Beam optimization for soft physical cell identifier change

Abstract

This disclosure relates to various aspects of a network node for changing its Physical Cell Identifier (PCI). The network node transmits a first signal based on a first PCI during a first Synchronization Block (SSB) opportunity, transmits a second signal based on the first PCI during a second SSB opportunity, and transitions from the first PCI to the second PCI. During the transition period, the network node transmits the first signal based on the second PCI during the first SSB opportunity and continues to transmit the second signal based on the first PCI during the second SSB opportunity. After the transition period ends, the network node continues to transmit the first signal based on the second PCI during the first SSB opportunity and ceases to transmit the second signal based on the first PCI during the second SSB opportunity. Other aspects and features are also claimed and described.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and interest in non-provisional application No. 17 / 362,759, filed June 29, 2021, and provisional application No. 63 / 047,207, filed July 1, 2020, both of which are incorporated herein by reference in their entirety, as if their entire contents and all applicable purposes were fully set forth herein. Technical Field

[0003] The techniques discussed below typically relate to wireless communication systems, specifically to network nodes used to change the Physical Cell Identifier (PCI). Background Technology

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, and broadcasting. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Wireless multiple access communication systems may include multiple base stations or network access nodes, each supporting communication with multiple communication devices simultaneously, which may also be referred to as user equipment (UEs).

[0005] Multiple access technologies have been adopted in various telecommunications standards to provide a common protocol enabling different wireless devices to communicate at the municipal, national, regional, and even global levels. An example telecommunications standard is 5G New Radio (NR). 5G / NR is part of the Continuous Mobile Broadband Evolution (CMB) initiative released by the 3rd Generation Partnership Project (3GPP) to meet new requirements related to latency, reliability, security, scalability (e.g., with the Internet of Things (IoT),) and other requirements. 5G / NR includes services associated with enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low latency communications (URLLC). Some aspects of 5G / NR can be based on the 4G Long Term Evolution (LTE) standard. Further improvements to 5G / NR technology are needed. These improvements can also be applied to other multiple access technologies and telecommunications standards that employ these technologies. Summary of the Invention

[0006] The following provides an overview of one or more aspects to offer a basic understanding of these aspects of the disclosure. This overview is not a general description of all anticipated features of the disclosure and is neither intended to identify key or essential elements of all aspects of the disclosure, nor to depict the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in the form of a preface to a more detailed description that will follow.

[0007] In one example, a method for changing a Physical Cell Identifier (PCI) performed at a network node is disclosed. The method includes: transmitting a first signal based on a first PCI during a first Synchronization Signal Block (SSB) opportunity, transmitting a second signal based on the first PCI during a second SSB opportunity, wherein the first and second SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame, transitioning from the first PCI to the second PCI, wherein during the transition period, the transition includes transmitting the first signal based on the second PCI during the first SSB opportunity and continuing to transmit the second signal based on the first PCI during the second SSB opportunity, and wherein after the transition period ends, the transition includes continuing to transmit the first signal based on the second PCI during the first SSB opportunity and ceasing to transmit the second signal based on the first PCI during the second SSB opportunity, receiving configuration information from a control node, and selecting the first SSB opportunity based on the configuration information to transmit the first signal based on the second PCI during the transition period.

[0008] In another example, a network node for changing a Physical Cell Identifier (PCI) is disclosed. The network node includes at least one processor and a memory coupled to the at least one memory. The at least one processor and the memory are configured to: transmit a first signal based on a first Physical Cell Identifier (PCI) during a first Synchronization Signal Block (SSB) opportunity, transmit a second signal based on the first PCI during a second SSB opportunity, wherein the first SSB opportunity and the second SSB opportunity are part of a set of SSB opportunities in a periodically repeating time frame, transition from the first PCI to the second PCI, wherein during the transition period, the transition includes transmitting the first signal based on the second PCI during the first SSB opportunity and continuing to transmit the second signal based on the first PCI during the second SSB opportunity, and wherein after the end of the transition period, the transition includes continuing to transmit the first signal based on the second PCI during the first SSB opportunity and ceasing to transmit the second signal based on the first PCI during the second SSB opportunity, receiving configuration information from a control node, and selecting the first SSB opportunity based on the configuration information to transmit the first signal based on the second PCI during the transition period.

[0009] In another example, a network node for changing a Physical Cell Identifier (PCI) is disclosed. The network node includes: a unit for transmitting a first signal based on the first PCI during a first Synchronization Block (SSB) opportunity; a unit for transmitting a second signal based on the first PCI during a second SSB opportunity, wherein the first and second SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame; a unit for transitioning from the first PCI to the second PCI, wherein during the transition period, the unit for transitioning is configured to transmit the first signal based on the second PCI during the first SSB opportunity and continue transmitting the second signal based on the first PCI during the second SSB opportunity; and wherein after the transition period ends, the unit for transitioning is configured to continue transmitting the first signal based on the second PCI during the first SSB opportunity and stop transmitting the second signal based on the first PCI during the second SSB opportunity; a unit for receiving configuration information from a control node; and a unit for selecting the first SSB opportunity based on the configuration information to transmit the first signal based on the second PCI during the transition period.

[0010] In yet another example, a non-transitory computer-readable medium is disclosed storing computer-executable code at a network node for changing a Physical Cell Identifier (PCI). The non-transitory computer-readable medium includes code for instructing a computer to: transmit a first signal based on a first Physical Cell Identifier (PCI) during a first Synchronization Signal Block (SSB) opportunity; transmit a second signal based on the first PCI during a second SSB opportunity, wherein the first and second SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame; transition from the first PCI to the second PCI; wherein, during the transition period, the transition includes transmitting the first signal based on the second PCI during the first SSB opportunity and continuing to transmit the second signal based on the first PCI during the second SSB opportunity; and wherein, after the transition period ends, the transition includes continuing to transmit the first signal based on the second PCI during the first SSB opportunity and ceasing to transmit the second signal based on the first PCI during the second SSB opportunity; receiving configuration information from a control node; and selecting the first SSB opportunity based on the configuration information to transmit the first signal based on the second PCI during the transition period.

[0011] In one example, a method for changing the Physical Cell Identifier (PCI) performed at a network node is disclosed. The method includes: transmitting a first signal based on the first PCI during a first Synchronization Signal Block (SSB) opportunity, transmitting a second signal based on the first PCI during a second SSB opportunity, and transmitting a third signal based on the first PCI during a third SSB opportunity, wherein the first, second, and third SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame, transitioning from the first PCI to the second PCI, wherein during a first transition period, the transition includes transmitting the first signal based on the second PCI during the first SSB opportunity, continuing to transmit the second signal based on the first PCI during the second SSB opportunity, and continuing to transmit the third signal based on the first PCI during the third SSB opportunity, wherein during a second transition period, the transition packet... The transition includes continuing to transmit the first signal based on the second PCI during the first SSB opportunity period, continuing to transmit the second signal based on the second PCI during the second SSB opportunity period, and continuing to transmit the third signal based on the first PCI during the third SSB opportunity period, wherein, after the end of the second transition period, the transition includes continuing to transmit the first signal based on the second PCI during the first SSB opportunity period, continuing to transmit the second signal based on the second PCI during the second SSB opportunity period, stopping the transmission of the third signal based on the first PCI during the third SSB opportunity period, and selecting the first SSB opportunity to transmit the first signal based on the second PCI during the first transition period and the second SSB opportunity to transmit the second signal based on the second PCI during the second transition period.

[0012] In another example, a network node for changing a Physical Cell Identifier (PCI) is disclosed. The network node includes at least one processor and a memory coupled to the at least one memory. The at least one processor and the memory are configured to: transmit a first signal based on the first PCI during a first Synchronization Signal Block (SSB) opportunity, transmit a second signal based on the first PCI during a second SSB opportunity, and transmit a third signal based on the first PCI during a third SSB opportunity, wherein the first, second, and third SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame, transitioning from the first PCI to the second PCI, wherein during a first transition period, the transition includes transmitting the first signal based on the second PCI during the first SSB opportunity, continuing to transmit the second signal based on the first PCI during the second SSB opportunity, and continuing to transmit the third signal based on the first PCI during the third SSB opportunity, wherein during a second transition period... The transition includes continuing to transmit the first signal based on the second PCI during the first SSB opportunity period, continuing to transmit the second signal based on the second PCI during the second SSB opportunity period, and continuing to transmit the third signal based on the first PCI during the third SSB opportunity period, wherein, after the end of the second transition period, the transition includes continuing to transmit the first signal based on the second PCI during the first SSB opportunity period, continuing to transmit the second signal based on the second PCI during the second SSB opportunity period, stopping the transmission of the third signal based on the first PCI during the third SSB opportunity period, and selecting the first SSB opportunity to transmit the first signal based on the second PCI during the first transition period and the second SSB opportunity to transmit the second signal based on the second PCI during the second transition period.

[0013] In another example, a network node for changing a Physical Cell Identifier (PCI) is disclosed. The network node includes: a unit for transmitting a first signal based on the first PCI during a first Synchronization Block (SSB) opportunity; a unit for transmitting a second signal based on the first PCI during a second SSB opportunity; a unit for transmitting a third signal based on the first PCI during a third SSB opportunity, wherein the first, second, and third SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame; and a unit for transitioning from the first PCI to the second PCI, wherein during a first transition period, the unit for transitioning is configured to transmit the first signal based on the second PCI during the first SSB opportunity, continue transmitting the second signal based on the first PCI during the second SSB opportunity, and continue transmitting the third signal based on the first PCI during the third SSB opportunity, wherein during the second transition period... The unit for switching is configured to continue transmitting the first signal based on the second PCI during the first SSB opportunity, continue transmitting the second signal based on the second PCI during the second SSB opportunity, and continue transmitting the third signal based on the first PCI during the third SSB opportunity, wherein, after the end of the second switching period, the unit for switching is configured to continue transmitting the first signal based on the second PCI during the first SSB opportunity, continue transmitting the second signal based on the second PCI during the second SSB opportunity, and stop transmitting the third signal based on the first PCI during the third SSB opportunity, and to select the first SSB opportunity to transmit the first signal based on the second PCI during the first switching period and the second SSB opportunity to transmit the second signal based on the second PCI during the second switching period.

[0014] In another example, a non-transitory computer-readable medium is disclosed that stores computer-executable code at a network node for changing a Physical Cell Identifier (PCI). The non-transitory computer-readable medium includes code for causing a computer to: transmit a first signal based on a first Physical Cell Identifier (PCI) during a first Synchronization Signal Block (SSB) opportunity, transmit a second signal based on the first PCI during a second SSB opportunity, transmit a third signal based on the first PCI during a third SSB opportunity, wherein the first, second, and third SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame, transitioning from the first PCI to the second PCI, wherein during a first transition period, the transition includes transmitting the first signal based on the second PCI during the first SSB opportunity, continuing to transmit the second signal based on the first PCI during the second SSB opportunity, and continuing to transmit the third signal based on the first PCI during the third SSB opportunity, wherein during the second... During the transition period, the transition includes continuing to transmit the first signal based on the second PCI during the first SSB opportunity period, continuing to transmit the second signal based on the second PCI during the second SSB opportunity period, and continuing to transmit the third signal based on the first PCI during the third SSB opportunity period, and wherein, after the end of the second transition period, the transition includes continuing to transmit the first signal based on the second PCI during the first SSB opportunity period, continuing to transmit the second signal based on the second PCI during the second SSB opportunity period, stopping the transmission of the third signal based on the first PCI during the third SSB opportunity period, and selecting the first SSB opportunity to transmit the first signal based on the second PCI during the first transition period and the second SSB opportunity to transmit the second signal based on the second PCI during the second transition period.

[0015] These and other aspects will become more fully understood after reading the following detailed description. Other aspects and features will become apparent to those skilled in the art upon reading the following description of specific exemplary aspects in conjunction with the accompanying drawings. While features may be discussed with respect to certain aspects and figures below, all aspects may include one or more advantageous features discussed herein. In other words, while one or more aspects may be discussed as having certain advantageous features, one or more of these features may also be used according to the various aspects discussed herein. Similarly, while exemplary aspects may be discussed as aspects of an apparatus, system, or method, it should be understood that such exemplary aspects can be implemented in a variety of apparatuses, systems, and methods. Attached Figure Description

[0016] Figure 1 It is a schematic diagram of a wireless communication system based on some aspects.

[0017] Figure 2 (a) in the figure is an example of the first subframe within the 5G / NR frame structure.

[0018] Figure 2 (b) in the figure is a diagram showing an example of a DL channel within a 5G / NR subframe.

[0019] Figure 2 (c) in the figure is an example of the second subframe within the 5G / NR frame structure.

[0020] Figure 2 (d) in the figure is a diagram showing an example of a UL channel within a 5G / NR subframe.

[0021] Figure 3 This is a block diagram of communication between the base station and the UE in the access network.

[0022] Figure 4 An example of an integrated access and backhaul (IAB) system is shown.

[0023] Figure 5 An example network topology of an IAB system based on various aspects of this disclosure is shown.

[0024] Figure 6 This is a diagram illustrating a Physical Cell Identifier (PCI) conflict.

[0025] Figure 7 This is a diagram illustrating the period of the synchronization signal block (SSB) within a serving cell according to various aspects of this disclosure.

[0026] Figure 8 This is a diagram illustrating the movement of network nodes according to various aspects of this disclosure.

[0027] Figure 9 An example of three phases associated with soft PCI changes at network nodes is shown, according to various aspects of this disclosure.

[0028] Figure 10 and 11 Examples of optimizing the transmission beam across stages associated with soft PCI changes at network nodes, according to various aspects of this disclosure, are shown.

[0029] Figure 12 This is a block diagram illustrating an example hardware implementation scheme for an exemplary network node employing a processing system, according to various aspects of this disclosure.

