EP-4176632-B1 - BEAM OPTIMIZATION FOR SOFT PHYSICAL CELL IDENTIFIER CHANGE

EP4176632B1EP 4176632 B1EP4176632 B1EP 4176632B1EP-4176632-B1

Inventors

AKL, Naeem
ABEDINI, NAVID
LUO, Jianghong
HAMPEL, KARL GEORG
BLESSENT, LUCA
LI, JUNYI
LUO, TAO

Dates

Publication Date: 20260513
Application Date: 20210630

Claims (18)

A method (1300) performed at a network node for changing a physical cell identifier, PCI when a network node migrates from one controlling node to anther controlling node in an integrated access and backhaul, IAB, system, comprising: transmitting (1302) a first signal based on a first physical cell identifier, PCI, during a first synchronization signal block, SSB, occasion; transmitting (1304) a second signal based on the first PCI during a second SSB occasion, wherein the first SSB occasion and the second SSB occasion are part of a set of SSB occasions in a periodically repeating time frame; and transitioning (1310) from the first PCI to a second PCI, wherein during a transition period, the transitioning comprises: transmitting the first signal based on the second PCI during the first SSB occasion, and continuing to transmit the second signal based on the first PCI during the second SSB occasion, and wherein after an end of the transition period, the transitioning comprises: continuing to transmit the first signal based on the second PCI during the first SSB occasion, and ceasing transmission of the second signal based on the first PCI during the second SSB occasion.
The method of claim 1, wherein the transitioning further comprises: transmitting the second signal based on the second PCI during the second SSB occasion after the end of the transition period.
The method of claim 1, wherein the transitioning further comprises: transmitting a third signal based on the second PCI during a third SSB occasion of the set of SSB occasions during and/or after the end of the transition period.
The method of claim 1, further comprises: prior to the transition period, transmitting the first signal based on the first PCI during the first SSB occasion via a first beam; and transmitting the second signal based on the first PCI during the second SSB occasion via a second beam.
The method of claim 4, wherein the transitioning further comprises transmitting the first beam and the second beam in a same direction.
The method of claim 4, wherein the transitioning further comprises selecting (1308) the first SSB occasion to transmit the first signal based on the second PCI during the transition period, wherein the selecting is based on: the network node serving no child nodes on the first beam and serving one or more child nodes on the second beam; the network node serving a number of child nodes on the first beam that is less than a number of child nodes served on the second beam; the network node delivering a total throughput to child nodes served on the first beam that is less than a total throughput delivered to child nodes served on the second beam; the network node providing a service to child nodes served on the first beam that has a lower quality of service, QoS, requirement than a service provided to child nodes served on the second beam; the network node serving a child node on the first beam with a lower link quality than a link quality of a child node served on the second beam; communication between the network node and a child node served on the first beam incurring more interference than communication between the network node and a child served on the second beam; or communication between the network node and a child node served on the first beam causing more interference to communication of another cell served by a second network node than communication between the network node and a child node served on the second beam.
The method of claim 5, further comprising receiving (1306) configuration information from a controlling node, wherein the selecting of the first SSB occasion 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 occasion; an indication of an SSB area associated with the first SSB occasion or the first beam transmitted during the first SSB occasion; 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 delivered to served child nodes, wherein a total throughput delivered 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.
The method of claim 7, further comprising receiving from the controlling node second configuration information associated with a second network node.
The method of claim 1, wherein the transitioning further comprises one of the following: i) receiving from a controlling node an indication 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, wherein the transitioning further comprises indicating to the controlling node a start of the transition from the first PCI to the second PCI; or ii) 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.
The method of claim 1, further comprising one of the following: i) 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; or ii) wherein the transitioning is performed while 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 occasion using a beam that is quasi-collocated 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 occasion using a beam that is quasi-collocated with the first beam.
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.
The method of claim 1, wherein the transitioning further comprises performing a System Information Block Type 1, SIB1, update during the transition period, the SIB 1 update comprising at least one of: updating a bitmap of indices of the SSB occasions in which a signal based on the first PCI is transmitted; updating a quasi-collocated, QCL, relationship among beams associated with the SSB occasions in which a signal based on the first PCI is transmitted; sending an updated SIB1 message to a controlling node; or updating a SIB1 transmission.
The method of claim 1, wherein the transitioning further comprises one of the following: i) sending a System Information Block Type 1, SIB1, message corresponding to a signal transmitted based on the second PCI during the transition period; and sending an updated SIB1 message after the end of the transition period; ii) sending 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, wherein the updated SIB1 message is sent in a dedicated manner to a connected or idle child node; iii) sending a short message to a child node or sending a paging message to an idle user equipment, UE, to indicate an update of system information; or iv) refraining from sending 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 sending a new SIB1 message corresponding to a signal transmitted based on the second PCI after the end of the transition period.
The method of claim 1, further comprising: receiving configuration information from a controlling 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 to indicate an update of system information during the transition period, or sending a paging message to an idle user equipment, UE, to indicate an update of system information during the transition period.
A method (1400) performed at a network node for changing a physical cell identifier, PCI, when a network node migrates from one controlling node to anther controlling node in an integrated access and backhaul, IAB, system, comprising: transmitting (1402) a first signal based on a first physical cell identifier, PCI, during a first synchronization signal block, SSB, occasion; transmitting (1404) a second signal based on the first PCI during a second SSB occasion; transmitting (1406) a third signal based on the first PCI during a third SSB occasion, wherein the first, second, and third SSB occasions are part of a set of SSB occasions in a periodically repeating time frame; and transitioning (1412) from the first PCI to a second PCI, wherein during a first transition period, the transitioning comprises: transmitting the first signal based on the second PCI during the first SSB occasion, continuing to transmit the second signal based on the first PCI during the second SSB occasion, and continuing to transmit the third signal based on the first PCI during the third SSB occasion, wherein during a second transition period, the transitioning comprises: continuing to transmit the first signal based on the second PCI during the first SSB occasion, transmitting the second signal based on the second PCI during the second SSB occasion, and continuing to transmit the third signal based on the first PCI during the third SSB occasion, and wherein after an end of the second transition period, the transitioning comprises: continuing to transmit the first signal based on the second PCI during the first SSB occasion, continuing to transmit the second signal based on the second PCI during the second SSB occasion, and ceasing transmission of the third signal based on the first PCI during the third SSB occasion.
