EP4670416A1

EP4670416A1 - Switching off cells to save energy in a wireless communication system

Info

Publication number: EP4670416A1
Application number: EP24701055.6A
Authority: EP
Inventors: Prateek Basu Mallick; Genadi Velev; Joachim Löhr; Ravi Kuchibhotla
Original assignee: Lenovo Singapore Pte Ltd
Current assignee: Lenovo Singapore Pte Ltd
Priority date: 2023-02-22
Filing date: 2024-01-09
Publication date: 2025-12-31
Also published as: CN120712845A; GB202511489D0; WO2024110946A1; GB2641472A

Abstract

Various aspects of the present disclosure relate to energy savings in a wireless communications system. A determination is made to switch off a first serving cell of a first public land mobile network (PLMN), such as based on time of day or load information at the first serving cell. A network entity in the first serving cell transmits, to a UE being served by the first serving cell, an indication that the first serving cell is to be switched off. In response to the indication, the UE selects a second serving cell of a second PLMN, and begins transmitting signals to and receiving signals from the second serving cell rather than the first serving cell. Additionally, after transmitting the indication, the cell transmission and reception at the first serving cell is switched off.

Description

SWITCHING OFF CELLS FOR ENERGY SAVING IN A WIRELESS COMMUNICATIONS SYSTEM

RELATED APPLICATION

[0001] This application claims priority to U.S. Patent Application Serial No. 63/486,335 filed February 22, 2023 entitled “SWITCHING OFF CELLS FOR ENERGY SAVING IN A WIRELESS COMMUNICATIONS SYSTEM,” the disclosure of which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

[0002] The present disclosure relates to wireless communications, and more specifically to switching off cells for energy saving in a wireless communications system.

BACKGROUND

[0003] A wireless communications system may include one or multiple network communication devices, such as base stations, which may be otherwise known as an eNodeB (eNB), a nextgeneration NodeB (gNB), or other suitable terminology. Each network communication devices, such as a base station may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (UE), or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers). Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G)).

[0004] The wireless communications system includes numerous devices that consume power. Various different techniques may be used by the different devices in the wireless communications system in order to reduce power usage in the wireless communications system. SUMMARY

[0005] The present disclosure relates to methods, apparatuses, and systems that support switching off cells for energy saving in a wireless communications system. A determination is made to switch off a first serving cell of a first public land mobile network (PLMN), such as based on time of day or load information at the first serving cell. A network entity in the first serving cell transmits, to a UE being served by the first serving cell, an indication that the first serving cell is to be switched off. In response to the indication, the UE selects a second serving cell of a second PLMN, and begins transmitting signals to and receiving signals from the second serving cell rather than the first serving cell. Additionally, after transmitting the indication, the cell transmission and reception at the first serving cell is switched off. By switching off the first serving cell and notifying the UE, power is conserved in the wireless communications system due to the first serving cell not transmitting or receiving signals while switched off, and the UE is still able to communicate in the wireless communications system via the second serving cell.

[0006] Some implementations of the method and apparatuses described herein may further include to: receive, from a first serving cell of a first PLMN, a first signaling indicating an intention of the first serving cell to switch off the first serving cell; select, in response to the first signaling, a second serving cell of a second PLMN; and transmit, to the second cell of the second PLMN, a second signaling.

[0007] In some implementations of the method and apparatuses described herein, the first signaling comprises a broadcast signaling. Additionally or alternatively, the first signaling includes a radio resource control message. Additionally or alternatively, the first signaling is at an access stratum layer and the method and apparatuses further include to forward cell switch off information to a non access stratum layer. Additionally or alternatively, the method and apparatuses further include to select the second PLMN based at least in part on information received from the non access stratum layer. Additionally or alternatively, the method and apparatuses further include to determine that a registration procedure is to be performed for the second cell; and perform the registration procedure for the second cell. Additionally or alternatively, the method and apparatuses further include to determine that the registration procedure is to be performed based on an indication in the first signaling. Additionally or alternatively, the first signaling indicates at least one of an identification of the second PLMN, frequency information, or an identifier of the second cell. Additionally or alternatively, the method and apparatuses further include to select the second serving cell without having performed a reference signal measurement on the second serving cell. Additionally or alternatively, the first signaling includes an indication of a time when the first serving cell will switch on. Additionally or alternatively, the method and apparatuses further include to release, in response to the first signaling, a small data transmission (SDT) configuration for the first serving cell. Additionally or alternatively, the apparatus comprises a user equipment.

