Device, method and computer program

Abstract

An apparatus comprises a component for performing the following operations: determining information, the information comprising: a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and / or a number of successful random access channel attempts in at least one cell controlled by the apparatus and a number of failed random access channel attempts in at least one cell controlled by the apparatus; and sending the information from the apparatus to a second apparatus.

Description

Technical Field

[0001] The present disclosure relates to wireless communications. Some examples relate to random access channel (RACH) procedures. Background Art

[0002] In some wireless networks, such as, for example, Long Term Evolution (LTE) or fifth generation (5G) networks, a user equipment (UE) may attempt to connect to an access node using a random access channel (RACH) procedure.

[0003] In some networks, such as, for example, 5G networks, an access node such as a gNB may internally split the functionality into a centralized unit (CU) and at least one decentralized unit (DU). Summary of the invention

[0004] According to a first aspect, there is provided an apparatus comprising means for determining information comprising a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and sending the information from the apparatus to a second apparatus.

[0005] According to an example, the component is further configured to perform: receiving a message from the second device, the message comprising a failure rate of random access channel attempts in at least one other cell.

[0006] According to an example, at least one other cell in the network is not controlled by the apparatus.

[0007] According to an example, the message comprising the failure rate of random access channel attempts in at least one other cell in the network comprises the total failure rate of two or more other cells in the network.

[0008] According to an example, a message comprising a failure rate of random access channel attempts in at least one other cell in the network is received over the F1 interface.

[0009] According to an example, determining a failure rate of random access channel attempts including in at least one cell controlled by the device is based on: determining a ratio of failed random access channel attempts in at least one cell controlled by the device to a total number of random access channel attempts in at least one cell controlled by the device, wherein the total number of random access channel attempts in at least one cell controlled by the device is determined as the sum of: the number of failed random access channel attempts in at least one cell controlled by the device; and the number of successful random access channel attempts in at least one cell controlled by the device.

[0010] According to an example, the apparatus comprises means for counting a number of successful random access channel attempts in at least one cell controlled by the apparatus.

[0011] According to the example, the component is configured to perform: receiving information about random access channel reports related to random access channel attempts in at least one cell controlled by the device from a second device; and determining a value indicating a failed random access channel attempt in at least one cell controlled by the device based on the information about random access channel reports related to random access channel attempts in at least one cell controlled by the device received from the second device.

[0012] According to an example, when the number of failed random access channel attempts in at least one cell controlled by the apparatus exceeds a threshold, a failure rate of random access channel attempts in at least one cell controlled by the apparatus is determined.

[0013] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with a user equipment.

[0014] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with the user equipment by using the UE context information.

[0015] According to an example, the component is further configured to perform: comparing information including a failure rate of random access channel attempts in at least one cell controlled by the device with a failure rate of random access channel attempts in at least one other cell in the network; and based on the comparison, determining to change the random access channel configuration of the device.

[0016] According to an example, the component is further configured to perform: based on the comparison, determining to change a physical random access channel configuration of the apparatus.

[0017] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per synchronization signal block per cell.

[0018] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per cell.

[0019] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per synchronization signal block per cell.

[0020] According to an example, the apparatus includes a gNB-DU.

[0021] According to an example, the second device comprises an access node.

[0022] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0023] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0024] According to the example, the second device includes a gNB-CU.

[0025] According to a second aspect, an apparatus is provided, comprising at least one processor; and at least one memory comprising computer program code; the at least one memory and the computer program code being configured to, together with the at least one processor, cause the apparatus to at least perform: determining information comprising a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and sending the information from the apparatus to a second apparatus.

[0026] According to an example, the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least perform: receiving a message from a second apparatus, the message comprising a failure rate of random access channel attempts in at least one other cell.

[0027] According to an example, at least one other cell in the network is not controlled by the apparatus.

[0028] According to an example, the message comprising the failure rate of random access channel attempts in at least one other cell in the network comprises the total failure rate of two or more other cells in the network.

[0029] According to an example, a message comprising a failure rate of random access channel attempts in at least one other cell in the network is received over the F1 interface.

[0030] According to an example, determining a failure rate of random access channel attempts including in at least one cell controlled by the device is based on: determining a ratio of failed random access channel attempts in at least one cell controlled by the device to a total number of random access channel attempts in at least one cell controlled by the device, wherein the total number of random access channel attempts in at least one cell controlled by the device is determined as the sum of: the number of failed random access channel attempts in at least one cell controlled by the device; and the number of successful random access channel attempts in at least one cell controlled by the device.

[0031] According to an example, the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least perform: counting a number of successful random access channel attempts in at least one cell controlled by the apparatus.

[0032] According to an example, the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least perform: receiving information about random access channel reports related to random access channel attempts in at least one cell controlled by the device from a second device; and determining a value indicating a failed random access channel attempt in at least one cell controlled by the device based on the information about random access channel reports related to random access channel attempts in at least one cell controlled by the device received from the second device.

[0033] According to an example, when the number of failed random access channel attempts in at least one cell controlled by the apparatus exceeds a threshold, a failure rate of random access channel attempts in at least one cell controlled by the apparatus is determined.

[0034] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with a user equipment.

[0035] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with the user equipment by using the UE context information.

[0036] According to an example, the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to at least perform: comparing information including a failure rate of random access channel attempts in at least one cell controlled by the apparatus with a failure rate of random access channel attempts in at least one other cell in a network; and based on the comparison, determining to change a random access channel configuration of the apparatus.

[0037] According to an example, the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least perform: based on the comparison, determining to change a physical random access channel configuration of the apparatus.

[0038] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per synchronization signal block per cell.

[0039] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per cell.

[0040] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per synchronization signal block per cell.

[0041] According to an example, the apparatus includes a gNB-DU.

[0042] According to an example, the second device comprises an access node.

[0043] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0044] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0045] According to the example, the second device includes a gNB-CU.

[0046] According to a third aspect, an apparatus is provided, comprising: circuitry for determining information including a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and circuitry for sending the information from the apparatus to a second apparatus.

[0047] According to a fourth aspect, there is provided a method comprising: determining information comprising a failure rate of random access channel attempts in at least one cell controlled by a device; and sending the information from the device to a second device.

[0048] According to an example, the method comprises: receiving a message from the second device, the message comprising a failure rate of random access channel attempts in at least one other cell.

[0049] According to an example, at least one other cell in the network is not controlled by the apparatus.

[0050] According to an example, the message comprising the failure rate of random access channel attempts in at least one other cell in the network comprises the total failure rate of two or more other cells in the network.

[0051] According to an example, a message comprising a failure rate of random access channel attempts in at least one other cell in the network is received over the F1 interface.

[0052] According to an example, determining a failure rate of random access channel attempts including in at least one cell controlled by the device is based on: determining a ratio of failed random access channel attempts in at least one cell controlled by the device to a total number of random access channel attempts in at least one cell controlled by the device, wherein the total number of random access channel attempts in at least one cell controlled by the device is determined as the sum of: the number of failed random access channel attempts in at least one cell controlled by the device; and the number of successful random access channel attempts in at least one cell controlled by the device.

[0053] According to an example, the apparatus comprises means for counting a number of successful random access channel attempts in at least one cell controlled by the apparatus.

[0054] According to the example, the method includes: receiving information about a random access channel report related to a random access channel attempt in at least one cell controlled by the device from a second device; and determining a value indicating a failed random access channel attempt in at least one cell controlled by the device based on the information about a random access channel report related to a random access channel attempt in at least one cell controlled by the device received from the second device.

[0055] According to an example, when the number of failed random access channel attempts in at least one cell controlled by the apparatus exceeds a threshold, a failure rate of random access channel attempts in at least one cell controlled by the apparatus is determined.

[0056] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with a user equipment.

[0057] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with the user equipment by using the UE context information.

[0058] According to an example, the method includes: comparing information including a failure rate of random access channel attempts in at least one cell controlled by the device with a failure rate of random access channel attempts in at least one other cell in the network; and based on the comparison, determining to change the random access channel configuration of the device.

[0059] According to an example, the component is further configured to perform: based on the comparison, determining to change a physical random access channel configuration of the apparatus.

[0060] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per synchronization signal block per cell.

[0061] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per cell.

[0062] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per synchronization signal block per cell.

[0063] According to an example, the apparatus includes a gNB-DU.

[0064] According to an example, the second device comprises an access node.

[0065] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0066] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0067] According to the example, the second device includes a gNB-CU.

[0068] According to a fifth aspect, there is provided a computer program comprising instructions for causing an apparatus to at least perform the following operations: determine information comprising a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and send the information from the apparatus to a second apparatus.

[0069] According to a sixth aspect, there is provided a computer program comprising instructions stored thereon for performing at least the following operations: determining information comprising a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and sending the information from the apparatus to a second apparatus.

[0070] According to a seventh aspect, a non-transitory computer-readable medium comprising program instructions is provided, which are used to cause a device to at least perform the following operations: determine information, the information comprising a failure rate of random access channel attempts in at least one cell controlled by the device; and send the information from the device to a second device.

[0071] According to an eighth aspect, a non-transitory computer-readable medium is provided comprising program instructions stored thereon, the program instructions being used to perform at least the following operations: determining information comprising a failure rate of random access channel attempts in at least one cell controlled by the device; and sending the information from the device to a second device.

[0072] According to a ninth aspect, an apparatus is provided, comprising means for receiving information comprising a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and sending the information from the apparatus to a network entity.

[0073] According to an example, the network entity comprises at least one of: an access node; a decentralized unit of an access node; a centralized unit of an access node.

[0074] According to an example, information comprising a failure rate of random access channel attempts in at least one other cell in the network is received over the F1 interface.

[0075] According to an example, the information further comprises random access channel reports, and wherein the component is further configured to perform: filtering the random access channel reports to contain information about random access channel reports for cells controlled by the third device; sending the filtered random access channel reports to the third device.

[0076] According to an example, the third device may include an access node.

[0077] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0078] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0079] According to an example, the third device may include a gNB-DU.

[0080] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the second apparatus is associated with the user equipment.

[0081] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with the user equipment by using the UE context information.

[0082] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per synchronization signal block per cell.

[0083] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per cell.

[0084] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per synchronization signal block per cell.

