A wireless communication method, network element and storage medium

Abstract

The present disclosure generally relates to a wireless communication method, a network element, and a storage medium. The method is performed by a first network element in a network, and includes: receiving a first message from a second network element of the network; deriving a UE-specific paging resource configuration associated with a user equipment (UE) based on the first message; selecting a paging radio resource based on the UE-specific paging resource configuration and based on a radio resource-specific paging configuration predefined in the first network element; and sending a paging message to the UE through the selected paging radio resource when the UE is in a radio resource control (RRC) inactive state.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This case is a divisional application of the invention patent application with international application number PCT / CN2020 / 121065, international application date October 15, 2020, date of entry into the Chinese national phase November 15, 2022, Chinese national application number 202080100981.0, and invention name "Method, device and system for paging resource selection and system information transmission / acquisition in wireless networks". Technical Field

[0003] The present disclosure relates generally to wireless communications, and more particularly to methods, systems, and devices for adaptive paging resource allocation and system information (SI) acquisition. Background Art

[0004] Paging mechanisms can be used to notify wireless devices of communication needs. Efficient allocation of paging radio resources is critical to reducing the power consumption of these devices during the paging process. The ability of wireless devices to reliably and timely obtain system information updates with minimal power consumption is another important factor in ensuring optimal network performance, especially for low-power wireless terminals such as narrowband Internet of Things (NB-IoT), machine type communication (MTC) and enhanced machine type communication (eMTC) devices. Summary of the invention

[0005] The present disclosure relates to methods, systems and devices for paging resource selection and SI acquisition in a wireless communication network.

[0006] In some implementations, a method for paging using adaptively allocated paging resources is disclosed, the method being performed by a first network element in a network. The method may include receiving a first message from a second network element of the network; deriving a UE-specific paging resource configuration associated with a user equipment (UE) based on the first message; selecting a paging radio resource based on the UE-specific paging resource configuration and based on a radio resource-specific paging configuration predefined in the first network element; and sending a paging message to the UE via the selected paging radio resource.

[0007] In some other implementations, a method for transmitting system information is disclosed, the method being performed by a first network element in a network. The method may include sending a first message to a UE in the network during a first predetermined system information (SI) acquisition period, the first message including an SI update indicator, the SI update indicator indicating that the UE obtains SI updates from the beginning of a second predetermined SI acquisition period after the first predetermined SI acquisition period; and sending the updated SI to the UE within the second predetermined SI acquisition period.

[0008] In some other implementations, a method for acquiring system information is disclosed, the method being performed by a UE in a network. The method includes: receiving a first message sent from a first network element in the network during a first predetermined system information (SI) acquisition period, the first message including an SI update indicator, the SI update indicator indicating that the UE acquires SI updates from the beginning of a second predetermined SI acquisition period after the first predetermined SI acquisition period; and receiving updated SI sent from the first network element within the second predetermined SI acquisition period.

[0009] A network element and / or UE is further disclosed. The network element and / or UE comprises a processor and a memory, wherein the processor is configured to read a computer code from the memory to implement the above method.

[0010] A computer-readable medium is further disclosed. The computer-readable medium includes instructions or a computer program, which, when executed by a wireless terminal, causes the wireless terminal to perform the above method.

[0011] Other aspects and alternatives of the above-described embodiments and their implementations are described in more detail in the following figures, description and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 An exemplary wireless communication network is shown.

[0013] Figure 2 Various exemplary time periods for system information (SI) acquisition are shown.

[0014] Figure 3 An exemplary message flow for sending UE-specific paging resource configuration using S1 Application Protocol (S1AP) or NG Application Protocol (NGAP) messages is shown.

[0015] Figure 4 An exemplary message flow for sending UE-specific paging resource configuration using a paging information update request and a paging message is shown.

[0016] Figure 5 An exemplary message flow for sending UE-specific paging resource configuration using XnAP messaging is shown.

[0017] Figure 6 An exemplary message flow for sending UE-specific paging resource configuration using F1AP messaging is shown.

[0018] Figure 7 An exemplary message flow for sending a system information update is shown.

[0019] Figure 8Another exemplary message flow for sending a system information update is shown.

[0020] Fig. 9 An exemplary message flow is shown, which illustrates that the UE-specific paging resource configuration is only used in the last used cell for RAN paging.

[0021] Fig.10 An exemplary message flow is shown, which illustrates that the UE-specific paging resource configuration is only used in the last used cell for core network paging. DETAILED DESCRIPTION

[0022] The following description and accompanying drawings set forth in detail certain illustrative implementations of the present disclosure, which implement several example modes in which the various principles of the present disclosure may be implemented. However, the illustrated examples are not exhaustive of many possible embodiments of the present disclosure. Other purposes, advantages and novel features of the present disclosure will be set forth in the detailed description below in conjunction with the accompanying drawings.

[0023] Certain features are described using the NB-IoT / eMTC wireless communication protocol as an example. However, the applicability of the disclosed technology is not limited to the NB-IoT / eMTC wireless communication protocol, and therefore the disclosed implementations are applicable to any wireless standard. The section headings used in this disclosure are only for readability and do not limit the scope of the embodiments and techniques disclosed in each section to that section.

[0024] Wireless communication network

[0025] Figure 1 An exemplary wireless communication network 100 is shown including a core network 110 and a radio access network (RAN) 120. The core network 110 also includes at least one mobility management entity (MME) 112 and / or at least one access and mobility management function (AMF) 114. Other functions that may be included in the core network 110 are described in detail in the following sections. Figure 1 1. The RAN 120 also includes a plurality of base stations, such as base stations (BS) 122 and 124. The base stations may include at least one evolved NodeB (eNB) 122 for 4G LTE, or a next generation base station (gNB) 124 for 5G New Radio (NR), or any other type of signal transmission / reception device, such as a UMTS NodeB. The example eNB 122 communicates with the MME 112 via an S1 interface. Both the eNB 122 and the gNB 124 may be connected to the AMF 114 via an Ng interface.