[0008] Some implementations of the method and apparatuses described herein may further include to: transmit, to a UE, a first signaling indicating an intention of a first serving cell of a first PLMN to switch off the first serving cell; and switch off cell transmission and reception at the first serving cell.

[0009] In some implementations of the method and apparatuses described herein are further to determine to switch off the first cell based on load information at the first serving cell. Additionally or alternatively, the load information comprises at least one of a total number of a number of radio resource control connected UEs of the first serving cell, an amount of downlink data at the first serving cell, an amount of uplink data at the first serving cell, or a transmission power of the first serving cell. Additionally or alternatively, the method and apparatuses further include to determine to switch off the first cell based on whether a current time at the first serving cell is within a particular time range. Additionally or alternatively, the apparatus comprises a base station of the first serving cell. Additionally or alternatively, the first signaling comprises a broadcast signaling. Additionally or alternatively, the first signaling includes a radio resource control message. Additionally or alternatively, the method and apparatuses further include to perform a registration procedure with the UE. Additionally or alternatively, the first signaling includes an indication that the registration procedure is to be performed. Additionally or alternatively, the first signaling indicates at least one of an identification of a second PLMN for the UE to switch to, frequency information, or an identifier of a second cell for the UE to switch to. Additionally or alternatively, the first signaling includes an indication of a time when the first serving cell will switch on. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 illustrates an example of a wireless communications system that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure.

[0011] FIGs. 2A and 2B illustrate an example of changing serving cells that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure.

[0012] FIG. 3 illustrates an example of redirection information that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure.

[0013] FIG. 4 illustrates an example of handing over a UE that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure.

[0014] FIG. 5 illustrates a message that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure.

[0015] FIG. 6 illustrates an example of handing over a UE that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure.

[0016] FIGs. 7 and 8 illustrate examples of block diagrams of devices that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure.

[0017] FIGs. 9 through 14 illustrate flowcharts of methods that support switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

[0018] Emissions and energy consumption from different elements of a wireless communications system can adversely contribute to the climate. Furthermore, the operating expenses to run a wireless communications system are huge, and a number of industry-specific factors rooted in countering rising network costs have further shaped efficiency efforts. A continued rise in mobile data traffic, combined with the rising costs of spectrum, capital, investment and ongoing RAN maintenance or upgrades, make energy-saving measures in network operations desirable. 5G New Radio (NR) offers a significant energy-efficiency improvement per gigabyte over previous generations of mobility.

[0019] Using the techniques discussed herein, a determination is made to switch off a first serving cell of a first PLMN. This determination can be made based on various criteria, such as time of day (e.g., the first cell is switched off daily from 1 : 00 am to 3:00 am), load information at the first serving cell (e.g., the first cell is switched off if a number of radio resource control (RRC) connected UEs of the first serving cell drop below a threshold number), and so forth. A network entity in the first serving cell transmits, to UEs being served by the first serving cell, an indication that the first serving cell is to be switched off. In response to the indication, the UEs each select a second serving cell of a second PLMN, and each UE begins transmitting signals to and receiving signals from their selected second serving cell rather than the first serving cell. Additionally, after transmitting the indication, the cell transmission and reception at the first serving cell is switched off. The criteria used to determine when to switch off the first serving cell can be decided on by, for example, operators of the first PLMN and the second PLMN.

[0020] Switching off the first serving cell conserves power in the wireless communications system because the first serving cell is not transmitting or receiving signals while switched off. Furthermore, by notifying the UEs being served by the first serving cell of the upcoming switching off of the first serving cell, the UEs are able to begin communicating with a different serving cell of a different PLMN, allowing the UEs to continue communicating in the wireless communications system without interruption.