[0085] According to an example, the apparatus includes a gNB-DU.

[0086] According to an example, the apparatus comprises an access node.

[0087] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0088] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0089] According to the example, the second device includes a gNB-CU.

[0090] According to the tenth aspect, a device is provided, comprising at least one processor; and at least one memory comprising computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least perform: receiving information comprising a failure rate of random access channel attempts in at least one cell controlled by a second device; and sending the information from the device to a network entity.

[0091] According to an example, the network entity comprises at least one of: an access node; a decentralized unit of an access node; a centralized unit of an access node.

[0092] According to an example, information comprising a failure rate of random access channel attempts in at least one other cell in the network is received over the F1 interface.

[0093] According to an example, the information further includes random access channel reports, and wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least perform: filtering these random access channel reports to include information about random access channel reports for cells controlled by a third device; and sending the filtered random access channel reports to the third device.

[0094] According to an example, the third device may include an access node.

[0095] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0096] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0097] According to an example, the third device may include a gNB-DU.

[0098] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the second apparatus is associated with the user equipment.

[0099] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with the user equipment by using the UE context information.

[0100] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per synchronization signal block per cell.

[0101] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per cell.

[0102] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per synchronization signal block per cell.

[0103] According to an example, the apparatus includes a gNB-DU.

[0104] According to an example, the apparatus comprises an access node.

[0105] According to the example, the second device includes a gNB-CU.

[0106] According to an eleventh aspect, an apparatus is provided, comprising a circuit for receiving information including a failure rate of random access channel attempts in at least one cell controlled by a second apparatus; and a circuit for sending the information from the apparatus to a network entity.

[0107] According to a twelfth aspect, a method is provided, comprising: receiving information comprising a failure rate of random access channel attempts in at least one cell controlled by an apparatus; and sending the information from the apparatus to a network entity.

[0108] According to an example, the network entity comprises at least one of: an access node; a decentralized unit; a centralized unit of an access node.

[0109] According to an example, information comprising a failure rate of random access channel attempts in at least one other cell in the network is received over the F1 interface.

[0110] According to an example, the information further comprises random access channel reports, and wherein the method comprises: filtering the random access channel reports to contain information about random access channel reports for cells controlled by the second device; sending the filtered random access channel reports to the second device.

[0111] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the second apparatus is associated with the user equipment.

[0112] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with the user equipment by using the UE context information.

[0113] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per synchronization signal block per cell.

[0114] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per cell.

[0115] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per synchronization signal block per cell.

[0116] According to the example, the method is performed by the gNB-CU.

[0117] According to an example, the method is performed by an access node.

[0118] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0119] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0120] According to an example, the apparatus includes a gNB-DU.

[0121] According to an example, the second device may include an access node.

[0122] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0123] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0124] According to an example, the second device may include a gNB-DU.

[0125] According to a thirteenth aspect, there is provided a computer program comprising instructions for causing an apparatus to at least perform the following operations: receive information comprising a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and send the information to a network entity.

[0126] According to a fourteenth aspect, there is provided a computer program comprising instructions stored thereon for performing at least the following operations: receiving information comprising a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and sending the information to a network entity.

[0127] According to the fifteenth aspect, a non-transitory computer-readable medium comprising program instructions is provided, which are used by the device to perform at least the following operations: receiving information including a failure rate of random access channel attempts in at least one cell controlled by the device; and sending the information to a network entity.

[0128] According to the sixteenth aspect, a non-transitory computer-readable medium is provided comprising program instructions stored thereon, the program instructions being used to perform at least the following operations: receiving information comprising a failure rate of random access channel attempts in at least one cell controlled by the device; and sending the information to a network entity.

[0129] According to the seventeenth aspect, a device is provided, comprising a component for performing the following operations: determining information, the information comprising: a failure rate of random access channel attempts in at least one cell controlled by the device; and / or the number of successful random access channel attempts in at least one cell controlled by the device and the number of failed random access channel attempts in at least one cell controlled by the device; and sending the information from the device to a second device.

[0130] According to an example, the component is further configured to perform: receiving a message from the second device, the message comprising a failure rate of random access channel attempts in at least one other cell.

[0131] According to an example, at least one other cell in the network is not controlled by the apparatus.

[0132] According to an example, the message comprising the failure rate of random access channel attempts in at least one other cell in the network comprises the total failure rate of two or more other cells in the network.

[0133] According to an example, a message comprising a failure rate of random access channel attempts in at least one other cell in the network is received over the F1 interface.

[0134] According to an example, determining information includes determining a failure rate of random access channel attempts in at least one cell controlled by the device, and is based on: determining a ratio of failed random access channel attempts in at least one cell controlled by the device to a total number of random access channel attempts in at least one cell controlled by the device, wherein the total number of random access channel attempts in at least one cell controlled by the device is determined as the sum of: the number of failed random access channel attempts in at least one cell controlled by the device; and the number of successful random access channel attempts in at least one cell controlled by the device.

[0135] According to an example, the apparatus comprises means for counting a number of successful random access channel attempts in at least one cell controlled by the apparatus.

[0136] According to the example, the component is configured to perform: receiving information about random access channel reports related to random access channel attempts in at least one cell controlled by the device from a second device; and determining a value indicating the number of failed random access channel attempts in at least one cell controlled by the device based on the information about random access channel reports related to random access channel attempts in at least one cell controlled by the device received from the second device.

[0137] According to an example, when the number of failed random access channel attempts in at least one cell controlled by the apparatus exceeds a threshold, a failure rate of random access channel attempts in at least one cell controlled by the apparatus is determined.

[0138] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with a user equipment.

[0139] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with the user equipment by using the UE context information.

[0140] According to an example, the component is further configured to perform: comparing information including a failure rate of random access channel attempts in at least one cell controlled by the device with a failure rate of random access channel attempts in at least one other cell; and based on the comparison, determining to change a random access channel configuration of the device.

[0141] According to an example, the component is further configured to perform: based on the comparison, determining to change a physical random access channel configuration of the apparatus.

[0142] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per synchronization signal block per cell.

[0143] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per cell.

[0144] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per synchronization signal block per cell.

[0145] According to an example, the apparatus includes a gNB-DU.

[0146] According to an example, the second device comprises an access node.

[0147] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0148] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0149] According to the example, the second device includes a gNB-CU.

[0150] According to the eighteenth aspect, a device is provided, comprising at least one processor; and at least one memory comprising computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least perform: determine information comprising: a failure rate of random access channel attempts in at least one cell controlled by the device; and / or the number of successful random access channel attempts in at least one cell controlled by the device and the number of failed random access channel attempts in at least one cell controlled by the device; and send the information from the device to a second device.

[0151] According to an example, at least one other cell in the network is not controlled by the apparatus.

[0152] According to an example, the message comprising the failure rate of random access channel attempts in at least one other cell in the network comprises the total failure rate of two or more other cells in the network.

[0153] According to an example, a message comprising a failure rate of random access channel attempts in at least one other cell in the network is received over the F1 interface.

[0154] According to an example, determining information includes determining a failure rate of random access channel attempts in at least one cell controlled by the device, and is based on: determining a ratio of failed random access channel attempts in at least one cell controlled by the device to a total number of random access channel attempts in at least one cell controlled by the device, wherein the total number of random access channel attempts in at least one cell controlled by the device is determined as the sum of: the number of failed random access channel attempts in at least one cell controlled by the device; and the number of successful random access channel attempts in at least one cell controlled by the device.

[0155] According to an example, the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least perform: counting a number of successful random access channel attempts in at least one cell controlled by the apparatus.

[0156] According to the example, the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least perform: receiving information about random access channel reports related to random access channel attempts in at least one cell controlled by the device from a second device; and determining a value indicating the number of failed random access channel attempts in at least one cell controlled by the device based on the information about random access channel reports related to random access channel attempts in at least one cell controlled by the device received from the second device.

[0157] According to an example, when the number of failed random access channel attempts in at least one cell controlled by the apparatus exceeds a threshold, a failure rate of random access channel attempts in at least one cell controlled by the apparatus is determined.

[0158] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with a user equipment.

[0159] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with the user equipment by using the UE context information.

[0160] According to an example, the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to at least perform: comparing information including a failure rate of random access channel attempts in at least one cell controlled by the apparatus with a failure rate of random access channel attempts in at least one other cell; and based on the comparison, determining to change a random access channel configuration of the apparatus.

[0161] According to an example, the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least perform: based on the comparison, determining to change a physical random access channel configuration of the apparatus.

[0162] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per synchronization signal block per cell.

[0163] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per cell.

[0164] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per synchronization signal block per cell.

[0165] According to an example, the apparatus includes a gNB-DU.

[0166] According to an example, the second device comprises an access node.

[0167] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0168] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0169] According to the example, the second device includes a gNB-CU.

[0170] According to the nineteenth aspect, a device is provided, comprising: a circuit for determining information, the information comprising: a failure rate of random access channel attempts in at least one cell controlled by the device; and / or the number of successful random access channel attempts in at least one cell controlled by the device and the number of failed random access channel attempts in at least one cell controlled by the device; and a circuit for sending the information from the device to a second device.

[0171] According to another aspect, a method is provided, comprising: determining information including: a failure rate of random access channel attempts in at least one cell controlled by the device; and / or the number of successful random access channel attempts in at least one cell controlled by the device and the number of failed random access channel attempts in at least one cell controlled by the device; and sending the information from the device to a second device.

[0172] According to an example, the method comprises: receiving a message from the second device, the message comprising a failure rate of random access channel attempts in at least one other cell.

[0173] According to an example, at least one other cell in the network is not controlled by the apparatus.

[0174] According to an example, the message comprising the failure rate of random access channel attempts in at least one other cell in the network comprises the total failure rate of two or more other cells in the network.

[0175] According to an example, a message comprising a failure rate of random access channel attempts in at least one other cell in the network is received over the F1 interface.

[0176] According to an example, determining information includes determining a failure rate of random access channel attempts in at least one cell controlled by the device, and is based on: determining a ratio of failed random access channel attempts in at least one cell controlled by the device to a total number of random access channel attempts in at least one cell controlled by the device, wherein the total number of random access channel attempts in at least one cell controlled by the device is determined as the sum of: the number of failed random access channel attempts in at least one cell controlled by the device; and the number of successful random access channel attempts in at least one cell controlled by the device.

