CN117320089A - RedCAP terminal and reselection control method thereof - Google Patents

Abstract

The invention discloses a reselection control method of a RedCAP terminal. And in the process of reselecting any NR cell B by the RedCAP terminal, if the RedCAP terminal finds that the NR cell B does not allow the access of the RedCAP terminal, adding the information of the NR cell B into a forbidden access list. When the RedCAP terminal meets the condition of reselecting a certain target NR cell, judging whether the target NR cell exists in a forbidden access list or not; if yes, the RedCAP terminal does not execute a reselection process and is maintained in the original cell; if not, the RedCAP terminal executes a normal reselection flow. The invention controls the RedCAP terminal not to frequently initiate the cell reselection attempt to the 5G common NR cell, ensures that the service of the RedCAP terminal can be normally initiated, is not easy to lose the paging message of the network, and avoids the increase of power consumption.

Description

RedCAP terminal and reselection control method thereof

Technical Field

The invention relates to a control method for Intra-radio access technology (Intra Radio Access Technology, intra-RAT) reselection and Inter-radio access technology (Inter Radio Access Technology, inter-RAT) reselection of a RedCAP (Reduced Capability, reduced performance) terminal.

Background

The RedCap terminal is also called a lightweight NR (NR-Light) terminal, and the main application scene comprises industrial applications such as an industrial sensor, video monitoring and the like and consumer applications of wearable equipment. The remote upgrade and maintenance are needed for the most part of industry application-oriented RedCAP terminals in an unattended scene, so that the RedCAP terminals have high requirements on network coverage and connection reliability, and meanwhile, the RedCAP terminals need to keep low power consumption.

Whether or not the RedCap terminal can access a cell is mainly in accordance with the specifications of the existing communication protocols 3gpp TS 38.300, 38.304 and 38.331. The parameter cellbarreddedcap 1Rx, cellBarredRedCap Rx in SIB1 (System Information Block Type, system information block one) indicates whether the own cell allows a 1Rx (single receive antenna), 2Rx (dual receive antenna) end access; the parameter halfdupex RedCap indicates whether the cell allows the RedCap terminal supporting only half duplex to access or not, and the parameter is only applicable to FDD (Frequency Division Duplexing, frequency division duplex) system. If the INTRAFreqReselection RedCAP does not appear in SIB1, the cell prohibits access of the RedCAP terminal. And the RedCAP terminal judges the indication information, and can reside in a cell and initiate random access when the requirement of allowing access is met. The RedCap terminal can only camp on an NR cell supporting RedCap (hereinafter referred to as a 5G RedCap cell) and cannot camp on a normal NR cell not supporting RedCap (hereinafter referred to as a 5G normal NR cell) in a 5G NR (New Radio) network.

Cell reselection (reselection), redirection (redirection), handover (handover) are three basic procedures for mobility management in a mobile communication system. The reselection refers to that the mobile terminal selects a resident cell according to the reselection parameter configuration (configured in a broadcast message of the cell for all mobile terminals in the cell) and neighbor cell measurement results of the network in an IDLE state (rrc_idle) or a non-active state (rrc_inactive), and the mobile terminal is in the IDLE state or the non-active state before and after reselection. The redirection refers to that when the mobile terminal is switched to an idle state or an inactive state in a connection state (RRC_CONNECTED), the network designates the frequency point of a neighboring cell in the RRCRelease message, the mobile terminal is switched to the idle state or the inactive state from the connection state, searches for the residence of a target cell on the designated frequency point, and the mobile terminal is switched to the idle state or the inactive state after redirection. The switching refers to the behavior of the mobile terminal in the connection state, the target cell is explicitly specified by the network, and the mobile terminal is still in the connection state after switching to the target cell. The reselection is performed by the mobile terminal autonomously deciding based on the measurement result (which is not reported to the network) and the reselection parameter configuration. Redirection and handover are indicated by network-issued commands, typically triggered by the mobile terminal sending measurement reports.

