WO2024093394A1

WO2024093394A1 - Retrieval of system information

Info

Publication number: WO2024093394A1
Application number: PCT/CN2023/109369
Authority: WO
Inventors: Yuantao Zhang; Zhi YAN
Original assignee: Lenovo (Beijing) Limited
Priority date: 2023-07-26
Filing date: 2023-07-26
Publication date: 2024-05-10

Abstract

Various aspects of the present disclosure relate to retrieval of system information. In an aspect, a user equipment receives, from a base station, first downlink control information (DCI) for paging in a first carrier or a first synchronization signal and physical broadcast channel (PBCH) block (SSB) in a second carrier, wherein the first DCI comprises a short message. In the case of receiving the first DCI, the user equipment retrieves, in the first carrier, system information of the second carrier based on the short message. In the case of receiving the first SSB, the user equipment determines whether a system information block (SIB) is transmitted in the second carrier based on the first SSB. In this way, a scheme for indicating the UE to retrieve the system information of the second carrier is designed.

Description

RETRIEVAL OF SYSTEM INFORMATION

TECHNICAL FIELD

The present disclosure relates to wireless communications, and more specifically to a user equipment (UE) , a base station, processors for wireless communication, methods, and non-transitory computer readable media for retrieving system information.

BACKGROUND

A wireless communications system may include one or multiple network communication devices, such as base stations, which may be otherwise known as an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. Each network communication devices, such as a base station may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (UE) , or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) . Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G) ) .

In 5G new radio (NR) systems, a synchronization signal and physical broadcast channel (PBCH) block (SSB) is used for UEs to obtain a physical cell identification (ID) , fulfil downlink (DL) synchronization, and obtain system information. For example, a UE could determine whether a control resource set#0 (CORESET#0) is present in the cell based on the SSB. If the UE determines that a CORESET#0 is present, the UE may retrieve system information block1 (SIB1) for the cell at least based on a configuration of the CORESET#0. Enhancements on retrieval of system information are still needed.

SUMMARY

The present disclosure relates to a UE, a base station, processors for wireless communication, methods, and non-transitory computer readable media for retrieving system information.

In a first aspect of the solution, a user equipment receives, from a base station, first downlink control information (DCI) for paging in a first carrier or a first synchronization signal and physical broadcast channel (PBCH) block (SSB) in a second carrier, wherein the first DCI comprises a short message. In the case of receiving the first DCI, the user equipment retrieves, in the first carrier, system information of the second carrier based on the short message. In this way, a scheme for on-demand system information retrieving is proposed, thus reducing resource consumption in transmission of system information. Besides, reusing the DCI for paging for the indication of retrieving system information of another carrier is beneficial in terms of e.g., lower signalling overhead and lower UE implementation effort. In the case of receiving the first SSB, the user equipment determines whether a system information block (SIB) is transmitted in the second carrier based on the first SSB. In this way, the UE may be aware whether the second carrier is an energay saving (ES) carrier or a non-ES carrier. If the second carrier is an ES carrier, the UEs supporting ES may thus be indicated to perform the related actions to retrieve system information of the ES carrier. To sum up, a scheme for indicating the UE supporting an ES carrier to retrieve the system information of an ES carrier is designed.

Some implementations of the method and apparatuses described herein may further include: in the case of receiving the first DCI, switching from the first carrier to the second carrier; and receiving, from the base station in the second carrier, the first SSB of the second carrier.

In some implementations of the method and apparatuses described herein, the short message may include a bit field indicating at least one of the following: system information retrieving; or carrier switching.

In some implementations of the method and apparatuses described herein, the first DCI may include scheduling information of the system information of the second carrier, and the system information of the second carrier is scheduled by the scheduling information.

In some implementations of the method and apparatuses described herein, the first DCI may include an indication that the scheduling information is present in the first DCI.

Some implementations of the method and apparatuses described herein may further include: receiving, from the base station in the first carrier, a second DCI in a first timing associated with scheduling of system information block. The first timing is subsequent to a paging occasion associated with the first DCI or a paging frame containing the paging occasion.

Some implementations of the method and apparatuses described herein may further include: receiving, from the base station in the first carrier, a second DCI in a time window comprising at least one timing associated with scheduling of system information block. The time window is subsequent to a paging occasion associated with the first DCI or a paging frame containing the paging occasion.

In some implementations of the method and apparatuses described herein, the second DCI is scrambled by a radio network temporary identity (RNTI) different from a system information RNTI (SI-RNTI) , and the system information is scheduled by scheduling information in the second DCI.

In some implementations of the method and apparatuses described herein, the second DCI is scrambled by a SI-RNTI. Some implementations of the method and apparatuses described herein may further include: receiving, from the base station in the first carrier, a SIB scheduled by the second DCI. The SIB may include an indication indicating whether the system information of the second carrier or scheduling information of the system information of the second carrier is comprised in the SIB.

In some implementations of the method and apparatuses described herein, the second DCI is scrambled by a SI-RNTI. Some implementations of the method and apparatuses described herein may further include: receiving, from the base station in the first carrier, a SIB scheduled by the second DCI. The second DCI may include an indication indicating whether the system information of the second carrier or scheduling information of the system information of the second carrier is comprised in the SIB.

In some implementations of the method and apparatuses described herein, the first SSB may include an information element regarding a subcarrier offset parameter. Some implementations of the method and apparatuses described herein may further include: in the case that a first value is indicated in the information element, determine a configuration of a control resource set (CORESET) of the second carrier based on the first SSB of the second carrier.

Some implementations of the method and apparatuses described herein may further include: in the case that the first value is indicated in the information element, determining that the first SSB provides a valid configuration of the CORESET.

In some implementations of the method and apparatuses described herein, determining whether a SIB is transmitted in the second carrier may include: in the case that the first value is indicated in the information element, determining that SIB is not transmitted in the second carrier.

Some implementations of the method and apparatuses described herein may further include: receiving, from the base station in the first carrier, a second SSB of the first carrier; and determining a subcarrier offset for a frequency position of the CORESET of the second carrier based on an information element in the second SSB.

In some implementations of the method and apparatuses described herein, the first SSB may include an information element regarding a subcarrier offset parameter. Some implementations of the method and apparatuses described herein may further include: in the case that a second value is indicated in the information element, determining the first carrier based on the first SSB; and determining a configuration of a CORESET of the second carrier and system information of the second carrier in the first carrier.

In some implementations of the method and apparatuses described herein, determining whether a SIB is transmitted in the second carrier may include: in the case that the second value is indicated in the information element, determining that SIB is not transmitted in the second carrier.

In some implementations of the method and apparatuses described herein, the information element is a subcarrier offset field comprised in PBCH in the first SSB.

In a second aspect of the solution, a base station transmits, to a user equipment, first downlink control information (DCI) for paging in a first carrier. The first DCI may include a short message to indicate the user equipment to retrieve system information of a second carrier in the first carrier. Alternatively or additionally, the base station transmits, to the user equipment in the second carrier, a first synchronization signal and physical broadcast channel (PBCH) block (SSB) indicating the user equipment to determine whether a system information block (SIB) is transmitted in the second carrier based on the first SSB. In this way, a scheme for indicating the UE to retrieve the system information of the second carrier is designed.

In some implementations of the method and apparatuses described herein, the short message may include a bit filed indicating at least one of the following: system information retrieving; or carrier switching.

Some implementations of the method and apparatuses described herein may further include: transmitting, to the user equipment in the first carrier, a second DCI in a first timing associated with scheduling of system information block. The first timing is subsequent to a paging occasion associated with the first DCI or a paging frame containing the paging occasion.

Some implementations of the method and apparatuses described herein may further include: transmitting, to the user equipment in the first carrier, a second DCI in a time window comprising at least one timing associated with scheduling of system information block. The time window is subsequent to a paging occasion associated with the first DCI or a paging frame containing the paging occasion.

In some implementations of the method and apparatuses described herein, the second DCI is scrambled by a SI-RNTI. Some implementations of the method and apparatuses described herein may further include: transmitting, to the user equipment in the first carrier, a SIB scheduled by the second DCI. The SIB may include an indication indicating whether the system information of the second carrier or scheduling information of the system information of the second carrier is comprised in the SIB.

In some implementations of the method and apparatuses described herein, the second DCI is scrambled by a SI-RNTI. Some implementations of the method and apparatuses described herein may further include: transmitting, to the user equipment in the first carrier, a SIB scheduled by the second DCI. The second DCI may include an indication indicating whether the system information of the second carrier or scheduling information of the system information of the second carrier is comprised in the SIB.

In some implementations of the method and apparatuses described herein, the first SSB may include an information element regarding a subcarrier offset parameter. A first value is indicated in the information element, indicating that the first SSB provides a valid configuration of a control resource set (CORESET) of the second carrier for user equipments with a first capability. A configuration of the CORESET of the second carrier for user equipments with the first capability is associated with the fist SSB of the second carrier.

Some implementations of the method and apparatuses described herein may further include: transmitting, to the user equipment in the first carrier, a second SSB of the first carrier. A subcarrier offset for a frequency position of the CORESET of the second carrier is associated with an information element in the second SSB.