[0177] According to an example, the apparatus comprises means for counting a number of successful random access channel attempts in at least one cell controlled by the apparatus.

[0178] According to an example, the method includes: receiving information of a random access channel report related to random access channel attempts in at least one cell controlled by the device from a second device; determining a value indicating the number of failed random access channel attempts in at least one cell controlled by the device based on the information of the random access channel report related to the random access channel attempts in at least one cell controlled by the device received from the second device. According to an example, when the number of failed random access channel attempts in at least one cell controlled by the device exceeds a threshold, determining a failure rate of random access channel attempts in at least one cell controlled by the device.

[0179] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with a user equipment.

[0180] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with the user equipment by using the UE context information.

[0181] According to an example, the method includes: comparing information including a failure rate of random access channel attempts in at least one cell controlled by the device with a failure rate of random access channel attempts in at least one other cell in the network; and based on the comparison, determining to change the random access channel configuration of the device.

[0182] According to an example, the method further comprises: based on the comparison, determining to change a physical random access channel configuration of the apparatus.

[0183] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per synchronization signal block per cell.

[0184] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per cell.

[0185] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per synchronization signal block per cell.

[0186] According to an example, the method is performed by a gNB-DU.

[0187] According to an example, the second device comprises an access node.

[0188] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0189] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0190] According to the example, the second device includes a gNB-CU.

[0191] According to another aspect, a computer program comprising instructions is provided, the instructions being used to cause an apparatus to at least perform the following operations: determine information comprising: a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and / or the number of successful random access channel attempts in at least one cell controlled by the apparatus and the number of failed random access channel attempts in at least one cell controlled by the apparatus; and send the information from the apparatus to a second apparatus.

[0192] According to another aspect, a computer program is provided comprising instructions stored thereon for performing at least the following operations: determining information comprising: a failure rate of random access channel attempts in at least one cell controlled by the device; and / or a number of successful random access channel attempts in at least one cell controlled by the device and a number of failed random access channel attempts in at least one cell controlled by the device; and sending the information from the device to a second device.

[0193] According to another aspect, a non-transitory computer-readable medium comprising program instructions is provided, which are used to cause an apparatus to at least perform the following operations: determine information, the information comprising: a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and / or the number of successful random access channel attempts in at least one cell controlled by the apparatus and the number of failed random access channel attempts in at least one cell controlled by the apparatus; and send the information from the apparatus to a second apparatus.

[0194] According to another aspect, a non-transitory computer-readable medium is provided including program instructions stored thereon, the program instructions being used to perform at least the following operations: determining information including: a failure rate of random access channel attempts in at least one cell controlled by the device; and / or a number of successful random access channel attempts in at least one cell controlled by the device and a number of failed random access channel attempts in at least one cell controlled by the device; and sending the information from the device to a second device.

[0195] According to another aspect, a device is provided, comprising a component for performing the following operations: receiving information comprising: a failure rate of random access channel attempts in at least one cell controlled by a second device; and / or the number of successful random access channel attempts in at least one cell controlled by the device and the number of failed random access channel attempts in at least one cell controlled by the device; and sending the information from the device to a network entity.

[0196] According to an example, the network entity comprises at least one of: an access node; a decentralized unit of an access node; a centralized unit of an access node.

[0197] According to an example, information comprising a failure rate of random access channel attempts in at least one other cell in the network is received over the F1 interface.

[0198] According to an example, the information further comprises random access channel reports, and wherein the component is further configured to perform: filtering the random access channel reports to contain information about random access channel reports for cells controlled by the third device; sending the filtered random access channel reports to the third device.

[0199] According to an example, the third device may include an access node.

[0200] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0201] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0202] According to an example, the third device may include a gNB-DU.

[0203] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the second apparatus is associated with the user equipment.

[0204] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with the user equipment by using the UE context information.

[0205] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per synchronization signal block per cell.

[0206] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per cell.

[0207] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per synchronization signal block per cell.

[0208] According to an example, the apparatus includes a gNB-DU.

[0209] According to an example, the apparatus comprises an access node.

[0210] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0211] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0212] According to the example, the second device includes a gNB-CU.

[0213] According to another aspect, a device is provided, comprising at least one processor; and at least one memory comprising computer program code; the at least one memory and the computer program code being configured to, together with the at least one processor, cause the device to at least perform: receiving information comprising: a failure rate of random access channel attempts in at least one cell controlled by a second device; and / or the number of successful random access channel attempts in at least one cell controlled by the device and the number of failed random access channel attempts in at least one cell controlled by the device; and sending the information from the device to a network entity.

[0214] According to an example, the network entity comprises at least one of: an access node; a decentralized unit of an access node; a centralized unit of an access node.

[0215] According to an example, information comprising a failure rate of random access channel attempts in at least one other cell in the network is received over the F1 interface.

[0216] According to an example, the information further includes random access channel reports, and wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least perform: filtering these random access channel reports to include information about random access channel reports for cells controlled by a third device; and sending the filtered random access channel reports to the third device.

[0217] According to an example, the third device may include an access node.

[0218] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0219] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0220] According to an example, the third device may include a gNB-DU.

[0221] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the second apparatus is associated with the user equipment.

[0222] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with the user equipment by using the UE context information.

[0223] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per synchronization signal block per cell.

[0224] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per cell.

[0225] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per synchronization signal block per cell.

[0226] According to an example, the apparatus includes a gNB-DU.

[0227] According to an example, the apparatus comprises an access node.

[0228] According to the example, the second device includes a gNB-CU.

[0229] According to another aspect, a device is provided, comprising: a circuit for receiving information comprising: a failure rate of random access channel attempts in at least one cell controlled by a second device; and / or the number of successful random access channel attempts in at least one cell controlled by the device and the number of failed random access channel attempts in at least one cell controlled by the device; and a circuit for sending the information from the device to a network entity.

[0230] According to another aspect, a method is provided, comprising: receiving information comprising: a failure rate of random access channel attempts in at least one cell controlled by a second device; and / or the number of successful random access channel attempts in at least one cell controlled by the device and the number of failed random access channel attempts in at least one cell controlled by the device; and sending the information to a network entity.

[0231] According to an example, the network entity comprises at least one of: an access node; a decentralized unit; a centralized unit of an access node.

[0232] According to an example, information comprising a failure rate of random access channel attempts in at least one other cell in the network is received over the F1 interface.

[0233] According to an example, the information further comprises random access channel reports, and wherein the method comprises: filtering the random access channel reports to contain information about random access channel reports for cells controlled by the second device; sending the filtered random access channel reports to the second device.

[0234] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the second apparatus is associated with the user equipment.

[0235] According to an example, information of random access channel reports related to random access channel attempts in at least one cell controlled by the apparatus is associated with the user equipment by using the UE context information.

[0236] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per synchronization signal block per cell.

[0237] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per cell.

[0238] According to an example, the failure rate of random access channel attempts in at least one cell comprises a failure rate calculated per random access channel opportunity per synchronization signal block per cell.

[0239] According to the example, the method is performed by the gNB-CU.

[0240] According to an example, the method is performed by an access node.

[0241] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0242] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0243] According to an example, the apparatus includes a gNB-DU.

[0244] According to an example, the second device comprises an access node.

[0245] According to an example, an access node may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, or a NG-RAN node.

[0246] According to an example, the NG-RAN node may include a gNB or an ng-eNB.

[0247] According to an example, the second device may include a gNB-DU.

[0248] According to another aspect, a computer program comprising instructions is provided, the instructions being used to cause a device to perform at least the following operations: receive information comprising: a failure rate of random access channel attempts in at least one cell controlled by a second device; and / or the number of successful random access channel attempts in at least one cell controlled by the device and the number of failed random access channel attempts in at least one cell controlled by the device; and send the information to a network entity.

[0249] According to another aspect, a computer program is provided comprising instructions stored thereon, the instructions being used to perform at least the following operations: receiving information comprising: a failure rate of random access channel attempts in at least one cell controlled by a second device; and / or the number of successful random access channel attempts in at least one cell controlled by the device and the number of failed random access channel attempts in at least one cell controlled by the device; and sending the information to a network entity.

[0250] According to another aspect, a non-transitory computer-readable medium comprising program instructions is provided, which are used to cause a device to perform at least the following operations: receive information, the information comprising: a failure rate of random access channel attempts in at least one cell controlled by a second device; and / or the number of successful random access channel attempts in at least one cell controlled by the device and the number of failed random access channel attempts in at least one cell controlled by the device; and send the information to a network entity.

[0251] According to another aspect, a non-transitory computer-readable medium is provided including program instructions stored thereon, the program instructions being used to perform at least the following operations: receiving information including: a failure rate of random access channel attempts in at least one cell controlled by a second device; and / or the number of successful random access channel attempts in at least one cell controlled by the device and the number of failed random access channel attempts in at least one cell controlled by the device; and sending the information to a network entity. BRIEF DESCRIPTION OF THE DRAWINGS

[0252] The invention will now be described in more detail, by way of example only, with reference to the following examples and accompanying drawings, in which:

[0253] Figure 1A showing a schematic representation of a network;

[0254] Figure 1B Shows a schematic representation of the network process;

[0255] Figure 2A shows a schematic representation of the network architecture;

[0256] Figure 2B shows a schematic representation of the network architecture;

[0257] Figure 3 A schematic representation showing a message flow is shown;

[0258] Figure 4 A schematic representation showing the method is shown;

[0259] Figure 5 shows a schematic representation of an apparatus according to an example;

[0260] Figure 6 shows a schematic representation of an apparatus according to an example;

[0261] Figure 7 a flow chart showing the method; and

[0262] Figure 8 A flow chart showing the method is shown. DETAILED DESCRIPTION

[0263] The present disclosure relates to wireless communications. Some examples relate to RACH procedures.

[0264] The 5G New Radio (NR) architecture also allows for a split architecture where an access node such as a gNB can internally split functionality into a centralized unit (CU) serving a potentially large number of decentralized units (DUs). The CU can operate on a different protocol layer than the DU. The functional split and architectural choices are specified in "3GPP Technical Specification 38.401, "Technical Specification Group Radio Access Network; NG-RAN; Architecture description (Release 16)", Version 16.0.0, December 2019".