A Serving Cell (SCELL) refers to a Cell in which a mobile terminal currently resides, and a Neighbor Cell (NCELL) refers to other cells adjacent to the Serving Cell. When the RedCap terminal successfully camps on the serving Cell, it is required to continuously monitor the signal quality (reference signal received quality RSRQ, reference Signal Receiving Quality) and the signal strength (reference signal received power RSRP, reference Signal Receiving Power) of the serving Cell and the neighboring cells, and select a better Cell to camp on according to a certain Reselection rule, which is Cell Reselection. The reselection configuration information is obtained from a system information block (System Information Block, SIB) received by the mobile terminal from a Broadcast Channel (BCH) of the serving cell, and includes Intra-Frequency (Intra-Frequency) reselection configuration information, inter-Frequency (Inter-Frequency) reselection configuration information, and Inter-radio access technology reselection configuration information. If a certain co-frequency neighbor cell or inter-frequency neighbor cell satisfies a corresponding cell reselection rule, the cell reselection process triggered by the corresponding cell reselection rule is called Intra-radio access technology reselection (Intra-RAT Cell Reselection), which is also simply referred to as Intra-system reselection or Intra-mode reselection. If a certain Inter-system neighbor cell meets the corresponding cell reselection rule, the cell reselection process triggered by the corresponding cell reselection rule is called Inter-radio access technology reselection (Inter-RAT Cell Reselection), and is also simply called Inter-system reselection, or Inter-mode reselection.

RedCap is a technology introduced by the Release 17 (3 gpp Release 17) Release 5g version, the access of which is constrained by the above protocol specifications. To support RedCap, the 5G base station needs to be upgraded to the R17 protocol version. A 5G base station supporting only the R15 or R16 protocol version does not support access of the RedCap terminal. For the condition that the RedCAP terminal is in a non-RedCAP network environment or in a network environment where a 5GRedCap cell and a 5G common NR cell coexist, how to ensure normal initiation of the service influences the user experience of the service of the RedCAP terminal. The scale application of the RedCAP terminal depends on the large-scale coverage of the 5G network, the coverage breadth and depth of the 5G commercial network still have the defects at present, and the access of the RedCAP terminal is supported to adapt and upgrade the 5G commercial network. Therefore, when the 5G network does not fully realize breadth and depth coverage, the RedCap terminal needs to be compatible to support 4G mode access in an application scenario with high requirements on network coverage continuity and mobility, which can enable the RedCap terminal to have wider service access and processing capability and forward compatibility between the terminal device and the network device. Therefore, the RedCAP multimode terminal can drive large-scale development through wider access capability. Because RedCap is a technology introduced by 5G r17, the existing 4G LTE network needs to be upgraded or compatible to support RedCap multimode capability, and the RedCap multimode terminal needs to be actively compatible with the existing 4G network capability, otherwise, compatibility problems are easily caused, and normal service access is affected.

The RedCap terminal in the present invention includes both a RedCap single-mode terminal supporting only the RedCap cell access of the 5G NR network and a RedCap multimode terminal supporting both the RedCap cell of the 5G NR network and the 4G LTE network access.

Referring to fig. 1, the existing intra-radio access technology cell reselection procedure of the RedCap terminal sequentially includes the following steps. This occurs when the RedCap terminal is in a 5G network environment where 5G RedCap cells and 5G normal NR cells coexist.

Step A1: the RedCap terminal currently resides in 5G RedCap cell a supporting access by the RedCap terminal.

Step A2: when the RedCap terminal enters an NR mode idle state or inactive state, the network configures co-frequency and/or inter-frequency measurements via system messages (e.g., SIB2, SIB3, SIB 4). There may be 5G RedCap cells or 5G normal NR cells in the configured NR frequency points.

Step A3: the RedCap terminal performs the same-frequency measurement and/or different-frequency measurement. The identification of the 5G RedCap cell by the RedCap terminal depends on the parameters in the obtained SIB1, and the RedCap terminal cannot identify whether the neighboring cell is the 5G RedCap cell in the measurement process performed in the idle state or the inactive state.