The method of claim 15, comprising one of the following: i) wherein the transitioning further comprises: transmitting the third signal based on the second PCI during the third SSB occasion after the end of the second transition period; or ii) selecting (1410) the first SSB occasion to transmit the first signal based on the second PCI during the first transition period and the second SSB occasion to transmit the second signal based on the second PCI during the second transition period, wherein the selecting is based on at least one of: a configuration received from a controlling node providing an index of the first SSB occasion and an index of the second SSB occasion; the network node switching a PCI during the first SSB occasion where no child nodes are served on a first beam associated with the first SSB occasion; child nodes served on a second beam associated with the second SSB occasion migrating to the second PCI, wherein the child nodes are served on a beam that is quasi-collocated with the second beam and is transmitted during the first SSB occasion; or no child nodes are served on the second beam associated with the second SSB occasion.
A network node for changing a physical cell identifier, PCI when a network node migrates from one controlling node to anther controlling node in an integrated access and backhaul, IAB, system, 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, occasion; transmit a second signal based on the first PCI during a second SSB occasion, wherein the first SSB occasion and the second SSB occasion are part of a set of SSB occasions in a periodically repeating time frame; and transition from the first PCI to a second PCI, wherein during a transition period, the at least one processor and the memory configured to transition are configured to: transmit the first signal based on the second PCI during the first SSB occasion, and continue to transmit the second signal based on the first PCI during the second SSB occasion, and wherein after an end of the transition period, the at least one processor and the memory configured to transition are configured to: continue to transmit the first signal based on the second PCI during the first SSB occasion, and cease transmission of the second signal based on the first PCI during the second SSB occasion.
A network node for changing a physical cell identifier, PCI, when a network node migrates from one controlling node to anther controlling node in an integrated access and backhaul, IAB, system, 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, occasion; transmit a second signal based on the first PCI during a second SSB occasion; transmit a third signal based on the first PCI during a third SSB occasion, wherein the first, second, and third SSB occasions are part of a set of SSB occasions 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: transmit the first signal based on the second PCI during the first SSB occasion, continue to transmit the second signal based on the first PCI during the second SSB occasion, and continue to transmit the third signal based on the first PCI during the third SSB occasion, wherein during a second transition period, the at least one processor and the memory configured to transition are configured to: continue to transmit the first signal based on the second PCI during the first SSB occasion, transmit the second signal based on the second PCI during the second SSB occasion, and continue to transmit the third signal based on the first PCI during the third SSB occasion, and wherein after an end of the second transition period, the at least one processor and the memory configured to transition are configured to: continue to transmit the first signal based on the second PCI during the first SSB occasion, continue to transmit the second signal based on the second PCI during the second SSB occasion, and cease transmission of the third signal based on the first PCI during the third SSB occasion.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of Non-Provisional Application Serial No. 17/362,759 filed in the United States Patent Office on June 29, 2021 and Provisional Application Serial No. 63/047,207 filed in the United States Patent Office on July 1, 2020. INTRODUCTION The technology discussed below relates generally to wireless communication systems, and more particularly, to a network node for changing a physical cell identifier (PCI). Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). A wireless multiple-access communication system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). Multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with 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 may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies. BRIEF SUMMARY OF SOME EXAMPLES The following presents a summary of one or more aspects of the present disclosure, in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate 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 a form as a prelude to the more detailed description that is presented later. In one example, a method performed at a network node for changing a physical cell identifier (PCI) is disclosed. The method includes transmitting a first signal based on a first physical cell identifier (PCI) during a first synchronization signal block (SSB) occasion, transmitting a second signal based on the first PCI during a second SSB occasion, wherein the first SSB occasion and the second SSB occasion are part of a set of SSB occasions in a periodically repeating time frame, transitioning from the first PCI to a second PCI, wherein during a transition period, the transitioning includes transmitting the first signal based on the second PCI during the first SSB occasion, and continuing to transmit the second signal based on the first PCI during the second SSB occasion, and wherein after an end of the transition period, the transitioning includes continuing to transmit the first signal based on the second PCI during the first SSB occasion, and ceasing transmission of the second signal based on the first PCI during the second SSB occasion, receiving configuration information from a controlling node, and selecting, based on the configuration information, the first SSB occasion to transmit the first signal based on the second PCI during the transition period. 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 processor. 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) occasion, transmit a second signal based on the first PCI during a second SSB occasion, wherein the first SSB occasion and the second SSB occasion are part of a set of SSB occasions in a periodically repeating time frame, transition from the first PCI to a second PCI, wherein during a transition period, the transitioning includes transmitting the first signal based on the second PCI during the first SSB occasion, and continuing to transmit the second signal based on the first PCI during the second SSB occasion, and wherein after an end of the transition period, the transitioning includes continuing to transmit the first signal based on the second PCI during th