[0021] Another technique to improve network energy savings are techniques in time domain , such as cell discontinuous transmission (DTX)/discontinuous reception (DRX). Cell DTX/DRX is applied to at least UEs in an RRC CONNECTED state. A periodic cell DTX/DRX (e.g., active and non-active periods) can be configured by the network entity via UE-specific RRC signaling per serving cell. While a technique like cell DTX/ DRX allows some power saving for the wireless communications system, it still needs the network entity to be transmitting downlink (DL), and be listening for any possible uplink (UL) transmissions from time to time, depending on the DTX/DRX configuration. This prevents the wireless communications system from realizing power saving beyond a conservative level. The techniques discussed herein provide greater power saving because transmissions and receptions by the cell are turned off - there is no transmitting DL or listening for possible UL transmissions while the cell is turned off.

[0022] Aspects of the present disclosure are described in the context of a wireless communications system. Aspects of the present disclosure are further illustrated and described with reference to device diagrams and flowcharts.

[0023] FIG. 1 illustrates an example of a wireless communications system 100 that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more network entities 102, one or more UEs 104, a core network 106, and a packet data network 108. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as an LTE network or an LTE- Advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a 5G network, such as an NR network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA), frequency division multiple access (FDMA), or code division multiple access (CDMA), etc.

[0024] The one or more network entities 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the network entities 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a radio access network (RAN), a base transceiver station, an access point, a NodeB, an eNodeB (eNB), a next-generation NodeB (gNB), or other suitable terminology. A network entity 102 and a UE 104 may communicate via a communication link 110, which may be a wireless or wired connection. For example, a network entity 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

[0025] A network entity 102 may provide a geographic coverage area 112 for which the network entity 102 may support services (e.g., voice, video, packet data, messaging, broadcast, etc.) for one or more UEs 104 within the geographic coverage area 112. For example, a network entity 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc.) according to one or multiple radio access technologies. In some implementations, a network entity 102 may be moveable, for example, a satellite associated with a non-terrestrial network. In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but the different geographic coverage areas 112 may be associated with different network entities 102. Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0026] The one or more UEs 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a mobile device, a wireless device, a remote device, a remote unit, a handheld device, or a subscriber device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (loT) device, an Internet- of-Everything (loE) device, or machine-type communication (MTC) device, among other examples. In some implementations, a UE 104 may be stationary in the wireless communications system 100. In some other implementations, a UE 104 may be mobile in the wireless communications system 100.

[0027] The one or more UEs 104 may be devices in different forms or having different capabilities. Some examples of UEs 104 are illustrated in FIG. 1. A UE 104 may be capable of communicating with various types of devices, such as the network entities 102, other UEs 104, or network equipment (e.g., the core network 106, the packet data network 108, a relay device, an integrated access and backhaul (IAB) node, or another network equipment), as shown in FIG. 1. Additionally, or alternatively, a UE 104 may support communication with other network entities 102 or UEs 104, which may act as relays in the wireless communications system 100.

[0028] A UE 104 may also be able to support wireless communication directly with other UEs 104 over a communication link 114. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

[0029] A network entity 102 may support communications with the core network 106, or with another network entity 102, or both. For example, a network entity 102 may interface with the core network 106 through one or more backhaul links 116 (e.g., via an SI, N2, N6, or another network interface). The network entities 102 may communicate with each other over the backhaul links 116 (e.g., via an X2, Xn, or another network interface). In some implementations, the network entities 102 may communicate with each other directly (e.g., between the network entities 102). In some other implementations, the network entities 102 may communicate with each other or indirectly (e.g., via the core network 106). In some implementations, one or more network entities 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC). An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs).