Step A4: the cell signal quality of the neighbor cell B under the NR frequency point measured by the RedCAP terminal meets the reselection evaluation criterion under the idle state or the inactive state, which is a 5G common NR cell. For some objective reasons, for example, the network neighbor relation may be dynamically added, or the network optimization work is not completed, or the network side may cause that the network does not limit or ensure that the neighbor cell of the network under the same frequency and/or different frequency points of the system message configuration is necessarily supported by the access of the RedCap terminal, and the target cell meeting the reselection criterion in the idle state or the inactive state may not support the access of the RedCap.

Step A5: the RedCap terminal attempts to reselect to the NR neighbor B within the radio access technology, but fails to reselect to the target cell B because it does not support RedCap terminal access.

Step A6: the RedCap terminal rolls back the original 5G RedCap cell a or searches the network and resides in other 5G RedCap cells supporting access of the RedCap terminal.

Then repeating steps A2-A6, the target cell B or other 5G normal NR cells may satisfy the reselection criteria in the idle state or inactive state, and the prior art does not add the target cell of this type to the forbidden list of the reselection evaluation, and the RedCap terminal continues to try reselection, and the reselection fails. This process of repeating steps A2-A6 may be repeated a number of times. Such repeated and unnecessary cell reselection attempts, reselection failures, rollbacks, and network searches in the radio access technology may cause difficulty in service initiation of the RedCap terminal, missed reception of paging messages (paging) issued by the network, and even have to exit from an inactive state, while increasing power consumption of the RedCap terminal.

Referring to fig. 2, the inter-radio access technology cell reselection procedure of the conventional RedCap multimode terminal sequentially includes the following steps. This occurs when the RedCap multimode terminal is in a network environment where a 4G LTE network and a 5G NR network coexist.

Step B1: the RedCap multimode terminal currently resides in 4G LTE cell a.

Step B2: when the RedCap multimode terminal enters an LTE mode idle state or an inactive state, since the network generally deploys 5G mode preference, the LTE network generally configures inter-radio access technology measurements (including information such as NR frequency points, threshX, q-RxLevMin, etc.) of the NR network for the RedCap multimode terminal through a system message (e.g., SIB 24). There may be 5G RedCap cells or 5G normal NR cells in the configured NR frequency points.

Step B3: the RedCap multimode terminal performs inter-radio access technology NR measurements. The identification of 5G RedCap cells by the RedCap multimode terminal depends on obtaining parameters in SIB1, and the RedCap multimode terminal cannot identify whether these NR cells are 5G RedCap cells or not in the course of performing measurements in idle or inactive states.

Step B4: the cell signal quality of the neighbor cell B under the NR frequency point measured by the RedCAP multimode terminal meets the reselection evaluation criterion under the idle state or the inactive state, which is a 5G common NR cell. For some objective reasons, for example, the network neighbor relation may be dynamically added, or the network optimization work is not completed, or the network side may not limit or ensure that the NR target cells under the frequency points between the radio access technologies are necessarily supported by the access of the RedCap terminal, and the target cells meeting the reselection criteria in the idle state or the inactive state may not support the access of the RedCap.

Step B5: the RedCap multimode terminal attempts an inter-radio access technology reselection to NR neighbor B, but fails because it does not support RedCap terminal access.

Step B6: the RedCAP multimode terminal backs off the original 4G LTE cell A, or searches the network in the LTE mode and camps on other 4GLTE cells.

Then repeating steps B2-B6, where the target cell B or other 5G normal NR cells may satisfy the reselection criteria in the idle state or inactive state, the prior art does not add the target cell of this type to the forbidden list of the reselection evaluation, and the RedCap multimode terminal continues to attempt the inter-radio access technology reselection, and the reselection fails. This process of repeating steps B2-B6 may be repeated a number of times. The repeated and unnecessary inter-radio access technology cell reselection attempt, reselection failure, rollback and network searching processes can cause difficulty in service initiation of the RedCap multimode terminal, missed reception of paging messages issued by the network, even have to exit from an inactive state, and increase power consumption of the RedCap multimode terminal.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: how to enable the RedCAP terminal to maintain the normal initiation of the service in the network environment where the 5G RedCAP cell and the 5G common NR cell coexist or in the network environment where the 4G and the 5G coexist.