[0265] exist Figure 1A The 5G NR architecture is depicted in FIG. The 5G NR split architecture introduces two new interfaces, which are named E1 (between the control plane and the user plane in the CU (e.g., in the gNB-CU 14A)) and F1 (e.g., 16A and 16B between the CU 14A and the DUs 14B and 14C). These interfaces are specified, for example, in the Third Generation Partnership Technology Standard (3GPP TS) 38.460 (E1 Stage 2), 3GPP TS 38.463 (E1 Stage 3), 3GPP TS 38.470 (F1 Stage 2), and 3GPP TS 38.473 (F1 Stage 3). Figure 1A Also depicted are the Xn-C interface 15 between the two gNBs 13 and 14, which provides a means for coordinating them using the XnAP procedure as defined in 3GPP TS 38.423; and the NG interfaces 12A and 12B with the 5G Core Network (5GC) 11 using the NGAP protocol as defined in TS 38.413.

[0266] A wireless terminal can use RACH to access a mobile network. RACH access has limited control information. RACH access between wireless terminals (such as UEs) attempting to access a mobile network may result in conflicts. For example, when two or more wireless terminals simultaneously access a mobile network using the same RACH resources, they may conflict and not be granted access to the mobile network. In addition, the RACH process may fail when relevant RACH parameters (such as the Root Sequence Index used to create a RACH preamble) are selected in a non-optimized manner; this may result in the use of non-orthogonal preambles in adjacent cells. In addition, the use of inappropriate UE power settings may generate inter-cell interference from adjacent cells, resulting in RACH failure.

[0267] There are contention-based (CB) and contention-free (CF) random access. As an example, Figure 1B A 4-step contention based random access (CBRA) procedure is shown.

[0268] exist Figure 1B At step 105, when the CBRA procedure is triggered, the UE 101 sends a random access preamble to the access node 103. According to some examples, the access node 103 may include a base station, an evolved Node B (eNB), a gNB, an ng-eNB, an NG-RAN node, etc. The NG-RAN node may include a gNB or an ng-eNB. Different preamble groups used at this step are defined according to the size of the message to be sent at step 109 and according to the channel conditions of the UE 101. The UE may obtain information on how to access the channel from the system information block 1 (SIB1) broadcasted in the system information (SI).

[0269] exist Figure 1B At step 107, the network (in this case, access node 103) responds with a Random Access Response (RAR) to UE 101 after receiving the preamble. In turn, during a window starting at the subframe containing the end of the preamble transmission, UE 101 monitors the Physical Downlink Control Channel (PDCCH) channel identified by a Random Access Radio Network Temporary Identifier (RA-RNTI).

[0270] After receiving the RAR message sent at 107, UE 101 may send an uplink transmission to the network (access node 103) at step 109. The size of the transmission depends on the grant received at 107.

[0271] Figure 1B Step 111 relates to a contention resolution phase, in which contention between different UEs is resolved.

[0272] It should be noted that the scope of application is not limited to Figure 1B This is an example of a 4-step RACH and may also be applied to other RACH procedures.

[0273] The random access procedure involves several parameters, which are provided by the network (e.g., by the access node 103) to the UE (such as Figure 1B UE 101). Examples of such parameters include: physical random access channel (PRACH) configuration index; initial random access preamble power; power ramping step in case of PRACH failure; scaling factor for prioritized random access procedures; random access preamble index; one or more thresholds for selecting a synchronization system block (SSB); and channel state information reference signal (CSI-RS). CSI-RS can be useful, for example, during a beam failure recovery procedure. These parameters can be provided to the UE via system information (e.g., SIB1). The same parameters are provided for the purpose of contention-free random access.

[0274] The network selects RACH parameters to provide to the UE using a RACH optimization procedure. The RACH parameters that may be optimized may include, but are not limited to: RACH configuration (resource unit allocation); RACH preamble split (between dedicated, group A, group B); RACH backoff parameter value; RACH transmission power control parameter. The information reported by the UE may support RACH optimization. PRACH parameter exchange between access nodes may support RACH optimization. A UE receiving polling signaling may report the number of RACH preambles sent until the RACH is successfully completed, and may also report contention resolution failures. "3rd Generation Partnership Project (3GPP) TS 36.300: Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 15); December 2019" describes support for RACH optimization in the case of LTE.

[0275] In some examples, when a RACH procedure fails, a UE RACH report is created by the UE. If the network requests a UE RACH report from the UE, the UE may respond with a message including the UE RACH report. For example, in LTE, the UE RACH report may include the number or preamble sent for the last successfully completed random access procedure. An indicator may also be provided as to whether contention is detected with another UE that wants to use the same resources of the network.

[0276] For example, in LTE, if the parameter rach-ReportReq is set to "true", the content of the rach-Report in the UEInformationResponse message is set to include numberOfPreamblesSent, which is the number of preambles sent by the media access control (MAC) for the last successfully completed random access procedure and an indicator as to whether contention is detected. This is described, for example, in 3rd Generation Partnership Project (3GPP) TS 36.331; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification (Release 15) (December 2019); as described below, where references to TS 36.321 are to 3rd Generation Partnership Project (3GPP) TS 36.321; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Medium Access Control (MAC) Protocol Specification (Release 15) Reference from the Medium Access Control (MAC) protocol specification (Release 15)) (December 2019):

[0277] 5.6.5.3 Receiving UEInformationRequest message

[0278] 1> If rach-ReportReq is set to true, set the content of rach-Report in the UEInformationResponse message as follows:

[0279] 2> Set numberOfPreamblesSent to indicate the number of preambles sent by the MAC for the last successfully completed random access procedure;

[0280] 2> If for at least one of the preambles sent for the last successfully completed random access procedure, contention resolution as specified in TS 36.321 was less than successful, then:

[0281] 3> Set contentionDetected to true;

[0282] 2> Otherwise:

[0283] 3> Set contentionDetected to "false"

[0284] In New Radio (NR), the random access procedure can be triggered by multiple events, which in some examples may be different from those in LTE. Examples of such events are described in 3rd Generation Partnership Project (3GPP) TS 38.300; Technical Specification Group Radio Access Network; NR; NR and NG-RAN Overall Description; Stage 2 (Release 15), v.16.0.0 (January 2020) as follows: Initial access from RRC_IDLE; RRC connection re-establishment procedure; DL or UL data arrives during RRC_CONNECTED when the UL synchronization state is "out of sync"; When there is no request for scheduling (Scheduling UL data arrives during RRC_CONNECTED when physical uplink control channel (PUCCH) resources are available for a random access request (SR); SR fails; is requested by RRC at synchronization reconfiguration (e.g., handover); transitions from RRC_INACTIVE; establishes time alignment for secondary TAG; requests additional SI; beam failure recovery. It should be noted that other events can trigger the random access procedure.

[0285] In some examples, the UE may store UE RACH reports associated with more than one RACH procedure. In some examples and in accordance with the RAN2 NR protocol (e.g., 3GPP TSG-RAN3 Meeting #106, Reno, NV, USA, November 18-22, 2019, R3-196409), the UE may store up to 8 UE RACH reports. This number may be increased in future releases so that the UE may store more UE RACH reports.

[0286] According to the RAN2 NR protocol also found in R3-196409, the UE RACH report includes "indexes of the SSBs and number of RACH preambles sent on each tried SSB listed inchronological order of attempts".

[0287] In LTE, UE RACH reports may be sent as part of a Radio Link Failure (RLF) report. In such a UE RACH report, there may be no information identifying the cell involved in the UE RACH report. However, in NR, there are cases where RACH may fail without triggering RLF. In these cases, it may be useful to include information about where (in which cell) the RACH failed in the UE RACH report. Additionally, it may be useful to characterize the gNB where the RACH failed, as a RACH procedure may be attempted on one gNB and fail only to eventually succeed at a different gNB.

[0288] In some examples, the RACH configuration conflict detection and resolution functionality is located at the gNB-DU. In some cases, it can be useful for the gNB-DU to know the physical RACH (PRACH) configurations of some or all neighboring cells to the cell suffering from the RACH configuration conflict, in order to efficiently select a new PRACH configuration for the conflicting cells.

[0289] In some examples (including some examples related to LTE), the UE stores the last RACH procedure. The network collects UE RACH reports through the UEInformationRequest / Response procedure, and the network will retrieve the last procedure recorded by the UE. The trigger of the RACH procedure may or may not involve dedicated RRC signaling.

[0290] In some examples (including some examples related to NR), the UE may have a report storing up to 8 RACH procedures. For the purpose of providing examples only, a list of RACH trigger types classified based on whether they have RRC impact is given as follows:

[0291] Triggering of RRC dedicated signaling Device

[0292] - Initial access from RRC_IDLE;

[0293] -RRC connection reestablishment process;

[0294] - Requested by RRC during synchronous reconfiguration (e.g. handover);

[0295] - Transition from RRC_INACTIVE;

[0296] - Request additional SI (may involve dedicated signalling)

[0297] Does not involve RRC triggering Device (e.g. not visible to gNB-CU)

[0298] -DL or UL data arrives during RRC_CONNECTED when the UL synchronization state is "out of sync";

[0299] - UL data arrives during RRC_CONNECTED when no Physical Uplink Control Channel (PUCCH) resources are available for Scheduling Request (SR);

[0300] -SR failed;

[0301] - Establish time alignment for secondary TAG;

[0302] - Request additional SI (using special preamble, handled locally in gNB-DU)

[0303] -Beam failure recovery.

[0304] As shown in the figure, some triggers of the RACH procedures stored in the UE RACH report may involve Radio Resource Control (RRC) dedicated signaling, while some triggers may not. Therefore, in a single UE RACH report, RACH procedures with different triggers can coexist. The gNB-CU becomes aware of the RACH procedures that do not involve RRC signaling through the UE RACH report.

[0305] Figure 2AAn example of a network is shown. In this example, the access node 203 includes a gNB. The gNB includes a centralized unit (CU), namely gNB-CU 205, and at least one distributed unit (DU) illustrated as gNB-DU 211a and gNB-DU 211b. The gNB-DU 211a of the access node 203 can communicate with the gNB-CU 205 via an F1 interface, and the gNB-DU 211b of the access node 203 can also communicate with the gNB-CU 205 via an F1 interface.