[0030] Figure 13This is a flowchart illustrating an exemplary process for changing the Physical Cell Identifier (PCI) at a network node, according to various aspects of this disclosure.

[0031] Figure 14 This is a flowchart illustrating an exemplary process for changing the Physical Cell Identifier (PCI) at a network node, according to other aspects of this disclosure. Detailed Implementation

[0032] The specific embodiments described below with reference to the accompanying drawings are intended as descriptions of various configurations and are not intended to represent the only configuration in which the concepts described herein can be practiced. The specific embodiments include detailed descriptions to provide a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring these concepts.

[0033] While this application describes aspects by way of illustrations, those skilled in the art will understand that additional implementations and use cases can be implemented in many different arrangements and scenarios. The innovative solutions described herein can be implemented across different platform types, devices, systems, shapes, sizes, and package arrangements. For example, aspects and / or uses can be implemented via integrated chip aspects or other devices based on non-modular components (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchasing devices, medical devices, AI-based devices, etc.). While some examples may or may not be specific to a particular use case or application, broad applicability of the described innovative solutions is possible. The range of implementations can extend from chip-level or modular components to non-modular, non-chip-level implementations, and may also include aggregated, distributed, or OEM devices or systems that integrate one or more aspects of the described innovative solutions. In some practical settings, devices incorporating the described aspects and features must also include additional components and features for implementing and enforcing the claimed and described aspects. For example, the transmission and reception of wireless signals necessarily involve multiple components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders / summers, etc.). The innovative solutions described herein are expected to be implementable in devices, chip-level components, systems, distributed deployments, end-user devices, etc., of various sizes, shapes, and structures.

[0034] This disclosure provides and implements techniques for changing the Physical Cell Identifier (PCI) at a network node. A network node can facilitate a change from one PCI to another (e.g., via optimization of the transmitted signal beam) to avoid PCI conflicts with neighboring nodes, thereby improving timing synchronization, channel estimation, and data decoding at the network node and / or neighboring nodes. This disclosure relates to a network node for changing its Physical Cell Identifier (PCI). The network node transmits a first signal based on a first PCI during a first Synchronization Block (SSB) opportunity, transmits a second signal based on the first PCI during a second SSB opportunity, and transitions from the first PCI to the second PCI. During the transition period, the network node transmits the first signal based on the second PCI during the first SSB opportunity and continues to transmit the second signal based on the first PCI during the second SSB opportunity. After the transition period ends, the network node continues to transmit the first signal based on the second PCI during the first SSB opportunity and ceases to transmit the second signal based on the first PCI during the second SSB opportunity. Other aspects and features are also claimed and described.

[0035] Figure 1 This diagram illustrates an example of a wireless communication system and access network 100. The wireless communication system (also known as a wireless wide area network (WWAN)) includes base station 102, UE 104, evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). Base station 102 may include macro cells (high-power cellular base stations) and / or small cells (low-power cellular base stations). Macro cells include base stations. Small cells include femtocells, picocells, and microcells.

[0036] Base station 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with EPC 160 via backhaul link 132 (e.g., S1 interface). Base station 102 configured for 5G / NR (collectively referred to as Next Generation RAN (NG-RAN)) can interface with core network 190 via backhaul link 184. Among other functions, base station 102 can also perform one or more of the following functions: transmission of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and device tracking, RAN information management (RIM), paging, location, and delivery of warning messages. Base stations 102 can communicate with each other directly or indirectly (e.g., via EPC 160 or core network 190) via backhaul link 134 (e.g., X2 interface). Backhaul link 134 can be wired or wireless.

[0037] Base station 102 can wirelessly communicate with UE 104. Each base station 102 can provide communication coverage for a corresponding geographic coverage area 110. There can be overlapping geographic coverage areas 110. For example, a small cell 102' can have a coverage area 110' that overlaps with the coverage areas 110 of one or more macro base stations 102. A network that includes both small cells and macro cells can be referred to as a heterogeneous network. The heterogeneous network can also include evolved home node B (eNB) (HeNB), which can provide services to a restricted group called a closed subscriber group (CSG). The communication link 120 between base station 102 and UE 104 can include uplink (UL) (also known as reverse link) transmission from UE 104 to base station 102 and / or downlink (DL) (also known as forward link) transmission from base station 102 to UE 104. The communication link 120 can use multiple-input multiple-output (MIMO) antenna technologies, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link can carry one or more carriers. Base station 102 / UE 104 can use spectrum allocated in carrier aggregation of up to Y x MHz (x component carriers) for transmission in each direction, with a bandwidth of up to Y MHz per carrier (e.g., 5, 10, 15, 20, 100, 400, etc.). Carriers may be adjacent to each other or not. Carrier allocation may be asymmetric relative to DL and UL (e.g., more or fewer carriers may be allocated to DL than to UL). Component carriers may include primary component carriers and one or more secondary component carriers. The primary component carrier may be referred to as the primary cell (PCell), and the secondary component carriers may be referred to as secondary cells (SCells).

[0038] Some UEs 104 can communicate with each other using device-to-device (D2D) communication link 158. D2D communication link 158 can use DL / UL WWAN spectrum. D2D communication link 158 can use one or more sidelink channels, such as the Physical Sidelink Broadcast Channel (PSBCH), Physical Sidelink Discovery Channel (PSDCH), Physical Sidelink Shared Channel (PSSCH), and Physical Sidelink Control Channel (PSCCH). D2D communication can be conducted through various wireless D2D communication systems, such as, for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

[0039] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 in an unlicensed 5 GHz spectrum via a communication link 154. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a free channel assessment (CCA) to determine whether the channel is available before communication begins.

[0040] Small cell 102' can operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, small cell 102' can employ NR and use the same 5 GHz unlicensed spectrum as used by Wi-Fi AP 150. Small cell 102' employing NR in unlicensed spectrum can improve access network coverage and / or increase access network capacity.

[0041] Base station 102, whether a small cell 102' or a large cell (e.g., a macro base station), may include an eNB, a g-node B (gNB), an integrated access and backhaul (IAB) provider, an IAB-node, or another type of base station. Some base stations (e.g., gNB 180) may communicate with UE 104 in the conventional sub-6 GHz spectrum at millimeter wave (mmW) frequencies and / or near-mmW frequencies. When gNB 180 operates at mmW or near-mmW frequencies, gNB 180 may be referred to as an mmW base station. Extremely high frequency (EHF) is a portion of the RF spectrum in the electromagnetic spectrum. The EHF range is from 30 GHz to 300 GHz, with wavelengths ranging from 1 mm to 10 mm. Radio waves in this band may be referred to as millimeter waves. Near-mmW can extend down to frequencies of 3 GHz with wavelengths of 100 mm. The ultra-high frequency (SHF) band extends between 3 GHz and 30 GHz and is also known as centimeter waves. Communication using mmW / near mmW radio frequency bands (e.g., 3 GHz - 300 GHz) has extremely high path loss and short range. mmW base station 180 can utilize beamforming 182 with UE 104 to compensate for the extremely high path loss and short range.

[0042] The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc., based on frequency / wavelength. In 5G / NR, the two initial operating bands have been designated as frequency range names FR1 (410MHz-7.125GHz) and FR2 (24.25GHz-52.6GHz). It should be understood that although a portion of FR1 is greater than 6GHz, FR1 is generally (interchangeably) referred to as the "Sub-6GHz" band in various documents and articles. Similar naming issues sometimes arise regarding FR2; although different from the Extremely High Frequency (EHF) band (30GHz-300GHz) designated as the "millimeter wave" band by the International Telecommunication Union (ITU), FR2 is generally (interchangeably) referred to as the "millimeter wave" band in various documents and articles.

[0043] Frequencies between FR1 and FR2 are generally referred to as intermediate frequency (IF) bands. Recent 5G / NR research has designated the operating bands of these IF bands as the frequency range name FR3 (7.125 GHz – 24.25 GHz). Bands falling within FR3 can inherit FR1 and / or FR2 characteristics, and thus can effectively extend the characteristics of FR1 and / or FR2 to IF band frequencies. Furthermore, higher frequency bands are currently being explored to extend 5G / NR operation above 52.6 GHz. For example, three higher operating frequency bands have been designated as the frequency range names FR4a or FR4-1 (52.6 GHz – 71 GHz), FR4 (52.6 GHz – 114.25 GHz), and FR5 (114.25 GHz – 300 GHz). Each of these higher frequency bands falls within the EHF band.

[0044] In light of the foregoing, unless otherwise specifically stated, it should be understood that when the term "sub-6GHz" is used herein, it can broadly refer to frequencies that are less than 6GHz, within FR1, or may include intermediate frequency band frequencies. Furthermore, unless otherwise specifically stated, it should be understood that when the term "millimeter wave" is used herein, it can broadly refer to frequencies that may include intermediate frequency band frequencies, within FR2, FR4, FR4-a or FR4-1 and / or FR5, or within the EHF band.

[0045] Base station 180 may transmit beamformed signals to UE 104 in one or more transmit directions 182'. UE 104 may receive beamformed signals from base station 180 in one or more receive directions 182'. UE 104 may also transmit beamformed signals to base station 180 in one or more transmit directions. Base station 180 may receive beamformed signals from UE 104 in one or more receive directions. Base station 180 / UE 104 may perform beam training to determine the optimal receive and transmit directions for each of base station 180 / UE 104. The transmit and receive directions of base station 180 may be the same or different. The transmit and receive directions of UE 104 may be the same or different.

[0046] EPC 160 may include Mobility Management Entity (MME) 162, other MMEs 164, Serving Gateway 166, Multimedia Broadcast Multicast Service (MBMS) Gateway 168, Broadcast Multicast Service Center (BM-SC) 170, and Packet Data Network (PDN) Gateway 172. MME 162 can communicate with Home Subscriber Server (HSS) 174. MME 162 is the control node controlling signaling between UE 104 and EPC 160. Typically, MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through Serving Gateway 166, which is itself connected to PDN Gateway 172. PDN Gateway 172 provides UE IP address allocation and other functions. PDN Gateway 172 and BM-SC 170 are connected to IP Service 176. IP Service 176 may include the Internet, intranet, IP Multimedia Subsystem (IMS), PS streaming service, and / or other IP services. The BM-SC 170 can provide functions for MBMS user service provisioning and delivery. The BM-SC 170 can serve as an entry point for content provider MBMS transmissions, authorize and initiate MBMS bearer services within a Public Land Mobile Network (PLMN), and schedule MBMS transmissions. The MBMS gateway 168 can allocate MBMS services to base station 102 belonging to a Multicast-Broadcast Single Frequency Network (MBSFN) area belonging to a broadcast-specific service, and can be responsible for session management (start / stop) and collecting billing information related to eMBMS.

[0047] Core network 190 may include Access and Mobility Management Functions (AMF) 192, other AMFs 193, Session Management Functions (SMF) 194, and User Plane Functions (UDP) 195. AMF 192 can communicate with Unified Data Management (UDM) 196. AMF 192 is the control node that handles signaling between UE 104 and core network 190. Typically, AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transmitted via UPF 195. UPF 195 provides UE IP address allocation and other functions. UPF 195 connects to IP service 197. IP service 197 may include the Internet, intranet, IP Multimedia Subsystem (IMS), PS streaming service, and / or other IP services.

[0048] A base station may also be referred to as a gNB, IAB-Provider, IAB-Node, Node B, NB, Evolved Node B (eNB), Access Point, Base Transceiver Station, Radio Base Station, Radio Transceiver, Transceiver Functionality, Basic Services Set (BSS), Extended Services Set (ESS), Transmitter Receiver Point (TRP), or any other suitable term. Base station 102 provides UE 104 with access to EPC 160 or core network 190. Examples of UE 104 include cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, GPS devices, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, tablets, smart devices, wearable devices, vehicles, meters, air pumps, large or small kitchen appliances, healthcare devices, implants, sensors / brakes, displays, or any other similar functional devices. Some UE 104 devices may be referred to as IoT devices (e.g., parking timers, air pumps, toasters, vehicles, heart monitors, etc.). UE 104 may also be referred to as a station, mobile station, subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, mobile phone, user agent, mobile client, client, or any other suitable term.

[0049] Refer again Figure 1 In some respects, base station 180 may be an IAB node 180 including a mobile terminal unit (MT) and a distributed unit (DU), and / or base station 102 may be an IAB-provider 102 including a central unit (CU) and a distributed unit (DU). Thus, the IAB-node DU may include a Physical Cell Identifier (PCI) conversion manager 198, and the IAB-provider DU may include a PCI conversion manager 199. The PCI conversion managers 198 / 199 are configured to optimize the transmission beam to facilitate soft PCI changes. For example, the PCI conversion managers 198 / 199 are configured to transmit a first signal based on a first PCI during a first synchronization signal block (SSB) opportunity, transmit a second signal based on the first PCI during a second SSB opportunity, and transmit a third signal based on the first PCI during a third SSB opportunity, wherein the first, second, and third SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame, and a transition from the first PCI to the second PCI.