In some implementations of the method and apparatuses described herein, the first value in the information element in the first SSB of the second carrier indicates that SIB is not transmitted in the second carrier.

In some implementations of the method and apparatuses described herein, the first SSB may include an information element regarding a subcarrier offset parameter, a second value is indicated in the information element. The second value in the information element in the first SSB of the second carrier indicates that SIB is not transmitted in the second carrier.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an example of a wireless communications system that supports retrieval of system information in accordance with aspects of the present disclosure.

FIG. 1B illustrates an example of multiplexing of a SSB and a CORESET#0 in FR1 in accordance with some example embodiments of the present disclosure.

FIG. 2A illustrates an example signaling chart of a communication process that supports retrieval of system information in accordance with some example embodiments of the present disclosure.

FIG. 2B illustrates another example signaling chart of a communication process that supports retrieval of system information in accordance with some example embodiments of the present disclosure.

FIGS. 3A through 3B illustrate examples of obtaining scheduling information for the system information of an energy saving (ES) carrier in a non-ES carrier in accordance with some example embodiments of the present disclosure.

FIGS. 4 through 5 illustrate examples of devices that support retrieval of system information in accordance with aspects of the present disclosure.

FIGS. 6 through 7 illustrate examples of processors that support retrieval of system information in accordance with aspects of the present disclosure.

FIGS. 8 through 15 illustrate flowcharts of methods that support retrieval of system information in accordance with aspects of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar elements.

DETAILED DESCRIPTION

Principles of the present disclosure will now be described with reference to some embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein may be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an example embodiment, ” “an embodiment, ” “some embodiments, ” and the like indicate that the embodiment (s) described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment (s) . Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” or the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could also be termed as a second element, and similarly, a second element could also be termed as a first element, without departing from the scope of embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. For example, the term “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The use of an expression such as “A and/or B” can mean either “only A” or “only B” or “both A and B. ” Other definitions, explicit and implicit, may be included below.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as, 5G NR, long term evolution (LTE) , LTE-advanced (LTE-A) , wideband code division multiple access (WCDMA) , high-speed packet access (HSPA) , narrow band internet of things (NB-IoT) , and so on. Further, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will also be future type communication technologies and systems in which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned systems.

As used herein, the term “network device” generally refers to a node in a communication network via which a terminal device can access the communication network and receive services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , a radio access network (RAN) node, an evolved NodeB (eNodeB or eNB) , an NR NB (also referred to as a gNB) , a remote radio unit (RRU) , a radio header (RH) , an infrastructure device for a V2X (vehicle-to-everything) communication, a transmission and reception point (TRP) , a reception point (RP) , a remote radio head (RRH) , a relay, an integrated access and backhaul (IAB) node, a low power node such as a femto BS, a pico BS, and so forth, depending on the applied terminology and technology.

As used herein, the term “terminal device” generally refers to any end device that may be capable of wireless communications. By way of example rather than a limitation, a terminal device may also be referred to as a communication device, a user equipment (UE) , an end user device, a subscriber station (SS) , an unmanned aerial vehicle (UAV) , a portable subscriber station, a mobile station (MS) , or an access terminal (AT) . The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet, a wearable terminal device, a personal digital assistant (PDA) , a portable computer, a desktop computer, an image capture terminal device such as a digital camera, a gaming terminal device, a music storage and playback appliance, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , a USB dongle, a smart device, wireless customer-premises equipment (CPE) , an internet of things (loT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device (for example, a remote surgery device) , an industrial device (for example, a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms: “terminal device, ” “communication device, ” “terminal, ” “user equipment” and “UE, ” may be used interchangeably.

As used herein, the term “carrier” generally refers to a network frequency carrier of either in low frequency range (e.g., FR1) or high frequency range (e.g., FR2) . Besides, the “carrier” may be identical to “a cell” and these two might be used interchangeably.

As mentioned above, in a NR initial access procedure, a SSB is used in NR for UEs to obtain physical cell ID, fulfil DL synchronization, and obtain system information. A SSB consists of primary synchronization signal (PSS) , secondary synchronization signal (SSS) and physical broadcast channel (PBCH) . A master information block (MIB) is transmitted in the PBCH. The MIB carries configurations as in below.

Among the information provided in MIB, ssb-SubcarrierOffset corresponds to a parameter k_SSB, which indicates a frequency domain offset between SSB and the overall resource block grid in number of subcarriers. The value in field ssb-SubcarrierOffset may be within [0, 15] .

For FR2, the k_SSB value can be determined via the ssb-SubcarrierOffset in MIB, and the value range of k_SSB may be 0≤k_SSB≤15. For FR1, the value range of k_SSB may be extended by an additional most significant bit encoded within PBCH. That is, the 4 least significant bits (LSB) sof k_SSB are indicated by ssb-SubcarrierOffset in MIB, and 1 most significant bit (MSB) of k_SSB is carried in the physical layer payload of PBCH. Thus, for FR1, the value range of k_SSB may be 0≤k_SSB≤31.

Besides, the field ssb-SubcarrierOffset may indicate that there is no CORESET#0 configured in MIB. In this case, the field pdcch-ConfigSIB1 may indicate the frequency positions where the UE may (not) find a synchronization signals and PBCH (SS/PBCH) with a control resource set and a search space set for SIB1, wherein SIB1 carries remaining system information of the cell.

The field pdcch-ConfigSIB1 is used to configure CORESET#0, search space set#0 and necessary PDCCH parameters. If the field ssb-SubcarrierOffset indicates that CORESET#0 is absent, the field pdcch-ConfigSIB1 indicates the frequency positions where the UE may find SS/PBCH block with CORESET#0 or the frequency range where the network does not provide SS/PBCH block with CORESET#0.

The CORESET#0 is used to accommodate PDCCH for scheduling channel/signals transmitted during initial access procedure, including e.g., SIB1, random access messages, paging, etc. The UE could determine whether an CORESET#0 is present based on the determined k_SSB.

As specified in 3GPP technical specification (TS) 38.213, for FR1, if k_SSB is within [0, 23] , the CORESET#0 is present; if k_SSB is within [24, 31] , the CORESET#0 is not present. For FR2, if k_SSB is within [0, 11] , the CORESET#0 is present; if k_SSB is within [12, 15] , the CORESET#0 is not present.

In cases that 0≤k_SSB≤23 for FR1 or 0≤k_SSB≤11 for FR2, the SIB1 may be transmitted in the same initial bandwidth part (BWP) where the SSB is detected. From the perspective of a UE, if the UE detects a SSB and determines that 0≤k_SSB≤ 23 for FR1 or 0≤k_SSB≤11 for FR2, the UE may determine that a CORESET#0 is present. Then, the UE may retrieve SIB1 for the cell based on the CORESET#0 configuration, search space set#0 configuration and other PDCCH parameters.

If the UE detects a first SSB and determines that k_SSB>23 for FR1 or k_SSB>11 for FR2, then the UE may determine that a CORESET#0 is not present for a given search space. In this case, the UE may search for a synchronization raster based on an offset configured in association with the k_SSB.

For 24≤k_SSB≤29 for FR1 or for 12≤k_SSB≤13 for FR2 based on the first SSB, the UE may determine information of a second SSB having a CORESET#0. For example, the nearest (in the corresponding frequency direction) global synchronization channel number (GSCN) of the second SSB having a CORESET#0 may be determined asis the GSCN of the first SS/PBCH block, in FR1 (410 MHz –7.125 GHz) and FR2-1 (24.25 GHz –52.6 GHz) , in FR2-2 (52.6 GHz –71 GHz) , andis a GSCN offset provided by Table 1-1 for FR1 and Table 1-2 for FR2. As shown in Table 1-1 and Table 1-2, k_SSB=30 for FR1 and k_SSB=14 for FR2 are reserved.

Table 1-1: Mapping between the combination of k_SSB and controlResourceSetZero and searchSpaceZero in pdcch-ConfigSIB1 tofor FR1

Table 1-2: Mapping between the combination of k_SSB and controlResourceSetZero and searchSpaceZero in pdcch-ConfigSIB1 tofor FR2

If the UE detects the second SSB and the second SSB does not provide CORESET#0, the UE may ignore the information related to GSCN of SS/PBCH block locations for performing cell search.

If the UE detects a SSB and determines that k_SSB=31 for FR1 or k_SSB=14 for FR2, the UE determine that CORESET#0 is not present and that there is no SSB having an associated CORESET#0 within a GSCN range andare respectively determined by controlResourceSetZero and searchSpaceZero in pdcch-ConfigSIB1. If the GSCN range isthe UE determines that there is no information for a second SSB with a CORESET#0 on the detected SSB.

The above describes the procedure for a UE to retrieve the SIB1 based on the detected SSB in an initial access procedure in the third generation partnership project (3GPP) . Next, a NR paging procedure in 3GPP will be described.

Paging allows the network to reach UEs in RRC_IDLE state or in RRC_INACTIVE state through paging messages. Paging also allows the network to notify UEs in RRC_IDLE, RRC_INACTIVE and RRC_CONNECTED states for system information (SI) modification, indication information for earthquake and tsunami warning system (ETWS) or indication information for commercial mobile alert system (CMAS) through short messages. The short message is defined in Table 1-3 as below.