[0306] exist Figure 2A In the example of , one or more UEs 201a and 201b can communicate with access node 203. A UE such as UE 201a or UE 201b can connect to the network via a cell of gNB-DU 211a or gNB-DU 211b. In addition, gNB-CU 205 can be connected to gNB-CU 207 via an Xn-C interface. In some examples, for example if the access node is a NG-RAN node, gNB-CU 205 can be connected to access node 209 via an Xn interface.

[0307] Examples of the present invention use the RACH Failure Rate calculated at the gNB-DU to provide information about the RACH performance at the cell of the gNB-DU to the gNB-CU.

[0308] For example, the RACH failure rate calculated at the gNB-DU 211a may provide information to the gNB-CU 205 about the RACH performance (in terms of average failed RACH accesses) at the cell of the gNB-DU 211a. In some examples, the NG-RAN node 203 may forward the RACH failure rate to other neighboring NG-RAN nodes via the Xn or Xn-C interface. These neighboring NG-RAN nodes may not have active UE contexts about specific UEs of their neighbors. In these cases, the RACH information may be used in a statistical sense. Therefore, the RACH failure rate may be useful to neighboring NG-RAN nodes. By forwarding the RACH failure rate, unnecessary signaling of full UE RACH reporting information is avoided.

[0309] In some examples, gNB-DU 211a can provide gNB-CU 205 with information about RACH performance at the cell of gNB-DU 211a by separately sending success information about RACH access locally available at gNB-DU 211a and failure information about RACH access that gNB-DU 211a has received via UE RACH reports.

[0310] In some examples, success information of the RACH access may also be obtained in the UE RACH report provided to the gNB-DU 211a. Success information may be provided as the last RACH attempt in a RACH procedure that includes multiple unsuccessful attempts and results in the success of the RACH procedure. In some examples, the NG-RAN node 203 may forward success information and failure information about the RACH procedure to other neighboring NG-RAN nodes via an Xn or Xn-C interface.

[0311] In the example, gNB-CU 205 forwards the RACH failure rate of the cells of its neighboring gNB-CU or the cells of other gNB-DUs under the gNB-CU to gNB-DU 211a and 211b through the F1 interface (for example, gNB-DUCU 205 can forward the RACH failure rate of the cell of gNB-DU 211a to gNB-DU 211b).

[0312] In some other examples, gNB-CU 205 forwards information about successful and failed RACH attempts (regarding cells of its neighboring gNB-CUs or about cells of other gNB-DUs under the gNB-CU) to gNB-DU 211a and 211b, respectively, via the F1 interface, instead of (or in some cases also forwarding) the calculated failure rate (e.g., gNB-CU 205 may forward information about RACH success and RACH failure of RACH access of the cell of gNB-DU 211a to gNB-DU 211b).

[0313] In some examples, the gNB-CU receives UE RACH reports from UEs connected to the gNB-CU. For example, gNB-CU 205 may receive UE RACH reports from UE 201a and / or UE 201b. The UE RACH report may contain: old RACH information for which no active UE context exists; new RACH information for which an active UE context exists; or a combination of old RACH information and new RACH information. The gNB-CU may forward the UE RACH reports it receives from the UE to each gNB-DU under the gNB-CU. For example, gNB-CU 205 may forward UE RACH reports from UE 201a and UE 201b to gNB-DU 211a or gNB-DU 211b.

[0314] In some examples, such as in examples related to NR for example, the UE may store up to 8 UE RACH reports of RACH procedures attempted by the UE. Thus, the UE RACH report may include 8 separate UE RACH reports relating to RACH procedures that may have occurred at the gNB to which the UE is connected or connected, or at some other gNB, or a mix of these cases. The gNB to which the UE is connected will not have an active UE context for RACH procedures / reports that have occurred at other gNBs. RACH procedures / reports that have occurred at other gNBs may be defined as "old RACH information". Since the UE RACH report contains the cell id in which the RACH attempt occurred, the gNB may, for example, know that the RACH attempt did not occur at its cell and is part of the old RACH information.

[0315] In some examples, the gNB keeps a list of all UE contexts for active UEs. Therefore, the RACH procedure that occurs for an active UE can be defined as "new RACH information". This will be at the cell of that gNB (i.e., the gNB can match its cell information with the cell id reported by the UE RACH).

[0316] In some examples, if the UE RACH report includes RACH information about cells of gNB-DUs under the gNB-CU, the UE RACH report is forwarded by the gNB-CU (via the F1 interface) to the gNB-DU. For example, if the UE RACH report includes information about cells of gNB-DU 211a under gNB-CU 205, the UE RACH report is forwarded to gNB-DU 211a.

[0317] In some examples, if the UE RACH report contains mixed RACH information about the cell of the gNB-DU and about other cells of other gNB-DUs (of the same or neighboring gNB-CU), the UE RACH report can be filtered at the gNB-CU and the filtered UE RACH report (with relevant information about RACH access on the cell of the gNB-DU) is forwarded over the F1 interface. Filtering of RACH content can reduce unnecessary information received at the gNB-DU. For example, if the UE RACH report includes information about the cell of gNB-DU 211a under gNB-CU 205 and about gNB-DU 211b, the UE RACH report can be filtered to remove some information, i.e., information related to the cell of gNB-DU 211b, before the filtered UE RACH report is forwarded from the gNB-CU to gNB-DU 211a.

[0318] As mentioned above, the UE RACH report may contain information about RACH accesses at both a given gNB-DU and other gNB-DUs. In some examples, the gNB-DU does not need to know the (original) information about the RACH procedures at other gNB-DUs as contained in the UE RACH report. When the gNB-CU sends a UE RACH report to a gNB-DU, the gNB-CU may remove (filter out) RACH information related to cells of other gNB-DUs. When the gNB-CU forwards to a first gNB-DU a UE RACH report involving cells of a second gNB-DU that has been received from a UE, the information of the UE RACH report may be filtered based on at least one cell id indication in the UE RACH report and based on information at the gNB-CU about which cells the first gNB-DU is controlling. Thus, the gNB-CU may remove from the UE RACH report information related to cells that are not controlled by the first gNB-DU. In this way, when the gNB-CU filters the UE RACH report before forwarding, the first gNB-DU does not receive information not relevant to the first gNB-DU in the forwarded UE RACH report. The information filtered out at the gNB-CU can be considered as not necessary for the first gNB-DU.

[0319] The UE RACH report can be considered to provide "raw" RACH information. Based on the RACH information of the UE RACH report and the total number of successful RACH attempts, the RACH failure rate can be calculated. The RACH failure rate can be calculated by the gNB-DU or another node provided with the total number of successful RACH attempts. The RACH Outcome information includes the RACH failure rate. The RACH outcome information can be considered to be different information from the UE RACH report. The RACH outcome information can include an IE indicating the RACH failure rate.

[0320] Even if only necessary RACH report information is forwarded to the gNB-DU in some examples, the RACH failure rate attempted at other cells (e.g., at neighboring cells controlled by other gNB-DUs) may still be included after filtering for the gNB-DU, because the RACH failure rate gives statistical information about the RACH performance in other cells. Thus, in some examples, the overall RACH information for a given gNB-DU may include the RACH failure rate attempted at other cells of other gNB-DUs (under the same or different gNB-CU) and the original UE RACH report information of the cell of the given gNB-DU, rather than the original UE RACH report information of the cells of other gNB-DUs.

[0321] In some examples, if the UE RACH report contains RACH information about cells that do not involve a neighboring NG-RAN node (or gNB-CU in case of CU-DU split), the corresponding information is filtered out and the filtered UE RACH report is sent to the neighboring NG-RAN node (or gNB-CU in case of CU-DU split) via, for example, an Xn interface. In some examples, the NG-RAN node may decide not to filter the UE RACH report and send the entire UE RACH report to the neighboring NG-RAN node via the Xn interface, in which case the processing of the UE RACH report is left to the receiving NG-RAN node.

[0322] In some examples, the UE RACH report includes an index of the SSB and the number of RACH preambles sent per RACH opportunity on each attempted SSB listed in chronological order of the attempts.

[0323] exist Figure 2B An example of a network architecture is shown in . Figure 2B The DU and CU can be, for example, gNB-DU and gNB-CU, respectively.

[0324] Figure 2B The example of can be used to illustrate the flow of RACH information from CU 292a to CU 292b. Although not discussed below, RACH information can flow from CU 292b to CU 292a in the same manner. The RACH information can include, for example, information about RACH success and RACH failure of one or more UEs (e.g., UE 201c) at one or more cells of DU 290a1 to DU 290am (where m is an integer value greater than 1).

[0325] In some examples, UE 201c may be connected to DU 290a1. UE 201c sends a UE RACH report to CU 292a. In some examples, the UE RACH report may be sent using RRC transmission. The UE RACH report may include information about the number of failed RACH attempts for one or more cells of DU 290a1 being controlled by CU 292a. In some examples, the included information about the number of failed RACH attempts for one or more cells of DU 290a1 may be forwarded from CU 292a to DU 290a1. In some examples, the UE RACH report sent to CU 292a may be sent to DU 290a1. Based on this information, DU 290a1 may determine the number of failed RACH attempts. In turn, DU 290a1 may send information including the number of failed RACH attempts and the number of successful RACH attempts to CU 292a. DU 290a1 may correlate the number of failed RACH attempts sent to CU 292a with the number of successful RACH attempts to ensure that both numbers are for the same observation period (ie, measured over the same time period).

[0326] In some examples, DU 290a1 may send information about a successful RACH attempt to CU 292a. The success information may be sent via the F1 interface. The success information may be for one or more cells of DU 290a1. The success information may be stored internally at DU 290a1.

[0327] In some examples, CU 292a may send RACH information regarding successful RACH attempts and failed RACH attempts to CU 292b.

[0328] In some examples, UE 201d may send RACH report information to CU 292b. The UE RACH report information may include, for example, information about RACH failure of UE 201d at DU 290bm (m is an integer value greater than 1).