[0050] Figure 2 (a) in the figure is a schematic diagram 200 illustrating an example of the first subframe in the 5G / NR frame structure. Figure 2(b) is a schematic diagram 230 illustrating an example of a DL channel within a 5G / NR subframe. Figure 2 (c) in the figure is a schematic diagram 250 illustrating an example of the second subframe in the 5G / NR frame structure. Figure 2 (d) in the diagram is a schematic diagram 280 illustrating an example of a UL channel within a 5G / NR subframe. The aspects of this disclosure relating to beam optimization and / or changing the Physical Cell Identifier (PCI) can be used with reference to... Figure 2 Signaling is implemented using the 5G / NR frame structures described in (a), 2B, 2C, and 2D. The 5G / NR frame structure can be FDD type, where, for a specific set of subcarriers (carrier system bandwidth), subframes within that set are dedicated to either DL or UL; or the 5G / NR frame structure can be TDD type, where, for a specific set of subcarriers (carrier system bandwidth), subframes within that set are dedicated to both DL and UL. Figure 2 In the examples provided in (a) and 2C, the 5G / NR frame structure is assumed to be TDD type, where subframe 4 is configured with slot format 28 (primarily DL), where D is DL, U is UL, and X is flexible for use between DL / UL, and subframe 3 is configured with slot format 34 (primarily UL). Although subframes 3 and 4 are shown with slot formats 34 and 28 respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are full DL and full UL, respectively. Other slot formats 2-61 include a mixture of DL symbols, UL symbols, and flexible symbols. The slot format is configured for the UE via the received Slot Format Indicator (SFI) (dynamically via DL Control Information (DCI) or semi-statically / statically via Radio Resource Control (RRC) signaling. Note that the following description also applies to TDD 5G / NR frame structures.

[0051] Other wireless communication technologies may have different frame structures and / or different channels. A frame (10 ms) can be divided into 10 equal-sized subframes (1 ms). Each subframe may include one or more time slots. Subframes may also include mini-time slots, which may include 7, 4, or 2 symbols. Depending on the time slot configuration, each time slot may include 7 or 14 symbols. For time slot configuration 0, each time slot may include 14 symbols, and for time slot configuration 1, each time slot may include 7 symbols. Symbols on the DL can be Cyclic Prefix (CP) OFDM (CP-OFDM) symbols. Symbols on the UL can be CP-OFDM symbols (for high-throughput scenarios) or Discrete Fourier Transform (DFT) Extended OFDM (DFT-s-OFDM) symbols (also known as Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols) (for power-constrained scenarios; limited to single-stream transmission). The number of time slots within a subframe is based on the time slot configuration and the numbering scheme. For slot configuration 0, different digital schemes μ0 to 4 allow 1, 2, 4, 8, 16, and 32 slots per subframe, respectively. For slot configuration 1, different digital schemes 0 to 2 allow 2, 4, and 8 slots per subframe, respectively. Therefore, for slot configuration 0 and digital scheme μ, each slot has 14 symbols, and each subframe has 2 μ The number of time slots. Subcarrier spacing and symbol length / duration are functions of the digital scheme. Subcarrier spacing can be equal to 2. μ *15kHz, where μ represents digital schemes 0 through 5. Therefore, digital scheme μ = 0 has a subcarrier spacing of 15kHz, and digital scheme μ = 5 has a subcarrier spacing of 480kHz. The symbol length / duration is inversely proportional to the subcarrier spacing. Figure 2 (a) to Figure 2 Example (d) in the diagram provides examples of slot configuration 0 and digital scheme μ=0. In slot configuration 0, each slot has 14 symbols, and in digital scheme μ=0, each subframe has 1 slot. The subcarrier spacing is 15 kHz, and the symbol duration is approximately 66.67 μs.

[0052] A resource grid can be used to represent the frame structure. Each time slot includes a resource block (RB) (also known as a physical RB (PRB)) extending for 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0053] like Figure 2 As shown in (a), some REs carry reference (pilot) signals (RS) for the UE. The RS may include demodulated RS (DM-RS) for channel estimation at the UE (although indicated as an RS for a specific configuration). x(Where 100x is the port number, but other DM-RS configurations are also possible) and Channel State Information Reference Signal (CSI-RS). RS can also include Beam Measurement RS (BRS), Beam Refinement RS (BRRS), and Phase Tracking RS (PT-RS).

[0054] Figure 2 (b) shows examples of various DL channels within a subframe of a frame. The Physical Downlink Control Channel (PDCCH) carries the DCI in one or more Control Channel Elements (CCEs), each CCE comprising nine RE Groups (REGs), each REG comprising four consecutive REs in an OFDM symbol. The Primary Synchronization Signal (PSS) may be located within symbol 2 of a specific subframe of the frame. UE104 uses the PSS to determine subframe timing / symbol timing and physical layer identity. The Secondary Synchronization Signal (SSS) may be located within symbol 4 of a specific subframe of the frame. The UE uses the SSS to determine the Physical Layer Cell Identifier Group Number and radio frame timing. Based on the Physical Layer Identifier and Physical Layer Cell Identifier Group Number, the UE can determine the Physical Cell Identifier (PCI). Based on the PCI, the UE can determine the location of the aforementioned DM-RS. The Physical Broadcast Channel (PBCH) carrying the Primary Information Block (MIB) can be logically grouped with the PSS and SSS to form a Synchronization Signal (SS) / PBCH block. The MIB provides the number of RBs in the system bandwidth and the System Frame Number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information (such as System Information Blocks (SIBs)) not transmitted via the PBCH, and paging messages.

[0055] like Figure 2 As shown in (c), some REs carry DM-RS for channel estimation at the base station (although indicated as Rs for a specific configuration, other DM-RS configurations are possible). The UE can transmit DM-RS for the Physical Uplink Control Channel (PUCCH) and DM-RS for the Physical Uplink Shared Channel (PUSCH). The PUSCH DM-RS can be transmitted in the first one or two symbols preceding the PUSCH. Depending on whether a short or long PUCCH is transmitted and depending on the specific PUCCH format used, the PUCCH DM-RS can be transmitted in different configurations. As shown, the UE can transmit a Sounding Reference Signal (SRS). The SRS can be used by the base station for channel quality estimation to implement frequency-dependent scheduling on the UL.

[0056] Figure 2(d) shows an example of the individual UL channels within a subframe of a frame. The PUCCH can be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and HARQ ACK / NACK feedback. The PUCCH carries data and can also be used to carry buffer status reports (BSR), power clearance reports (PHR), and / or UCI.

[0057] Figure 3 This is a block diagram illustrating communication between base station 310 and UE 350 in the access network. In the DL, IP packets from EPC 160 can be provided to controller / processor 375. Controller / processor 375 implements Layer 3 and Layer 2 functions. Layer 3 includes the Radio Resource Control (RRC) layer, and Layer 2 includes the Service Data Adaptation Protocol (SDAP) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Media Access Control (MAC) layer. The controller / processor 375 provides RRC layer functions associated with broadcast system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-Radio Access Technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with upper-layer packet data unit (PDU) transmission, error correction via ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, reporting of scheduling information, error correction via HARQ, priority processing, and logical channel priority allocation.

[0058] Transmit (TX) processor 316 and receive (RX) processor 370 implement Layer 1 functions associated with various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) encoding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. TX processor 316 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), and M-quadrature amplitude modulation (M-QAM)). The encoded and modulated symbols can then be divided into parallel streams. Each stream can then be mapped to OFDM subcarriers, multiplexed with a reference signal (e.g., a pilot) in the time and / or frequency domains, and then combined using inverse fast Fourier transform (IFFT) to produce a physical channel carrying a stream of time-domain OFDM symbols. The OFDM streams are spatially precoded to produce multiple spatial streams. The channel estimate from channel estimator 374 can be used to determine coding and modulation schemes, as well as for spatial processing. The channel estimate can be derived from the reference signal and / or channel condition feedback transmitted by UE 350. Each spatial stream can then be provided to different antennas 320 via separate transmitters 318TX. Each transmitter 318TX can modulate an RF carrier with the corresponding spatial stream for transmission.

[0059] At UE 350, each receiver 354RX receives signals through its respective antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides this information to the receive (RX) processor 356. The TX processor 368 and RX processor 356 implement Layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial stream destined for UE 350. If multiple spatial streams are destined for UE 350, they can be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then uses a Fast Fourier Transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal consists of a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols and reference signals on each subcarrier are recovered and demodulated by determining the most probable signal constellation point transmitted by base station 310. These soft decisions can be based on channel estimates calculated by channel estimator 358. The soft decision is then decoded and deinterleaved to recover the data and control signals originally transmitted by base station 310 on the physical channel. The data and control signals are then provided to controller / processor 359, which implements layer 3 and layer 2 functions.

[0060] The controller / processor 359 may be associated with a memory 360 that stores program code and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller / processor 359 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between transport and logical channels to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operation.

[0061] Similar to the functions described in conjunction with DL transmissions performed by base station 310, controller / processor 359 provides RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with upper-layer PDU transmission, error correction via ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs to TBs, demultiplexing of MAC SDUs from TBs, reporting of scheduling information, error correction via HARQ, priority processing, and logical channel priority allocation.

[0062] The channel estimate derived by channel estimator 358 from the reference signal transmitted by base station 310 or feedback can be used by TX processor 368 to select appropriate coding and modulation schemes and to facilitate spatial processing. The spatial stream generated by TX processor 368 can be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX can use the corresponding spatial stream to modulate an RF carrier for transmission.

[0063] UL transmissions are processed at base station 310 in a manner similar to that described in conjunction with the receiver function at UE 350. Each receiver 318RX receives signals via its corresponding antenna 320. Each receiver 318RX recovers the information modulated onto the RF carrier and provides that information to RX processor 370.

[0064] The controller / processor 375 may be associated with a memory 376 that stores program code and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller / processor 375 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between transport and logical channels to recover IP packets from the UE 350. IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operation.

[0065] At least one of the TX processor 316, RX processor 370, and controller / processor 375 can be configured to perform operations related to... Figure 1 This relates to aspects of the PCI conversion manager 198 and / or PCI conversion manager 199. For example, if base station 310 is an IAB-node, then base station 310 may include PCI conversion manager 398. If base station 310 is an IAB-provider, then base station 310 may include PCI conversion manager 399. PCI conversion managers 398 / 399 are configured to optimize the transmission beam to facilitate soft PCI changes (e.g., by transmitting a first signal based on a first PCI during a first synchronization signal block (SSB) opportunity, transmitting a second signal based on the first PCI during a second SSB opportunity, and transmitting a third signal based on the first PCI during a third SSB opportunity, wherein the first, second, and third SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame, and a transition from the first PCI to the second PCI).

[0066] Figure 4 An example of an Integrated Access and Backhaul (IAB) system 400 is shown. 5G NR technologies (such as mmWave technology) can be used to support the IAB system 400. The IAB system 400 may include one or more anchor nodes 402, one or more access / relay nodes 404, and one or more UEs 406.

[0067] In one aspect, anchor node (also known as IAB-provider) 402 can be an access node with a wired connection to the network. Relay node (also known as IAB-node) 404 can be an access node relaying services to and from anchor node 402 via single-hop or multi-hop connections. Access / relay node 404 can be connected to UE 406 via an access link. The network of the access link between access / relay node 404 and UE 406 can be called an access network. Access / relay nodes 404 can be connected to each other via backhaul links. The network of backhaul links between access / relay nodes can be called a backhaul network.

[0068] In IAB system 400, access links (between access / relay nodes 404 and UE 406) and backhaul links (between access / relay nodes 404) can share the same transmission resources used for uplink and / or downlink communication. In one respect, the access network framework can be reused to optimize communication operations within the IAB system.

[0069] Figure 5 An example network topology 500 of an IAB system according to various aspects of this disclosure is illustrated. As shown, the example network topology 500 may include a core network 510, an IAB provider 502, an IAB node 504, and a UE 506. Topology 500 may also include a radio backhaul link 512 between IAB provider 502 and IAB node 504, or between IAB node 502 and a sub-IAB node 503. Topology 500 may also include a radio access link 514 between IAB provider 502 and UE 506, or between IAB node 504 and UE 506.

[0070] In one aspect, IAB-Provider 502 is an enhanced network node (gNB) with functions for controlling the IAB network. IAB-Provider 502 may include a Central Unit (CU) and a Distributed Unit (DU). The CU is a central entity that controls the entire IAB network and maintains RRC / PDCP layer functions. The DU is a scheduling node that schedules child nodes associated with IAB-Provider 502. The DU maintains RLC / MAC / PHY layer functions. IAB-Node 504 is an L2 relay node that may include Mobile Terminal (MT) functions and DU functions. The MT unit is a scheduled node similar to a UE scheduled by its corresponding parent IAB-Node 504 or IAB-Provider 502. The DU in IAB-Node 504 is a scheduling node that schedules child nodes associated with IAB-Provider 502.

[0071] This disclosure relates to various aspects of the Physical Cell Identifier (PCI) in 5G NR. The PCI is the ID of a cell, and a total of 1008 ID values ​​can be supported in a 5G NR system. Notably, the PCI can be reused by multiple geographically separated cells in the network. Cells using the same PCI can be distinguished by their unique Cell Global Identifier (NCGI). The PCI can be carried by the Primary Synchronization Signal (PSS) / Secondary Synchronization Signal (SSS) in the Synchronization Signal Block (SSB).

[0072] In one respect, PCI can be used to determine the scrambling sequence of physical signals / channels. For example, for PBCH, PDCCH CoreSet0, or cell-specific PDSCH transmissions, PCI can be used as a scrambling seed. For other channels, configured scrambling seeds other than PCI can be supported.

[0073] Figure 6 Figure 600 illustrates a Physical Cell Identifier (PCI) conflict. Figure 6 In this configuration, the first neighboring cell 602 and the second neighboring cell 604 use the same PCI to scramble the reference signal sent to the UE 606. A PCI collision occurs when the UE 606 cannot distinguish between the reference signal sent from the first neighboring cell 602 and the reference signal sent from the second neighboring cell 604, since both types of reference information are scrambled using the same PCI. PCI collisions can lead to problems with timing synchronization and channel estimation, and result in the inability to decode data services sent from the first neighboring cell 602 and / or the second neighboring cell 604.