Table 1-3: Short Messages

Both paging messages and short messages are addressed by a DCI format 1_0 identified with paging radio network temporary identity (P-RNTI) . The DCI format 1_0 contains at least one of a short message indicator, a short message and the scheduling information for paging. The short message indicator may be used to indicate whether the short message only, or scheduling information for paging only, or both the short message and scheduling information for paging are carried in the DCI. The UE may interpret the bit filed of the short message indicator in the DCI as defined in Table 1-4.

Table 1-4: Short Message indicator

As shown in Table 4, bit filed 00 is reserved for future usage. If only scheduling information for paging is present in the short message indicator (bit 01) , the bit field for short message is reserved. In other words, if the two-bit indicator is 01, the short message indicator may indicate that the DCI is a normal DCI carrying the control information to schedule the associated physical data shared channel (PDSCH) . The UE may receive the related paging message based on the scheduled PDSCH.

If only short message is present in the short message indicator (bit 10) , the bit field for scheduling information for paging is reserved. In other words, if the two-bit indicator is 10, the short message indicator may indicate that the DCI is a specific DCI carrying a short message without the associated PDSCH. The UE may check the information carried in the corresponding short message in this specific DCI to perform the related actions, which are defined in the table for short messages, i.e., Table 1-3.

If both scheduling information and paging and short message are presented in the short message indicator (bit 11) , all the information in the DCI is effective. In other words, if the two-bit indicator is 11, the short message indicator may indicate that the DCI carries both a short message and the control information to schedule the associated PDSCH. The UE may check the information carried in the corresponding short message in the DCI to perform the related actions. The UE may also receive the related paging message based on the scheduled PDSCH.

For a UE in RRC_IDLE state or RRC_INACTIVE state, it is required to monitor paging channels during one paging occasion (PO) per discontinuous reception (DRX) cycle, while the UE in RRC_CONNECTED state monitors the paging channels in any PO signalled in system information for SI change indication and public warning system (PWS) notification. A DRX cycle might be configured to contain one or multiple paging fames (PFs) , and one paging frame might be configured to contain one or multiple POs. Each PO corresponds to a set of PDCCH monitoring occasions, and each PDCCH monitoring occasion is associated with a transmission beam.

Network energy savings (NES) for NR has been agreed at RAN plenary #98-e meeting. One objective among others is to have SIB1-less in a carrier (or cell) such that energy saving in BS is achieved by not sending SIB1 in this carrier. From the perspective of UEs, a UE may obtain system information for this carrier from another carrier. In the following description, the term “network energy savings (NES) may be used interchangeably with the term “energy savings (ES) ” . In the following description, a SIB1-less carrier may also be referred to as an ES carrier. The UE may obtain system information of an ES carrier/cell from other associated carriers/cells and synchronize from other associated carriers/cells and/or synchronize from signal (s) transmitted on the cell.

In view of the above, embodiments of the present disclosure provide a solution for retrieval of system information of an ES carrier from a non-ES carrier. In an aspect of the solution, a user equipment may receive a first DCI for paging in a first carrier (e.g., a non-ES carrier) . The first DCI comprises a short message. The user equipment retrieves, in the first carrier, system information of a second carrier based on the short message. In this way, a scheme for on-demand system information retrieving is proposed, thus reducing resource consumption in transmission of system information. Besides, reusing the DCI for paging for the indication of retrieving system information of another carrier is beneficial in terms of e.g., lower signalling overhead and lower UE implementation effort. In the following description, the terms “DCI for paging” and “paging DCI” may be used interchangeably.

Alternatively, the user equipment may receive a first SSB in a second carrier and determine whether a SIB is transmitted in the second carrier based on the first SSB. In this way, the UE may be aware whether the second carrier is a non-ES carrier or an ES carrier. If the second carrier is a non-ES carrier, the UE may retrieve the SIB1 based on the detected SSB as described above. If the second carrier is an ES carrier and the UE camping on the second carrier and detecting the SSB, the UE may perform the related actions to retrieve system information of the ES carrier in another carrier. In this manner, the UEs supporting ES may be indicated to retrieve system information of the ES carrier in another carrier. In addition, it may avoid the UEs not supporting ES to detect the SIB1 (which is not provided) in the ES carrier, thus avoiding unnecessary power consumption.

Aspects of the present disclosure are described in the context of a wireless communications system.

FIG. 1A illustrates an example of a wireless communications system 100 that supports retrieval of system information in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more network entities 102 (also referred to as network equipment (NE) ) , one or more UEs 104, a core network 106, and a packet data network 108. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as an LTE network or an LTE-Advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a 5G network, such as an NR network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.

The one or more network entities 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the network entities 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a radio access network (RAN) , a base transceiver station, an access point, a NodeB, an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. A network entity 102 and a UE 104 may communicate via a communication link 110, which may be a wireless or wired connection. For example, a network entity 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

A network entity 102 may provide a geographic coverage area 112 for which the network entity 102 may support services (e.g., voice, video, packet data, messaging, broadcast, etc. ) for one or more UEs 104 within the geographic coverage area 112. For example, a network entity 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, a network entity 102 may be moveable, for example, a satellite associated with a non-terrestrial network. In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but the different geographic coverage areas 112 may be associated with different network entities 102. Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The one or more UEs 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a mobile device, a wireless device, a remote device, a remote unit, a handheld device, or a subscriber device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (IoT) device, an Internet-of-Everything (IoE) device, or machine-type communication (MTC) device, among other examples. In some implementations, a UE 104 may be stationary in the wireless communications system 100. In some other implementations, a UE 104 may be mobile in the wireless communications system 100.

The one or more UEs 104 may be devices in different forms or having different capabilities. Some examples of UEs 104 are illustrated in FIG. 1A. A UE 104 may be capable of communicating with various types of devices, such as the network entities 102, other UEs 104, or network equipment (e.g., the core network 106, the packet data network 108, a relay device, an integrated access and backhaul (IAB) node, or another network equipment) , as shown in FIG. 1A. Additionally, or alternatively, a UE 104 may support communication with other network entities 102 or UEs 104, which may act as relays in the wireless communications system 100.

A UE 104 may also be able to support wireless communication directly with other UEs 104 over a communication link 114. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

A network entity 102 may support communications with the core network 106, or with another network entity 102, or both. For example, a network entity 102 may interface with the core network 106 through one or more backhaul links 116 (e.g., via an S1, N2, N2, or another network interface) . The network entities 102 may communicate with each other over the backhaul links 116 (e.g., via an X2, Xn, or another network interface) . In some implementations, the network entities 102 may communicate with each other directly (e.g., between the network entities 102) . In some other implementations, the network entities 102 may communicate with each other or indirectly (e.g., via the core network 106) . In some implementations, one or more network entities 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC) . An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs) .

In some implementations, a network entity 102 may be configured in a disaggregated architecture, which may be configured to utilize a protocol stack physically or logically distributed among two or more network entities 102, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance) , or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN) ) . For example, a network entity 102 may include one or more of a central unit (CU) , a distributed unit (DU) , a radio unit (RU) , a RAN Intelligent Controller (RIC) (e.g., a Near-Real Time RIC (Near-RT RIC) , a Non-Real Time RIC (Non-RT RIC) ) , a Service Management and Orchestration (SMO) system, or any combination thereof.

An RU may also be referred to as a radio head, a smart radio head, a remote radio head (RRH) , a remote radio unit (RRU) , or a transmission reception point (TRP) . One or more components of the network entities 102 in a disaggregated RAN architecture may be co-located, or one or more components of the network entities 102 may be located in distributed locations (e.g., separate physical locations) . In some implementations, one or more network entities 102 of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU) , a virtual DU (VDU) , a virtual RU (VRU) ) .

Split of functionality between a CU, a DU, and an RU may be flexible and may support different functionalities depending upon which functions (e.g., network layer functions, protocol layer functions, baseband functions, radio frequency functions, and any combinations thereof) are performed at a CU, a DU, or an RU. For example, a functional split of a protocol stack may be employed between a CU and a DU such that the CU may support one or more layers of the protocol stack and the DU may support one or more different layers of the protocol stack. In some implementations, the CU may host upper protocol layer (e.g., a layer 3 (L3) , a layer 2 (L2) ) functionality and signaling (e.g., Radio Resource Control (RRC) , service data adaption protocol (SDAP) , Packet Data Convergence Protocol (PDCP) ) . The CU may be connected to one or more DUs or RUs, and the one or more DUs or RUs may host lower protocol layers, such as a layer 1 (L1) (e.g., physical (PHY) layer) or an L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU 160.

Additionally, or alternatively, a functional split of the protocol stack may be employed between a DU and an RU such that the DU may support one or more layers of the protocol stack and the RU may support one or more different layers of the protocol stack. The DU may support one or multiple different cells (e.g., via one or more RUs) . In some implementations, a functional split between a CU and a DU, or between a DU and an RU may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU, a DU, or an RU, while other functions of the protocol layer are performed by a different one of the CU, the DU, or the RU) .

