integrity protection and encryption functions.

[0119] Otherwise, that is, if it is not satisfied that the UE has sent an RRC connection recovery request message and has not received a corresponding response message, then

[0120] Action 8: Release the MAC configuration.

[0121] If the T300 timer is turned on in step 1, then in step 3, the execution condition of the above operation is that T300 is running. The T300 is an RRC timer used to monitor the RRC connection establishment / recovery process. The timer starts when the RRC process of initial access is initiated and stops when the corresponding response message is received. If the timer times out, it is considered that the RRC connection establishment / recovery process has failed.

[0122] Example 6

[0123] This embodiment proposes a method for a UE to ensure that the latest pre-configured uplink resource request information is delivered to a target base station during a handover process.

[0124] Step 1: The UE receives the handover command and performs the handover.

[0125] The handover command refers to an RRC connection reconfiguration message including a mobility control information element (MobilityControlInfo), or an RRC reconfiguration message including a synchronization reconfiguration information element (reconfigurationWithSync). The mobility control information element and the synchronization reconfiguration information element are used to carry target cell information for handover in the LTE system and the NR system, respectively.

[0126] Step 2: The MAC layer successfully completes the random access process. Or if the handover command is configured not to perform random access (i.e., the rach-Skip information element), the MAC indicates that it has successfully received the Physical Downlink Control Channel (PDCCH) addressed by the UE's radio network identifier (i.e., Radio Network Temporary Identifier, RNTI).

[0127] Step 3: If the target cell of switching (i.e., the serving cell after switching) enables the sending of pre-configured uplink resource request information, and if the UE has sent a pre-configured uplink resource request message to the network side within a recent period of time before receiving the switching command, the UE initiates the sending of a pre-configured uplink resource request message to the target cell.

[0128] In this step, the target cell enables the sending of pre-configured uplink resource request information, preferably, it refers to the enabling / configuration information of the pre-configured uplink resource request information included in the system information. Alternatively, it refers to the enabling / configuration information of the pre-configured uplink resource request information included in the handover command or in the RRC connection reconfiguration message received after the handover is completed.

[0129] Example 7

[0130] This embodiment provides a method for a UE to send pre-configured uplink resource request information.

[0131] Step 1: The UE initiates the sending of pre-configured uplink resource request information.

[0132] In this step, the UE initiating the sending of the pre-configured uplink resource request information further includes if the uplink resource request information prohibition timer is not running, the UE initiating the sending of the pre-configured uplink resource request information.

[0133] Step 2: The UE starts the pre-configured uplink resource request information prohibition timer.

[0134] Optionally, the following step 3 is also included.

[0135] Step 3: When the UE initiates the RRC connection re-establishment process or the UE performs a handover, the pre-configured uplink resource request information prohibition timer is stopped. The UE performs a handover, that is, the UE receives a handover command.

[0136] Before step 1, the method further includes: the UE receiving a pre-configured uplink resource configuration including a pre-configured uplink resource request information prohibit timer configuration from the base station. The pre-configured uplink resource request information prohibit timer configuration at least includes a value of the pre-configured uplink resource request information prohibit timer.

[0137] The prohibition timer defined in this embodiment can achieve the purpose of preventing the UE from sending pre-configured uplink resource request information to the base station too frequently.

[0138] Example 8

[0139] This embodiment provides a method for configuring pre-configured uplink resources.

[0140] Step 1: The UE receives an RRC message containing a pre-configured uplink resource configuration from a base station, which contains the maximum number of HARQ transmissions on the pre-configured resources. The maximum number of HARQ transmissions may also be the maximum number of HARQ retransmissions.

[0141] Step 2: The UE performs uplink transmission on the pre-configured uplink resources. When the HARQ transmission number or HARQ retransmission number of the uplink transmission reaches (greater than or greater than or equal to) the HARQ maximum transmission number or HARQ maximum retransmission number configured in step 1, the UE considers that the uplink transmission of the pre-configured uplink resources has failed, that is, the UE will stop listening to the scheduling information for retransmission from the base station in the corresponding search space. The search space is the PDCCH search space, and the scheduling information is the PDCCH used to schedule retransmission or downlink control information (DCI).