[0026] The gNB 124 may also include a central unit (CU) 126 and at least one distribution unit (DU) 128. The CU and DU may be co-located at the same location, or they may be split at different locations. The CU 126 and the DU 128 may be connected via an F1 interface. Alternatively, for an eNB capable of connecting to a 5G network, it may also be similarly divided into a CU and at least one DU, referred to as ng-eNB-CU and ng-eNB-DU, respectively. The ng-eNB-CU and the ng-eNB-DU may be connected via a W1 interface.

[0027] The wireless communication network 100 may further include at least one user equipment (UE) 130. The UE 130 may be implemented as a mobile or fixed communication device capable of accessing the wireless communication network 100. The UE 130 may include, but is not limited to, a mobile phone, a laptop, a tablet, a personal digital assistant, a wearable device, an IoT / NB-IoT device, an MTC / eMTC device, a distributed remote sensing device, a roadside assistance device, and a desktop computer. The UE 130 may communicate with the base station via an over-the-air (OTA) radio communication interface and resources. Figure 1 As shown, the OTA interface may include multiple radio carriers 132 and 134. The radio carriers may also be anchor carriers or non-anchor carriers.

[0028] The wireless communication network 100 may be implemented as, for example, a 2G, 3G, 4G / LTE, or 5G cellular communication network. Accordingly, the base stations 122 and 124 may be implemented as 2G base stations, 3G NodeBs, LTE eNBs, or 5G NR gNBs (although for illustration purposes, the base station 122 is labeled as an eNB and the base station 124 is labeled as a gNB).

[0029] Although the following description focuses on Figure 1 The cellular wireless communication system shown is illustrated, but the basic principles are applicable to other types of wireless communication systems that support wireless devices. These other wireless systems may include, but are not limited to, Wi-Fi, Bluetooth, ZigBee, and WiMax networks.

[0030] Paging Radio Resource Selection

[0031] In the wireless communication network 100, the UE can be located and / or awakened by the core network 110 using a paging mechanism that utilizes a paging radio resource. The paging radio resource includes at least one of a paging carrier, a paging narrowband, a paging physical resource block (PRB), a paging bandwidth part (BWP), or a paging control resource set (CORESET). Each paging radio resource has its corresponding configuration, which is referred to as a radio resource-specific paging configuration. The radio resource-specific paging configuration includes a carrier-specific paging configuration configured per paging carrier, a narrowband-specific paging configuration configured per paging narrowband, a paging PRB-specific paging configuration configured per paging physical resource block (PRB), a BWP-specific paging configuration configured per paging bandwidth part (BWP), or at least one of a CORESET-specific paging configuration configured per paging control resource set (CORESET). In the present disclosure, the term “radio resource specific paging configuration” may be used to refer to any radio resource specific paging configuration in any wireless communication environment including eMTC, NB-IoT and NR.

[0032] In the wireless communication network 100, UEs, especially eMTC and NB-IoT devices, are deployed in different areas under different cellular coverage levels. For example, the UE may be deployed in an office building, a warehouse, a grocery store, or an underground parking lot. These locations may have different cellular signal qualities. Coverage enhancement may be introduced, and different coverage conditions may correspond to different coverage enhancement levels (CELs). Different UEs may be at different coverage enhancement levels (CELs), and UEs of different coverage enhancement levels may be configured with different maximum repetitions of the NPDCCH common search space (CSS) for paging (e.g., Rmax-paging). CEL and Rmax-paging are considered to be part of a UE-specific paging resource configuration. In some implementations, the UE-specific paging resource configuration also includes a discontinuous reception (DRX) cycle configured for the UE.

[0033] With the introduction of CEL and Rmax-paging, paging resources such as paging carriers and paging narrowbands can be associated with UE-specific paging resource configurations. For example, carrier 1 can be associated with a lower CEL and carrier 2 can be associated with a higher CEL. Alternatively, carrier 3 can be associated with a lower Rmax-paging and carrier 4 can be associated with a higher Rmax-paging. Therefore, radio resources can be flexibly and dynamically allocated and scheduled, taking into account the UE's UE-specific paging resource configuration. For example, for UEs under poor coverage, which may be indicated by a higher CEL, radio resources configured with stronger transmission power (such as stronger downlink (DL) transmission power) can be selected. In addition, radio resources configured with a larger Rmax-paging can be selected for UEs configured with a larger PDCCH repetition number (Rmax-paging).

[0034] It should be understood that the above scheme of selecting paging radio resources based on UE-specific paging resource configuration requires negotiation and coordination between UE, base station and core network. Negotiation can be further based on paging configuration specific to radio resources. Negotiation enables these network elements to have a consistent consensus on radio resource selection. Negotiation can be implemented through various types of signaling or messages. For example, when the UE is in the radio resource control idle (RRC_IDLE) state, the UE and / or BS can select the best paging radio resources including paging carrier or paging narrowband to reduce or minimize UE power consumption without affecting reliable signal transmission. For example, the UE, base station and core network can negotiate / renegotiate the carrier selection capability based on CEL, Rmax-paging or DRX cycle for the UE, and the core network can send the negotiated carrier selection capability based on CEL, Rmax-paging or DRX cycle to the base station in messages such as S1AP / NGAP messages. In the subsequent process, the base station can select paging radio resources such as paging carrier or paging narrowband based on CEL or Rmax-paing and paging configuration specific to radio resources. The base station may broadcast a radio resource specific paging configuration to the UE via a system information block (SIB).

[0035] However, for a UE in the RRC_INACTIVE state, the base station may not be able to obtain UE-specific paging resource configuration, such as carrier selection capability based on CEL, Rmax-paging, and DRX cycle. Therefore, the base station may not be able to perform radio resource selection based on the UE-specific paging resource configuration.

[0036] In addition, for CEL or Rmax-paging negotiation using access stratum (AS) signaling, the updated CEL or Rmax-paging is transmitted to the core network via a UE-specific S1AP or NGAP release message. However, when the UE is in the RRC_INACTIVE state, the UE-specific S1AP or NGAP release message is not available, so the CEL or Rmax-paging may not be updated in the core network and / or the base station.