In order to solve the technical problems, the invention provides a reselection control method of a RedCAP terminal, which comprises the following steps. Step S1: and in the process of reselecting any NR cell B by the RedCAP terminal, if the RedCAP terminal finds that the NR cell B does not allow the access of the RedCAP terminal, adding the information of the NR cell B into a forbidden access list. Step S2: when the RedCAP terminal meets the condition of reselecting a certain target NR cell, the RedCAP terminal judges whether the target NR cell exists in a forbidden access list currently or not; if yes, the RedCAP terminal does not execute a reselection process and is maintained in the original cell; if not, the RedCAP terminal executes a normal cell reselection procedure.

Further, the reselection is an intra-radio access technology reselection; the step S1 is executed during the intra-radio access technology reselection of the RedCap terminal from any 5G RedCap cell a to any NR cell B, and the step S2 is executed when a certain 5G RedCap cell satisfies a condition of intra-radio access technology reselection to a certain target NR cell.

Further, the reselection is an inter-radio access technology reselection; the step S1 is executed during the process of reselecting the radio access technology from any 4G LTE cell a to any NR cell B by the RedCap terminal, and the step S2 is executed when a certain 4G LTE cell satisfies a condition of reselecting a certain target NR cell between radio access technologies.

Further, in the step S1, the information added in the forbidden access list includes a cell frequency point (NR-ARFCN, NR Absolute Radio Frequency Channel Number), a physical layer cell identifier (PCI, physical Cell Identity), and a subcarrier spacing (Subcarrier Spacing) of a synchronization signal block (SSB, synchronization Signal Block) of the NR cell B; the information is stored in a nonvolatile memory of the RedCAP terminal; in the step S2, the judgment basis is that the three pieces of information of the cell frequency point of the target NR cell, the physical layer cell identifier, the subcarrier interval of the synchronization signal block and the certain NR cell in the forbidden access list are all consistent.

Further, in the step S1, the information added in the forbidden access list further includes a global cell identifier of the original cell a; in the step S2, the judgment basis is that the four pieces of information of the cell frequency point of the target NR cell, the physical layer cell identifier, the subcarrier interval of the synchronization signal block, the global cell identifier of the current cell and the four pieces of information of a certain NR cell in the forbidden access list are all identical.

Further, in the step S1, the RedCap terminal further sets an expiration date for adding the information of the NR cell B to the forbidden access list; when the validity period of the cell B is exceeded, the RedCap terminal deletes the information of the NR cell B from the access forbidden list.

Preferably, the step S1 is performed during the first reselection of the RedCap terminal to any NR cell B.

The invention also provides a RedCAP terminal for realizing reselection control, which comprises a reselection failure recording unit and a reselection judgment executing unit. The reselection failure recording unit is used for adding the information of the NR cell B into a forbidden access list if the NR cell B is found not to allow the access of the RedCAP terminal in the process of reselecting the RedCAP terminal to any NR cell B. The reselection judging and executing unit is used for judging whether the target NR cell exists in the forbidden access list or not when the RedCAP terminal meets the condition of reselecting a certain target NR cell; if so, the RedCAP terminal does not perform a reselection procedure and remains in the original cell.

The invention has the technical effects that: and controlling the RedCAP terminal not to initiate a cell reselection attempt to the confirmed 5G common NR cell, ensuring that the service of the RedCAP terminal can be normally initiated, and avoiding the increase of power consumption because the paging message of the network is not easy to be lost.

Drawings

Fig. 1 is a schematic diagram of a cell reselection procedure in a radio access technology of a conventional RedCap terminal.

Fig. 2 is a schematic diagram of a cell reselection procedure between radio access technologies of a conventional RedCap multimode terminal.

Fig. 3 is a flow chart of a reselection control method in a radio access technology of a RedCap terminal according to the present invention.