[0030] In some implementations, a network entity 102 may be configured in a disaggregated architecture, which may be configured to utilize a protocol stack physically or logically distributed among two or more network entities 102, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance), or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN)). For example, a network entity 102 may include one or more of a central unit (CU), a distributed unit (DU), a radio unit (RU), a RAN Intelligent Controller (RIC) (e.g., a Near-Real Time RIC (Near-RT RIC), a Non-Real Time RIC (Non-RT RIC)), a Service Management and Orchestration (SMO) system, or any combination thereof. [0031] An RU may also be referred to as a radio head, a smart radio head, a remote radio head (RRH), a remote radio unit (RRU), or a transmission reception point (TRP). One or more components of the network entities 102 in a disaggregated RAN architecture may be co-located, or one or more components of the network entities 102 may be located in distributed locations (e.g., separate physical locations). In some implementations, one or more network entities 102 of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU), a virtual DU (VDU), a virtual RU (VRU)).

[0032] Split of functionality between a CU, a DU, and an RU may be flexible and may support different functionalities depending upon which functions (e.g., network layer functions, protocol layer functions, baseband functions, radio frequency functions, and any combinations thereof) are performed at a CU, a DU, or an RU. For example, a functional split of a protocol stack may be employed between a CU and a DU such that the CU may support one or more layers of the protocol stack and the DU may support one or more different layers of the protocol stack. In some implementations, the CU may host upper protocol layer (e.g., a layer 3 (L3), a layer 2 (L2)) functionality and signaling (e.g., Radio Resource Control (RRC), service data adaption protocol (SDAP), Packet Data Convergence Protocol (PDCP)). The CU may be connected to one or more DUs or RUs, and the one or more DUs or RUs may host lower protocol layers, such as a layer 1 (LI) (e.g., physical (PHY) layer) or an L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU.

[0033] Additionally, or alternatively, a functional split of the protocol stack may be employed between a DU and an RU such that the DU may support one or more layers of the protocol stack and the RU may support one or more different layers of the protocol stack. The DU may support one or multiple different cells (e.g., via one or more RUs). In some implementations, a functional split between a CU and a DU, or between a DU and an RU may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU, a DU, or an RU, while other functions of the protocol layer are performed by a different one of the CU, the DU, or the RU).

[0034] A CU may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU may be connected to one or more DUs via a midhaul communication link (e.g., Fl, Fl-c, Fl-u), and a DU may be connected to one or more RUs via a fronthaul communication link (e.g., open fronthaul (FH) interface). In some implementations, a midhaul communication link or a fronthaul communication link may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 102 that are in communication via such communication links.

[0035] The core network 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The core network 106 may be an evolved packet core (EPC), or a 5G core (5GC), which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management functions (AMF)) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P- GW), a user plane function (UPF)), or a location management function (LMF), which is a control plane entity that manages location services. In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc.) for the one or more UEs 104 served by the one or more network entities 102 associated with the core network 106.

[0036] The core network 106 may communicate with the packet data network 108 over one or more backhaul links 116 (e.g., via an SI, N2, N6, or another network interface). The packet data network 108 may include an application server 118. In some implementations, one or more UEs 104 may communicate with the application server 118. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the core network 106 via a network entity 102. The core network 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server 118 using the established session (e.g., the established PDU session). The PDU session may be an example of a logical connection between the UE 104 and the core network 106 (e.g., one or more network functions of the core network 106).

[0037] In the wireless communications system 100, the network entities 102 and the UEs 104 may use resources of the wireless communication system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) to perform various operations (e.g., wireless communications). In some implementations, the network entities 102 and the UEs 104 may support different resource structures. For example, the network entities 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the network entities 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the network entities 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures). The network entities 102 and the UEs 104 may support various frame structures based on one or more numerologies.

[0038] One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., /r=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. The first numerology (e.g., /r=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., /r=l) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., /r=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., /r=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., /r=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

[0039] A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames). Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

[0040] Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. Each slot may include a number (e.g., quantity) of symbols (e.g., orthogonal frequency division multiplexing (OFDM) symbols). In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing), a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., /r=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

[0041] In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz - 7.125 GHz), FR2 (24.25 GHz - 52.6 GHz), FR3 (7.125 GHz - 24.25 GHz), FR4 (52.6 GHz - 114.25 GHz), FR4a or FR4-1 (52.6 GHz - 71 GHz), and FR5 (114.25 GHz - 300 GHz). In some implementations, the network entities 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the network entities 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data). In some implementations, FR2 may be used by the network entities 102 and the UEs 104, among other equipment or devices for short- range, high data rate capabilities.