[0037] During the paging process, the DRX cycle (T) is used to determine when the UE needs to wake up to detect potential paging messages. The determination of the DRX cycle (denoted by T) depends on the extended discontinuous reception (eDRX) cycle used for paging, UE-specific DRX and the RAN paging cycle. In some scenarios, wake-up signal (WUS) auxiliary information (described in more detail below) is further necessary for group wake-up signal (GWUS) resource selection. If the UE is in RRC_INACTIVE state and needs to select a target base station, for example, as a result of cell reselection, the target base station may not be aware of these parameters. For the NB-CU and NB-DU split case, the NB-DU may also not be aware of these parameters.

[0038] The following description discloses in detail implementations and embodiments for selecting paging resources for a UE in RRC_INACTIVE state based on a UE-specific paging resource configuration.

[0039] System information acquisition

[0040] UE power consumption is an important factor to consider when designing wireless communication systems. Figure 1 , when there is no active communication session between UE 130 and the base station, UE 130 stays in an idle or inactive state, such as RRC_IDLE or RRC_INACTIVE state. UE 130 continues to monitor paging signals while limiting its use of radio resources during the idle state to reduce power consumption. For example, UE 130 can monitor paging signals by using technologies including but not limited to DRX or eDRX. In addition, a wake-up signal (WUS) can be introduced as an enhancement to existing paging technology to further reduce the power consumption of mobile devices and achieve longer battery life by reducing hardware resource usage when monitoring paging information. The wake-up mechanism in paging monitoring is particularly beneficial for low-power devices, such as NB-IoT (Internet of Things) and eMTC (enhanced machine type communication) devices.

[0041] In DRX, resource monitoring and communication activities are managed in cycles, called DRX cycles. In particular, in wireless communication systems such as LTE and 5G, radio signals are transmitted in radio frames. At the system level, radio frames are identified in sequence, and each radio frame is numbered with a system frame number (SFN), which cycles from 0 to 1023, for example. In DRX mode, the UE can enter sleep mode to reduce battery consumption. The UE periodically monitors paging opportunities (POs). POs include a set of physical downlink control channel (PDCCH) monitoring opportunities and may include multiple time slots (e.g., subframes or OFDM symbols) in which paging DCIs may be sent. The purpose of periodic monitoring of POs is to check whether there are paging messages for the UE and to obtain system information updates so that the UE can be synchronized with the network. If there are no paging messages for a specific UE, the UE can return to sleep and wake up in the next cycle to monitor POs. This cycle is called a paging cycle or a DRX cycle. The length of the paging cycle is given by the number of radio frames in each cycle and can be configured to different lengths in a wireless communication system. Figure 2 An exemplary paging cycle 102 is shown.

[0042] In eDRX, the UE is able to set and adjust the time it stays in low-power sleep mode before waking up to monitor any wireless signals. The eDRX mechanism enables UEs, especially NB-IoT or eMTC devices, to further reduce battery consumption. As another enhancement, the WUS mechanism utilizes low-power hardware circuits operating on the physical layer, which can further help extend battery life.

[0043] In a wireless communication system, system information (SI) may change from time to time, and the network needs to inform the UE about the changes in SI. System information can be transmitted multiple times with the same content within a modification period such as a BCCH (Broadcast Control Channel) modification period or an eDRX acquisition period. The modification period boundary is defined by the SFN value of SFN mod m=0, where m is the number of radio frames including the modification period. For example, m=modifyPeriodCoeff*defaultPagingCycle. Where modifyPeriodCoeff and defaultPagingCycle can be pre-defined by the network and can be further broadcast to the UE via the system information block (SIB). The modification period boundary can also be similarly defined using the hyper-system frame number (H-SFN). SI update is a two-step process as described below:

[0044] Step 1: The network (e.g., base station) first uses a paging message or downlink control information (DCI) to notify the UE of the SI change in the first modification period. This period may also be referred to as a change notification period. In some implementations, the SI change notification may be repeated several times within the change notification period. The first modification period may be a BCCH modification period or an eDRX acquisition period.

[0045] Step 2: In the next modification period, the network sends the updated SI to the UE. This period may also be called the updated information period.

[0046] refer to Figure 2 , assuming that there is an SI change during the first BCCH modification period 210, the base station sends a paging message or DCI to the UE as a notification to indicate that there is an SI change in the period 210. In the next BCCH modification period 212, the base station sends updated SI information to the UE, and the period 212 is considered to be an updated information period.

[0047] On the UE side, the UE monitors the SI change indication based on the BCCH modification period or the eDRX acquisition period (for example, expressed as the maximum value of the superframe number = paging eDRX cycle). For example, the base station sends a paging message or DCI carrying the SI change indication to the UE. For each type of modification period, there may be a corresponding SI change indicator, such as a BCCH SI change indicator, to indicate that the SI is updated in the next BCCH modification period, or there may be an eDRX SI change to indicate that the SI is updated in the next eDRX acquisition period. Therefore, based on the SI change indicator, the UE can select the corresponding period to obtain the updated SI information. In some implementations, the BCCH SI change indicator and the eDRX SI change indicator may be sent together in a paging message or DCI. In this case, the UE can choose to obtain the updated SI information in the next BCCH modification period and / or the next eDRX acquisition period.

[0048] In Figure 2 In the example, the SI change in the first eDRX acquisition period 230 is taken as an example, so the base station sends a paging message or DCI carrying an eDRX SI change indicator, and the eDRX SI change indicator instructs the UE to obtain updated SI information in the next eDRX acquisition period 232.

[0049] When the UE is in RRC_INACTIVE state, the maximum possible DRX cycle can be longer than the BCCH modification period. Figure 2As shown, the DRX cycle 202 is longer than the BCCH modification period 210. This may cause desynchronization because if the UE happens to be in sleep mode in the DRX cycle when the SI change notification is sent, the UE may miss the BCCH SI change indicator sent in 210. Figure 2 As further shown, the eDRX SI change indicator may also be sent via a paging message or DCI in the eDRX acquisition period 230. Since the eDRX acquisition period 230 is longer than the maximum DRX cycle, and since the SI change notification may be sent multiple times in the eDRX acquisition period 230, the UE is able to detect the SI notification and will be able to obtain updated SI information in the next eDRX acquisition period 232. However, due to the long eDRX acquisition period, the waiting time to the next eDRX acquisition period for obtaining the updated SI information may be too long, resulting in a longer delay in SI update. As an example, for an eMTC device, the eDRX acquisition period may be as long as 256 superframes (about 43 minutes).