A CU may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU may be connected to one or more DUs via a midhaul communication link (e.g., F1, F1-c, F1-u) , and a DU may be connected to one or more RUs via a fronthaul communication link (e.g., open fronthaul (FH) interface) . In some implementations, a midhaul communication link or a fronthaul communication link may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 102 that are in communication via such communication links.

The core network 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The core network 106 may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management functions (AMF) ) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc. ) for the one or more UEs 104 served by the one or more network entities 102 associated with the core network 106.

The core network 106 may communicate with the packet data network 108 over one or more backhaul links 116 (e.g., via an S1, N2, N2, or another network interface) . The packet data network 108 may include an application server 118. In some implementations, one or more UEs 104 may communicate with the application server 118. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the core network 106 via a network entity 102. The core network 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server 118 using the established session (e.g., the established PDU session) . The PDU session may be an example of a logical connection between the UE 104 and the core network 106 (e.g., one or more network functions of the core network 106) .

In the wireless communications system 100, the network entities 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) ) to perform various operations (e.g., wireless communications) . In some implementations, the network entities 102 and the UEs 104 may support different resource structures. For example, the network entities 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the network entities 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the network entities 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures) . The network entities 102 and the UEs 104 may support various frame structures based on one or more numerologies.

One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames) . Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., OFDM symbols) . In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing) , a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, the network entities 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the network entities 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data) . In some implementations, FR2 may be used by the network entities 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies) . For example, FR1 may be associated with a first numerology (e.g., μ=0) , which includes 15 kHz subcarrier spacing; a second numerology (e.g., μ=1) , which includes 30 kHz subcarrier spacing; and a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies) . For example, FR2 may be associated with a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., μ=3) , which includes 120 kHz subcarrier spacing.

FIG. 1B illustrates an example of multiplexing of a SSB and a CORESET#0 in FR1 in accordance with some example embodiments of the present disclosure. As shown in FIG. 1B, the SSB bandwidth comprises 20 RBs with a subcarrier spacing of 15 kHz. Based on the SSB, the value of k_SSB may be determined to be 15, indicating a frequency domain offset between SSB and the overall resource block grid in number of subcarriers. The UE detecting the SSB may thus determine that a CORESET#0 is present. The configuration of the CORESET#0 may be determined based on the SSB. Then, the UE may retrieve SIB1 for the cell based on the CORESET#0 configuration, search space set#0 configuration and other PDCCH parameters.

Reference is now made to FIG. 2A, which illustrates an example signaling chart of a communication process 200A that supports retrieval of system information in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the process 200A will be described with reference to FIG. 1A. The process 200A may involve the UE 104 and the network entity (also referred to as a BS) 102. It is to be understood that the steps and the order of the steps in FIG. 2A are merely for illustration, and not for limitation. It is to be understood that process 200A may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard. Embodiments of the present disclosure focuses on the operations of UEs supporting ES. In the following embodiments, unless explicitly indicated, the UE 104 refers to a UE supporting ES.

As shown in FIG. 2A, the BS 102 transmits 202, in a first carrier, a first DCI 204 for paging. The first DCI 204 includes a short message to indicate the UE to retrieve system information of the second carrier in the first carrier. The UE 104 receives 206 the first DCI 204 in the first carrier. The UE 104 retrieves 208, in the first carrier, system information of the second carrier based on the short message. In this way, a scheme for on-demand system information retrieving is proposed, thus reducing resource consumption in transmission of system information.

In an example implementation, a UE supporting ES and camping on a first carrier (e.g., a non-ES carrier) may be indicated to retrieve system information of a second carrier (e.g., an ES carrier) . The short message in the DCI for paging may be reused for the indication. The on-demand system information retrieving requires the BS to send the system information of an ES carrier only when needed, which is beneficial for overhead reduction. Besides, reusing the DCI for paging for the indication of retrieving system information of another carrier (e.g., an ES carrier) is beneficial in terms of e.g., lower signalling overhead and lower UE implementation effort.

In some example embodiments, the short message in the first DCI 204 may include a bit field indicating system information retrieving. In other words, the short message may indicate the UE to retrieve system information of another carrier (e.g., an ES carrier) . As an example implementation, upon reception of this short message, the UE may retrieve the system information of a configured ES carrier and may switch to the ES carrier.

Alternatively or additionally, the bit field in the short message in the first DCI 204 may indicate carrier switching. In other words, the short message may explicitly indicate the UE to perform carrier switching. As an example implementation, the UE may retrieve the system information of a configured ES carrier based on this message and switches to the ES carrier.

As mentioned above, the order of the steps in FIG. 2A are merely for illustration, and not for limitation. For example, the retrieval 208 may be performed prior to the reception 206. For example, the short message may explicitly indicate the UE to perform carrier switching. The UE may have already obtained the system information of an ES carrier before receiving the short message in the non-ES carrier, in which case the UE just switches to the ES carrier based on this short message.

In some example embodiments, after receiving the first DCI 204, the UE 104 may switch from the first carrier to the second carrier. The UE 104 may then receive, from the BS 102 in the second carrier, a first SSB of the second carrier. In this manner, based on the system information of the second carrier retrieved in the first carrier and the SSB of the second carrier received in the second carrier, the UE 104 may communicate with the BS 102 in the second carrier. In this way, a scheme for indicating the UE to perform carrier switching is designed. Reusing the short message in the DCI for paging for the indication of carrier switching is beneficial in terms of e.g., lower signalling overhead and lower UE implementation effort.

In some example implementations, a bit currently reserved in the short message may be used to indicate UEs supporting ES to retrieve the system information of an ES carrier and/or to perform carrier switching. This ensures no impact to UEs not supporting ES (also referred to as legacy UEs) . One example implementation of the short message according to some embodiments of the disclosure is given in Table 2-1, where a new parameter SystemIofoRetrieving-ES is defined in the short message and is indicated by the fifth bit in the short message, which is reserved for legacy UEs.

Table 2-1: Short Messages

As shown in Table 2-1, if SystemIofoRetrieving-ES is set to 1, it represents an indication of UEs supporting ES to retrieving the system information of an ES carrier. In other words, for UEs supporting ES, upon reception of this short message with SystemIofoRetrieving-ES set to 1, the UE will retrieve the system information of an ES carrier in the currently camped carrier and may perform carrier switching to the ES carrier. The UEs not supporting ES will just omit this indication in the short message.

As proposed, upon reception of the short message on either system information retrieving or carrier switching in a DCI for paging in a non-ES carrier, the UE may retrieve the system information of the ES carrier in the non-ES carrier. Embodiments on the specific aspect of how to indicate the UE to retrieve the system information of an ES carrier and/or perform carrier switching are described. Another specific aspect of the disclosure is how to retrieve the system information of the ES carrier.

In some example embodiments, the first DCI 204 may include scheduling information of the system information of the second carrier, and the system information of the second carrier may be scheduled by the scheduling information. In one embodiment, the first DCI 204 may include an indication that the scheduling information is present in the first DCI 204.

As an example, the DCI for paging may carry the scheduling information for PDSCH for system information of the ES carrier. The idea is to configure the short message indicator in the paging DCI to be “00” , which is reserved for now as shown in Table 1-4, for the indication that both scheduling information and short message are present in the DCI. Here, the scheduling information is not for scheduling paging message, but for scheduling PDSCH carrying system information of an ES carrier for UEs supporting ES. An example of the short message indicator according to some embodiments of the disclosure is shown in Table 2-2.

Table 2-2: Short Message indicator

With the short message indicator configured as “00” and the short message configured as an indication of system information retrieving (e.g., the fifth bit of the short message in Table 2-1 configured as “1” ) or carrier switching, the UEs supporting ES will interpret that the DCI is for scheduling a PDSCH that carries the system information of an ES carrier. The UE may detect the scheduled PDSCH, get the system information of the ES carrier and then switch to the ES carrier. For the UEs not supporting ES, the UEs may just ignore the DCI with the bit field in short message indicator setting to be “00” , which is reserved for the legacy UEs as shown in Table 1-4. Using the reserved bits for the indication does not impact much the behavior of UEs not supporting ES.

In some example embodiments, scheduling information of the system information of the second carrier may be transmitted in another message after the first DCI 204 for paging. For example, the DCI for scheduling the PDSCH that carries the system information of an ES carrier may be received in a predefined timing or within a predefined time window after the UE received the short message in a PO. From the perspective of a BS, the system information of an ES carrier might be sent only in such corresponding timing. This reduces the overhead on the system information configuration.

In an example embodiment, the UE 104 may receive, from the BS 102 in the first carrier, a second DCI (e.g., a SIB1 DCI) in a first timing associated with scheduling of system information block. The first timing may be subsequent to a PO associated with the first DCI 204 or a PF containing the PO. For example, the UE 104 may receive, from the BS 102 in the non-ES carrier on which the UE 104 is camping, a SIB1 DCI in a first SIB1 scheduling timing after the PO associated with the DCI 204 for paging or the first SIB1 scheduling timing after the PF containing the PO. In other words, the SIB1 DCI for scheduling the PDSCH carrying the system information of the ES carrier may be received in the SIB1 scheduling timing after the last symbol of the PO with the short message, or after the last symbol of the last PO of the corresponding PF.