Fig. 4 is a flow chart of a reselection control method between radio access technologies of the RedCap multimode terminal according to the present invention.

Fig. 5 is a schematic structural diagram of a RedCap terminal for implementing intra-radio access technology reselection control according to the present invention.

Fig. 6 is a schematic structural diagram of a RedCap multimode terminal for implementing inter-radio access technology reselection control according to the present invention.

The reference numerals in the drawings illustrate: 1 is a reselection failure recording unit in a wireless access technology, 2 is a reselection judgment executing unit in the wireless access technology, 3 is a reselection failure recording unit among wireless access technologies, and 4 is a reselection judgment executing unit among wireless access technologies.

Detailed Description

Referring to fig. 3, the intra-radio access technology reselection control method for a RedCap terminal according to the present invention includes the following steps. The method is suitable for a 5G network environment where the RedCAP terminal is in a 5G RedCAP cell and a 5G common NR cell coexist.

Step SA1: in the process that the RedCAP terminal reselects from any 5G RedCAP cell A to any NR cell B in the wireless access technology, if the RedCAP terminal finds that the NR cell B does not allow the access of the RedCAP terminal, the information of the 5G ordinary NR cell B is added into a forbidden access list, wherein the information indicates that the NR cell B belongs to the 5G ordinary NR cell. The added information comprises the cell frequency point, physical layer cell identification and subcarrier spacing of the synchronous signal block of the 5G common NR cell B. The information is stored in a nonvolatile memory of the RedCAP terminal, so that the RedCAP terminal can still be used after being started next time.

Optionally, the RedCap terminal further sets a validity period for adding information of the 5G normal NR cell B to the forbidden access list. And deleting the information of the 5G ordinary NR cell B from the forbidden access list when the validity period of the 5G ordinary NR cell B is exceeded. Thus, after the 5G common NR cell B is accessed by the network upgrading support RedCAP terminal, the 5G common NR cell B is changed into the 5G RedCAP cell B, and the RedCAP terminal can be normally accessed into the 5G RedCAP cell B.

In this step, the RedCap terminal determines that a certain NR cell B is a target cell through intra-radio access technology reselection (for example, first time) from the 5G RedCap cell a, obtains downlink synchronization of the target cell B in the process of attempting to access the target cell B, and successfully receives a system message MIB (master information block ) and SIB1. If the parameter in SIB1 indicates that the NR cell B allows access of the RedCap terminal, the RedCap terminal determines that the target cell B is a 5G RedCap cell, and the RedCap terminal continues to perform a normal intra-radio access technology cell reselection procedure. If the parameter in SIB1 indicates that the NR cell B does not allow the access of the RedCAP terminal, the RedCAP terminal judges that the target cell B is not a 5G RedCAP cell but a 5G common NR cell, and adds the information of the target cell B into a forbidden access list.

Step SA2: when the RedCap terminal meets the condition of reselecting a certain target NR cell in the radio access technology in a certain 5G RedCap cell (not limited to the 5G RedCap cell a), the RedCap terminal judges whether the target NR cell currently exists in the forbidden access list. The comparison range is the three information of the cell frequency point, the physical layer cell identification, the subcarrier interval of the synchronous signal block and each NR cell in the forbidden access list of the target NR cell. If the three pieces of information of the target NR cell are the same as the three pieces of information of one NR cell in the forbidden access list, the target NR cell is indicated to exist in the forbidden access list currently; otherwise, the target NR cell is not currently in the forbidden access list.

Because the cell frequency point and the physical layer cell identification are multiplexed in the mobile communication network, the mobile terminal may meet the condition that the information of the three different cells is consistent in the moving process. In order to solve this problem, it is preferable to record in the forbidden access list in step SA1 the global cell identity (Global cell identity) of the original 5G RedCap cell a where the 5G normal NR cell B was located before the attempt of reselection to the 5G normal NR cell B, and add a criterion in step SA 2-to compare whether the global cell identity of the current serving cell of the RedCap terminal is identical with the global cell identity of the original 5G RedCap cell a in the forbidden access list. If the sum of the three information of the target NR cell and the global cell identifier of the current cell is the same as the four information of a certain NR cell in the forbidden access list, the target NR cell is indicated to exist in the forbidden access list currently; otherwise, the target NR cell is not currently in the forbidden access list.