[0050] In the present disclosure, a new SI acquisition period and a corresponding mechanism for adapting the new SI acquisition period to a wireless communication system are implemented. The new SI acquisition period is called a short eDRX acquisition period. The short eDRX acquisition period can be predefined to be longer than the BCCH modification period but shorter than the eDRX acquisition period. Further details are described in the relevant embodiments below. In this way, a balance is achieved so that the UE does not miss the SI update notification, but can capture the SI update more quickly than the implementation using the eDRX acquisition period.

[0051] Brief Description of Embodiments

[0052] Various specific example embodiments are described for enabling adaptive and dynamic paging radio resource selection when a UE is in RRC_INACTIVE state. Mechanisms for delivering UE-specific paging resource configurations are also disclosed.

[0053] Various specific example embodiments for performing system information (SI) acquisition for a UE in RRC_INACTIVE state are further described.

[0054] Example 1

[0055] An exemplary procedure for delivering UE-specific paging resource configuration is provided in Figure 3 In this process, the core network (MME / AMF) sends the UE-specific paging resource configuration to the base station. When the UE-specific S1AP / NGAP connection is established, the base station selects the paging radio resource based on the UE-specific paging resource configuration. Details are described below.

[0056] Step 301: The base station sends a radio resource-specific paging configuration to the UE via a system information block (SIB). The radio resource-specific paging configuration includes at least one of the following:

[0057] ·CEL;

[0058] Rmax-paging;

[0059] A radio resource specific DRX cycle for paging; or

[0060] • The number of Paging Occasions (PO) per DRX cycle specific to the radio resource (eg, nB).

[0061] For example, for a specific paging radio resource, such as a radio carrier (also referred to alternatively as a carrier for brevity), the radio resource-specific paging configuration of the carrier may include CEL or Rmax-paging supported by the carrier. A carrier may be an anchor carrier or a non-anchor carrier.

[0062] Step 302: When the UE-specific S1AP / NGAP connection is established, the core network sends a message to the base station. The message carries the UE-specific paging resource configuration, for example, by embedding the UE-specific paging resource configuration into one or more information elements (IEs) of the message. In some implementations, the message may be one of the following:

[0063] Initial context establishment request;

[0064] UE context modification request;

[0065] A handover request; or

[0066] · Path switch request confirmation.

[0067] The UE-specific paging resource configuration includes at least one of the following:

[0068] ·CEL;

[0069] Rmax-paging;

[0070] · Paging radio resource selection capability based on DRX cycle; or

[0071] Paging eDRX information.

[0072] Upon receiving the message, the base station stores the UE-specific paging resource configuration and an S1AP / NGAP connection is established. A communication session is established for the UE for data transmission.

[0073] Step 303: The base station triggers the UE to enter the RRC_INACTIVE state by sending an RRC connection release message to the UE. In some implementations, the base station includes the UE-specific paging resource configuration received in step 302 in the message to ensure that the UE has a synchronized consensus on the UE-specific paging resource configuration when in the RRC_INACTIVE state. The UE-specific paging resource configuration includes at least one of the following:

[0074] CEL; or

[0075] ·Rmax-paging.

[0076] In some other implementations, the base station may choose not to include UE-specific paging resource configuration in the RRC connection release message. In this case, the UE uses the previously configured CEL and Rmax-paging when in the RRC_INACTIVE state.

[0077] After the UE processes the RRC connection release message, the UE enters the RCC_INACTIVE state.

[0078] Step 304: The base station selects a paging radio resource, such as a specific paging carrier or a specific paging narrowband, and sends a paging message to the UE using the selected paging radio resource. The base station makes this selection based on the radio resource-specific paging configuration sent in the SIB in step 301 and based on the UE-specific paging resource configuration. Specifically, if the UE-specific paging resource configuration is included in step 303, the CEL or Rmax-paging carried in step 303 is used; otherwise, the previously configured CEL or Rmax-paging is used.

[0079] On the UE side, the UE needs to determine its own DRX cycle, also called the paging DRX cycle (T). If the UE-specific paging resource configuration of step 302 includes paging eDRX information but does not include a paging time window (PTW), the DRX cycle (T) of the UE in the RRC_INACTIVE state is determined by the shortest of the paging eDRX cycle (from the paging eDRX information) and the RAN paging cycle. For example, the RAN paging cycle may be sent to the UE via the SIB in step 301.

[0080] Furthermore, if the paging message is initiated from the core network, such as via S1AP PAGING or NGAP PAGING, and the paging message includes a paging eDRX cycle IE but does not include a PTW, the UE's DRX cycle (T) is determined by the paging eDRX cycle carried in the paging eDRX cycle IE.

[0081] As mentioned above, the paging radio resource includes at least one of the following:

[0082] Paging carrier;

[0083] ·Paging narrowband;

[0084] Paging physical resource blocks (PRBs);

[0085] Paging Bandwidth Part (BWP); or

[0086] · Paging Control Resource Set (CORESET).

[0087] The radio resource-specific paging configuration includes at least one of the following:

[0088] Carrier-specific paging configuration per paging carrier configuration;

[0089] Narrowband-specific paging configuration per paging narrowband configuration;

[0090] · Paging configuration specific to each paging physical resource block (PRB);

[0091] · BWP-specific paging configuration per Paging Bandwidth Part (BWP); or

[0092] • CORESET-specific paging configuration configured per Paging Control Resource Set (CORESET).

[0093] Example 2

[0094] Another exemplary procedure for updating UE-specific paging resource configuration is shown in Figure 4 In this process, the UE sends a paging information request message to the base station to request the base station to estimate the UE-specific CEL or Rmax-paging. After the estimation, the base station forwards the updated UE-specific paging resource configuration (e.g., CEL or Rmax-paging) to the core network (MME / AMF) via an S1AP / NGAP update message. Details are as follows.

[0095] Step 401: The base station sends a radio resource-specific paging configuration to the UE via the SIB. The radio resource-specific paging configuration includes at least one of the following:

[0096] ·CEL;

[0097] Rmax-paging;

[0098] A radio resource specific DRX cycle for paging; or

[0099] • The number of paging occasions (PO) per DRX cycle specific to a radio resource (eg, nB).