[0042] FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies). For example, FR1 may be associated with a first numerology (e.g., /r=0), which includes 15 kHz subcarrier spacing; a second numerology (e.g., /r=l), which includes 30 kHz subcarrier spacing; and a third numerology (e.g., /r=2), which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies). For example, FR2 may be associated with a third numerology (e.g., /r=2), which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., /r=3), which includes 120 kHz subcarrier spacing.

[0043] Emissions and energy consumption from different elements of a wireless communications system can adversely contribute to the climate. Furthermore, the operating expenses to run a wireless communications system are huge, and a number of industry-specific factors rooted in countering rising network costs have further shaped efficiency efforts. A continued rise in mobile data traffic, combined with the rising costs of spectrum, capital, investment and ongoing RAN maintenance or upgrades, make energy-saving measures in network operations desirable. 5G New Radio (NR) offers a significant energy-efficiency improvement per gigabyte over previous generations of mobility. [0044] Network energy saving is of great importance for environmental sustainability, to reduce environmental impact (greenhouse gas emissions), and for operational cost savings. As 5G is becoming pervasive across industries and geographical areas, handling more advanced services and applications requiring very high data rates (e.g., extended reality (XR)), networks are being denser, are using more antennas, are having larger bandwidths, and are having more frequency bands. The environmental impact of 5G should stay under control, and solutions to improve network energy savings should be used.

[0045] Energy consumption has become a key part of the operators’ operating expenditure. Most of the energy consumption comes from the radio access network and in particular from the active antenna unit (AAU), with data centers and fiber transport accounting for a smaller share. The power consumption of a radio access can be split into two parts: the dynamic part which is only consumed when data transmission/reception is ongoing, and the static part which is consumed all the time to maintain the necessary operation of the radio access devices, even when the data transmission/reception is not on-going.

[0046] Therefore, more efficient operation dynamically and/or semi-statically and finer granularity adaptation of transmissions and/or receptions in one or more of network energy saving techniques in time, frequency, spatial, and power domains, with potential support/feedback from UE, potential UE assistance information, and information exchange/coor dination over network interfaces is desired.

[0047] In addition to network energy consumption gains, the impact on network and user performance, e.g., by looking at KPIs such as spectral efficiency, capacity, user perceived throughput (UPT), latency, UE power consumption, complexity, handover performance, call drop rate, initial access performance, service level agreement (SLA) assurance related key performance indicators (KPIs), and so forth is also taken into consideration.

[0048] Using the techniques discussed herein, a determination is made to switch off a first serving cell of a first PLMN. This determination can be made based on various criteria, such as time of day (e.g., the first cell is switched off daily from 1 : 00 am to 3:00 am), load information at the first serving cell (e.g., the first cell is switched off if a number of radio resource control (RRC) connected UEs of the first serving cell drop below a threshold number), and so forth. A network entity 102 in the first serving cell transmits, to a UE 104 being served by the first serving cell, a switch off indication 120 indicating that the first serving cell is to be switched off. In response to the indication 120, a cell selection system 122 of the UE 104 selects a second serving cell of a second PLMN, and the UE 104 begins transmitting signals to and receiving signals from the second serving cell rather than the first serving cell.

[0049] Communication between devices discussed herein, such as between UEs 104 and network entities 102, is performed using any of a variety of different signaling. For example, such signaling can be any of various messages, requests, or responses, such as triggering messages, configuration messages, and so forth. By way of another example, such signaling can be any of various signaling mediums or protocols over which messages are conveyed, such as any combination of radio resource control (RRC), downlink control information (DCI), uplink control information (UCI), sidelink control information (SCI), medium access control element (MAC-CE), sidelink positioning protocol (SLPP), PC5 radio resource control (PC5-RRC) and so forth.