[0074] Figure 7 Figure 700 illustrates period 702 (SSB-periodicityServingCell) of the Synchronization Signal Block (SSB) within the serving cell. As shown, frame 704 may include a first half-frame and a second half-frame. A set of SSB opportunities (e.g., 4 SSBs) may be provided within a single half-frame (e.g., the second half-frame). For example, in the second half-frame 706, a first SSB with a first SSB index (SSB index 1), a second SSB with a second SSB index (SSB index 2), a third SSB with a third SSB index (SSB index 3), and a fourth SSB with a fourth SSB index (SSB index 4) are provided. Figure 7 The diagram further illustrates the transmission directions of the beam associated with the first SSB index (SSB index 1) and the beam associated with the third SSB index (SSB index 3). In one aspect, frame 704 is a periodically repeating time frame. Thus, this set of SSB opportunities can be provided periodically according to period 702 (e.g., in the second half-frame 708 that appears later). Furthermore, the beam associated with the SSB index can be transmitted periodically based on period 702.

[0075] In one aspect, the UE can identify the SSB index corresponding to the beam with the strongest signal strength. Furthermore, the SSB transmission mode can be indicated in ssb-PositionsInBurst (e.g., as part of an SIB1 message or RRC-specific signaling).

[0076] Figure 8Figure 800 illustrates the movement of network nodes. In one aspect, some network nodes, such as IAB-node 802, can move around within the network. For example, such mobile network nodes can be installed on buses, trains, or taxis. The network can include a mixture of fixed and mobile nodes. Mobile IAB-nodes can be leaf nodes or have child IAB-nodes.

[0077] In one aspect, IAB-node 802 may be a fixed node at the boundary between the first gNB 804 and the second gNB 806, wherein the MT unit (IAB-MT) within IAB-node 804 may perform a handover due to low link quality. In another aspect, IAB-node 802 may be a mobile node moving from the area of ​​the first gNB 804 to the area of ​​the second gNB 806. In either case, migration from the first gNB 804 to the second gNB 806 may involve a PCI change to avoid PCI conflicts. Therefore, aspects of this disclosure provide and implement techniques for reconfiguring a new PCI to avoid PCI conflicts when a network node migrates from one control node to another. For example, IAB-node 802 may include PCI conversion managers 198 / 398 configured to optimize the transmission beam to facilitate soft PCI changes (e.g., by transmitting a first signal based on a first PCI during a first Synchronization Signal Block (SSB) opportunity, a second signal based on the first PCI during a second SSB opportunity, and a third signal based on the first PCI during a third SSB opportunity, wherein the first, second, and third SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame, and a transition from the first PCI to the second PCI). In another example, control nodes such as the first gNB 804 (IAB-Provider DU) and / or gNB 806 (IAB-Provider DU) may include PCI conversion managers 199 / 399 to facilitate soft PCI changes as described herein.

[0078] Figure 9An example of three phases associated with a soft PCI change at a network node is shown. For example, the network node could be a gNB, gNB DU, IAB-supply-side DU, or IAB-node DU. During the first phase 902, before the soft PCI change begins, network node 950 can serve the current cell C1 (old cell) based on the current PCI (old PCI). For example, network node 950 can periodically transmit (broadcast) the current PCI on SSB indices 1, 2, and 3 within time frames (e.g., half-frames). As shown during the first phase 902, beams corresponding to the current PCI (PCI 1) can be periodically transmitted (broadcast) on SSB indices 1 (SSB1), 2 (SSB2), and 3 (SSB3).

[0079] During Phase 2, 904, during the soft PCI change, Network Node 950 can serve the current cell C1 (old cell) based on the current PCI (old PCI) and the new cell C2 based on the new PCI. For example, Network Node 950 can periodically transmit (broadcast) the current PCI on SSB indices 1 and 3 within a time frame. As shown during Phase 2, 904, the beam corresponding to the current PCI (PC1) can be periodically transmitted (broadcast) on SSB indices 1 (SSB1) and 3 (SSB3). Furthermore, Network Node 950 can periodically transmit (broadcast) the new PCI on SSB indices 2 and 4 within a time frame. As shown during Phase 2, 904, the beam corresponding to the new PCI (PC2) can be periodically transmitted (broadcast) on SSB indices 2 (SSB2) and 4 (SSB4).

[0080] During Phase 3, 906, after the soft PCI change is completed, network node 950 can serve the new cell C2 based on the new PCI. For example, network node 950 can periodically transmit (broadcast) the new PCI on SSB indices 1, 2, and 4 within a time frame. As shown during Phase 3, 906, the beam corresponding to the new PCI (PCI2) can be periodically transmitted (broadcast) on SSB indices 1 (SSB1), 2 (SSB2), and 4 (SSB4).

[0081] Figure 10 and 11 An example of optimizing the transmission beam across stages associated with soft PCI changes at network nodes is shown. For example, the network node could be a gNB, gNB DU, IAB-supply-side DU, or IAB-node DU. (See reference...) Figure 10During the first phase 1000 of the soft PCI change, network nodes can periodically transmit a first beam 1002 associated with a first SSB index (SSB1) and a first PCI (PCI a) within a time frame. A first child node (Child 1) 1022 and a second child node (Child 2) 1024 can be served on the first beam 1002 associated with SSB1 and PCI a. Furthermore, network nodes can periodically transmit a second beam 1004 associated with a second SSB index (SSB2) and the first PCI (PCI a) within a time frame. Network nodes can also periodically transmit a third beam 1006 associated with a third SSB index (SSB3) and the first PCI (PCI a) within a time frame. A third child node (Child 3) 1026 can be served on the third beam 1006 associated with SSB3 and PCI a.

[0082] Still refer to Figure 10 During the second phase 1020 of the soft PCI change, the network node can continue to periodically transmit the first beam 1002 associated with the first SSB index (SSB1) and the first PCI (PCI a) and periodically transmit the third beam 1006 associated with the third SSB index and the first PCI (PCIa) within the time frame. Furthermore, the network node can stop transmitting the second beam 1004 associated with the second SSB index (SSB2) and the first PCI (PCIa), for example, because no child node is served by such a beam. Thus, the network node can then periodically transmit the fourth beam 1008 associated with the second SSB index (SSB2) and the second PCI (PCIb) and periodically transmit the fifth beam 1010 associated with the fourth SSB index (SSB4) and the second PCI (PCIb) within the time frame. In one aspect, the first beam 1002 may be quasi-co-located (QCL) with the fourth beam 1008, and the third beam 1006 may be quasi-co-located (QCL) with the fifth beam 1010. In another aspect, the first beam 1002 is transmitted in the same direction as the fourth beam 1008, and the third beam 1006 is transmitted in the same direction as the fifth beam 1010.

[0083] Now refer to Figure 11 During the third phase 1040 of the soft PCI change, network nodes can serve the first child node (Child 1) 1022 and the second child node (Child 2) 1024 on the fourth beam 1008 associated with SSB2 and the second PCI (PCI b) (instead of as Figure 10The first beam 1002 is shown, associated with SSB1 and the first PCI (PCIa). Furthermore, network nodes can be associated with the fifth beam 1010, associated with SSB4 and the second PCI (PCI b) (instead of the previously shown beam 1002). Figure 10 The third child node (Child 3) 1026 shown is served on the third beam 1006 associated with SSB3 and the first PCI (PCI a).

[0084] Still refer to Figure 11 During the fourth phase 1060 of the soft PCI change, the network node can continue to periodically transmit the fourth beam 1008 associated with the second SSB index (SSB2) and the second PCI (PCIb) within the time frame, and periodically transmit the fifth beam 1010 associated with the fourth SSB index (SSB4) and the second PCI (PCIb). ​​Furthermore, the network node can stop transmitting the first beam 1002 associated with the first SSB index (SSB1) and the first PCI (PCIa), and stop transmitting the third beam 1006 associated with the third SSB index (SSB3) and the first PCI (PCIa), for example, because no child node is served by such a beam. Thus, the network node can then periodically transmit the sixth beam 1012 associated with the first SSB index (SSB1) and the second PCI (PCIb) within the time frame.

[0085] Various aspects of this disclosure relate to network nodes (e.g., gNB, gNB-DU, IAB-Supply-Side DU, or IAB-Node DU) that perform soft PCI changes from a first PCI to a second PCI. In one aspect, prior to the transition from the first PCI to the second PCI (a transition phase or period), the network node may periodically broadcast (transmit) the first PCI on a set of SSB opportunities, including a first SSB opportunity and a second SSB opportunity, within a half-frame. During the transition phase, the network node may periodically broadcast the second PCI on the first SSB opportunity and continue periodically broadcasting the first PCI on the second SSB opportunity within a half-frame. After the transition phase ends, the network node may stop broadcasting the first PCI on the second SSB opportunity and continue periodically broadcasting the second PCI on the first SSB opportunity within a half-frame.

[0086] On the other hand, after the transition phase ends, network nodes may periodically transmit a second PCI on a second SSB opportunity within a half-frame. Furthermore, during and / or after the transition phase ends, network nodes may also periodically transmit a second PCI on a third SSB opportunity within a set of SSB opportunities within a half-frame, wherein the first PCI was not initially broadcast prior to the transition phase.

[0087] In one aspect, when the first PCI is transmitted before the transition phase, the network node may use the first beam at the first SSB opportunity and the second beam at the second SSB opportunity. The first and second beams may be transmitted in the same direction.

[0088] In one aspect, a network node may select a first SSB opportunity to broadcast a second PCI during the transition based on one or more conditions being met. For example, the conditions may include: 1) the network node does not serve child nodes (e.g., IAB-node MT or UE) on the first beam but serves one or more child nodes on the second beam; 2) the network node serves a number of child nodes on the first beam less than the number of child nodes served on the second beam; 3) the network node delivers less total throughput to the child nodes served on the first beam than to the child nodes served on the second beam, where the throughput may be directional; 4) the network node provides the child nodes served on the first beam with lower Quality of Service (QoS) requirements compared to the service provided to the child nodes served on the second beam. 5) The network node serves a child node on the first beam with a lower link quality compared to the link quality of the child node served on the second beam; 6) The communication between the network node and the child node served on the first beam causes more interference than the communication between the network node and the child node served on the second beam; and 7) The communication between the network node and the child node served on the first beam causes more interference to the communication of another cell (e.g., gNB, gNB-DU, IAB-Provider DU, or IAB-Node DU) served by the second network node than the communication between the network node and the child node served on the second beam.

[0089] In one aspect, network nodes may choose a first SSB opportunity to broadcast a second PCI during the transition phase, such that it does not induce an SIB1 update associated with the first PCI. For example, the compressed bitmap in SIB1 remains unaffected.

[0090] In one aspect, a network node may receive a configuration from a control node (e.g., gNB-CU) based on which it selects a first SSB opportunity to broadcast a second PCI during the transition phase. This configuration may include: 1) an index of the first SSB opportunity; 2) an indication of the SSB area associated with the first SSB opportunity or the first beam broadcast on the first SSB opportunity; 3) a threshold for the number of child nodes served, wherein the number of child nodes served by the first beam is less than or equal to the threshold, and wherein the threshold may be zero; 4) a threshold for the total throughput delivered to the served child nodes, wherein the total throughput delivered to the child nodes served by the first beam is less than the threshold, and wherein the threshold may be directional; 5) a condition associated with a QoS requirement, wherein the service provided to the child nodes served on the first beam satisfies the condition (e.g., QoS requirement: RLCCH QoS category); and 6) channel quality information, wherein the network node serves the child nodes on the first beam with a link quality lower than that carried by the configuration. The control node (e.g., gNB-CU) can forward the configuration of the second network node (e.g., second gNB, gNB-DU, IAB-Provider DU, or IAB-Node DU) to the network node.

[0091] In one respect, a network node can initiate a soft PCI change based on an instruction from the control node or by detecting a first PCI sent by a different network node. The network node can also indicate the initiation of a soft PCI change to the control node.

[0092] In one respect, a network node can be a distributed unit (DU) of an IAB-node. Furthermore, soft PCI changes can be triggered by handover commands / cell group changes from co-located mobile terminal (MT) units of an IAB-node.

[0093] In one aspect, the network node can perform a soft PCI change along with the migration of a child node (e.g., an IAB-node MT or UE) from a first PCI to a second PCI. Thus, the child node can serve on the second beam, and the network node periodically transmits the second PCI on the first SSB opportunity using a beam with quasi-co-addressable (QCL) to the second beam. Alternatively, the child node can serve on the first beam, and the gNB-DU periodically transmits the second PCI on the first SSB opportunity using a beam with quasi-co-addressable (QCL) to the first beam.

[0094] In one aspect, a soft PCI change may include multiple transition phases. For example, prior to the first transition phase, a network node may send a first PCI at a first SSB opportunity, a second SSB opportunity, and a third SSB opportunity. During the first transition phase, a network node may send a second PCI at the first SSB opportunity, and a first PCI at the second and third SSB opportunities. During the second transition phase, a network node may send a second PCI at the first and second SSB opportunities, and a first PCI at the third SSB opportunity. At the end of the second transition phase, a network node may send a second PCI at the first and second SSB opportunities, and cease sending a first PCI at the third SSB opportunity. In another aspect, at the end of the second transition phase, a network node may also send a second PCI at the third SSB opportunity (where the first PCI is no longer sent).

[0095] In one aspect, in the case of multiple transitions, a network node can select a first SSB opportunity and a second SSB opportunity based on one or more conditions or by receiving a configuration as described above. For example, the selection can be based on a configuration received from a control node (e.g., gNB-CU) that provides an index of the first SSB opportunity and an index of the second SSB opportunity. In another example, the selection can be based on the network node switching PCI on the first SSB opportunity, wherein no child node is served on the first beam associated with the first SSB opportunity. In another example, the selection can be based on a child node serving on the second beam associated with the second SSB opportunity migrating to the second PCI, wherein the child node is served on a beam quasi-co-located (QCL) with the second beam and periodically broadcast on the first SSB opportunity. In yet another example, the selection can be based on no child node being served on the second beam, and therefore, the network node switches PCI on the second SSB opportunity; and so on.