[0329] In some examples, CU 292b may send RACH success information from DU 290a1 under CU 292a, RACH failure information from DU 290a1 under CU 292a, and a UE RACH report from UE 201d received at CU 292b to DU 290b1 and / or DU 290bm.

[0330] By using the above Figure 2BAs described in the message, a UE (eg, UE 201c) may send a RACH report to a CU (eg, CU 292a) having RACH failure information on cells of one or more DUs (eg, DU 290am) that the CU (eg, CU 292a) is controlling.

[0331] By using the above Figure 2B As described above, a CU (e.g., CU 292a) may receive RACH failure and success information from DU 290am. A CU (e.g., CU 292a) may forward the RACH success information and RACH failure information to other CUs (e.g., CU 292b) via Xn.

[0332] Since both RACH failure information and RACH success information are sent from the same DU, the DU can ensure that the number of failed RACH attempts and the number of successful RACH attempts are recorded in the same time period (same observation period). In some examples, the DU may also include information about successful and failed RACH attempts, which may not be signaled to the CU controlling the DU through RRC messages. For example, the DU may include information about the RACH process that occurs locally at the DU, which may be used, for example, for beam failure recovery. In turn, the DU may combine this information with information received in the UE RACH report from its controlling CU.

[0333] As described above, a CU may send RACH success information and RACH failure information on a cell of a neighboring CU to a DU under the CU. For example, RACH success information and RACH failure information of a cell of DU 290a1 may be forwarded to one or more DUs (e.g., DU 290b1, ..., DU 290bm) of CU 292b.

[0334] RACH success information and RACH failure information may be used at the DU to determine a RACH failure rate in a cell of a neighboring CU. According to some examples, the gNB-DU may send the RACH failure rate at the cell of the gNB-DU to the gNB-CU. The RACH result information may include the RACH failure rate and may be sent over the F1 interface.

[0335] According to some examples, the gNB-DU may send information about RACH success to the gNB-CU and separately send information about RACH failure at the cell of the gNB-DU. The RACH result information in these examples may include RACH success and RACH failure information about the RACH attempt and may be sent over the F1 interface in some examples.

[0336] According to some examples, a first access node may send a UE RACH report and RACH result information at a cell sending the first access node to a second access node.

[0337] According to some examples, the first access node may send a filtered UE RACH report to the second access node, the filtered UE RACH report including RACH information about the cell of the second access node. This may be sent over an Xn interface. Alternatively, the UE RACH report may be sent unfiltered, containing RACH information about all cells of the network (e.g., cells that are also the first access node). In some examples, the first access node may include a NG-RAN node. The second access node may include a NG-RAN node. In some examples using a split network architecture, the first access node may include a gNB-CU and the second access node may include a gNB-CU.

[0338] According to some examples, the gNB-CU may send to the gNB-DU the RACH failure rate on cells of other gNB-DUs managed by the gNB-CU.

[0339] According to some examples, the gNB-CU may send filtered UE RACH reports of RACH accesses at the cell of the gNB-DU to the gNB-DU.

[0340] According to some examples, the gNB-CU may send an unfiltered UE RACH report to the gNB-DU, which includes all RACH information logged by the UE (regarding different gNB-DUs of the gNB-CU or potentially neighboring gNB-CUs).

[0341] exist Figure 3 An example message flow between entities in a network is shown in FIG. Figure 3 In a network of FIG. 1 , an access node 303 (which may include a gNB, for example) includes a CU1 305. CU1 305 may be connected to one or more DUs, such as DU1 311a and DUk 311c. DU1 311a may be connected to one or more UEs, such as UE 1 (DU1) 301a and UEn (DU1) 301b, for example. DUk 311c may be connected to one or more UEs, such as UE 1 (DUk) 301c and UEm (DUk) 301d, for example.

[0342] Figure 3 The access node 315 (which may, for example, include a gNB) includes CU 2307 and DU313.

[0343] According to some examples, the DU controls at least one cell of the network. When the DU is part of the gNB, the DU may be a gNB-DU. When the CU is part of the gNB, the CU may be a gNB-CU.

[0344] At step 302, access node 315 sends a failure indication message to access node 303. The failure indication message sent at 302 may include an XnAP FAILURE INDICATION message. The message sent at 302 may include a UE RACH report from a RACH attempt at a cell of access node 315. In some examples, the FAILURE INDICATION message may include a UE RACH report regarding a failed RACH attempt at the cell of access node 303 if the UE attempted RACH at access node 303 and failed but the UE succeeded at access node 315.

[0345] In some examples, access node 303 comprises a NG-RAN node. In some examples, access node 315 comprises a NG-RAN node. For example, access node 315 may send a failure indication message including a UE RACH report in a cell of DU 313.

[0346] In an example, the failure indication message is sent from CU 2 307 to CU1 305. The failure indication message may include one or more UE RACH reports. The failure indication message may include an information element (IE). In some examples, the failure indication message may be exchanged via an Xn interface.

[0347] In an example, the NR Cell Global Identity (CGI) or some other cell identifier (e.g., Physical Cell Identity (PCI)) may be used to identify the cell in which the RACH failed and, in this case, the gNB (access node 303) that owns the cell. In some examples, filtering of UE RACH reports may be used to isolate only RACH information related to the cell of the recipient of the failure indication message (in this case, the cell of access node 303). This filtering may be performed on the sending access node 315 side. In an example where NG-RAN inter-node communication is performed via 5GC, similar entries in the corresponding NG signaling procedure may be used.

[0348] In some examples, for the uplink (UL) direction, normal uplink (NUL) and supplemental uplink (SUL) carriers may be reported separately.

[0349] The gNB-DU may further calculate the failure rate information at a per-RACH opportunity granularity. This may be achieved by further including information about the per-RACH opportunity granularity in the UE RACH report. In this case, each entry of the UE RACH report includes the index of the SSB and the number of UE RACH preambles sent per RACH opportunity on each attempted SSB listed in the order of the attempt time. This may further help the gNB-DU (e.g., gNB-DU1 311a) under gNB-CU1 305 to identify conflicting RACH opportunities in the PRACH configuration.

[0350] The failure indication message sent at 302 may correspond to an XnAP failure indication message. The failure indication message sent at 302 may include an additional IE to indicate a UERACH report that has been received from access node 315 and relates to a cell of access node 303.

[0351] At step 304, CU1 305 sends a CU-DU RADIO INFORMATION message to DU1 311a. The CU-DU RADIO INFORMATION may include the UE RACH report information received by CU1 305 at step 302, or any other UE RACH report information accessible to CU1 305.

[0352] The CU-DU Radio Information message sent at 304 may include at least one UE RACH report indicating information about failed RACH attempts at the cell of the access node 303, and more specifically about failed RACH attempts at the cell of DU1 311a.

[0353] The message transmitted at step 304 may be transmitted via a newly defined F1 Application Protocol (F1AP) message, or may reuse a CU-DU Radio Information message.

[0354] The CU-DU radio information sent at 304 may be per cell ID such that the CU-DU radio information message is associated with a cell identifier (ID).

[0355] At step 306, CU1 305 sends a UE RACH report request to UE 1 (DU1) 301a. UE 1 (DU1) 301a responds at 308 by sending a UE RACH report to CU1 305. Step 306 may be performed, for example, with UEInformationRequest and UEInformationResponse procedures as described in LTE.

[0356] At step 310, CU1 305 sends a CU-DU radio information message to DU1 311a. The CU-DU radio information may include a filtered UE RACH report of RACH accesses at the cell of DU 311a. Alternatively, the CU-DU radio information message sent at 310 may include an unfiltered UE RACH report that includes all RACH information that the UE has logged (regarding different gNB-DUs of CU1 305 or potential neighboring gNB-CUs such as CU 2 307 other than DU1 311a). The UE RACH report information sent at 310 may have been previously received at CU 1 from a UE (such as at step 308) or from a neighboring gNB-CU (such as at 302) over an Xn interface.

[0357] The CU-DU radio information sent at 310 may be sent in an F1AP message.

[0358] According to an embodiment, the message sent at 310 may be non-UE associated, such that the CU-DU radio information message of step 310 does not provide any UE context.

[0359] According to another embodiment, the message sent at 310 may be UE associated, if possible. Thus, when the UE context of the UE RACH report from the active UE is available. In some examples, the message sent at step 304 may be non-UE associated, and the message sent at step 310 may be UE associated. Non-UE associated information may be used at a point in time when a UE RACH report may be available but the UE connection has been released.

[0360] If a UE context is available in the gNB-DU for the UE RACH report transmitted in step 310, in some examples, DU1 311a can take into account the UE context to perform per-UE RACH optimization.

[0361] At step 312, DU1 311a calculates the RACH failure rate. To calculate the RACH failure rate, DU1 311a may use both internal information about the number of successful RACH procedures (per SSB index) and the number of failed RACH attempts from information obtained through UE RACH reports (which DU1 311a may have received at steps 304 or 310, for example). DU1 311a may use the knowledge of the number of successful RACH procedures (per SSB index). As an example, we refer to the number of successful RACH procedures (per SSB index) for the cell of DU1 311a as numSuccRACHSSB.

[0362] To calculate the RACH failure rate, according to one example, DU1 311a may use the UE RACH report information received at step 310 and / or step 304 and the numSuccRACHSSB. CU1 305, having a) received the UE RACH report from its UE (e.g., UE 301a) and b) received the forwarded (possibly filtered) UE RACH report related to the RACH attempt on the cell of CU1 305 from its neighbor (e.g., CU2 307), knows the number of failed RACH procedures both at the MAC level (e.g., initial access, BFR) and at the RRC level (e.g., due to handover) because they are indicated in the UE RACH report per SSB index. At step 310 and / or step 304, this information is forwarded by CU1 305 to DU1 311a by forwarding the UE RACH report or the filtered UE RACH report to DU1 311a. The UE RACH report indicates the "index of the SSB and the number of RACH preambles sent on each attempted SSB listed in chronological order of attempts" for which the UE (for which RACH failed) created the UE RACH report. As an example, the total number of failed attempts may be referred to as numFailRACHSSB.