If the target NR cell is currently in the forbidden access list, even if the intra-radio access technology reselection procedure is triggered, there is a high probability that the intra-radio access technology reselection will fail, and the RedCap terminal does not need to initiate such unnecessary abnormal reselection. At this time, the RedCap terminal decides that the target NR cell is not suitable for intra-radio access technology reselection, does not initiate an intra-radio access technology reselection procedure, and continues to maintain in the current 5G RedCap cell. The method and the device avoid the actions of the RedCAP terminal such as unnecessary initiation of abnormal reselection, cell rollback after reselection failure, network searching and the like, and the problems that the service initiation of the RedCAP terminal is difficult and the paging of the network side is difficult to lose in the process of the actions are avoided, so that the user experience can be effectively improved.

If the target NR cell is not currently in the forbidden access list, the RedCAP terminal continues to initiate a normal intra-radio access technology cell reselection procedure.

Referring to fig. 4, the inter-radio access technology reselection control method of the RedCap multimode terminal provided by the invention includes the following steps. The method is suitable for a network environment where the RedCAP multimode terminal is in a 4G LTE cell and a 5G NR cell coexist.

Step SB1: in the process that the RedCAP multimode terminal reselects between wireless access technologies from any 4G LTE cell A to any NR cell B, if the RedCAP multimode terminal finds that the NR cell B does not allow the access of the RedCAP terminal, the information of the 5G ordinary NR cell B is added into a forbidden access list, wherein the information indicates that the NR cell B belongs to the 5G ordinary NR cell. The added information comprises the cell frequency point, physical layer cell identification and subcarrier spacing of the synchronous signal block of the 5G common NR cell B. The information is stored in a nonvolatile memory of the RedCAP multimode terminal, so that the RedCAP multimode terminal can still be used after being started next time.

Optionally, the RedCap multimode terminal further sets a validity period for adding the information of the 5G normal NR cell B to the forbidden access list. And deleting the information of the 5G ordinary NR cell B from the forbidden access list when the validity period of the 5G ordinary NR cell B is exceeded. Thus, after the 5G common NR cell B is accessed by the network upgrading support RedCAP terminal, the 5G common NR cell B is changed into the 5G RedCAP cell B, and the RedCAP multimode terminal can normally access the 5G RedCAP cell B.

In this step, the RedCap multimode terminal determines that a certain NR cell B is a target cell from the 4G LTE cell a through inter-radio access technology reselection (for example, first time), obtains downlink synchronization of the target cell B in the process of attempting to access the target cell B, and successfully receives the system message MIB and SIB1. If the parameter in SIB1 indicates that the NR cell B allows access of the RedCap terminal, the RedCap multimode terminal determines that the target cell B is a 5G RedCap cell, and the RedCap multimode terminal continues to perform a normal inter-radio access technology cell reselection procedure. If the parameter in SIB1 indicates that the NR cell B does not allow the access of the RedCAP terminal, the RedCAP multimode terminal judges that the target cell B is not a 5G RedCAP cell but a 5G common NR cell, and adds the information of the target cell B into a forbidden access list.

Step SB2: when the RedCap multimode terminal meets the condition of reselecting a certain target NR cell among wireless access technologies in a certain 4G LTE cell (not limited to the 4G LTE cell A), the RedCap multimode terminal judges whether the target NR cell currently exists in a forbidden access list. The comparison range is the three information of the cell frequency point, the physical layer cell identification, the subcarrier interval of the synchronous signal block and each cell in the forbidden access list of the target NR cell. If the three pieces of information of the target NR cell are the same as the three pieces of information of one NR cell in the forbidden access list, the target NR cell is indicated to exist in the forbidden access list currently; otherwise, the target NR cell is not currently in the forbidden access list.