[0096] In one aspect, network nodes can perform SIB1 updates during the transition phase of a soft PCI change. Network nodes can update the bitmap of the index of the SSB opportunity in which the first PCI is broadcast. Network nodes can update the quasi-co-location (QCL) relationships between the beams associated with the SSB opportunity in which the first PCI is broadcast. Network nodes can send the updated SIB1 message to the control node (e.g., gNB-CU). Network nodes can update SIB1 broadcasts.

[0097] In one aspect, a network node can send an SIB1 message corresponding to the second PCI during the transition phase of a soft PCI change, and send an updated SIB1 message at the end of the soft PCI change. A control node can send the updated SIB1 message during the transition phase of a soft PCI change in a manner specific to connected child nodes or idle child nodes. A network node can avoid sending an SIB1 update during the transition phase of a soft PCI change, wherein a new SIB1 message corresponding to the second PCI is broadcast at the end of the soft PCI change. A network node can send short messages to child nodes or paging messages to idle UEs to indicate updates to system information.

[0098] In one aspect, network nodes can perform SIB1 updates, send short messages, or send paging messages during the transition phase of a soft PCI change, based on configurations from the control node. In another aspect, this configuration can be conditional (e.g., dependent on the length of the transition phase).

[0099] Figure 12 This is a block diagram illustrating an example hardware implementation of an exemplary network node 1200 employing the processing system 1214. For example, the network node 1200 may be a base station, gNB, gNB-DU, IAB-Provider DU, or IAB-Node DU, such as... Figure 1 , 3 As shown in any one or more of -6, 8, and / or 9. Network node 1200 may be implemented using a processing system 1214 including one or more processors 1204. Examples of processors 1204 include microprocessors, microcontrollers, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuitry, and other suitable hardware configured to perform the various functions described throughout this disclosure. In various examples, network node 1200 may be configured to perform any one or more of the functions described herein. That is, the processor 1204 used in network node 1200 may include PCI translation managers 198 / 398 and / or PCI translation managers 199 / 399, and is used to implement the functions described below and Figure 13 and 14 The processing procedures shown herein and any one or more of the procedures.

[0100] In this example, the processing system 1214 can be implemented using a bus architecture, typically represented by bus 1202. Depending on the specific application and overall design constraints of the processing system 1214, bus 1202 may include any number of interconnect buses and bridges. Bus 1202 communicatively couples together various circuits including one or more processors (typically represented by processor 1204), memory 1205, and computer-readable media (typically represented by computer-readable media 1206). Bus 1202 may also link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and will not be described further. Bus interface 1208 provides an interface between bus 1202 and transceiver 1210. Transceiver 1210 provides a communication interface or unit for communicating with various other devices via a transmission medium. In some examples, transceiver 1210 may include a phase shifter 1216 for digital and / or analog beamforming via one or more antenna arrays 1230. Depending on the nature of the device, a user interface 1212 (e.g., keyboard, display, speaker, microphone, joystick) may also be provided. Of course, such a user interface 1212 is optional and may be omitted in some examples such as base stations.

[0101] In some aspects of this disclosure, processor 1204 (e.g., PCI translation manager 198 / 398 or PCI translation manager 199 / 399) may include a first PCI transmit circuit 1240 configured for various functions, including, for example, transmitting a first signal based on a first physical cell identifier (PCI) during a first synchronization signal block (SSB) opportunity, transmitting a second signal based on the first PCI during a second SSB opportunity, and transmitting a third signal based on the first PCI during a third SSB opportunity, via transceiver 1210 and antenna array 1230 (e.g., using phase shifter 1216), wherein the first, second, and third SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame. For example, the first PCI transmit circuit 1240 may be configured to implement the following regarding Figure 13 (including, for example, boxes 1302 and 1304) and about Figure 14 (e.g., boxes 1402, 1404, and 1406) describe one or more functions. Processor 1204 may also include configuration information receiving circuitry 1242 configured for various functions, including, for example, receiving configuration information from a control node. For example, configuration information receiving circuitry 1242 may be configured to implement the following regarding... Figure 13 (including, for example, box 1306) and about Figure 14(Including, for example, box 1408) one or more functions described. Processor 1204 may also include PCI conversion circuitry 1244 configured for various functions, including, for example, selecting a first SSB opportunity to transmit a first signal based on a second PCI during a conversion period via transceiver 1210 and antenna array 1230 (e.g., using phase shifter 1216), selecting a first SSB opportunity to transmit a first signal based on a second PCI during a first conversion period, and selecting a second SSB opportunity to transmit a second signal based on a second PCI during a second conversion period, and converting from the first PCI to the second PCI. For example, PCI conversion circuitry 1244 may be configured to implement the following regarding... Figure 13 (including, for example, boxes 1308 and 1310) and about Figure 14 (Including, for example, boxes 1410 and 1412) one or more functions described. Processor 1204 may also include a second PCI transmit circuit 1246 configured for various functions, including, for example, switching from a first PCI to a second PCI via transceiver 1210 and antenna array 1230 (e.g., using phase shifter 1216). For example, the second PCI transmit circuit 1246 may be configured to implement the following regarding... Figure 13 (including, for example, box 1310) and about Figure 14 (Including one or more functions described, for example, in box 1412).

[0102] Processor 1204 is responsible for managing bus 1202 and general processing, including executing software stored on computer-readable medium 1206. When the software is executed by processor 1204, the software causes processing system 1214 to perform the various functions described below for any particular device. Computer-readable medium 1206 and memory 1205 can also be used to store data manipulated by processor 1204 during software execution.

[0103] One or more processors 1204 in the processing system can execute software. Software should be interpreted broadly as instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable programs, executing threads, procedures, functions, etc., whether referring to software, firmware, middleware, microcode, hardware description languages, or others. Software may reside on a computer-readable medium 1206. The computer-readable medium 1206 may be a non-transitory computer-readable medium. As examples, non-transitory computer-readable media include magnetic storage devices (e.g., hard disks, floppy disks, magnetic stripes), optical disks (e.g., compressed optical discs (CDs) or digital versatile discs (DVDs)), smart cards, flash memory devices (e.g., cards, sticks, or key drives), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, and any other suitable medium for storing software and / or instructions that can be accessed and read by a computer. The computer-readable medium 1206 may reside in, be outside of, or be distributed across multiple entities including the processing system 1214. The computer-readable medium 1206 may be implemented in a computer program product. As an example, the computer program product may include the computer-readable medium in encapsulation material. Those skilled in the art will recognize how the functionality described throughout this disclosure is best implemented, depending on the specific application and the overall design constraints imposed on the system.

[0104] In one or more examples, the computer-readable storage medium 1206 may include a first PCI transmit instruction 1250 configured for various functions, including, for example, transmitting a first signal based on a first physical cell identifier (PCI) during a first synchronization signal block (SSB) opportunity, transmitting a second signal based on the first PCI during a second SSB opportunity, and transmitting a third signal based on the first PCI during a third SSB opportunity, wherein the first, second, and third SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame. For example, the first PCI transmit instruction 1250 may be configured to implement the following regarding Figure 13 (including, for example, boxes 1302 and 1304) and about Figure 14 (e.g., boxes 1402, 1404, and 1406) describe one or more functions. The computer-readable storage medium 1206 may also include a configuration information receiving instruction 1252 configured for various functions, including, for example, receiving configuration information from a control node. For example, the configuration information receiving instruction 1252 may be configured to implement the following regarding... Figure 13 (including, for example, box 1306) and about Figure 14 (Including, for example, box 1408) one or more functions described. The computer-readable storage medium 1206 may also include PCI translation instructions 1254 configured for various functions, including, for example, selecting a first SSB opportunity to send a first signal based on a second PCI during a translation period, selecting a first SSB opportunity to send a first signal based on a second PCI during a first translation period, and a second SSB opportunity to send a second signal based on a second PCI during a second translation period, and translating from the first PCI to the second PCI. For example, the PCI translation instructions 1254 may be configured to implement the following regarding... Figure 13 (including, for example, boxes 1308 and 1310) and about Figure 14 (Including, for example, boxes 1410 and 1412) one or more functions. The computer-readable storage medium 1206 may also include a second PCI transmission instruction 1256 configured for various functions, including, for example, switching from a first PCI to a second PCI. For example, the second PCI transmission instruction 1256 may be configured to implement the following regarding... Figure 13 (including, for example, box 1310) and about Figure 14 (Including one or more functions described, for example, in box 1412).

[0105] Figure 13 This is a flowchart illustrating an exemplary process 1300 for changing the Physical Cell Identifier (PCI) at a network node according to various aspects of this disclosure. As described below, in certain implementations within the scope of this disclosure, some or all of the illustrated features may be omitted, and for all aspects of the implementation, some illustrated features may not be required. In some examples, process 1300 may be... Figure 12 The network node 1200 shown performs this action. This network node 1200 can be a base station, gNB, gNB-DU, IAB-Provider DU, or IAB-Node DU, such as... Figure 1 , 3 -6, 8, and / or 9 are shown as any one or more. In some examples, process 1300 may be performed by any suitable means or unit for performing the functions or algorithms described below.

[0106] In block 1302, the network node transmits a first signal based on a first physical cell identifier (PCI) during a first synchronization signal block (SSB) opportunity. In block 1304, the network node transmits a second signal based on the first PCI during a second SSB opportunity. The first and second SSB opportunities may be part of a set of SSB opportunities within a periodically repeating time frame (e.g., a half-frame).

[0107] In box 1306, the network node receives configuration information from a control node (e.g., gNB-CU). The configuration information may include an index of a first SSB opportunity, or an indication of an SSB area associated with the first SSB opportunity or a first beam transmitted during the first SSB opportunity. The configuration information may include a threshold for the number of child nodes served, wherein the number of child nodes served by the first beam is less than or equal to the threshold (the child node threshold may be zero). The configuration information may also include a threshold for the total throughput delivered to the served child nodes, wherein the total throughput delivered to the child nodes served by the first beam is less than the threshold (the throughput threshold may be directional). The configuration information may include conditions associated with QoS requirements, wherein the service provided to the child nodes served on the first beam satisfies the condition (e.g., QoS requirement: RLC CH QoS category). The configuration information may also include channel quality information, wherein the network node serves the child nodes on the first beam with a link quality lower than the link quality carried by the configuration information. The network node may also receive second configuration information associated with a second network node from the control node.

[0108] In box 1308, the network node selects a first SSB opportunity to send a first signal based on a second PCI during the transition period. Selection may be based on received configuration information. Furthermore, selection may be based on one or more conditions (triggered by them). Conditions may include: the network node does not serve a child node on the first beam and serves one or more child nodes on the second beam; the network node serves one or more fewer child nodes on the first beam than two or more child nodes on the second beam; the network node delivers a smaller total throughput (which may be directional) to the child nodes served on the first beam than to the child nodes served on the second beam; the network node provides services with lower Quality of Service (QoS) requirements to the child nodes served on the first beam compared to the services provided to the child nodes served on the second beam; the communication between the network node and the child nodes served on the first beam causes more interference than the communication between the network node and the child nodes served on the second beam; and / or the communication between the network node and the child nodes served on the first beam causes more interference to communication in another cell served by the second network node compared to the communication between the network node and the child nodes served on the second beam. In one aspect, the network node performs a selection such that it does not cause an update to the System Information Block Type 1 (SIB1) associated with the first PCI (e.g., the compressed bitmap in SIB1 is unaffected).

[0109] In box 1310, a network node transitions from a first PCI to a second PCI. During the transition period, the network node transmits a first signal based on the second PCI during the first SSB opportunity and continues to transmit a second signal based on the first PCI during the second SSB opportunity. After the transition period ends, the network node continues to transmit the first signal based on the second PCI during the first SSB opportunity and ceases transmitting the second signal based on the first PCI during the second SSB opportunity. The network node may also transmit a second signal based on the second PCI during the second SSB opportunity after the transition period ends. In one aspect, the network node may transmit a third signal based on the second PCI during the transition period and / or during a third SSB opportunity in the set of SSB opportunities (where the first PCI was not initially transmitted before the transition period) after the transition period ends.

[0110] In one aspect, the network node performs a switching operation by transmitting a first signal based on a first PCI during a first SSB opportunity via a first beam, and a second signal based on the first PCI during a second SSB opportunity via a second beam. The first and second beams may be transmitted in the same direction.

[0111] In one aspect, the network node performs a transition by receiving an instruction from a control node (e.g., gNB-CU) for a transition from a first PCI to a second PCI, and determining the transition based on that instruction. In another aspect, the network node performs a transition by instructing the control node to initiate the transition from the first PCI to the second PCI.

[0112] In one aspect, network nodes perform the transition by detecting signals sent by different network nodes based on a first PCI, and determining a transition from the first PCI to a second PCI based on that detection.

[0113] In one aspect, a network node is a distributed unit (DU) of an integrated access and backhaul (IAB) node, and the network node is triggered to perform a handover by a handover command / cell group change of the co-located mobile terminal (MT) unit of the IAB node.

[0114] In one aspect, the network node performs the transition when a child node (e.g., a UE or IAB-node MT) migrates from a first PCI to a second PCI. Here, the child node is served on the second beam, and the network node transmits a first signal based on the second PCI during the first SSB opportunity using a beam quasi-co-located with the second beam. Alternatively, the child node is served on the first beam, and the network node transmits a first signal based on the second PCI during the first SSB opportunity using a beam quasi-co-located with the first beam.