[0363] To calculate the RACH failure rate, according to another example, DUk 311c may use the RACH result information received by CU1 305 at step 314, which in turn is forwarded to DUk 311c in some examples. In some examples, DUk 311c may additionally or alternatively use the RACH result information received by CU2 307 in step 316 and forwarded to DUk 311c in the inter-gNB scenario. The RACH result information may include information about successful and failed RACH attempts on cells of its neighbors under the same or other gNB-CUs that are signaled separately. In this case, the calculated RACH failure rate corresponds to the ratio of the failed RACH attempts signaled in the RACH result information to the sum of the total failed and successful RACH attempts in the cell.

[0364] Therefore, DU1 311a knows the number of failed RACH procedures at the cell of DU1 311a.

[0365] According to one example, the RACH failure rate per SSB index at the cell of DU1 311a may in turn be calculated at DU1 311a as the ratio numFailRACHSSB / (numSuccRACHSSB+numFailRACHSSB).

[0366] According to another example, the RACH failure rate per SSB index at the cell of DU1 311a may in turn be calculated at a different gNB-DU (e.g., DUk 311c) as a ratio numFailRACHSSB / (numSuccRACHSSB+numFailRACHSSB), where numFailRACHSSB (e.g., RACH failure information) and numSuccRACHSSB (e.g., RACH success information) are signaled in step 318 as part of the RACH result information or forwarded from CU 2 307.

[0367] The RACH failure rate may be indicated as a value between 0 and 100 to indicate a percentage (e.g., a number x is understood to be x% in meaning). The RACH result entry may indicate the RACH failure rate per SSB index reported for both NUL and SUL carriers for each cell of the NG-RAN node (gNB / ng-eNB). The failure rate information at a per RACH opportunity granularity may further help DU1 311a identify conflicting PRACH configurations within a RACH opportunity.

[0368] In some examples, a counter may be used at DU1 311a to count the number of successful / failed RACH attempts.

[0369] In some examples, a counter at DU1 311a is used to count the number of successful RACH attempts. This measurement counts the number of successful RACH procedures at DU1 311a. In some examples, the measurement can be split into sub-counters per SSB index. In some examples, the measurement can be split into sub-counters per SSB index per RACH opportunity. RACH opportunities can be viewed as resources in which RACH access can be performed. RACH opportunities are allocated in time so that there is an opportunity to send a RACH preamble from time to time. The number of successful RACH attempts is an integer value.

[0370] In some examples, a counter at DU1 311a is used to count the number of failed RACH attempts. This measurement can be split into sub-counters to collect / count failed RACH procedures for L1 / L2 RACH attempts and failed RACH procedures for L3 RACH attempts (e.g., information received via CU-DU Radio Information messages on the F1 interface at steps 304 and 310). These two counters can be further subdivided to collect failed RACH attempts for L1 / L2 RACH procedures or L3 RACH attempts per SSB index (or per RACH opportunity per SSB index).

[0371] In some examples, the multiple failed RACH attempts may also include a cause value to indicate the RACH trigger that triggered the failed RACH procedure. The cause value may be an integer value (e.g., cause = 1 may indicate initial access, cause = 10 may indicate beam failure recovery, etc.). A counter at DU1 311a may be used to count the number of failed RACH attempts per RACH trigger type or per group of trigger types. For example, this counter may count failed RACH procedures for L1 / L2 RACH attempts or corresponding to L3 RACH attempts.

[0372] Step 312 may be optional, or the counter used for RACH failure rate calculation in step 312 may serve node internal purposes or be used for reporting to, for example, an operations, administration, and maintenance (OAM) system. In all of these cases, the RACH result information in step 314 may include separate RACH success information and RACH failure information regarding RACH attempts.

[0373] At step 314, the RACH result information at the cell of DU1 311a calculated at 312 may be sent from DU1 311a to CU1 305. The message sent at step 314 may be sent via a newly defined F1AP message or may be part of a DU-CU radio information message.

[0374] At step 314, RACH result information including the RACH failure rate calculated at 312 or including separate RACH success information and RACH failure information about the RACH attempt may be sent from DU1 311a to CU1 305. DU1 311a may indicate the RACH failure rate of DU1 311a to CU1 305 through a newly defined F1AP message or through a DU-CU radio information message. DU1 311a may also indicate separate information about successful and failed RACH attempts of DU1 311a to CU1 305 through a newly defined F1AP message or through a DU-CU radio information message. In addition, the message sent at step 314 may be sent to a neighboring CU via an Xn interface, such as CU 2 307 as shown in step 316. As shown at step 318, CU1 305 managing DU1 311a may further forward the RACH result information to other DUs (such as DUk 311c) managed by CU1 305.

[0375] The RACH result information sent at 314, 316 and 318 may be per cell ID and indicate an average number of failed RACH attempts per SSB index. The average number may be indicated as a value between 0 and 100. The value may represent a percentage value. Alternatively, if DU1 does not calculate this average and bypasses step 312, the RACH result information sent at 314, 316 and 318 may include separate information about successful RACH attempts and failed RACH attempts per SSB index. The RACH result information may indicate, for each cell of the access node (gNB / ng-eNB), the RACH failure rate or successful and failed RACH attempts per SSB index reported for both NUL and SUL carriers.

[0376] In some examples, the RACH result messages sent at 314, 316, and 318 may include total RACH result information that has been received at CU1 305 from different gNB-DUs under the gNB-CU or gNB-DUs in other access nodes. In some examples, the RACH result information may not be aggregated.

[0377] DU1 311a may also receive RACH result information about DUs under other access nodes or other DUs under CU1 305. DU1 311a may compare the failure rate at DU1 311a with this information.

[0378] It will be understood that according to some examples, the steps of the described method need not be completely sequential. For example, in terms of timing, there may be overlap between steps 302, 304, 306. In some examples, there may be overlap between steps 316 and 318.

[0379] Figure 4 An example of a method performed at an access node 403 is shown. In some examples, the access node 403 may include a gNB. The access node 403 may be split into a CU 405 and a DU 411.

[0380] At step 450, DU 411 evaluates the failed RACH attempts. For example, at step 450, DU 411 may count the number of failed RACH attempts by using a counter.

[0381] At step 452, DU 411 determines whether the number of failed RACH attempts measured at step 450 exceeds a threshold. In some examples, the threshold may be a predetermined value stored at DU 411. The threshold may be dependent on a trigger that triggered the RACH attempt. If the number of failed RACH attempts does not exceed the threshold, the process returns to step 450. If the number of failed RACH attempts measured at step 450 exceeds the threshold, DU 411 is triggered to calculate a RACH failure rate based on the received UE RACH reports and successful RACH transmissions at step 454. As an alternative to or in addition to sending the RACH failure rate, if the number of failed RACH attempts measured at step 450 exceeds the threshold, DU 411 is triggered to send RACH result information including information about successful and failed RACH attempts to its CU. In some examples, after step 454, the method may proceed to other steps, such as providing the calculated RACH failure rate to CU 405.

[0382] When the gNB-DU has knowledge of the RACH failure rate in its cell and the RACH failure rate of the cells of other nodes (obtained by receiving the calculated RACH failure rate information or by receiving the number of failed and successful RACH attempts), the gNB-DU can reconfigure its PRACH configuration based on a comparison of these ratios. For example, if the RACH failure rate in the gNB-DU's cell is lower than the RACH failure rate of the cells of other nodes, the gNB-DU can reduce power usage. Alternatively, if the RACH failure rate in the gNB-DU's cell is higher than the RACH failure rate of the cells of other nodes, the gNB-DU can increase power usage. By using the RACH failure rate instead of the full UE RACH report information from the cells of other nodes, the amount of information that needs to be signaled is reduced. This can be particularly useful, for example, in NR networks, where the size of the UE RACH report information is larger than in LTE networks, and where the number of possible triggers is greater than in LTE networks.

[0383] Now refer to Figure 5 describing in more detail possible wireless communication devices, Figure 5A schematic partial cutaway view of a communication device 500 is shown. Such a communication device is generally referred to as a user equipment (UE) or terminal. Suitable mobile communication devices can be provided by any device capable of sending and receiving radio signals. Non-limiting examples include a mobile station (MS) or mobile device (such as a mobile phone or so-called "smart phone"), a computer equipped with a wireless interface card or other wireless interface facilities (e.g., a USB dongle), a personal data assistant (PDA) or a tablet computer with wireless communication capabilities, or any combination of these, etc. Mobile communication devices can, for example, provide data communications for carrying communications such as voice, e-mail (email), text messages, multimedia, etc. Therefore, a variety of services can be supplied and provided to the user via the user's communication device. Non-limiting examples of these services include two-way or multi-way calls, data communications or multimedia services, or access to data communication network systems such as the Internet alone. Broadcast or multicast data can also be provided to users. Non-limiting examples of the content include downloads, television and radio programs, videos, advertisements, various alarms, and other information.

[0384] A wireless communication device may be, for example, a mobile device (that is, a device that is not fixed to a particular location), or it may be a fixed device. A wireless device may or may not require human interaction to communicate. In this teaching, the term "UE" or "user" is used to refer to any type of wireless communication device.

[0385] The wireless device 500 may receive signals over the air or through the radio interface 507 via suitable means for receiving radio signals, and may transmit signals via suitable means for transmitting radio signals. Figure 5 In the embodiment of the present invention, the transceiver arrangement is schematically designated by block 506. The transceiver arrangement 506 may be provided, for example, by a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the wireless device.

[0386] The wireless device is typically equipped with at least one data processing entity 501, at least one memory 502, and other possible components 503 for use in software and hardware assisted execution of the tasks it is designed to perform, including controlling access to access systems and other communication devices and communicating with them. Data processing, storage and other related control devices can be provided on a suitable circuit board and / or in a chipset. This feature is indicated by reference numeral 504. The user can control the operation of the wireless device with the help of a suitable user interface such as a keypad 505, voice commands, a touch-sensitive screen or pad, and combinations thereof. A display 508, a speaker, and a microphone may also be provided. In addition, the wireless communication device may include suitable connectors (wired or wireless) to other devices and / or for connecting external accessories (e.g., hands-free devices). The communication devices 502, 504, 505 can access the communication system based on various access technologies.