FIG. 3A illustrates an example of obtaining scheduling information for the system information of an ES carrier in a non-ES carrier in accordance with some example embodiments of the present disclosure. For the purpose of discussion, FIG. 3A will be described with reference to FIGS. 1A and 2A and may involve the UE 104 and the BS 102.

As shown in FIG. 3A, the network may use four beams for transmitting SIB1 (and also for transmitting SIB1 DCIs) and for paging (including transmitting paging DCIs and paging messages) . Each beam is illustrated with a specific filling pattern as shown in FIG. 3A. The UE 104 may camp on a non-ES carrier. The BS 102 may determine to switch the camping carrier of the UE 104 to an ES carrier. The BS 102 may thus transmit, in the non-ES carrier, a short message in a paging DCI in beam #2 in PO#j, indicating the UE to retrieve the system information for an ES carrier. Then in the first SIB1 scheduling timing after the PO, the UE 104 may monitor a SIB1 DCI for scheduling PDSCH carrying the system information for the ES carrier. Upon receiving the SIB1 DCI for scheduling PDSCH carrying the system information for the ES carrier, the UE 104 may receive the PDSCH carrying the system information for the ES carrier based on the scheduling information in the SIB1 DCI.

In another example embodiment, the UE 104 may receive, from the BS 102 in the first carrier, a second DCI (e.g., a SIB1 DCI) in a time window comprising at least one timing associated with scheduling of system information block. The time window may be subsequent to a PO associated with the first DCI 204 or a PF containing the PO. In other words, the SIB1 DCI for scheduling the PDSCH carrying the system information of the ES carrier may be received within a predefined time window after the last symbol of the PO with the short message, or within a predefined time window after the symbol of the last PO of the related PF. The size of the time window may be configured or predefined.

FIG. 3B illustrates an example of obtaining scheduling information for the system information of an ES carrier in a non-ES carrier in accordance with some example embodiments of the present disclosure. For the purpose of discussion, FIG. 3B will be described with reference to FIGS. 1A and 2A and may involve the UE 104 and the BS 102.

As shown in FIG. 3B, the network may use four beams for transmitting SIB1 (and also for transmitting SIB1 DCIs) and for paging (including transmitting paging DCIs and paging messages) . Each beam is illustrated with a specific filling pattern as shown in FIG. 3B. The UE 104 may camp on a non-ES carrier. The BS 102 may determine to switch the camping carrier of the UE 104 to an ES carrier. The BS 102 may thus transmit, in the non-ES carrier, a short message in a paging DCI in beam #2 in PO#j, indicating the UE to retrieve the system information for an ES carrier. Then in a predefined/configured time window after the PO, the UE 104 may monitor the SIB1 DCI for scheduling PDSCH carrying the system information for the ES carrier. Upon receiving the SIB1 DCI for scheduling PDSCH carrying the system information for the ES carrier, the UE 104 may receive the PDSCH carrying the system information for the ES carrier based on the scheduling information in the SIB1 DCI.

Returning back to FIG. 2A, in some embodiments, the second DCI may be scrambled by a radio network temporary identity (RNTI) different from a system information RNTI (SI-RNTI) . The system information may be scheduled by scheduling information in the second DCI. In other words, the DCI for scheduling PDSCH carrying the system information of an ES carrier may be scrambled with a specific RNTI, in which case the PDSCH is separately transmitted (from the PDSCH for SIB1 of the camped non-ES carrier) .

In some embodiments, the second DCI may be scrambled by a SI-RNTI. The UE 104 may receive, from the BS 102 in the first carrier, a SIB scheduled by the second DCI. In addition to the system information of the first carrier, the SIB may further include the system information of the second carrier or scheduling information of the system information of the second carrier. The SIB may include an indication indicating whether the system information of the second carrier or scheduling information of the system information of the second carrier is comprised in the SIB. For example, there may be a bit field in the SIB1 based on which the UE could know whether the system information of the ES carrier or the scheduling information of the system information of the ES carrier is included in the SIB1 of the camped non-ES carrier. In an implementation, if the bit field is set as “0” , the UE 104 may determine that the system information of an ES carrier is included in the SIB1 of the non-ES carrier. If the bit field is set as “1” , the UE 104 may determine that scheduling information for the system information of the ES carrier is included in the SIB1 of the non-ES carrier. The UE 104 may further detect the PDSCH for system information of the ES carrier based on the scheduling information. In this manner, the size of the SIB1 may be limited, thus avoiding impacting the SIB1 PDSCH detection performance in the non-ES carrier.

In some embodiments, the second DCI may be scrambled by a SI-RNTI. The UE 104 may receive, from the BS 102 in the first carrier, a SIB scheduled by the second DCI. In addition to the system information of the first carrier, the SIB may further include the system information of the second carrier or scheduling information of the system information of the second carrier. The second DCI may include an indication indicating whether the system information of the second carrier or scheduling information of the system information of the second carrier is comprised in the SIB. For example, there may be a bit field in the second DCI based on which the UE could know whether the system information of the ES carrier or the scheduling information of the system information of the ES carrier is included in the SIB1 of the camped non-ES carrier. In an implementation, if the bit field is set as “0” , the UE 104 may determine that the system information of an ES carrier is included in the SIB1 of the non-ES carrier. If the bit field is set as “1” , the UE 104 may determine that scheduling information for the system information of the ES carrier is included in the SIB1 of the non-ES carrier. The UE 104 may further detect the PDSCH for system information of the ES carrier based on the scheduling information. In this manner, the size of the SIB1 may be limited, thus avoiding impacting the SIB1 PDSCH detection performance in the non-ES carrier.

One specific aspect of the retrieval of system information is how the UE gets the CORESET#0 and search space set#0 configuration of an ES carrier. When a UE camps on an ES carrier, e.g., based on BS configuration as described above, or the UE camps on the carrier without gNB indication, the UE needs to detect the SSB of the ES carrier to synchronize to the DL, get the cell ID and obtain the available information in MIB. Herein after, the SSB (s) transmitted in an ES carrier is defined as ES-SSB (s) .

In order not to impact the behavior of UEs not supporting ES (i.e., legacy UEs) , an ES-SSB (s) in an ES carrier should be a SSB that does not provide valid CORESET#0 configurations for these legacy UEs. Otherwise, the UEs not supporting ES might keep detecting the SIB1 (which is not provided) in the ES carrier and thus leads to unnecessary power consumption. While for UEs supporting ES, it is proposed that the ES-SSB (s) may or may not provide CORESET#0 configurations based on different embodiments of the disclosure. Various solutions may be proposed to enable the UEs to obtain the CORESET#0 and search space set#0 configuration of an ES carrier. Some embodiments may be designed based on the configuration of k_SSB.

In some example embodiments, the first SSB may include an information element regarding a subcarrier offset parameter. In some examples, the information element may be a subcarrier offset field comprised in PBCH in the first SSB. If a first value is indicated in the information element, the UE 104 may determine a configuration of a control resource set (CORESET) of the second carrier based on the first SSB of the second carrier. The first value in the information element may indicate that the first SSB provides a valid configuration of a CORESET of the second carrier for UEs with a first capability. Alternatively or additionally, the first value in the information element may indicate that a SIB may be not transmitted in the second carrier.

In some implementations, the UE 104 may receive, from the BS 102 in the first carrier, a second SSB of the first carrier. The UE 104 may determine a subcarrier offset for a frequency position of the CORESET of the second carrier based on an information element in the second SSB.

For example, the k_SSB may be configured as 30 for FR1 and 14 for FR2 for the ES-SSB (s) . In this case, for UEs NOT supporting ES, as specified (and refer to Table 1-1) , such a k_SSB value is a reserved value and it just indicates the UEs that the SSB does not provide configurations for CORESET#0.

For UEs supporting ES, the UE could interpret that such SSB is an ES-SSB and provides CORESET#0 configurations. The CORESET#0 is present in the ES carrier. Such interpretation could be based on a configuration in MIB of the ES-SSB, such as dmrs-TypeA-Position or the spare bit or other information filed. In this case, the subcarrier offset for determine CORESET#0 position should be provided in system information retrieved from the associated non-ES carrier.

In some example embodiments, the first SSB may include an information element regarding a subcarrier offset parameter. In some examples, the information element may be a subcarrier offset field comprised in the PBCH in the first SSB. If a second value is indicated in the information element, the UE 104 may determine a first carrier based on the first SSB. The UE may determine a configuration of a CORESET of the second carrier and system information of the second carrier in the first carrier. The second value in the information element may indicate that a SIB may be not transmitted in the second carrier.

For example, the k_SSB may be configured to be within [24, 29] for FR1 and [12, 13] for FR2 for the ES-SSB (s) . In this case, for UEs NOT supporting ES, as specified, such a k_SSB value indicates that CORESET#0 is not present, and the UE may find a SSB that provides the CORESET#0 configurations based on the PDCCH-configSIB1 in MIB.