Because the cell frequency point and the physical layer cell identification are multiplexed in the mobile communication network, the mobile terminal may meet the condition that the information of the three different cells is consistent in the moving process. In order to solve this problem, it is preferable to record in the forbidden access list in step SB1 the global cell identity of the original 4G LTE cell a where the radio access technology was located before the attempt to reselect to the 5G normal NR cell B, and add a criterion in step SB 2-further compare whether the global cell identity of the current serving cell of the RedCap terminal is identical with the global cell identity of the original 4G LTE cell a in the forbidden access list. If the sum of the three information of the target NR cell and the global cell identifier of the current cell is the same as the four information of a certain NR cell in the forbidden access list, the target NR cell is indicated to exist in the forbidden access list currently; otherwise, the target NR cell is not currently in the forbidden access list.

If the target NR cell is currently in the forbidden access list, there is a high likelihood that the inter-radio access technology reselection will fail even if the inter-radio access technology reselection procedure is triggered, then the RedCap multimode terminal need not initiate such an unnecessary abnormal reselection. At this time, the RedCap multimode terminal decides that the target NR cell is not suitable for reselection, does not initiate an inter-radio access technology reselection procedure, and continues to maintain in the current 4G LTE cell. The method and the device avoid the actions of the RedCAP multimode terminal such as the back-off of the original cell, the network searching and the like after the abnormal reselection and the reselection failure are not necessarily initiated, and the service initiation difficulty and the paging loss of the network side of the RedCAP multimode terminal are not caused in the period, so that the user experience can be effectively improved.

If the target NR cell is not currently in the forbidden access list, the RedCAP multimode terminal continues to initiate a normal inter-radio access technology cell reselection procedure.

Referring to fig. 5, the RedCap terminal for implementing intra-radio access technology reselection control according to the present invention includes an intra-radio access technology reselection failure recording unit 1 and an intra-radio access technology reselection determination executing unit 2. The apparatus shown in fig. 5 corresponds to the method shown in fig. 3.

The intra-radio access technology reselection failure recording unit 1 is configured to, in a process that the RedCap terminal performs intra-radio access technology reselection from any 5G RedCap cell a to any NR cell B, add information of the NR cell B to a forbidden access list if the NR cell B is found not to allow the RedCap terminal to access.

The intra-radio access technology reselection judging and executing unit 2 is configured to judge whether a target NR cell currently exists in the forbidden access list when the condition that the target NR cell is reselected in the radio access technology is satisfied by the 5G RedCap cell. If yes, the RedCAP terminal does not execute the intra-radio access technology reselection process and remains in the original cell. If not, the RedCap terminal performs a normal intra-radio access technology reselection procedure.

Referring to fig. 6, the RedCap multimode terminal for implementing inter-radio access technology reselection control according to the present invention includes an inter-radio access technology reselection failure recording unit 3 and an inter-radio access technology reselection judging executing unit 4. The apparatus shown in fig. 6 corresponds to the method shown in fig. 4.

The inter-radio access technology reselection failure recording unit 3 is configured to, in a process of performing inter-radio access technology reselection from any 4G LTE cell a to any NR cell B by a RedCap multimode terminal, add information of the NR cell B to a forbidden access list if the NR cell B is found to not allow access of the RedCap terminal.

The inter-radio access technology reselection judging and executing unit 4 is configured to judge whether a target NR cell currently exists in the forbidden access list when the condition that the inter-radio access technology reselection is performed by the RedCap multimode terminal in a certain 4G LTE cell satisfies a condition that the inter-radio access technology reselection is performed by the target NR cell. If so, the RedCAP multimode terminal does not execute the inter-radio access technology reselection process and remains in the original cell. If not, the RedCAP multimode terminal executes a normal inter-radio access technology reselection procedure.