[0387] Figure 6 An example of a control device for a communication system is shown, for example, the control device is coupled to and / or used to control a station of an access system, such as a RAN node (e.g., a base station, gNB), a central unit of a cloud architecture or a node of a core network (such as an MME or S-GW), a scheduling entity such as a spectrum management entity, or a server or host, or an IAB or a relay node. The control device may be integrated with or external to a node or module of a core network or RAN. In some embodiments, the base station includes a separate control device unit or module. In other embodiments, the control device may be another network unit such as a radio network controller or a spectrum controller. In some embodiments, each base station may have such a control device and a control device provided in a radio network controller. The control device 600 may be arranged to provide control of communications in a service area of ​​the system. The control device 600 includes at least one memory 601, at least one data processing unit 602, 603, and an input / output interface 604. Via the interface, the control device may be coupled to a receiver and a transmitter of a base station. The receiver and / or the transmitter may be implemented as a radio front end or a remote radio head. For example, the control device 600 or the processor 601 may be configured to execute appropriate software code to provide control functionality.

[0388] Figure 7 is a flow chart of a method according to an example. Figure 7 The flowchart of is, for example, from the perspective of a device such as DU1 311a.

[0389] At S701, the method includes determining information. The information may include a failure rate of random access channel attempts in at least one cell controlled by the device, and additionally or alternatively, a number of successful random access channel attempts in at least one cell controlled by the device and a number of failed random access channel attempts in at least one cell controlled by the device.

[0390] At S702 , the method includes sending the information from the device to a second device. The second device may be a device such as CU1 305 , for example.

[0391] Figure 8 is a flow chart of a method according to an example. Figure 8 The flowchart of FIG. 3 is, for example, from the perspective of a device such as CU1 305 .

[0392] At S801, the method includes receiving information. The information may include a failure rate of random access channel attempts in at least one cell controlled by a device (e.g., DU1 311a), and additionally or alternatively, a number of successful random access channel (RACH) attempts in at least one cell controlled by the device and a number of failed random access channel attempts in at least one cell controlled by the device.

[0393] At S802, the method includes sending the information to a network entity (eg, CU 2 307, DUk 301c).

[0394] In general, various embodiments may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device, but the invention is not limited thereto. Although various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other graphical representation, it is well understood that the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general purpose hardware or controllers or other computing devices, or some combination thereof, as non-limiting examples.

[0395] As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) a hardware circuit implementation only (such as an implementation of analog and / or digital circuits only); (b) a combination of hardware circuitry and software, such as (where applicable): (i) a combination of analog and / or digital hardware circuitry and software / firmware; and (ii) any portion of a hardware processor with software (including a digital signal processor, software, and memory that work together to enable a device such as a mobile phone or server to perform various functions); and (c) a hardware circuit and / or processor, such as a microprocessor or a portion of a microprocessor, that requires software (e.g., firmware) to operate, but software may not be present when the software is not required for operation. This definition of "circuitry" applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term "circuitry" also covers an implementation of a hardware circuit or processor (or multiple processors) only or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term "circuitry" also covers, for example and if applicable to the specifically claimed element, a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or networking equipment.

[0396] Embodiments of the present invention may be implemented by computer software executable by a data processor of a mobile device (such as in a processor entity), or by hardware, or by a combination of software and hardware. Computer software or programs (also referred to as program products) including software routines, applets and / or macros may be stored in a data storage medium readable by any device, and they include program instructions for performing specific tasks. A computer program product may include one or more computer executable components that are configured to perform embodiments when the program is running. One or more computer executable components may be at least one software code or a portion thereof.

[0397] Further, in this regard, it should be noted that any block of the logic flow as in the accompanying drawings may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on a physical medium such as a memory chip or memory block implemented within a processor, on a magnetic medium such as a hard disk or floppy disk, and on an optical medium such as, for example, a DVD and its data variants, a CD. A physical medium is a non-transitory medium.

[0398] The memory may be of any type suitable for the local technical environment and may be implemented using any appropriate data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The data processor may be of any type suitable for the local technical environment and may include, as non-limiting examples, one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an FPGA, a gate-level circuit, and a processor based on a multi-core processor architecture.

[0399] Embodiments of the present invention may be practiced in various components such as integrated circuit modules. The design of integrated circuits is generally a highly automated process. Complex and powerful software tools are available to convert a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0400] The foregoing description has provided a complete and useful description of exemplary embodiments of the present invention by way of non-limiting examples. However, when read in conjunction with the accompanying drawings and the appended claims, various modifications and adaptations will become apparent to those skilled in the relevant art in view of the above description. However, all these and similar modifications of the teachings of the present invention will still fall within the scope of the present invention as defined by the appended claims. In fact, there are further embodiments including combinations of one or more embodiments with any other embodiments discussed above.

Claims

1. A device comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least perform: Determine information, the information including: a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and / or a number of successful random access channel attempts in the at least one cell controlled by the apparatus and a number of failed random access channel attempts in the at least one cell controlled by the apparatus; and sending the information from the device to a second device; Wherein determining the information comprises determining a failure rate of the random access channel attempts in the at least one cell controlled by the apparatus, and is based on: determining a ratio of failed random access channel attempts in the at least one cell controlled by the device to a total number of random access channel attempts in the at least one cell controlled by the device, wherein the total number of random access channel attempts in the at least one cell controlled by the device is determined as the sum of: the number of failed random access channel attempts in the at least one cell controlled by the device; and the number of successful random access channel attempts in the at least one cell controlled by the device; comparing the information comprising a failure rate of random access channel attempts in at least one cell controlled by the apparatus with a failure rate of random access channel attempts in at least one other cell; and Based on the comparison, a determination is made to change a random access channel configuration of the apparatus.

2. The device according to claim 1, wherein: The at least one memory and the computer program code are configured to, with the at least one processor, further be configured to perform: A message is received from the second device, the message including a failure rate of random access channel attempts in at least one other cell.

3. The device according to claim 1, wherein: The at least one memory and the computer program code are configured to, together with the at least one processor, execute: receiving, from the second apparatus, information of a random access channel report related to a random access channel attempt in the at least one cell controlled by the apparatus; Based on the information of the random access channel report received from the second device regarding random access channel attempts in the at least one cell controlled by the device, a value indicating the number of failed random access channel attempts in the at least one cell controlled by the device is determined.

4. The device according to claim 1, wherein: When the number of failed random access channel attempts in the at least one cell controlled by the device exceeds a threshold, a failure rate of the random access channel attempts in the at least one cell controlled by the device is determined.

5. The device according to claim 3, wherein: The information of random access channel reports relating to random access channel attempts in the at least one cell controlled by the apparatus is associated with a user equipment.

6. A method comprising: Determine information, the information including: a failure rate of random access channel attempts in at least one cell controlled by the device; and / or a number of successful random access channel attempts in the at least one cell controlled by the apparatus and a number of failed random access channel attempts in the at least one cell controlled by the apparatus; and sending the information from the device to a second device; Wherein determining the information comprises determining a failure rate of the random access channel attempts in the at least one cell controlled by the apparatus, and is based on: determining a ratio of failed random access channel attempts in the at least one cell controlled by the device to a total number of random access channel attempts in the at least one cell controlled by the device, wherein the total number of random access channel attempts in the at least one cell controlled by the device is determined as the sum of: the number of failed random access channel attempts in the at least one cell controlled by the device; and the number of successful random access channel attempts in the at least one cell controlled by the device; comparing the information comprising a failure rate of random access channel attempts in at least one cell controlled by the apparatus with a failure rate of random access channel attempts in at least one other cell; and Based on the comparison, a determination is made to change a random access channel configuration of the apparatus.

7. The method according to claim 6, wherein: The method comprises: A message is received from the second device, the message including a failure rate of random access channel attempts in at least one other cell.

8. The method according to claim 6, wherein: The method comprises: receiving, from the second apparatus, information of a random access channel report related to a random access channel attempt in the at least one cell controlled by the apparatus; Based on the information of the random access channel report received from the second apparatus regarding random access channel attempts in the at least one cell controlled by the apparatus, a value indicative of the number of failed random access channel attempts in the at least one cell is determined.

9. The method according to claim 6, wherein: When the number of failed random access channel attempts in the at least one cell controlled by the device exceeds a threshold, a failure rate of the random access channel attempts in the at least one cell controlled by the device is determined.

10. The method according to claim 8, wherein: The information of random access channel reports relating to random access channel attempts in the at least one cell controlled by the apparatus is associated with a user equipment.

11. A non-transitory computer-readable medium comprising instructions for causing an apparatus to at least: Determine information, the information including: a failure rate of random access channel attempts in at least one cell controlled by the apparatus; and / or a number of successful random access channel attempts in the at least one cell controlled by the apparatus and a number of failed random access channel attempts in the at least one cell controlled by the apparatus; and sending the information from the device to a second device; Wherein determining the information comprises determining a failure rate of the random access channel attempts in the at least one cell controlled by the apparatus, and is based on: determining a ratio of failed random access channel attempts in the at least one cell controlled by the device to a total number of random access channel attempts in the at least one cell controlled by the device, wherein the total number of random access channel attempts in the at least one cell controlled by the device is determined as the sum of: the number of failed random access channel attempts in the at least one cell controlled by the device; and the number of successful random access channel attempts in the at least one cell controlled by the device; comparing the information comprising a failure rate of random access channel attempts in at least one cell controlled by the apparatus with a failure rate of random access channel attempts in at least one other cell; and Based on the comparison, a determination is made to change a random access channel configuration of the apparatus.

12. The non-transitory computer readable medium of claim 11, wherein: The non-transitory computer-readable medium further includes instructions for causing the apparatus to at least: A message is received from the second device, the message including a failure rate of random access channel attempts in at least one other cell.

13. The non-transitory computer readable medium of claim 11, wherein: The non-transitory computer-readable medium further includes instructions for causing the apparatus to at least: receiving, from the second apparatus, information of a random access channel report related to a random access channel attempt in the at least one cell controlled by the apparatus; Based on the information of the random access channel report received from the second apparatus regarding random access channel attempts in the at least one cell controlled by the apparatus, a value indicative of the number of failed random access channel attempts in the at least one cell is determined.

14. The non-transitory computer readable medium of claim 11, wherein: When the number of failed random access channel attempts in the at least one cell controlled by the device exceeds a threshold, a failure rate of the random access channel attempts in the at least one cell controlled by the device is determined.

Images