For UEs supporting ES, the UE may interpret that such SSB is an ES-SSB. The interpretation could be based on a configuration in MIB in the SSB, such as dmrs-TypeA-Position or the spare bit or other information field. The CORESET#0 is present, but the ES-SSB does not provide CORESET#0 configurations. Instead, the UE may find a SSB that provides CORESET#0 configurations and system information of the ES carrier in a SSB of a carrier based on the PDCCH-configSIB1 in MIB.

In detail, if the UE 104 supporting ES determines 24≤k_SSB≤29 for FR1 or 12≤k_SSB≤13 for FR2, the UE 104 may decide that the CORESET#0 is present, but CORESET#0 configurations are not provided by the ES-SIB1. The UE may determine the nearest (in the corresponding frequency direction) GSCN of a second SSB as is the GSCN of the first SS/PBCH block, in FR1 and FR2-1, in FR2-2, andis a GSCN offset provided by Table 1-1 for FR1 and Table 1-2 for FR2. The UE 104 may retrieve the CORESET#0 configuration and the symbol information in the carrier with the second SSB.

FIG. 2B illustrates another example signaling chart of a communication process 200B that supports retrieval of system information in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the process 200B will be described with reference to FIG. 1A. The process 200B may involve the UE 104 and the BS 102. It is to be understood that the steps and the order of the steps in FIG. 2B are merely for illustration, and not for limitation. It is to be understood that process 200B may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard. Embodiments of the present disclosure focuses on the operations of UEs supporting ES. In the following embodiments, unless explicitly indicated, the UE 104 refers to a UE supporting ES.

As shown in FIG. 2B, the BS 102 transmits 212, in a second carrier, a first SSB 214. The UE 104 receives 216 the first SSB 214 in the second carrier. Then, the UE 104 determines 218 whether a SIB may be transmitted in the second carrier based on the first SSB 214. In this way, the UE 104 may be aware whether the second carrier is an ES carrier or a non-ES carrier. If the second carrier is a non-ES carrier, the UE may retrieve the SIB1 based on the detected SSB as described above. If the second carrier is an ES carrier and the UE camping on the second carrier and detecting the SSB supports ES, the UE may perform the related actions to retrieve system information of the ES carrier in another carrier. In other words, the UEs supporting ES may be indicated to retrieve system information of the ES carrier in another carrier.

One specific aspect of the retrieval of system information is how the UE gets the CORESET#0 and search space set#0 configuration of an ES carrier. As mentioned above, in order not to impact the behavior of UEs not supporting ES (i.e., legacy UEs) , an ES-SSB (s) in an ES carrier should be a SSB that does not provide valid CORESET#0 configurations for these legacy UEs. Otherwise, the UEs not supporting ES might keep detecting the SIB1 (which is not provided) in the ES carrier and thus leads to unnecessary power consumption. While for UEs supporting ES, it is proposed that the ES-SSB (s) may or may not provide CORESET#0 configurations based on different embodiments of the disclosure. Various solutions may be proposed to enable the UEs to obtain the CORESET#0 and search space set#0 configuration of an ES carrier. Some embodiments may be designed based on the configuration of k_SSB.

In some example embodiments, the first SSB 214 may include an information element regarding a subcarrier offset parameter. In some examples, the information element may be a subcarrier offset field comprised in PBCH in the first SSB 214. If a first value is indicated in the information element, the UE 104 may determine a configuration of a control resource set (CORESET) of the second carrier based on the first SSB 214 of the second carrier. The first value in the information element may indicate that the first SSB 214 provides a valid configuration of a CORESET of the second carrier for UEs with a first capability. Alternatively or additionally, the first value in the information element may indicate that a SIB may be not transmitted in the second carrier.

For UEs supporting ES, the UE could interpret that such SSB is an ES-SSB and provides CORESET#0 configurations. The CORESET#0 is present in the ES carrier. Such interpretation could be based on a configuration in MIB of the ES-SSB, such as dmrs-TypeA-Position or the spare bit or other information filed. In this case, the subcarrier offset for determine CORESET#0 position should be provided in the associated non-ES carrier.

In some example embodiments, the first SSB 214 may include an information element regarding a subcarrier offset parameter. In some examples, the information element may be a subcarrier offset field comprised in PBCH in the first SSB 214. If a second value is indicated in the information element, the UE 104 may determine a first carrier based on the first SSB 214. The UE may determine a configuration of a CORESET of the second carrier and system information of the second carrier in the first carrier. The second value in the information element may indicate that a SIB may be not transmitted in the second carrier.

For UEs supporting ES, the UE may interpret that such SSB is an ES-SSB. The interpretation may be based on a configuration in MIB in the SSB, such as dmrs-TypeA-Position or the spare bit. The CORESET#0 is present, but the ES-SSB does not provide CORESET#0 configurations. Instead, the UE may find a SSB that provides CORESET#0 configurations and system information of the ES carrier in a SSB of a carrier based on the PDCCH-configSIB1 in MIB.

FIG. 4 illustrates an example of a device 400 that supports retrieval of system information in accordance with aspects of the present disclosure. The device 400 may be an example of a UE 104 as described herein. The device 400 may support wireless communication with one or more network entities 102, UEs 104, or any combination thereof. The device 400 may include components for bi-directional communications including components for transmitting and receiving communications, such as a processor 402, a memory 404, a transceiver 406, and, optionally, an I/O controller 408. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 402, the memory 404, the transceiver 406, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. For example, the processor 402, the memory 404, the transceiver 406, or various combinations or components thereof may support a method for performing one or more of the operations described herein.

In some implementations, the processor 402, the memory 404, the transceiver 406, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some implementations, the processor 402 and the memory 404 coupled with the processor 402 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 402, instructions stored in the memory 404) .

For example, the processor 402 may support wireless communication at the device 400 in accordance with examples as disclosed herein. The processor 402 may be configured to operable to support a means for receiving, from a base station, first downlink control information (DCI) for paging in a first carrier or a first synchronization signal and physical broadcast channel (PBCH) block (SSB) in a second carrier, wherein the first DCI comprises a short message; and in the case of receiving the first DCI, retrieve, in the first carrier, system information of the second carrier based on the short message; or in the case of receiving the first SSB, determine whether a system information block (SIB) is transmitted in the second carrier based on the first SSB.

The processor 402 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some implementations, the processor 402 may be configured to operate a memory array using a memory controller. In some other implementations, a memory controller may be integrated into the processor 402. The processor 402 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 404) to cause the device 400 to perform various functions of the present disclosure such that the device 400 may perform any process of the disclosure as discussed with reference to FIGS. 2 to 6.

The memory 404 may include random access memory (RAM) and read-only memory (ROM) . The memory 404 may store computer-readable, computer-executable code including instructions that, when executed by the processor 402 cause the device 400 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some implementations, the code may not be directly executable by the processor 402 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 404 may include, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The I/O controller 408 may manage input and output signals for the device 400. The I/O controller 408 may also manage peripherals not integrated into the device M02. In some implementations, the I/O controller 408 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 408 may utilize an operating system such as or another known operating system. In some implementations, the I/O controller 408 may be implemented as part of a processor, such as the processor 406. In some implementations, a user may interact with the device 400 via the I/O controller 408 or via hardware components controlled by the I/O controller 408.

In some implementations, the device 400 may include a single antenna 410. However, in some other implementations, the device 400 may have more than one antenna 410 (i.e., multiple antennas) , including multiple antenna panels or antenna arrays, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 406 may communicate bi-directionally, via the one or more antennas 410, wired, or wireless links as described herein. For example, the transceiver 406 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 406 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 410 for transmission, and to demodulate packets received from the one or more antennas 410. The transceiver 406 may include one or more transmit chains, one or more receive chains, or a combination thereof.

A transmit chain may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmit chain may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmit chain may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmit chain may also include one or more antennas 410 for transmitting the amplified signal into the air or wireless medium.

A receive chain may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receive chain may include one or more antennas 410 for receive the signal over the air or wireless medium. The receive chain may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receive chain may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receive chain may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

FIG. 5 illustrates an example of a device 500 that supports retrieval of system information in accordance with aspects of the present disclosure. The device 500 may be an example of a network entity 102 as described herein. The device 500 may support wireless communication with one or more network entities 102, UEs 104, or any combination thereof. The device 500 may include components for bi-directional communications including components for transmitting and receiving communications, such as a processor 502, a memory 504, a transceiver 506, and, optionally, an I/O controller 508. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 502, the memory 504, the transceiver 506, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. For example, the processor 502, the memory 504, the transceiver 506, or various combinations or components thereof may support a method for performing one or more of the operations described herein.

In some implementations, the processor 502, the memory 504, the transceiver 506, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some implementations, the processor 502 and the memory 504 coupled with the processor 502 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 502, instructions stored in the memory 504) .

For example, the processor 502 may support wireless communication at the device 500 in accordance with examples as disclosed herein. The processor 502 may be configured to operable to support a means for transmitting, to a user equipment, first downlink control information (DCI) for paging in a first carrier, wherein the first DCI comprises a short message to indicate the user equipment to retrieve system information of a second carrier in the first carrier.