[0100] For example, for a specific paging radio resource, such as a carrier, the radio resource-specific paging configuration for that carrier may include CEL or Rmax-paging supported by that carrier.

[0101] Step 402: The UE sends a paging information request to the base station in the data transmission state. The paging information request includes at least one of the following information:

[0102] · Preferred CEL;

[0103] ·CEL-based paging resource selection capability;

[0104] · Preferred Rmax-paging; or

[0105] · Paging resource selection capability based on Rmax-paging.

[0106] The paging information request may be sent via at least one of the following messages:

[0107] UL MAC CE;

[0108] ·RRCConnectionReconfigurationComplete;

[0109] ·RRCConnectionReestablishmentComplete;

[0110] ·RRCConnectionResumeComplete;

[0111] ·RRCConnectionSetupComplete;

[0112] RRCearlyDataRequest;

[0113] UEAssistanceInformation;

[0114] UECapabilityInformation; or

[0115] • New UL RRC message (eg, UE PagingInformationRequest).

[0116] The UE sends a paging information request message to the base station, for example, when the radio signal condition of the UE reaches a threshold. The paging information request message triggers the base station to estimate or configure / reconfigure paging resources. The paging resources include at least one of the following:

[0117] ·CEL;

[0118] Rmax-paging;

[0119] · CEL-based paging deactivation indication; or

[0120] · Paging deactivation indication based on Rmax-paging.

[0121] Step 403: Based on the paging information request message from the UE, the base station estimates the CEL or Rmax-paging for the UE in a data transmission state (e.g., RRC_CONNECTED state, RRC_INACTIVE state, preconfigured uplink resource (PUR) transmission procedure, early data transmission (EDT) procedure, NR small data transmission procedure).

[0122] Step 404: The base station sends a paging information update request to the core network in a UE-specific S1AP or NGAP message to update the UE-specific paging configuration. The UE-specific S1AP or NGAP message includes at least one of the following messages:

[0123] RRC INACTIVE TRANSITION REPORT; or

[0124] • New UE-specific S1AP or NGAP messages (eg, Paging Information Configuration Update message).

[0125] The paging information update request includes at least one of the following information:

[0126] ·CEL;

[0127] Rmax-paging;

[0128] · CEL-based paging deactivation indication; or

[0129] · Paging deactivation indication based on Rmax-paging.

[0130] The CEL-based paging deactivation indication is used to indicate whether CEL-based paging for the UE should be deactivated. The Rmax-paging-based paging deactivation indication is used to indicate whether Rmax-paging-based paging for the UE should be deactivated. In some implementations, if CEL is not included in the paging information update request, it implicitly indicates that CEL-based paging for the UE should be deactivated. In some other implementations, if Rmax-paging is not included in the paging information update request, it implicitly indicates that Rmax-paging-based paging for the UE should be deactivated.

[0131] Step 405: The base station sends an RRC connection release message to trigger the UE to enter the RRC_INACTIVE state. The RRC connection release message may include a UE-specific paging resource configuration. The UE-specific paging resource configuration includes at least one of the following information:

[0132] CEL; or

[0133] ·Rmax-paging.

[0134] Step 406: In some implementations, the base station initiates a PAGING sent on a paging radio resource, which is selected based on the radio resource-specific paging configuration sent via the SIB in step 401 and further based on the UE-specific paging resource configuration sent by the base station in step 405. If the UE-specific paging resource configuration is included in step 405, the UE CEL or Rmax-paging included in step 405 is used; otherwise, the previously configured CEL or Rmax-paging is used.

[0135] In some other implementations, the core network initiates paging. In this case, step 406 is split into steps 406a and 406b:

[0136] Step 406a: The core network sends a paging message to the base station. The paging message carries a UE-specific paging resource configuration, and the UE-specific paging resource configuration includes at least one of the following:

[0137] ·CEL;

[0138] ·CEL-based paging indication;

[0139] Rmax-paging; or

[0140] · Paging indication based on Rmax-paging.

[0141] Step 406b: At the base station side, if the paging message from the core network includes a paging indication based on CEL, the base station selects a paging radio resource based on CEL and a paging configuration specific to a radio resource. Similarly, if the paging message from the core network includes a paging indication based on Rmax-paging, the base station selects a paging radio resource based on Rmax-paging and a paging configuration specific to a radio resource. The base station then sends a paging message initiated from the core network to the UE using the selected paging radio resource.

[0142] The radio resource-specific paging configuration includes at least one of the following:

[0143] Carrier-specific paging configuration per paging carrier configuration;

[0144] Narrowband-specific paging configuration per paging narrowband configuration;

[0145] · Paging configuration specific to each paging physical resource block (PRB);

[0146] · BWP-specific paging configuration per Paging Bandwidth Part (BWP); or

[0147] • CORESET-specific paging configuration configured per Paging Control Resource Set (CORESET).

[0148] Example 3

[0149] An exemplary procedure for delivering UE-specific paging resource configuration via RAN initiated paging is described in Figure 5 In this process, the source base station sends the UE-specific paging resource configuration to the target base station via the X2 or Xn interface. The details are as follows.

[0150] The RAN initiated paging procedure is used by the source base station to request paging of the UE in the target base station. The RAN initiated paging message may carry a UE specific paging resource configuration to help the target base station determine the paging radio resources for paging the UE.

[0151] Step 501: The target base station (base station 2) sends a radio resource-specific paging configuration to the UE via the SIB. The radio resource-specific paging configuration includes at least one of the following:

[0152] ·CEL;

[0153] Rmax-paging;

[0154] A radio resource specific DRX cycle for paging; or

[0155] • The number of paging occasions (PO) per DRX cycle specific to a radio resource (eg, nB).

[0156] In this step, the UE is in RRC_INACTIVE state.

[0157] Step 502: When the UE-specific S1AP / NGAP connection is established, the source base station (base station 1) receives the UE-specific paging resource configuration from the core network. The source base station sends a RAN-initiated paging message to the target base station (base station 2). The RAN-initiated paging message contains the UE-specific paging resource configuration.