[0142] This embodiment avoids energy consumption caused by the UE monitoring the scheduling of retransmissions without restriction by timing the maximum number of transmissions of the uplink transmission on the pre-configured uplink resources.

[0143] Figure 4 1 is a simplified structural diagram of the user equipment UE involved in the present disclosure. Figure 4As shown, the user equipment UE400 includes a processor 401 and a memory 402. The processor 401 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 402 may include, for example, a volatile memory (such as a random access memory RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other memories, etc. The memory 402 stores program instructions. When the instructions are executed by the processor 401, the above method performed by the user equipment described in detail in the present disclosure may be executed.

[0144] The program running on the device according to the present disclosure may be a program that enables a computer to implement the functions of the embodiments of the present disclosure by controlling a central processing unit (CPU). The program or information processed by the program may be temporarily stored in a volatile memory (such as a random access memory RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other memory systems.

[0145] The program for realizing the functions of each embodiment of the present disclosure can be recorded on a computer-readable recording medium. The corresponding functions can be realized by making a computer system read the program recorded on the recording medium and executing these programs. The so-called "computer system" herein can be a computer system embedded in the device, and can include an operating system or hardware (such as a peripheral device). "Computer-readable recording medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium of a short-term dynamic storage program, or any other recording medium readable by a computer.

[0146] The various features or functional modules of the devices used in the above embodiments can be implemented or executed by circuits (e.g., monolithic or multi-chip integrated circuits). Circuits designed to perform the functions described in this specification may include general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above devices. The general-purpose processor may be a microprocessor, or any existing processor, controller, microcontroller, or state machine. The above circuits may be digital circuits or analog circuits. In the case where new integrated circuit technologies have emerged to replace existing integrated circuits due to advances in semiconductor technology, one or more embodiments of the present disclosure may also be implemented using these new integrated circuit technologies.

[0147] In addition, the present disclosure is not limited to the above-mentioned embodiments. Although various examples of the embodiments have been described, the present disclosure is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors can be used as terminal devices or communication devices, such as AV equipment, kitchen equipment, cleaning equipment, air conditioners, office equipment, vending machines, and other household appliances.

[0148] As mentioned above, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to the above embodiments, and the present disclosure also includes any design changes that do not deviate from the main purpose of the present disclosure. In addition, various changes can be made to the present disclosure within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. In addition, the components with the same effect described in the above embodiments can be replaced by each other.

Claims

1. A user equipment UE, comprising: processor; as well as A memory, wherein the memory stores instructions for causing the processor to: If the UE is recovering an RRC connection, initiating the sending of an RRC connection recovery request message, wherein the UE uses a pre-configured uplink resource PUR to send uplink data; deriving security keys; and If (i) cell reselection occurs, (ii) timer T300 is already running, and (iii) the UE has not received a corresponding response message after sending the RRC connection recovery request message, the following actions are performed: Reset media access control MAC; delete the derived security key; Reestablishing a radio link control RLC entity of a signaling radio bearer SRB and a data radio bearer DRB; Suspend all SRBs and DRBs except the first SRB, SRB0; Configure underlying layers to suspend integrity protection and encryption capabilities; and Notify upper layers of failure to establish an RRC connection or failure to resume an RRC connection with a suspend indication.

2. A control method in a user equipment UE, comprising: If the UE is recovering an RRC connection, initiating the sending of an RRC connection recovery request message, wherein the UE uses a pre-configured uplink resource PUR to send uplink data; deriving security keys; and If (i) cell reselection occurs, (ii) timer T300 is already running, and (iii) the UE has not received a corresponding response message after sending the RRC connection recovery request message, the following actions are performed: Reset media access control MAC; delete the derived security key; Reestablishing a radio link control RLC entity of a signaling radio bearer SRB and a data radio bearer DRB; Suspend all SRBs and DRBs except the first SRB, SRB0; Configure underlying layers to suspend integrity protection and encryption capabilities; and Notify upper layers of failure to establish an RRC connection or failure to resume an RRC connection with a suspend indication.

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