The processor 502 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some implementations, the processor 502 may be configured to operate a memory array using a memory controller. In some other implementations, a memory controller may be integrated into the processor 502. The processor 502 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 504) to cause the device 500 to perform various functions of the present disclosure such that the device 500 may perform any process of the disclosure as discussed with reference to FIGS. 2 to 6.

The memory 504 may include random access memory (RAM) and read-only memory (ROM) . The memory 504 may store computer-readable, computer-executable code including instructions that, when executed by the processor 502 cause the device 500 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some implementations, the code may not be directly executable by the processor 502 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 504 may include, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The I/O controller 508 may manage input and output signals for the device 500. The I/O controller 508 may also manage peripherals not integrated into the device M02. In some implementations, the I/O controller 508 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 508 may utilize an operating system such as or another known operating system. In some implementations, the I/O controller 508 may be implemented as part of a processor, such as the processor 506. In some implementations, a user may interact with the device 500 via the I/O controller 508 or via hardware components controlled by the I/O controller 508.

In some implementations, the device 500 may include a single antenna 510. However, in some other implementations, the device 500 may have more than one antenna 510 (i.e., multiple antennas) , including multiple antenna panels or antenna arrays, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 506 may communicate bi-directionally, via the one or more antennas 510, wired, or wireless links as described herein. For example, the transceiver 506 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 506 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 510 for transmission, and to demodulate packets received from the one or more antennas 510. The transceiver 506 may include one or more transmit chains, one or more receive chains, or a combination thereof.

A transmit chain may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmit chain may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmit chain may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmit chain may also include one or more antennas 510 for transmitting the amplified signal into the air or wireless medium.

A receive chain may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receive chain may include one or more antennas 510 for receive the signal over the air or wireless medium. The receive chain may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receive chain may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receive chain may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

FIG. 6 illustrates an example of a processor 600 that supports retrieval of system information in accordance with aspects of the present disclosure. The processor 600 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 600 may be implemented in a device or its components as described herein. For example, the device may be an example of a UE 104 as described herein. The processor 600 may include a controller 602 configured to perform various operations in accordance with examples as described herein. The processor 600 may optionally include at least one memory 604, such as L1/L2/L3 cache. Additionally, or alternatively, the processor 600 may optionally include one or more arithmetic-logic units (ALUs) 600. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 600 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 600) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 602 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 600 to cause the processor 600 to support various operations in accordance with examples as described herein. For example, the controller 602 may operate as a control unit of the processor 600, generating control signals that manage the operation of various components of the processor 600. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 602 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 604 and determine subsequent instruction (s) to be executed to cause the processor 600 to support various operations in accordance with examples as described herein. The controller 602 may be configured to track memory address of instructions associated with the memory 604. The controller 602 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 602 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 600 to cause the processor 600 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 602 may be configured to manage flow of data within the processor 600. The controller 602 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 600.

The memory 604 may include one or more caches (e.g., memory local to or included in the processor 600 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementation, the memory 604 may reside within or on a processor chipset (e.g., local to the processor 600) . In some other implementations, the memory 604 may reside external to the processor chipset (e.g., remote to the processor 600) .

The memory 604 may store computer-readable, computer-executable code including instructions that, when executed by the processor 600, cause the processor 600 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 602 and/or the processor 600 may be configured to execute computer-readable instructions stored in the memory 604 to cause the processor 600 to perform various functions. For example, the processor 600 and/or the controller 602 may be coupled with or to the memory 604, and the processor 600, the controller 602, and the memory 604 may be configured to perform various functions described herein. In some examples, the processor 600 may include multiple processors and the memory 604 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 600 may be configured to support various operations in accordance with examples as described herein. In some implementation, the one or more ALUs 600 may reside within or on a processor chipset (e.g., the processor 600) . In some other implementations, the one or more ALUs 600 may reside external to the processor chipset (e.g., the processor 600) . One or more ALUs 600 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 600 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 600 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 600 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 600 to handle conditional operations, comparisons, and bitwise operations.

The processor 600 may support wireless communication in accordance with examples as disclosed herein. The processor 600 may be configured to or operable to support a means for receiving, from a base station, first downlink control information (DCI) for paging in a first carrier or a first synchronization signal and physical broadcast channel (PBCH) block (SSB) in a second carrier, wherein the first DCI comprises a short message; and in the case of receiving the first DCI, retrieve, in the first carrier, system information of the second carrier based on the short message; or in the case of receiving the first SSB, determine whether a system information block (SIB) is transmitted in the second carrier based on the first SSB.

FIG. 7 illustrates an example of a processor 700 that supports retrieval of system information in accordance with aspects of the present disclosure. The processor 700 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 700 may be implemented in a device or its components as described herein. For example, the device may be an example of a network entity 102 as described herein. The processor 700 may include a controller 702 configured to perform various operations in accordance with examples as described herein. The processor 700 may optionally include at least one memory 704, such as L1/L2/L3 cache. Additionally, or alternatively, the processor 700 may optionally include one or more arithmetic-logic units (ALUs) 700. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 700 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 700) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 702 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 700 to cause the processor 700 to support various operations in accordance with examples as described herein. For example, the controller 702 may operate as a control unit of the processor 700, generating control signals that manage the operation of various components of the processor 700. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 702 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 704 and determine subsequent instruction (s) to be executed to cause the processor 700 to support various operations in accordance with examples as described herein. The controller 702 may be configured to track memory address of instructions associated with the memory 704. The controller 702 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 702 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 700 to cause the processor 700 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 702 may be configured to manage flow of data within the processor 700. The controller 702 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 700.

The memory 704 may include one or more caches (e.g., memory local to or included in the processor 700 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementation, the memory 704 may reside within or on a processor chipset (e.g., local to the processor 700) . In some other implementations, the memory 704 may reside external to the processor chipset (e.g., remote to the processor 700) .

The memory 704 may store computer-readable, computer-executable code including instructions that, when executed by the processor 700, cause the processor 700 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 702 and/or the processor 700 may be configured to execute computer-readable instructions stored in the memory 704 to cause the processor 700 to perform various functions. For example, the processor 700 and/or the controller 702 may be coupled with or to the memory 704, and the processor 700, the controller 702, and the memory 704 may be configured to perform various functions described herein. In some examples, the processor 700 may include multiple processors and the memory 704 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 700 may be configured to support various operations in accordance with examples as described herein. In some implementation, the one or more ALUs 700 may reside within or on a processor chipset (e.g., the processor 700) . In some other implementations, the one or more ALUs 700 may reside external to the processor chipset (e.g., the processor 700) . One or more ALUs 700 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 700 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 700 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 700 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 700 to handle conditional operations, comparisons, and bitwise operations.

The processor 700 may support wireless communication in accordance with examples as disclosed herein. The processor 700 may be configured to or operable to support a means for transmitting, to a user equipment, first downlink control information (DCI) for paging in a first carrier, wherein the first DCI comprises a short message to indicate the user equipment to retrieve system information of a second carrier in the first carrier.

FIG. 8 illustrates a flowchart of a method 800 that supports retrieval of system information in accordance with aspects of the present disclosure. The operations of the method 800 may be implemented by a device or its components as described herein. For example, the operations of the method 800 may be performed by a UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 805, the method may include receiving from a base station, first downlink control information (DCI) for paging in a first carrier, wherein the first DCI comprises a short message. The operations of 805 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 805 may be performed by a device as described with reference to FIG. 1A.

At 810, the method may include retrieving, in the first carrier, system information of the second carrier based on the short message. The operations of 810 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 81-may be performed by a device as described with reference to FIG. 1A.

FIG. 9 illustrates a flowchart of a method 900 that supports retrieval of system information in accordance with aspects of the present disclosure. The operations of the method 900 may be implemented by a device or its components as described herein. For example, the operations of the method 900 may be performed by a UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware. The method 900 may be deemed as a continuation of the method 800.

At 905, the method may include switching from the first carrier to the second carrier. The operations of 905 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 905 may be performed by a device as described with reference to FIG. 1A.

At 910, the method may include receiving, from the base station in the second carrier, the first SSB of the second carrier. The operations of 910 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 910 may be performed by a device as described with reference to FIG. 1A.

FIG. 10 illustrates a flowchart of a method 1000 that supports retrieval of system information in accordance with aspects of the present disclosure. The operations of the method 1000 may be implemented by a device or its components as described herein. For example, the operations of the method 1000 may be performed by a UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1005, the method may include receiving, from a base station, first downlink control information (DCI) for paging in a first carrier or a first synchronization signal and physical broadcast channel (PBCH) block (SSB) in a second carrier. The operations of 1005 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1005 may be performed by a device as described with reference to FIG. 1A.

At 1010, the method may include determining whether a system information block (SIB) is transmitted in the second carrier based on the first SSB. The operations of 1010 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1010 may be performed by a device as described with reference to FIG. 1A.

FIG. 11 illustrates a flowchart of a method 1100 that supports retrieval of system information in accordance with aspects of the present disclosure. The operations of the method 1100 may be implemented by a device or its components as described herein. For example, the operations of the method 1100 may be performed by a UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware. The method 1100 may be deemed as a continuation of the method 900 or the method 1000.