[0158] The UE-specific paging resource configuration includes at least one of the following:

[0159] ·CEL;

[0160] Rmax-paging;

[0161] · Paging radio resource selection capability based on DRX cycle;

[0162] WUS auxiliary information;

[0163] Paging probability information;

[0164] Paging eDRX information;

[0165] RAN paging cycle;

[0166] UE-specific DRX; or

[0167] Core network assistance information for UEs in RRC INACTIVE state.

[0168] Step 503, the target base station determines a paging radio resource for paging the UE based on the radio resource-specific paging configuration and the UE-specific paging resource configuration. In step 502, the target base station receives the UE-specific paging resource configuration. The paging radio resource includes at least one of the following:

[0169] Paging carrier;

[0170] ·Paging narrowband;

[0171] Paging physical resource blocks (PRBs);

[0172] Paging bandwidth part (BWP);

[0173] Paging control resource set (CORESET);

[0174] paging occasion (e.g., paging frame, paging subframe); or

[0175] GWUS resources.

[0176] On the UE side, the UE needs to determine the paging DRX cycle (T). If the UE-specific paging resource configuration of step 502 includes paging eDRX information but does not include a paging time window (PTW), the DRX cycle (T) of the UE in the RRC_INACTIVE state is determined by the shortest of the paging eDRX cycle (from the paging eDRX information) broadcast to the UE via the SIB in step 501 and the RAN paging cycle.

[0177] In addition, if the paging message is triggered by the core network, such as S1AP PAGING or NGAP PAGING, and the paging message includes the paging eDRX cycle IE but does not include PTW, the DRX cycle (T) of the UE is determined by the paging eDRX cycle carried in the paging eDRX cycle IE.

[0178] Example 4

[0179] An exemplary procedure for delivering UE-specific paging resource configuration from a gNB-CU of a gNB to a gNB-DU of the same gNB is described in Figure 6 In this process, the gNB-CU sends UE-specific paging resource configuration to the gNB-DU using F1 PAGING via the F1 interface. Details are described below.

[0180] Step 601: The gNB-CU of the gNB sends a radio resource-specific paging configuration to the gNB-DU of the same gNB via the SIB, and the gNB-DU forwards the radio resource-specific paging configuration to the UE via the SIB. The radio resource-specific paging configuration includes at least one of the following:

[0181] ·CEL;

[0182] Rmax-paging;

[0183] A radio resource specific DRX cycle for paging; or

[0184] • The number of paging occasions (PO) per DRX cycle specific to the radio resource (eg, nB).

[0185] The gNB-CU keeps and maintains the radio resource specific paging configuration, and the gNB-CU distributes the radio resource specific paging configuration to the gNB-DU for further broadcasting to the UE. In this step, the UE is in RRC_INACTIVE state.

[0186] Step 602: When the gNB-CU receives the UE-specific paging resource configuration from the core network, the gNB-CU sends the UE-specific paging resource configuration to the gNB-DU in a paging message via the F1 interface.

[0187] The UE-specific paging resource configuration includes at least one of the following:

[0188] ·CEL;

[0189] Rmax-paging;

[0190] · Paging radio resource selection capability based on DRX cycle;

[0191] WUS auxiliary information;

[0192] Paging probability information;

[0193] Paging eDRX information;

[0194] RAN paging cycle;

[0195] UE-specific DRX; or

[0196] Core network assistance information for UEs in RRC INACTIVE state.

[0197] Step 603: The gNB-DU determines a paging radio resource for paging the UE based on the radio resource specific paging configuration as in step 601 and based on the UE specific paging resource configuration. The gNB-DU sends a RAN based paging message to the UE using the determined paging radio resource. In step 602, the UE specific paging resource configuration is received by the gNB-DU. The paging radio resource includes at least one of the following:

[0198] Paging carrier;

[0199] ·Paging narrowband;

[0200] Paging physical resource blocks (PRBs);

[0201] Paging bandwidth part (BWP);

[0202] Paging control resource set (CORESET);

[0203] paging occasion (e.g., paging frame, paging subframe); or

[0204] GWUS resources.

[0205] On the UE side, the UE needs to determine the paging DRX cycle (T). If the UE-specific paging resource configuration of step 602 includes paging eDRX information but does not include PTW, the DRX cycle (T) of the UE in RRC_INACTIVE state is determined by the shortest of the paging eDRX cycle (from the paging eDRX information) and the RAN paging cycle.

[0206] In addition, if the paging message in step 602 includes the paging eDRX cycle IE but does not include the PTW, the DRX cycle (T) of the UE in the RRC_IDLE state is determined by the paging eDRX cycle carried in the paging eDRX cycle IE.

[0207] Example 5

[0208] In the previous embodiment, the paging resource selection based on the UE-specific paging resource configuration is performed only when the UE is in the last used cell of the UE. The last used cell is the cell where the RRC connection of the UE was last released normally (for example, the UE and the eNB / CN node (MME / AMF) can maintain consistent information about the last used cell based on this release process). For example, the cell where the UE last entered the RRC_IDLE or RRC_INACTIVE state is triggered by any of the following conditions:

[0209] Receipt of an RRCEarlyDataComplete message; or

[0210] Receipt of RRCConnectionRelease without noLastCellUpdate;

[0211] When the UE is not in the last used cell, the paging resource selection based on the UE-specific paging resource configuration is not performed. In this case, the page will be sent on the paging resource without considering the UE-specific paging resource configuration.

[0212] See examples Fig. 9 .

[0213] Step 901: The last used cell sends its radio resource specific paging configuration to the UE via a system information block (SIB).

[0214] Step 901a: Another cell except the last used cell transmits its radio resource specific paging configuration to the UE through a system information block (SIB).

[0215] Step 902: The last used cell sends a paging message to other cells. The paging message does not carry a paging resource configuration specific to the UE.

[0216] Step 903: The last used cell determines a paging radio resource for paging the UE based on the radio resource-specific paging configuration and the UE-specific paging resource configuration, and sends a RAN-based paging message to the UE using the determined paging radio resource.

[0217] Step 903a: Other cells send a RAN-based paging message to the UE using paging radio resources without regard to the UE-specific paging resource configuration.

[0218] For another example, see Fig.10 .

[0219] Steps 1001 and 1001a are similar to Fig. 9 The detailed description of steps 901 and 901a is omitted here.