[0050] FIGs. 2A and 2B illustrate an example of changing serving cells that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. FIG. 2A illustrates a wireless communications system 200 that includes a UE 104, a network entity 202 that provides a cell 204, and another network entity 206 that provides another serving cell 208. The UE 104 is being served by the serving cell 204 (and thus by the network entity 202). In the illustrated example of FIGs. 2A and 2B, the serving cells 204 and 208 are correspond to different PLMNs run by different operators.

[0051] In response to receiving an indication that the serving cell 204 intends to be switch off, the UE 104 selects serving cell 208 and begins transmitting signals to and receiving signals from the network entity 206. Accordingly, after the serving cell 204 is switched off, the UE 104 is being served by the serving cell 208 (and thus by the network entity 206) as illustrated in FIG. 2B.

[0052] Returning to FIG. 1, generally, a wireless operator may deploy its own radio infrastructures (base stations or cell, generally referred to as RAN) and also its packet core (the core network or CN). Such a network deployment results in many difficulties such as high deployment costs, spectrum license fees, site acquisition, etc., so using RAN sharing these save costs in radio infrastructure deployment. A network cell can be shared by operators other than the one deploying it. To this end, system information block 1 (SIB1) in 5G NR broadcasts a list of PLMNs, and up to 12 PLMNs can be broadcasted. The private network (standalone non- public network (SNPN) or public network integrated (PNI)-non- public network (NPN)) can also be part of this kind of “RAN sharing” approach. The total number of PLMNs (identified by a PLMN identity in plmn-Identity List), PNI-NPNs (identified by a PLMN identity and a closed access group (CAG)-identifier (ID)), and SNPNs (identified by a PLMN identity and a network identifier (NID)) together in the PLMN- Identity Info List and NPN-Identity Info List does not exceed 12, except for the NPN-only cells.

[0053] In one or more implementations, a scenario is assumed where a first operator A deploys a first RAN and a second operator B deploys a second RAN. The operators negotiate one or more time periods when the one operator (e.g., the first operator) switches off a radio cell and during this time the other operator (e.g., the second operator) ensures radio coverage covering the area of the cell of the first operator which is switched off. So, UEs that lose coverage because their serving cell(s) from the current registered PLMN (e.g., the first operator) are no more available, need to discover and select cells from the other operator. The operators can come to simple agreement allowing each in turn to switch off cells during different time durations or time periods. For example, operator A turns off its cell from 1 :00 AM to 3:00 AM and operator B turns off its cell from 3:00 AM to 5:00 AM. There can be other time shares possible, e.g., instead of a fixed time based approach these operators will agree on a load based power saving, where the load can be determined based on various different load information. The load based power saving means that if, for example, at least one of the total number of RRC Connected UEs goes below a certain threshold in a radio cell, a total amount of DL data goes below a certain threshold in the radio cell, a total amount of UL data goes below a certain threshold in the radio cell, equivalent transmission power goes below a certain (corresponding) threshold in a radio cell, the radio cell can be switched off with or without a signaling informing a second cell of the second operator about the impending cell switch off. The RRC Connected UEs refer to UEs that are in an RRC Connected state where radio resources are allocated to the UE and active communication (e.g., in a user plane or control plane) between the UE and the network entity is typically occurring.

[0054] In one or more implementations, the RRC Connected UEs of the switching off cell are informed apriori of the situation and preventive measures for loss of service is taken. [0055] In one example, an RRC Connected UE is redirected to an overlaying cell of the second operator, the redirection information providing at least the carrier frequency number of the overlaying cell of the second operator.

[0056] FIG. 3 illustrates an example of redirection information 300 that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure.

[0057] In another example an RRC Connected UE is handed over to the overlaying cell of the second operator, even blindly (e.g., without the UE performing any prior measurement or measurement reporting for the same, such as without performing any prior reference signal measurements or channel state information reporting).