[0115] In one aspect, network nodes perform a transition by performing a System Information Block Type 1 (SIB1) update during the transition period. The SIB1 update may include at least one of the following: updating a bitmap of the index of SSB opportunities in which first PCI-based signals are transmitted, or updating the quasi-co-location (QCL) relationship between beams associated with SSB opportunities in which first PCI-based signals are transmitted, sending the updated SIB1 message to a control node (e.g., gNB-CU), or updating the SIB1 transmission.

[0116] In one aspect, network nodes perform a transition by sending a System Information Block Type 1 (SIB1) message corresponding to a signal transmitted based on the second PCI during the transition period, and by sending an updated SIB1 message after the transition period ends.

[0117] In one aspect, a network node (e.g., a gNB-CU) performs a transition by sending an updated System Information Block Type 1 (SIB1) message corresponding to a signal transmitted based on a first PCI or a second PCI during the transition period. The updated SIB1 message is sent in a manner specific to connected child nodes or idle child nodes.

[0118] In one aspect, network nodes perform a transition by avoiding sending updated System Information Block Type 1 (SIB1) messages corresponding to signals sent based on the first PCI or the second PCI during the transition period, and by sending new SIB1 messages corresponding to signals sent based on the second PCI after the transition period ends.

[0119] In one aspect, network nodes perform the transition by sending short messages to child nodes or paging messages to idle user equipment (UEs) to indicate updates to system information.

[0120] In one aspect, based on configuration information (which may be conditional, for example, depending on the length of the transition period), network nodes may send short messages to child nodes during the transition period to indicate the update of system information by performing System Information Block Type 1 (SIB1) updates, or by sending paging messages to idle user equipment (UE) during the transition period to indicate the update of system information.

[0121] In one configuration, a network node 1200 for wireless communication includes: a unit (e.g., a first PCI transmitting circuit 1240, transceiver 1210, and / or antenna array 1230) for transmitting a first signal based on a first physical cell identifier (PCI) during a first synchronization signal block (SSB) opportunity; a unit (e.g., a first PCI transmitting circuit 1240, transceiver 1210, and / or antenna array 1230) for transmitting a second signal based on the first PCI during a second SSB opportunity, wherein the first and second SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame; and a unit (e.g., a PCI conversion circuit 1244, transceiver 1210, and / or antenna array 1230) for switching from the first PCI to the second PCI, wherein during the switching period, the unit for switching is configured to... The system transmits a first signal based on the second PCI during the transition period (e.g., via the second PCI transmission circuit 1246), and continues to transmit a second signal based on the first PCI during the second SSB opportunity period (e.g., via the first PCI transmission circuit 1240). After the transition period ends, the unit for transition is configured to continue transmitting the first signal based on the second PCI during the first SSB opportunity period (e.g., via the second PCI transmission circuit 1246), and to stop transmitting the second signal based on the first PCI during the second SSB opportunity period. This includes units for receiving configuration information from the control node (e.g., configuration information receiving circuit 1242), transceiver 1210, and / or antenna array 1230), and units for selecting a first SSB opportunity based on the configuration information to transmit the first signal based on the second PCI during the transition period (e.g., PCI conversion circuit 1244). In one aspect, the aforementioned units may be... Figure 12 The processor 1204 shown is configured to perform the functions described in the aforementioned unit. In another aspect, the aforementioned unit may be a circuit or any device configured to perform the functions described in the aforementioned unit.

[0122] Of course, in the above example, the circuitry included in processor 1204 is provided merely as an example, and other units for performing the described functions may be included in various aspects of this disclosure, including but not limited to instructions stored in computer-readable storage medium 1206, or... Figure 1 , 3 The descriptions in any of -6, 8, and / or 9, and the use of, for example, in this article regarding Figure 13 Any other suitable device or unit for the described processing procedure and / or algorithm.

[0123] Figure 14This is a flowchart illustrating an exemplary process 1400 for changing the Physical Cell Identifier (PCI) at a network node according to various aspects of this disclosure. As described below, in certain implementations within the scope of this disclosure, some or all of the illustrated features may be omitted, and for all aspects of the implementation, some illustrated features may not be required. In some examples, process 1400 may be... Figure 12 The network node 1200 shown performs this action. This network node 1200 can be a base station, gNB, gNB-DU, IAB-Provider DU, or IAB-Node DU, such as... Figure 1 , 3 -6, 8, and / or 9 are shown as any one or more. In some examples, process 1400 may be performed by any suitable means or unit for performing the functions or algorithms described below.

[0124] In block 1402, the network node transmits a first signal based on a first physical cell identifier (PCI) during a first synchronization signal block (SSB) opportunity. In block 1404, the network node transmits a second signal based on the first PCI during a second SSB opportunity. In block 1403, the network node transmits a third signal based on the first PCI during a third SSB opportunity. The first, second, and third SSB opportunities may be part of a set of SSB opportunities within a periodically repeating time frame (e.g., a half-frame).

[0125] In block 1408, the network node receives configuration information from a control node (e.g., gNB-CU). In block 1410, the network selects a first SSB opportunity to transmit a first signal based on a second PCI during a first transition period and a second SSB opportunity to transmit a second signal based on a second PCI during a second transition period. The selection may be based on configuration information received from the control node. This configuration may include an index of the first SSB opportunity and an index of the second SSB opportunity. Furthermore, the selection may be based on one or more conditions. Conditions may include: the network node switching PCIs during the first SSB opportunity, wherein no child nodes are served on the first beam associated with the first SSB opportunity; a child node serving on the second beam associated with the second SSB opportunity migrates to the second PCI, wherein the child node is served on the beam quasi-co-located with the second beam and transmitted during the first SSB opportunity; or no child nodes are served on the second beam associated with the second SSB opportunity, and therefore, the network node switches PCIs during the second SSB opportunity.

[0126] In box 1412, the network node transitions from a first PCI to a second PCI. During the first transition period, the network node transmits a first signal based on the second PCI during the first SSB opportunity, continues to transmit a second signal based on the first PCI during the second SSB opportunity, and continues to transmit a third signal based on the first PCI during the third SSB opportunity. During the second transition period, the network node continues to transmit the first signal based on the second PCI during the first SSB opportunity, transmits the second signal based on the second PCI during the second SSB opportunity, and continues to transmit the third signal based on the first PCI during the third SSB opportunity. After the second transition period ends, the network node continues to transmit the first signal based on the second PCI during the first SSB opportunity, continues to transmit the second signal based on the second PCI during the second SSB opportunity, and stops transmitting the third signal based on the first PCI during the third SSB opportunity. The network node may also transmit the third signal based on the second PCI during the third SSB opportunity after the second transition period ends.

[0127] In one configuration, a network node 1200 for wireless communication includes units (e.g., a first PCI transmitting circuit 1240, transceiver 1210, and / or antenna array 1230) for transmitting a first signal based on a first physical cell identifier (PCI) during a second synchronization signal block (SSB) opportunity, units (e.g., the first PCI transmitting circuit 1240, transceiver 1210, and / or antenna array 1230) for transmitting a second signal based on the first PCI during the second SSB opportunity, and units (e.g., the first PCI transmitting circuit 1240, transceiver 1210, and / or antenna array 1230) for transmitting a third signal based on the first PCI during a third SSB opportunity. 0), wherein the first SSB opportunity, the second SSB opportunity, and the third SSB opportunity are part of a set of SSB opportunities in a periodically repeating time frame, for units (e.g., PCI conversion circuit 1244, transceiver 1210, and / or antenna array 1230) for switching from the first PCI to the second PCI, wherein during the first switching period, the unit for switching is configured to transmit a first signal based on the second PCI (e.g., via the second PCI transmission circuit 1246) during the first SSB opportunity, continue to transmit a second signal based on the first PCI during the second SSB opportunity (e.g., via the first PCI transmission circuit 1240), and continue during the third SSB opportunity. The third signal is transmitted based on the first PCI (e.g., via the first PCI transmission circuit 1240), wherein during the second transition period, the unit for transition is configured to continue transmitting the first signal based on the second PCI during the first SSB opportunity period (e.g., via the second PCI transmission circuit 1246), continue transmitting the second signal based on the second PCI during the second SSB opportunity period (e.g., via the second PCI transmission circuit 1246), and continue transmitting the third signal based on the first PCI during the third SSB opportunity period (e.g., via the first PCI transmission circuit 1240), and wherein after the end of the second transition period, the unit for transition is configured to continue transmitting the third signal based on the first PCI during the third SSB opportunity period (e.g., via the first PCI transmission circuit 1240), and wherein after the end of the second transition period, the unit for transition is configured to continue transmitting the third signal based on the first SSB opportunity period. The system includes a unit for receiving configuration information from the control node (e.g., configuration information receiving circuit 1242, transceiver 1210, and / or antenna array 1230), and a unit for selecting a first SSB opportunity to transmit the first signal based on the second PCI during a first transition period and a second SSB opportunity to transmit the second signal based on the second PCI during a second transition period. In one aspect, the aforementioned unit may be... Figure 12The processor 1204 shown is configured to perform the functions described in the aforementioned apparatus. Alternatively, the aforementioned unit may be a circuit or any apparatus configured to perform the functions described in the aforementioned apparatus.

[0128] Of course, in the above example, the circuitry included in processor 1204 is provided merely as an example, and other units for performing the described functions may be included in various aspects of this disclosure, including but not limited to instructions stored in computer-readable storage medium 1206, or... Figure 1 , 3 The descriptions in any of -6, 8, and / or 9, and the use of, for example, in this article regarding Figure 14 Any other suitable device or unit for the described processing procedure and / or algorithm.

[0129] Various aspects of wireless communication networks have been presented with reference to exemplary implementations. As will be readily understood by those skilled in the art, the various aspects described herein can be extended to other telecommunications systems, network architectures, and communication standards.

[0130] For example, these aspects can be implemented within other systems defined by 3GPP, such as Long Term Evolution (LTE), Evolved Packet System (EPS), Universal Mobile Telecommunications System (UMTS), and / or Global System for Mobile Communications (GSM). The aspects can also be extended to systems defined by 3GPP2 (3rd Generation Partnership Project 2), such as CDMA2000 and / or Evolved Data Optimized (EV-DO). Other examples include implementations within systems employing IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra Wideband (UWB), Bluetooth, and / or other suitable systems. The specific telecommunications standards, network architecture, and / or communication standards employed will depend on the specific application and the overall design constraints imposed on the system.

[0131] In this disclosure, the term “exemplary” is used to mean “serving as an example, instance, or illustration.” Any implementation or aspect described herein as “exemplary” is not necessarily to be construed as superior to or better than other aspects of this disclosure. Similarly, the term “aspect” does not require that all aspects of this disclosure include the features, advantages, or modes of operation discussed. The term “coupling” is used herein to refer to direct or indirect coupling between two objects. For example, if object A physically contacts object B, and object B contacts object C, then objects A and C can be considered coupled to each other even if they are not in direct physical contact. For example, a first object can be coupled to a second object even if the first object never directly physically contacts the second object. The terms “circuit” and “circuit” are used broadly and are intended to include, but are not limited to, hardware implementations of electrical devices and conductors that, when connected and configured, implement the execution of the functions described in this disclosure; and software implementations of information and instructions that, when executed by a processor, implement the execution of the functions described in this disclosure.

[0132] Figures 1 to 14 One or more components, steps, features, and / or functions shown may be rearranged and / or combined into a single component, step, feature, or function, or implemented in several components, steps, or functions. Additional elements, components, steps, and / or functions may be added without departing from the novel features disclosed herein. Figures 1 to 14 The apparatus, devices, and / or components shown can be configured to perform one or more methods, features, or steps described herein. The novel algorithms described herein can also be effectively implemented in software and / or in hardware.

[0133] It should be understood that the specific order or hierarchy of steps in the disclosed method is an illustration of an exemplary process. Based on design preferences, it is understood that the specific order or hierarchy of steps in the method may be rearranged. The appended method requires that the elements of each step be presented in a sample order, and is not intended to be limited to the specific order or hierarchy presented, unless specifically stated herein.

[0134] The following provides an overview of aspects of this disclosure:

[0135] Aspect 1: A method for changing a Physical Cell Identifier (PCI) performed at a network node, comprising: transmitting a first signal based on a first Physical Cell Identifier (PCI) during a first Synchronization Signal Block (SSB) opportunity; transmitting a second signal based on the first PCI during a second SSB opportunity, wherein the first SSB opportunity and the second SSB opportunity are part of a set of SSB opportunities in a periodically repeating time frame; transitioning from the first PCI to the second PCI, wherein during a transition period, the transition comprises: transmitting the first signal based on the second PCI during the first SSB opportunity and continuing to transmit the second signal based on the first PCI during the second SSB opportunity, and wherein after the transition period ends, the transition comprises: continuing to transmit the first signal based on the second PCI during the first SSB opportunity and ceasing to transmit the second signal based on the first PCI during the second SSB opportunity.

[0136] Aspect 2: According to the method of aspect 1, wherein the conversion further includes: after the end of the conversion period, during the second SSB opportunity period, sending the second signal based on the second PCI.

[0137] Aspect 3: The method according to aspect 1 or 2, wherein the transition further includes: during the transition period and / or after the end of the transition period, during the third SSB opportunity in the set of SSB opportunities, transmitting a third signal based on the second PCI.

[0138] Aspect 4: The method according to any one of aspects 1 to 3, wherein the conversion further includes: transmitting the first signal based on the first PCI via a first beam during the first SSB opportunity; and transmitting the second signal based on the first PCI via a second beam during the second SSB opportunity.

[0139] Aspect 5: The method according to any one of aspects 1 to 4, wherein the conversion further includes: transmitting the first beam and the second beam in the same direction.