[0220] Step 1002: The core network sends a paging message to the cell last used by the UE, where the paging message carries a paging resource configuration specific to the UE.

[0221] Steps 1003 and 1003a are similar to Fig. 9 Likewise, other cells send core network initiated paging messages to the UE using paging radio resources without regard to the UE specific paging resource configuration.

[0222] Example 6

[0223] For an exemplary process for a base station to instruct a UE in the RRC_INACTIVE state to obtain SI update in the next short eDRX acquisition period, see Figure 7 .

[0224] Step 701, when the SI changes, the base station sends a paging message to the UE within the first short eDRX acquisition period. The paging message carries a systemInfoModification-short-eDRX indicator, which is used to indicate to the UE that an SI update is coming in the next short eDRX acquisition period, so that the UE can obtain the SI update. In some implementations, the paging message may also carry a systemInfoModification indicator, which is used to indicate to the UE that an SI update is coming in the next BCCH modification period, and / or the paging message may also carry a systemInfoModification-eDRX indicator, which is used to indicate to the UE that an SI update is coming in the next eDRX acquisition period. In some implementations, each of these indicators can be carried in the form of bits.

[0225] Alternatively, the base station may use DCI instead of a paging message in step 701 to serve the same purpose.

[0226] Step 702: The base station sends the updated SI in the next short eDRX acquisition period.

[0227] The short eDRX acquisition period is predefined to be longer than the BCCH modification period (corresponding to the systemInfoModification indicator) and shorter than the eDRX acquisition period (corresponding to the systemInfoModification-eDRX indicator). In addition, when the UE is in the RRC_INACTIVE state, the length of the short eDRX acquisition period is equal to the maximum value within the RAN paging cycle value range, or equal to the maximum value within the DRX cycle (T) value range. The length of the BCCH modification period and the length of the eDRX acquisition period are predefined in the wireless communication network. Similarly, the RAN paging cycle value range and the DRX cycle (T) value range are also predefined in the wireless communication network.

[0228] Example 7

[0229] For another exemplary process for the base station to instruct the UE in the RRC_INACTIVE state to obtain SI update within the short eDRX acquisition period, see Figure 8 .

[0230] Step 801: The UE and the core network negotiate eDRX parameters via NAS messages. In some implementations, the base station also participates in the negotiation.

[0231] Step 802: The base station sends an RRC connection release message carrying RAN paging DRX parameters to the UE, and triggers the UE to enter the RRC_INACTIVE state.

[0232] After the UE enters the RRC_INACTIVE state, the UE monitors a paging message or DCI carrying the systemInfoModification-short-eDRX indicator in at least one of the following cases:

[0233] Case 1: The RAN paging cycle is longer than the BCCH modification period. The RAN paging cycle can be acquired by the UE via the SIB.

[0234] Case 2: The idle mode paging eDRX cycle is longer than the BCCH modification period. The idle mode paging eDRX cycle can be obtained from the eDRX parameters in step 801 .

[0235] Case 3: Idle mode paging eDRX information is configured in the UE, and the ran-pagingCycle is longer than the BCCH modification period. The idle mode paging eDRX information may be acquired from the eDRX parameters in step 801 .

[0236] Step 803, when the SI changes, the base station sends a paging message to the UE within the first short eDRX acquisition period. The paging message carries the InfoModification-short-eDRX indicator, which is used to indicate to the UE that the SI update is about to be performed. Alternatively, the base station can send DCI instead of a paging message to serve the same purpose.

[0237] Subsequently, the UE captures the systemInfoModification-short-eDRX indicator and acquires the updated SI information in the next short eDRX acquisition period.

[0238] Example 8

[0239] UE in RRC_INACTIVE state obtains SI update during short eDRX acquisition period. Figure 2 .

[0240] In the short eDRX acquisition period 220 , the UE receives a paging message or DCI carrying the systemInfoModification-short-eDRX indicator.

[0241] In the next short eDRX acquisition period 222, the UE immediately acquires the updated system information from the beginning of the short eDRX acquisition period 222. In some implementations, the next short eDRX acquisition period may be immediately adjacent to the short eDRX acquisition period 220.

[0242] The following is an example for eMTC devices:

[0243] The BCCH modification period can be expressed by the number of radio frames = modificationPeriodCoeff*defaultPagingCycle.

[0244] The eDRX acquisition period may be expressed in terms of superframe numbers. For example, the boundaries of the eDRX acquisition period may be determined by the H-SFN value of H-SFN mod256=0. For eMTC devices, the length of the eDRX acquisition period may be set to 256 superframes, i.e., the maximum value within the range of paging eDRX cycle values.

[0245] The short eDRX acquisition period may be expressed in terms of a number of radio frames or superframes. For example, the boundaries of the short eDRX acquisition period may be determined by a radio frame value of SFN mod 1024 = 0. In one implementation, the length of the short eDRX acquisition period may be set to 1024 radio frames or 1 superframe, i.e., the maximum value within the range of RAN paging cycle values.

[0246] In summary, the above disclosure describes a method and system for adaptively allocating paging resources based on a UE-specific paging resource configuration. For a UE with a specific UE-specific paging resource configuration, such as a paging radio resource selection capability based on CEL, Rmax-paging, or DRX cycle, a base station can select a paging radio resource according to the UE-specific paging resource configuration, with specific reference to the paging configuration of the radio resource. The paging radio resource may include a paging carrier, a paging narrowband, etc.

[0247] The present disclosure also describes a new acquisition period for system information acquisition, i.e., a short eDRX acquisition period. The length of the short eDRX acquisition period is set to be longer than the BCCH modification period and shorter than the eDRX acquisition period. A new indicator corresponding to the new acquisition period is also introduced, which can be carried in a paging message or DCI, and is used to instruct the UE to acquire updated SI information in the next short eDRX acquisition period.

[0248] The above description and accompanying drawings provide specific example embodiments and implementations. However, the described subject matter may be embodied in a variety of different forms, and therefore, the subject matter covered or claimed is intended to be interpreted as not being limited to any example embodiment set forth herein. It is intended to provide a reasonably broad scope for the subject matter claimed or covered. For example, the subject matter may be embodied, in particular, as a non-transitory computer-readable medium for a method, device, component, system, or for storing computer code. Therefore, the embodiments may, for example, take the form of hardware, software, firmware, storage media, or any combination thereof. For example, the above method embodiments may be implemented by a component, device, or system including a memory and a processor by executing a computer code stored in the memory.