[0058] FIG. 4 illustrates an example 400 of handing over a UE that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. In the example 400, two cells 402 and 404 are shown. The cell 402 is a cell of one operator and the cell 404 is a cell of another operator. The two operators perform a cell switch-off for power saving negotiation 406. This can result in different criteria used to determine when to switch off the cell 402, such as time-based criteria, load information criteria, and so forth. Based on the criteria, a cell switch off decision 408 is made by the cell 402.

[0059] The cell 402 transmits a handover indication 410 to an RRC Connected UE 412 (a UE in an RRC Connected state) being served by the cell 402. The handover indication 410 is an indication of an intention of the cell 402 to switch off the cell 402. In response to the handover indication 410, the RRC Connected UE 412 performs a handover procedure 414 with the cell 404, which includes selecting the cell 404 and beginning to transmit signals to and receive signals from the cell 404 rather than the cell 402.

[0060] The core network (AMF, etc.) of the first operator (e.g., the operator of cell 402 in example 400) is awake and is ready to serve its subscriber. The overlaying cell of the second operator (e.g., the operator of cell 404 in example 400), has an interface towards the AMF of the first operator. Based on the information provided by the UE 412 in an RRC Connection Setup Complete message as part of the handover procedure 414, the second operator establishes the N2 interface for the UE 412 towards an appropriate AMF as determined from the received information. [0061] FIG. 5 illustrates a message 500 that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. The message 500 is an example of an RRC Connection Setup Complete message sent by the UE 412 as part of the handover procedure 414 of the example 400 of FIG. 4.

[0062] In one or more implementations, the RRC Idle UEs of the switching off cell are informed apriori of the situation and preventive measures for loss of service is taken. To this end, the switching off cell broadcasts information about its impending switch-off and possibly also the time when the cell is switching back on again.

[0063] At least one of frequency, physical cell identity, or other information may also be broadcasted by the switching off cell to help the RRC Idle UE find service on an overlaying cell of the second operator as part of the Carrier Info NR discussed above (e.g., with reference to FIG. 3).

[0064] One or more PLMN identifiers (IDs), e.g., of the second operator, and an indication that the one or more PLMN IDs should be selected while the coverage from the home operator may not be available may also be broadcasted by the switching off cell to help the RRC Idle UE find service on an overlaying cell of the second operator as part of the Carrier Info NR discussed above (e.g., with reference to FIG. 3). This information is used in the UEs registered currently with the first operator enabling the PLMN ID of the second operator to be treated as roaming partner (or registered PLMN in case of roaming UEs) for the time for which the serving cell indicates its absence or switch-off time. Accordingly, the indicated PLMN ID of the second operator need not be seen or used as an “equivalent PLMN”, and therefore NAS need not trigger a PLMN selection afresh, as shown in FIG. 6 below but without the “Re-registration” part. The core network AMF ensures that the UE’s registration area contains a tracking area identifier (TAI) list, e.g., a list of tracking areas with TAI that already includes the TAI of the overlaying cell of the second operator. Therefore, a re-registration upon selection of the overlaying cell of the second operator will not be necessary.

[0065] The PLMN ID (e.g., of the second operator) and an optional indication indicating if this PLMN ID is to be used for registration or re-registration while the coverage from the home operator may not be available may also be broadcasted by the switching off cell to help the RRC Idle UE find service on an overlaying cell of the second operator as part of the Carrier Info NR discussed above (e.g., with reference to FIG. 3). This will lead the UE Access Stratum (AS) to inform its Non- Access Stratum (NAS layer) about the serving cell switch off and provide the alternate PLMN. The NAS layer will then trigger a PLMN search and AS uses the other information (e.g., at least one of frequency, physical cell Identity, or other information as part of Carrier Info NR) to improve the PLMN or cell search. Upon a successful PLMN or cell selection, NAS will initiate a registration procedure, if needed, indicating the reason of registration as “Network Energy Saving” or an equivalent cause such as “serving cell switch off of a source operator”. The decision at the NAS to perform re-registration could be based on subscriber identity module (SIM) information of the UE, e.g., the SIM may tell the NAS that a registration procedure to a certain PLMN should always be performed when selecting a cell of that PLMN.