[0140] Aspect 6: The method according to any one of Aspects 1 to 5, wherein the transition further comprises: selecting the first SSB opportunity to transmit the first signal based on the second PCI during the transition period, wherein the selection is based on: the network node not serving child nodes on the first beam and serving one or more child nodes on the second beam; the network node serving one or more fewer child nodes on the first beam than serving two or more child nodes on the second beam; the network node delivering a smaller total throughput to the child nodes serving on the first beam than the total throughput delivered to the child nodes serving on the second beam; and the network node providing [something] to the child nodes serving on the first beam. The network node provides services with lower Quality of Service (QoS) requirements compared to the services provided to child nodes serving on the second beam; the network node serves child nodes on the first beam with lower link quality compared to the link quality of child nodes serving on the second beam; the communication between the network node and the child nodes serving on the first beam causes more interference than the communication between the network node and the child nodes serving on the second beam; or the communication between the network node and the child nodes serving on the first beam causes more interference to the communication of another cell served by the second network node compared to the communication between the network node and the child nodes serving on the second beam.

[0141] Aspect 7: The method according to any one of aspects 1 to 6, wherein selecting the first SSB opportunity to send the first signal based on the second PCI during the transition period comprises: making a selection such that it does not induce a System Information Block Type 1 (SIB1) update associated with the first PCI.

[0142] Aspect 8: The method according to any one of Aspects 1 to 7 further includes receiving configuration information from a control node, the selection of a first SSB opportunity to transmit a first signal based on a second PCI during a transition period being based on the configuration information, the configuration information including at least one of the following: an index of the first SSB opportunity; an indication of an SSB region associated with the first SSB opportunity or the first beam transmitted during the first SSB opportunity; a threshold for the number of child nodes served, wherein the number of child nodes served by the first beam is less than or equal to the threshold; a threshold for the total throughput delivered to the served child nodes, wherein the total throughput delivered to the child nodes served by the first beam is less than the threshold; a condition associated with a QoS requirement, wherein the service provided to the child nodes served on the first beam satisfies the condition; or channel quality information.

[0143] Aspect 9: The method according to any one of aspects 1 to 8 further includes: receiving second configuration information associated with the second network node from the control node.

[0144] Aspect 10: The method according to any one of aspects 1 to 9, wherein the transition further comprises: receiving from a control node an indication for transitioning from the first PCI to the second PCI; and determining, based on the indication, the transition from the first PCI to the second PCI.

[0145] Aspect 11: The method according to any one of aspects 1 to 10, wherein the transition further includes instructing the control node to initiate a transition from the first PCI to the second PCI.

[0146] Aspect 12: The method according to any one of aspects 1 to 11, wherein the transition further includes: detecting signals transmitted by different network nodes based on the first PCI; and determining a transition from the first PCI to the second PCI based on the detection.

[0147] Aspect 13: The method according to any one of Aspects 1 to 12, wherein: the network node is a distributed unit (DU) of integrated access and backhaul (IAB) nodes; and the transition is triggered by a handover command / cell group change for a co-located mobile terminal (MT) unit of the IAB node.

[0148] Aspect 14: The method according to any one of Aspects 1 to 13, wherein the transition is performed when a child node migrates from the first PCI to the second PCI, wherein: the child node is served on the second beam, and the network node transmits the first signal based on the second PCI during the first SSB opportunity using a beam quasi-co-located with the second beam; or the child node is served on the first beam, and the network node transmits the first signal based on the second PCI during the first SSB opportunity using a beam quasi-co-located with the first beam.

[0149] Aspect 15: The method according to any one of aspects 1 to 14, wherein the network node is: g node B; g node B-distributed unit (gNB-DU); integrated access and backhaul (IAB)-provider distributed unit (IAB-provider DU); or integrated access and backhaul (IAB)-node distributed unit (IAB-node DU).

[0150] Aspect 16: The method according to any one of Aspects 1 to 15, wherein the transition further comprises: performing a System Information Block Type 1 (SIB1) update during the transition period, the SIB1 update comprising at least one of the following: updating a bitmap of the index of the SSB opportunity in which the signal based on the first PCI is transmitted; updating the quasi-co-address (QCL) relationship between the beams associated with the SSB opportunity in which the signal based on the first PCI is transmitted; sending the updated SIB1 message to the control node; or updating the SIB1 transmission.

[0151] Aspect 17: The method according to any one of aspects 1 to 16, wherein the conversion further includes: sending a System Information Block Type 1 (SIB1) message corresponding to a signal transmitted based on the second PCI during the conversion period; and sending an updated SIB1 message after the end of the conversion period.

[0152] Aspect 18: The method according to any one of aspects 1 to 17, wherein the transition further includes: during the transition period, sending an updated System Information Block Type 1 (SIB1) message corresponding to a signal sent based on the first PCI or the second PCI, wherein the updated SIB1 message is sent in a dedicated manner for connected child nodes or idle child nodes.

[0153] Aspect 19: The method according to any one of aspects 1 to 18, wherein the transition further includes: avoiding the transmission of an updated System Information Block Type 1 (SIB1) message corresponding to a signal transmitted based on the first PCI or the second PCI during the transition period; and transmitting a new SIB1 message corresponding to a signal transmitted based on the second PCI after the end of the transition period.

[0154] Aspect 20: The method according to any one of aspects 1 to 19, wherein the conversion further includes: sending a short message to a child node or sending a paging message to an idle user equipment (UE) to indicate an update to system information.

[0155] Aspect 21: The method according to any one of aspects 1 to 20 further includes: receiving configuration information from a control node; and based on the configuration information: performing a System Information Block Type 1 (SIB1) update during the transition period, sending a short message to a child node during the transition period to indicate an update to the system information, or sending a paging message to an idle user equipment (UE) during the transition period to indicate an update to the system information.

[0156] Aspect 22: A method for changing a Physical Cell Identifier (PCI) performed at a network node, comprising: transmitting a first signal based on a first Physical Cell Identifier (PCI) during a first Synchronization Signal Block (SSB) opportunity; transmitting a second signal based on the first PCI during a second SSB opportunity; transmitting a third signal based on the first PCI during a third SSB opportunity, wherein the first, second, and third SSB opportunities are part of a set of SSB opportunities in a periodically repeating time frame; and transitioning from the first PCI to the second PCI, wherein during a first transition period, the transition comprises: transmitting the first signal based on the second PCI during the first SSB opportunity and continuing to transmit the second signal based on the first PCI during the second SSB opportunity. The transition includes: continuing to transmit the third signal based on the first PCI during the third SSB opportunity, and during the second transition period, the transition includes: continuing to transmit the first signal based on the second PCI during the first SSB opportunity, transmitting the second signal based on the second PCI during the second SSB opportunity, and continuing to transmit the third signal based on the first PCI during the third SSB opportunity, and wherein, after the end of the second transition period, the transition includes: continuing to transmit the first signal based on the second PCI during the first SSB opportunity, continuing to transmit the second signal based on the second PCI during the second SSB opportunity, and ceasing to transmit the third signal based on the first PCI during the third SSB opportunity.

[0157] Aspect 23: According to the method of aspect 22, the transition further includes: sending the third signal based on the second PCI during the third SSB opportunity period after the end of the second transition period.

[0158] Aspect 24: The method according to aspect 22 or 23 further includes: selecting the first SSB opportunity to transmit the first signal based on the second PCI during the first transition period, and the second SSB opportunity to transmit the second signal based on the second PCI during the second transition period, wherein the selection is based on at least one of the following: a configuration received from a control node providing an index of the first SSB opportunity and an index of the second SSB opportunity; the network node switching PCI during the first SSB opportunity, wherein no child node is served on the first beam associated with the first SSB opportunity; a child node serving on the second beam associated with the second SSB opportunity migrates to the second PCI, wherein the child node is served on the beam quasi-co-located with the second beam and transmitted during the first SSB opportunity; or no child node is served on the second beam associated with the second SSB opportunity.

[0159] Aspect 25: A network node for changing a physical cell identifier (PCI), comprising a processor and a memory coupled to the processor, the processor and the memory being configured to perform the method according to any one of aspects 1 to 21 or aspects 22 to 24.

[0160] Aspect 26: A network node for changing the Physical Cell Identifier (PCI), comprising at least one unit for performing the method according to any one of aspects 1 to 21 or aspects 22 to 24.

[0161] Aspect 27: A non-transitory computer-readable medium storing code for changing the Physical Cell Identifier (PCI) at a network node, said code comprising instructions executable by a processor to perform the method according to any one of aspects 1 to 21 or aspects 22 to 24.

[0162] The above description is provided to enable those skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but should be accorded the full scope consistent with the language of the claims, wherein, unless specifically stated otherwise, references to elements in the singular are not intended to mean “one and only one,” but rather “one or more.” Unless otherwise specifically stated otherwise, the term “some” refers to one or more. The phrase “at least one” referring to a list of items means any combination of these items, including individual members. For example, “at least one of a, b, or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, b, and c. All structural and functional equivalents of elements known or to be known later by those skilled in the art throughout the various aspects of this disclosure are expressly incorporated herein by reference and are intended to be covered by the claims. Furthermore, nothing disclosed herein is intended to be offered to the public, whether or not such disclosure is expressly listed in the claims.

Claims

1. A method performed at a network node for changing a physical cell identifier (PCI), comprising: transmitting a first signal based on a first physical cell identifier (PCI) during a first synchronization signal block (SSB) opportunity of a set of SSB opportunities; transmitting a second signal based on the first PCI during a second SSB opportunity of the set of SSB opportunities, wherein the first SSB opportunity and the second SSB opportunity are part of the set of SSB opportunities in a periodically repeating time frame; transitioning from the first PCI to a second PCI, wherein, during a transition period, the transitioning comprises: transitioning from transmitting the first signal based on the first PCI during the first SSB opportunity to transmitting the first signal based on the second PCI, and continuing to transmit the second signal based on the first PCI during the second SSB opportunity, and wherein, after the end of the transition period, the transitioning comprises: continuing to transmit the first signal based on the second PCI during the first SSB opportunity, and stopping transmitting the second signal based on the first PCI during the second SSB opportunity.

2. The method of claim 1, wherein, the transitioning further comprises: after the end of the transition period, transmitting the second signal based on the second PCI during the second SSB opportunity.

3. The method of claim 1, wherein, the transitioning further comprises: during the transition period and / or after the end of the transition period, transmitting a third signal based on the second PCI during a third SSB opportunity of the set of SSB opportunities.

4. The method of claim 1, wherein, the transitioning further comprises: transmitting the first signal based on the first PCI during the first SSB opportunity via a first beam; and transmitting the second signal based on the first PCI during the second SSB opportunity via a second beam.

5. The method of claim 4, wherein, the transitioning further comprises: transmitting the first beam and the second beam in the same direction.

6. The method of claim 4, wherein, the first SSB opportunity is selected based on at least one of: the network node does not serve a child node on the first beam and serves one or more child nodes on the second beam; the network node serves one or more child nodes on the first beam that is less than two or more child nodes served on the second beam; the network node delivers less total throughput to child nodes served on the first beam than total throughput delivered to child nodes served on the second beam; the network node provides services to child nodes served on the first beam with lower quality of service (QoS) requirements than services provided to child nodes served on the second beam; the network node serves child nodes on the first beam with lower link quality than link quality of child nodes served on the second beam; communications between the network node and child nodes served on the first beam incur more interference than communications between the network node and child nodes served on the second beam; or the first SSB opportunity is selected based on at least one of: communications between the network node and child nodes served on the first beam cause more interference to communications of another cell served by a second network node than communications between the network node and child nodes served on the second beam, wherein the child nodes comprise at least one of scheduled nodes or user equipment (UEs).

7. The method of claim 6, wherein, the selection of the first SSB opportunity comprises the selection of the first SSB opportunity in which a system information block type 1 (SIB1) update associated with the first PCI is not incurred.

8. The method of claim 6, further comprising: receiving configuration information from a control node, wherein the selection of the first SSB opportunity to transmit the first signal based on the second PCI during the transition period is based on the configuration information, the configuration information comprising at least one of: an index of the first SSB opportunity; an indication of an SSB region associated with the first SSB opportunity or the first beam transmitted during the first SSB opportunity; a threshold of a number of served child nodes, wherein a number of child nodes served by the first beam is less than or equal to the threshold; a threshold of a total throughput of delivery to served child nodes, wherein a total throughput of delivery to child nodes served by the first beam is less than the threshold; a condition associated with a QoS requirement, wherein a service provided to child nodes served on the first beam satisfies the condition; or channel quality information.

9. The method of claim 8, further comprising: receiving second configuration information associated with a second network node from the control node.

10. The method of claim 1, wherein, the transitioning further comprises: receiving an indication from a control node to transition from the first PCI to the second PCI; and determining to transition from the first PCI to the second PCI based on the indication.

11. The method of claim 10, wherein, the transitioning further comprises: indicating to the control node initiation of the transition from the first PCI to the second PCI.

12. The method of claim 1, wherein, the transitioning further comprises: detecting a signal transmitted by a different network node based on the first PCI; and determining to transition from the first PCI to the second PCI based on the detection.

13. The method of claim 1, wherein: the network node is a distributed unit (DU) of an integrated access and backhaul (IAB)-node; and the transitioning is triggered by a handover command / cell group change for a collocated mobile termination (MT) unit of the IAB-node.

14. The method of claim 1, wherein, the transitioning from the first PCI to the second PCI is performed when a child node migrates from the first PCI to the second PCI, wherein: the child node is served on a second beam and the network node transmits the first signal based on the second PCI during the first SSB opportunity using a beam that is quasi co-located with the second beam; or the child node is served on a second beam and the network node transmits the first signal based on the second PCI during the first SSB opportunity using a beam that is quasi co-located with the second beam; or the child node is served on a first beam, and the network node transmits the first signal during the first SSB opportunity based on the second PCI using a beam that is quasi co-located with the first beam.