[0249] Throughout the specification and claims, terms may have nuanced meanings suggested or implied by the context, beyond the explicitly stated meanings. Likewise, the phrase "in one embodiment / implementation" as used herein does not necessarily refer to the same embodiment, and the phrase "in another embodiment / implementation" as used herein does not necessarily refer to a different embodiment. For example, the claimed subject matter is intended to include combinations of all or part of the example embodiments.

[0250] In general, terms can be understood at least in part from the use in the context. For example, terms such as "and", "or" or "and / or" used in this article can include multiple meanings, which can depend at least in part on the context in which such terms are used. Usually, "or" is intended to represent A, B and C if used in an association list, such as A, B or C, which is used here for inclusive meanings, and A, B or C, which is used here for exclusive meanings. In addition, the term "one or more" used in this article can be used to describe any feature, structure or characteristic in a single sense, or can be used to describe a combination of features, structures or characteristics in a plural sense, depending at least in part on the context. Similarly, terms such as "a", "an" or "the" can be understood to convey singular usage or to convey plural usage, depending at least in part on the context. In addition, the term "based on" can be understood to not necessarily be intended to convey a set of exclusive factors, but can allow the presence of additional factors that are not necessarily explicitly described, which again depends at least in part on the context.

[0251] References to features, advantages, or similar language throughout the specification do not imply that all features and advantages that may be achieved with the present solution should be included in any single implementation thereof. Rather, language referring to features and advantages is understood to mean that a particular feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present solution. Thus, discussion of features and advantages and similar language throughout the specification may, but does not necessarily, refer to the same embodiment.

[0252] In addition, the described features, advantages, and characteristics of the present solution may be combined in any suitable manner in one or more embodiments. Based on the description herein, one of ordinary skill in the relevant art will recognize that the present solution may be practiced without one or more of the specific features or advantages of a particular embodiment. In other cases, additional features and advantages may be recognized in certain embodiments, which may not be present in all embodiments of the present solution.

Claims

1. A method for wireless communication, performed by a first network element in a network, the method comprising: receiving a first message including a paging message from a second network element of the network; deriving a UE-specific paging resource configuration associated with a user equipment UE based on the first message; In response to the UE being in a radio resource control (RRC) inactive state, selecting a paging radio resource based on the UE-specific paging resource configuration and based on a radio resource-specific paging configuration predefined in the first network element, the UE-specific paging resource configuration comprising paging extended discontinuous reception (eDRX) information and a radio access network (RAN) paging cycle; and A paging message is sent to the UE via the selected paging radio resource.

2. The method of claim 1 , wherein the UE-specific paging resource configuration further comprises at least one of the following parameters associated with the UE: UE-specific discontinuous reception (DRX); or Core network assistance information for the UE in a radio resource control (RRC) inactive state.

3. The method according to claim 1, wherein the paging radio resource comprises a paging occasion (PO).

4. The method of claim 1, wherein the paging message comprises at least one of: XnAP paging message; or F1AP paging message.

5. The method of claim 1, wherein the first message comprises the UE-specific paging resource configuration associated with the UE.

6. The method of claim 1, wherein the first network element comprises a first base station and the second network element comprises a second base station.

7. The method of claim 1, wherein the first network element comprises a gNB-DU and the second network element comprises a gNB-CU.

8. A first network element in a network, the first network element comprising a memory for storing computer instructions and a processor in communication with the memory, wherein: When the processor executes the computer instructions, the processor is configured to cause the first network element to: receiving a first message including a paging message from a second network element of the network; deriving a UE-specific paging resource configuration associated with a user equipment UE based on the first message; In response to the UE being in a radio resource control (RRC) inactive state, selecting a paging radio resource based on the UE-specific paging resource configuration and based on a radio resource-specific paging configuration predefined in the first network element, the UE-specific paging resource configuration comprising paging extended discontinuous reception (eDRX) information and a radio access network (RAN) paging cycle; and A paging message is sent to the UE via the selected paging radio resource.

9. The first network element of claim 8, wherein the UE-specific paging resource configuration further comprises at least one of the following parameters associated with the UE: UE-specific discontinuous reception (DRX); or Core network assistance information for the UE in RRC inactive state.

10. The first network element of claim 8, wherein the paging radio resource comprises a paging occasion (PO).

11. The first network element of claim 8, wherein the paging message comprises at least one of: XnAP paging message; or F1AP paging message.

12. The first network element of claim 8, wherein the first message includes the UE-specific paging resource configuration associated with the UE.

13. The first network element of claim 8, wherein the first network element comprises a first base station and the second network element comprises a second base station.

14. The first network element of claim 8, wherein the first network element comprises a gNB-DU and the second network element comprises a gNB-CU.

15. A non-transitory storage medium for storing computer-readable instructions that, when executed by a processor in a first network element in a network, cause the processor to: receiving a first message including a paging message from a second network element of the network; deriving a UE-specific paging resource configuration associated with a user equipment UE based on the first message; In response to the UE being in a radio resource control (RRC) inactive state, selecting a paging radio resource based on the UE-specific paging resource configuration and based on a radio resource-specific paging configuration predefined in the first network element, the UE-specific paging resource configuration comprising paging extended discontinuous reception (eDRX) information and a radio access network (RAN) paging cycle; and A paging message is sent to the UE via the selected paging radio resource.

16. The non-transitory storage medium of claim 15, wherein: The UE-specific paging resource configuration further includes at least one of the following parameters associated with the UE: UE-specific discontinuous reception (DRX); or core network assistance information for the UE in RRC inactive state; and The paging radio resources include paging occasions PO.

17. The non-transitory storage medium of claim 15, wherein: The paging message includes at least one of the following: XnAP paging message; or F1AP paging message; and The first message includes the UE-specific paging resource configuration associated with the UE.

18. The non-transitory storage medium of claim 17, wherein: A combination of the first network element and the second network element comprises one of the following: The first network element is a first base station, and the second network element is a second base station; or The first network element is a gNB-DU and the second network element is a gNB-CU.

Images