The reselection control method of the RedCAP terminal provided by the invention is optimized aiming at two network environments. The first network environment is a 5G network environment in which a 5G RedCAP cell and a 5G common NR cell coexist, and the RedCAP terminal is in an idle state or an inactive state in an NR mode. The second network environment is a network environment in which a 4G LTE cell and a 5G NR cell coexist, and the RedCAP multimode terminal is in an LTE mode idle state or an inactive state. In the two network environments, the invention can effectively control the RedCAP terminal not to initiate a cell reselection attempt to the 5G common NR cell which does not allow the access of the RedCAP, ensure that the service of the RedCAP terminal in the two network environments can be normally initiated, avoid losing paging information of the network easily, avoid increasing power consumption, ensure that the compatibility of the RedCAP terminal to the network is better, and effectively promote the user experience of the service of the RedCAP terminal.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Various modifications and variations of the present invention will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. A reselection control method of a RedCAP terminal is characterized by comprising the following steps of;

step S1: in the process that the RedCAP terminal reselects to any NR cell B, if the RedCAP terminal finds that the NR cell B does not allow the access of the RedCAP terminal, the information of the NR cell B is added into a forbidden access list;

step S2: when the RedCAP terminal meets the condition of reselecting a certain target NR cell, the RedCAP terminal judges whether the target NR cell exists in a forbidden access list currently or not; if yes, the RedCAP terminal does not execute a reselection process and is maintained in the original cell; if not, the RedCAP terminal executes a normal cell reselection procedure.

2. The method for controlling reselection of a RedCap terminal according to claim 1, wherein the reselection is an intra-radio access technology reselection; the step S1 is executed during the intra-radio access technology reselection of the RedCap terminal from any 5G RedCap cell a to any NR cell B, and the step S2 is executed when a certain 5G RedCap cell satisfies a condition of intra-radio access technology reselection to a certain target NR cell.

3. The method for controlling reselection of a RedCap terminal according to claim 1, wherein the reselection is an inter-radio access technology reselection; the step S1 is executed during the process of reselecting the radio access technology from any 4G LTE cell a to any NR cell B by the RedCap terminal, and the step S2 is executed when a certain 4G LTE cell satisfies a condition of reselecting a certain target NR cell between radio access technologies.

4. The method for controlling reselection of a RedCap terminal according to claim 2 or 3, wherein in the step S1, the information added in the forbidden access list includes a cell frequency point of the NR cell B, a physical layer cell identifier, and a subcarrier interval of a synchronization signal block; the information is stored in a nonvolatile memory of the RedCAP terminal; in the step S2, the judgment basis is that the three pieces of information of the cell frequency point of the target NR cell, the physical layer cell identifier, the subcarrier interval of the synchronization signal block and the certain NR cell in the forbidden access list are all consistent.

5. The method for controlling reselection of a RedCap terminal according to claim 4, wherein in the step S1, the information added in the forbidden access list further includes a global cell identifier of the original cell a; in the step S2, the judgment basis is that the four pieces of information of the cell frequency point of the target NR cell, the physical layer cell identifier, the subcarrier interval of the synchronization signal block, the global cell identifier of the current cell and the four pieces of information of a certain NR cell in the forbidden access list are all identical.

6. The method for controlling reselection of the RedCap terminal according to claim 1, wherein in the step S1, the RedCap terminal further sets a validity period for adding the information of the NR cell B to the forbidden access list; when the validity period of the cell B is exceeded, the RedCap terminal deletes the information of the NR cell B from the access forbidden list.

7. A method for controlling reselection of a RedCap terminal according to claim 2 or 3, characterized in that said step S1 is performed during the first reselection of the RedCap terminal to any NR cell B.

8. The RedCAP terminal for realizing reselection control is characterized by comprising a reselection failure recording unit and a reselection judgment executing unit;

the reselection failure recording unit is used for adding the information of the NR cell B into a forbidden access list if the NR cell B is found not to allow the access of the RedCAP terminal in the reselection process of the RedCAP terminal to any NR cell B;

the reselection judging and executing unit is used for judging whether the target NR cell exists in the forbidden access list or not when the RedCAP terminal meets the condition of reselecting a certain target NR cell; if so, the RedCAP terminal does not perform a reselection procedure and remains in the original cell.