15. The method of claim 1, wherein, the network node is: a gNodeB; a gNodeB-distributed unit (gNB-DU); an integrated access and backhaul (IAB)-donor distributed unit (IAB-donor DU); or an integrated access and backhaul (IAB)-node distributed unit (IAB-node DU).

16. The method of claim 1, wherein, the transitioning further comprises: performing a system information block type 1 (SIB1) update during the transition period, the SIB1 update comprising at least one of: updating a bitmap of indices of the SSB opportunities in which signals based on the first PCI are transmitted; updating a quasi co-location (QCL) relationship between beams associated with the SSB opportunities in which signals based on the first PCI are transmitted; transmitting an updated SIB1 message to a control node; or updating a SIB1 transmission.

17. The method of claim 1, wherein, the transitioning further comprises: transmitting a system information block type 1 (SIB1) message corresponding to signals transmitted based on the second PCI during the transition period; and transmitting an updated SIB1 message after the end of the transition period.

18. The method of claim 1, wherein, the transitioning further comprises: transmitting an updated system information block type 1 (SIB1) message corresponding to signals transmitted based on the first PCI or the second PCI during the transition period, wherein the updated SIB1 message is transmitted in a dedicated manner for connected child nodes or idle child nodes.

19. The method of claim 1, wherein, the transitioning further comprises: avoiding transmitting an updated system information block type 1 (SIB1) message corresponding to signals transmitted based on the first PCI or the second PCI during the transition period; and transmitting a new SIB1 message corresponding to signals transmitted based on the second PCI after the end of the transition period.

20. The method of claim 1, wherein, the transitioning further comprises: transmitting a short message to child nodes or a paging message to idle user equipment (UEs) to indicate an update to system information.

21. The method of claim 1, further comprising: receiving configuration information from a control node; and based on the configuration information: performing a system information block type 1 (SIB1) update during the transition period, transmitting a short message to child nodes during the transition period to indicate an update to system information, or transmitting a paging message to idle user equipment (UEs) during the transition period to indicate an update to system information.

22. A method for changing a physical cell identifier (PCI) performed at a network node, comprising: transmitting a first signal based on a first physical cell identifier (PCI) during a first synchronization signal block (SSB) opportunity of a set of SSB opportunities; transmitting a second signal based on the first PCI during a second SSB opportunity of the set of SSB opportunities; transmitting a third signal based on the first PCI during a third SSB opportunity of the set of SSB opportunities, wherein the first, second, and third SSB opportunities are part of the set of SSB opportunities in a periodically repeating time frame; and transitioning from the first PCI to a second PCI, wherein, during a first transition period, the transitioning comprises: transitioning from transmitting the first signal based on the first PCI during the first SSB opportunity to transmitting the first signal based on the second PCI, continuing to transmit the second signal based on the first PCI during the second SSB opportunity, and continuing to transmit the third signal based on the first PCI during the third SSB opportunity, wherein, during a second transition period, the transitioning comprises: continuing to transmit the first signal based on the second PCI during the first SSB opportunity, transitioning from transmitting the second signal based on the first PCI during the second SSB opportunity to transmitting the second signal based on the second PCI, and continuing to transmit the third signal based on the first PCI during the third SSB opportunity, and wherein, after the end of the second transition period, the transitioning comprises: continuing to transmit the first signal based on the second PCI during the first SSB opportunity, continuing to transmit the second signal based on the second PCI during the second SSB opportunity, and stopping transmitting the third signal based on the first PCI during the third SSB opportunity.

23. The method of claim 22, wherein, the transitioning further comprises: transmitting the third signal based on the second PCI during the third SSB opportunity after the end of the second transition period.

24. The method of claim 22, wherein, the first SSB opportunity and the second SSB opportunity are selected based on at least one of: a configuration received from a control node providing an index of the first SSB opportunity and an index of the second SSB opportunity; the network node switching a PCI during the first SSB opportunity, wherein no child node is served on a first beam associated with the first SSB opportunity; a child node served on a second beam associated with the second SSB opportunity migrates to the second PCI, wherein the child node is served on a beam that is quasi co-located with the second beam and transmitted during the first SSB opportunity; or no child node is served on the second beam associated with the second SSB opportunity, wherein the child node comprises at least one of a scheduled node or a user equipment (UE).

25. A network node for changing a physical cell identifier (PCI), comprising: at least one processor; and a memory coupled to the at least one processor, the at least one processor and the memory configured to: transmit a first signal based on a first physical cell identifier (PCI) during a first synchronization signal block (SSB) opportunity of a set of SSB opportunities; transmit a second signal based on the first PCI during a second SSB opportunity of the set of SSB opportunities, wherein the first SSB opportunity and the second SSB opportunity are part of the set of SSB opportunities in a periodically repeating time frame; transition from the first PCI to a second PCI, wherein, during the transition period, the at least one processor and the memory configured to transition are configured to: transition from transmitting the first signal based on the first PCI during the first SSB opportunity to transmitting the first signal based on the second PCI, and continue transmitting the second signal based on the first PCI during the second SSB opportunity, and wherein, after the end of the transition period, the at least one processor and the memory configured to transition are configured to: continue transmitting the first signal based on the second PCI during the first SSB opportunity, and stop transmitting the second signal based on the first PCI during the second SSB opportunity.

26. The network node of claim 25, further comprising: a transceiver, wherein the at least one processor and the memory configured to transition are further configured to: after the end of the transition period, transmit the second signal based on the second PCI during the second SSB opportunity.

27. The network node of claim 25, wherein, the at least one processor and the memory configured to transition are further configured to: transmit a third signal based on the second PCI during a third SSB opportunity of the set of SSB opportunities during the transition period and / or after the end of the transition period.

28. The network node of claim 25, wherein, the at least one processor and the memory configured to transition are further configured to: transmit the first signal based on the first PCI during the first SSB opportunity via a first beam; and transmit the second signal based on the first PCI during the second SSB opportunity via a second beam.

29. The network node of claim 28, wherein, the at least one processor and the memory configured to transition are further configured to: transmit the first beam and the second beam in the same direction.

30. The network node of claim 28, wherein, the first SSB opportunity is selected based on at least one of: the network node does not serve child nodes on the first beam and serves one or more child nodes on the second beam; the network node serves one or more child nodes on the first beam that is less than two or more child nodes served on the second beam; the network node delivers less total throughput to child nodes served on the first beam than total throughput delivered to child nodes served on the second beam; the network node provides services to child nodes served on the first beam with lower quality of service (QoS) requirements than services provided to child nodes served on the second beam; the network node serves child nodes on the first beam with lower link quality than link quality of child nodes served on the second beam; communications between the network node and child nodes served on the first beam incur more interference than communications between the network node and child nodes served on the second beam; or communications between the network node and child nodes served on the first beam cause more interference to communications of another cell served by a second network node than communications between the network node and child nodes served on the second beam, wherein the child nodes comprise at least one of scheduled nodes or user equipment (UE).

31. The network node of claim 30, wherein, the selection of the first SSB opportunity comprises a selection of the first SSB opportunity in which a system information block type 1 (SIB1) update associated with the first PCI is not incurred.

32. The network node of claim 30, wherein, the at least one processor and the memory are further configured to: receive configuration information from a control node, wherein the selection of the first SSB opportunity to transmit the first signal based on the second PCI during the transition period is based on the configuration information, the configuration information comprising at least one of: an index of the first SSB opportunity; an indication of an SSB region associated with the first SSB opportunity or the first beam transmitted during the first SSB opportunity; a threshold of a number of served child nodes, wherein a number of child nodes served by the first beam is less than or equal to the threshold; a threshold of a total throughput of delivery to served child nodes, wherein a total throughput of delivery to child nodes served by the first beam is less than the threshold; a condition associated with a QoS requirement, wherein a service provided to child nodes served on the first beam satisfies the condition; or channel quality information.

33. The network node of claim 32, wherein, the at least one processor and the memory are further configured to: receive second configuration information associated with a second network node from the control node.

34. The network node of claim 25, wherein, the at least one processor and the memory configured to transition are further configured to: receive an indication from a control node to transition from the first PCI to the second PCI; and determine to transition from the first PCI to the second PCI based on the indication.

35. The network node of claim 34, wherein, the at least one processor and the memory configured to transition are further configured to: indicate to the control node initiation of the transition from the first PCI to the second PCI.

36. The network node of claim 25, wherein, the at least one processor and the memory configured to transition are further configured to: detect a signal transmitted by a different network node based on the first PCI; and determine to transition from the first PCI to the second PCI based on the detection.

37. The network node of claim 25, wherein: the network node is a distributed unit (DU) of an integrated access and backhaul (IAB)-node; and the transition is triggered by a handover command / cell group change for a collocated mobile termination (MT) unit of the IAB-node.

38. The network node of claim 25, wherein, the transition from the first PCI to the second PCI is performed when a child node migrates from the first PCI to the second PCI, wherein: the child node is served on a second beam, and the network node transmits the first signal based on the second PCI during the first SSB opportunity using a beam that is quasi co-located with the second beam; or the child node is served on a first beam, and the network node transmits the first signal based on the second PCI during the first SSB opportunity using a beam that is quasi co-located with the first beam.

39. The network node of claim 25, wherein, the network node is: a gNodeB; a gNodeB-distributed unit (gNB-DU); an integrated access and backhaul (IAB)-donor distributed unit (IAB-donor DU); or an integrated access and backhaul (IAB)-node distributed unit (IAB-node DU).

40. The network node of claim 25, wherein, the at least one processor and the memory configured to convert are further configured to: perform a system information block type 1 (SIB1) update during the conversion period, the SIB1 update comprising at least one of: updating a bitmap of indices of the SSB opportunities in which signals based on the first PCI are transmitted; updating a quasi co-location (QCL) relationship between beams associated with the SSB opportunities in which signals based on the first PCI are transmitted; transmitting an updated SIB1 message to a control node; or updating a SIB1 transmission.

41. The network node of claim 25, wherein, the at least one processor and the memory configured to convert are further configured to: transmit a system information block type 1 (SIB1) message corresponding to signals transmitted based on the second PCI during the conversion period; and transmit an updated SIB1 message after the end of the conversion period.

42. The network node of claim 25, wherein, the at least one processor and the memory configured to convert are further configured to: transmit an updated system information block type 1 (SIB1) message corresponding to signals transmitted based on the first PCI or the second PCI during the conversion period, wherein the updated SIB1 message is transmitted in a dedicated manner for connected child nodes or idle child nodes.

43. The network node of claim 25, wherein, the at least one processor and the memory configured to convert are further configured to: avoid transmitting an updated system information block type 1 (SIB1) message corresponding to signals transmitted based on the first PCI or the second PCI during the conversion period; and transmit a new SIB1 message corresponding to signals transmitted based on the second PCI after the end of the conversion period.

44. The network node of claim 25, wherein, the at least one processor and the memory configured to convert are further configured to: transmit a short message to a child node, or a paging message to idle user equipment (UEs), to indicate an update to system information.

45. The network node of claim 25, wherein, the at least one processor and the memory are further configured to: receive configuration information from a control node; and based on the configuration information: perform a system information block type 1 (SIB1) update during the conversion period, transmit a short message to a child node to indicate an update to system information during the conversion period, or transmitting a paging message to idle user equipment (UE) during the transition period to indicate an update to system information.

46. A network node for changing a physical cell identifier (PCI), comprising: at least one processor; and a memory coupled to the at least one processor, the at least one processor and the memory configured to: transmit a first signal based on a first physical cell identifier (PCI) during a first synchronization signal block (SSB) opportunity of a set of SSB opportunities; transmit a second signal based on the first PCI during a second SSB opportunity of the set of SSB opportunities; transmit a third signal based on the first PCI during a third SSB opportunity of the set of SSB opportunities, wherein the first, second, and third SSB opportunities are part of the set of SSB opportunities in a periodically repeating time frame; and transition from the first PCI to a second PCI, wherein, during a first transition period, the at least one processor and the memory configured to transition are configured to: transition from transmitting the first signal based on the first PCI during the first SSB opportunity to transmitting the first signal based on the second PCI, continue transmitting the second signal based on the first PCI during the second SSB opportunity, and continue transmitting the third signal based on the first PCI during the third SSB opportunity, wherein, during a second transition period, the at least one processor and the memory configured to transition are configured to: continue transmitting the first signal based on the second PCI during the first SSB opportunity, transition from transmitting the second signal based on the first PCI during the second SSB opportunity to transmitting the second signal based on the second PCI, and continue transmitting the third signal based on the first PCI during the third SSB opportunity, and wherein, after the end of the second transition period, the at least one processor and the memory configured to transition are configured to: continue transmitting the first signal based on the second PCI during the first SSB opportunity, continue transmitting the second signal based on the second PCI during the second SSB opportunity, and stop transmitting the third signal based on the first PCI during the third SSB opportunity.

47. The network node of claim 46, further comprising: a transceiver, wherein the at least one processor and the memory configured to transition are further configured to: after the end of the second transition period, transmit the third signal based on the second PCI during the third SSB opportunity.

48. The network node of claim 46, wherein, the first SSB opportunity and the second SSB opportunity are selected based on at least one of: a configuration received from a control node providing an index of the first SSB opportunity and an index of the second SSB opportunity; the network node switches a PCI during the first SSB opportunity, wherein no child nodes are served on a first beam associated with the first SSB opportunity; a child node served on a second beam associated with the second SSB opportunity migrates to the second PCI, wherein the child node is served on a beam that is quasi co-located with the second beam and transmitted during the first SSB opportunity; or no child nodes are served on the second beam associated with the second SSB opportunity, wherein the child nodes comprise at least one of scheduled nodes or user equipment (UEs).

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