At 1105, the method may include determining whether a first value is indicated in the information element in the first SSB. The operations of 1105 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1105 may be performed by a device as described with reference to FIG. 1A.

If yes, at 1110, the method may include determining a configuration of a control resource set (CORESET) of the second carrier based on the first SSB of the second carrier. The operations of 1110 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1110 may be performed by a device as described with reference to FIG. 1A.

At 1115, the method may include receiving, from the base station in the first carrier, a second SSB of the first carrier. The operations of 1115 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1115 may be performed by a device as described with reference to FIG. 1A.

At 1120, the method may include determining a subcarrier offset for a frequency position of the CORESET of the second carrier based on an information element in the second SSB. The operations of 1120 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1120 may be performed by a device as described with reference to FIG. 1A.

FIG. 12 illustrates a flowchart of a method 1200 that supports retrieval of system information in accordance with aspects of the present disclosure. The operations of the method 1200 may be implemented by a device or its components as described herein. For example, the operations of the method 1200 may be performed by a UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware. The method 1200 may be deemed as a continuation of the method 900 or the method 1000.

At 1205, the method may include determining whether a second value is indicated in the information element in the first SSB. The operations of 1205 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1205 may be performed by a device as described with reference to FIG. 1A.

If yes, at 1210, the method may include determining the first carrier based on the first SSB. The operations of 1210 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1210 may be performed by a device as described with reference to FIG. 1A.

At 1215, the method may include determining a configuration of a CORESET of the second carrier and system information of the second carrier in the first carrier. The operations of 1215 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1215 may be performed by a device as described with reference to FIG. 1A.

FIG. 13 illustrates a flowchart of a method 1300 that supports retrieval of system information in accordance with aspects of the present disclosure. The operations of the method 1300 may be implemented by a device or its components as described herein. For example, the operations of the method 1300 may be performed by a network entity 102 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1305, the method may include transmitting, to a user equipment, first downlink control information (DCI) for paging in a first carrier, wherein the first DCI comprises a short message to indicate the user equipment to retrieve system information of a second carrier in the first carrier. The operations of 1305 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1305 may be performed by a device as described with reference to FIG. 1A.

FIG. 14 illustrates a flowchart of a method 1400 that supports retrieval of system information in accordance with aspects of the present disclosure. The operations of the method 1400 may be implemented by a device or its components as described herein. For example, the operations of the method 1400 may be performed by a network entity 102 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware. The method 1400 may be deemed as a continuation of the method 1300.

At 1405, the method may include transmitting, to the user equipment in the first carrier, a second DCI in a first timing associated with scheduling of system information block, wherein the first timing is subsequent to a paging occasion associated with the first DCI or a paging frame containing the paging occasion. The operations of 1405 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1405 may be performed by a device as described with reference to FIG. 1A.

FIG. 15 illustrates a flowchart of a method 1500 that supports retrieval of system information in accordance with aspects of the present disclosure. The operations of the method 1500 may be implemented by a device or its components as described herein. For example, the operations of the method 1500 may be performed by a network entity 102 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1505, the method may include transmitting, to the user equipment in the second carrier, a first synchronization signal and physical broadcast channel (PBCH) block (SSB) indicating the user equipment to determine whether a system information block (SIB) is transmitted in the second carrier based on the first SSB. The operations of 1505 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1505 may be performed by a device as described with reference to FIG. 1A.

It should be noted that the methods described herein describes possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor.

As used herein, including in the claims, an article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a, ” “at least one, ” “one or more, ” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” or “one or both of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. Further, as used herein, including in the claims, a “set” may include one or more elements.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A user equipment comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

receive, via the transceiver from a base station, first downlink control information (DCI) for paging in a first carrier or a first synchronization signal and physical broadcast channel (PBCH) block (SSB) in a second carrier, wherein the first DCI comprises a short message; and

in the case of receiving the first DCI, retrieve, in the first carrier, system information of the second carrier based on the short message; or

in the case of receiving the first SSB, determine whether a system information block (SIB) is transmitted in the second carrier based on the first SSB.
The user equipment of claim 1, wherein the processor is further configured to:

in the case of receiving the first DCI, switch from the first carrier to the second carrier; and

receive, via the transceiver from the base station in the second carrier, the first SSB of the second carrier.
The user equipment of claim 1, wherein the short message comprises a bit field indicating at least one of the following:

system information retrieving; or

carrier switching.
The user equipment of claim 1, wherein the first DCI comprises scheduling information of the system information of the second carrier, and the system information of the second carrier is scheduled by the scheduling information.
The user equipment of claim 4, wherein the first DCI comprises an indication that the scheduling information is present in the first DCI.
The user equipment of claim 1, wherein the processor is further configured to:

receive, via the transceiver from the base station in the first carrier, a second DCI in a first timing associated with scheduling of system information block, wherein the first timing is subsequent to a paging occasion associated with the first DCI or a paging frame containing the paging occasion.
The user equipment of claim 1, wherein the processor is further configured to:

receive, via the transceiver from the base station in the first carrier, a second DCI in a time window comprising at least one timing associated with scheduling of system information block, wherein the time window is subsequent to a paging occasion associated with the first DCI or a paging frame containing the paging occasion.
The user equipment of claim 6 or 7, wherein the second DCI is scrambled by a radio network temporary identity (RNTI) different from a system information RNTI (SI-RNTI) , and

wherein the system information is scheduled by scheduling information in the second DCI.
The user equipment of claim 6 or 7, wherein the second DCI is scrambled by a SI-RNTI and the processor is further configured to:

receiving, via the transceiver from the base station in the first carrier, a SIB scheduled by the second DCI, and

wherein the SIB comprises an indication indicating whether the system information of the second carrier or scheduling information of the system information of the second carrier is comprised in the SIB.
The user equipment of claim 6 or 7, wherein the second DCI is scrambled by a SI-RNTI and the processor is further configured to:

receiving, via the transceiver from the base station in the first carrier, a SIB scheduled by the second DCI,

wherein the second DCI comprises an indication indicating whether the system information of the second carrier or scheduling information of the system information of the second carrier is comprised in the SIB.
The user equipment of claim 1 or 2, wherein the first SSB comprises an information element regarding a subcarrier offset parameter, and wherein the processor is further configured to:

in the case that a first value is indicated in the information element, determine a configuration of a control resource set (CORESET) of the second carrier based on the first SSB of the second carrier.
The user equipment of claim 11, wherein the processor is further configured to:

in the case that the first value is indicated in the information element, determine that the first SSB provides a valid configuration of the CORESET.
The user equipment of claim 11, wherein determining whether a SIB is transmitted in the second carrier comprises:

in the case that the first value is indicated in the information element, determining that SIB is not transmitted in the second carrier.
The user equipment of claim 11, wherein the processor is further configured to:

receive, via the transceiver from the base station in the first carrier, a second SSB of the first carrier; and

determine a subcarrier offset for a frequency position of the CORESET of the second carrier based on an information element in the second SSB.
The user equipment of claim 1 or 2, wherein the first SSB comprises an information element regarding a subcarrier offset parameter, and the wherein processor is further configured to:

in the case that a second value is indicated in the information element,

determine the first carrier based on the first SSB; and

determine a configuration of a CORESET of the second carrier and system information of the second carrier in the first carrier.
The user equipment of claim 15, wherein determining whether a SIB is transmitted in the second carrier comprises:

in the case that the second value is indicated in the information element, determining that SIB is not transmitted in the second carrier.
The user equipment of claim 11 or 15, wherein the information element is a subcarrier offset field comprised in PBCH in the first SSB.
A base station comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

transmit, via the transceiver to a user equipment, first downlink control information (DCI) for paging in a first carrier, wherein the first DCI comprises a short message to indicate the user equipment to retrieve system information of a second carrier in the first carrier; or

transmit, via the transceiver to the user equipment in the second carrier, a first synchronization signal and physical broadcast channel (PBCH) block (SSB) indicating the user equipment to determine whether a system information block (SIB) is transmitted in the second carrier based on the first SSB.
A method performed by a user equipment, the method comprising:

receiving, from a base station, first downlink control information (DCI) for paging in a first carrier or a first synchronization signal and physical broadcast channel (PBCH) block (SSB) in a second carrier, wherein the first DCI comprises a short message; and

in the case of receiving the first DCI, retrieving, in the first carrier, system information of the second carrier based on the short message; or

in the case of receiving the first SSB, determining whether a system information block (SIB) is transmitted in the second carrier based on the first SSB.
A processor for wireless communication, comprising:

at least one memory; and

a controller coupled with the at least one memory and configured to cause the controller to:

receive, via the transceiver from a base station, first downlink control information (DCI) for paging in a first carrier or a first synchronization signal and physical broadcast channel (PBCH) block (SSB) in a second carrier, wherein the first DCI comprises a short message; and

in the case of receiving the first DCI, retrieve, in the first carrier, system information of the second carrier based on the short message; or

in the case of receiving the first SSB, determine whether a system information block (SIB) is transmitted in the second carrier based on the first SSB.