[0066] Broadcast information for indicating cell switch off may explicitly indicate a PLMN list containing at least one PLMN for that purpose (e.g., a PLMN from the PLMN list can only be used when the serving cell is switched off) and also indicate if the UE is to perform a registration procedure (a re-registration) upon selecting a cell of the second operator, as shown in FIG. 6 below.

[0067] FIG. 6 illustrates an example 600 of handing over a UE that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. In the example 600, two cells 602 and 604 are shown. The cell 602 is a cell of a first operator and the cell 604 is a cell of a second operator. The two operators perform a cell switch-off for power saving negotiation 606. This can result in different criteria used to determine when to switch off the cell 602, such as time-based criteria, load information criteria, and so forth. Based on the criteria, a cell switch off decision 608 is made by the cell 602.

[0068] The cell 602 transmits a handover indication 610 to an RRC Idle UE 612 (a UE in an RRC Idle state) being served by the cell 602. The handover indication 610 is an indication of an intention of the cell 602 to switch off the cell 602. In response to the handover indication 610, the RRC Idle UE 612 determines whether re-registration is required 614 and selects 616 a PLMN and cell of the second operator.

[0069] If re-registration is required, then a registration (or re-registration) procedure 618 is performed. In one or more implementations, the registration procedure 618 is performed in an analogous manner as any other time in which a UE is handed over from one cell to another. In the registration procedure 618, the RRC Idle UE 612 transmits an RRC Setup Request message 620 to the cell 604 (e.g., a network entity of the cell 604). The cell 604 responds by transmitting an RRC Setup message 622 to the RRC Idle UE 612. The RRC Idle UE 612 then sends an RRC Setup Complete message 624 including a registration request to the cell 604. The cell 604 sends an initial UE message and registration request 626 to an AMF 628. The AMF 628 is an AMF in the core network of the second operator. The AMF 628 responds by sending an initial context setup response and registration acceptance message 630 to the cell 604. The cell 604 then transmits a DL transfer message 632 indicating registration acceptance to the RRC Idle UE 612.

[0070] The RRC Idle UE 612 proceeds to transmit signals to and receive signals from the cell 604 rather than the cell 602.

[0071] In one or more implementations the RRC Inactive UEs of the switching off cell are informed in the same way as described for the RRC Idle UE, e.g., using broadcast signaling, apriori of the situation and preventive measures for loss of service is taken. The RRC Inactive UE upon receiving this information release SDT configuration (if configured) that enabled UL or DL data transfer in RRC Inactive state and starts transition to RRC idle state and thereafter behaves similarly to the RRC Idle UE, as described above.

[0072] Returning to FIG. 1, once the cell of the first operator is switched on again, RRC Connected UEs of the subscribed devices of the first operator are handed over or redirected back to the cell of the first operator. RRC Idle UEs will be informed using broadcast signaling about the switching on of the neighboring or overlaying cell of the first operator and thereafter the subscribed devices of the first operator will plan a return to its home (e.g., registered) PLMN. This may be an implicit PLMN or cell selection of the home PLMN and may not require a re-registration or, alternatively a re-registration may be required to ensure paging can be made accurately. This switch back to the cell of the first operator may be performed automatically after a time period or duration elapses (e.g., the time period or duration that the cell of the first operator is switched off).

[0073] Additionally or alternatively, the UE may be configured with a specific list of PLMNs (e.g., in priority order and RATs in priority order) which are to be used in case the current serving cell indicates its intention to switch off and there are no other available cells of the registered network. For example, such a list of PLMNs to be used during switch-off may be configured in the UE either in the UE subscription data (e.g., stored in the universal subscriber identity module (USIM)) or by using steering of roaming (SoR) procedure by the unified data management (UDM). When the UE AS layer receives a switch-off indication in the SIB, the UE AS may indicate this condition to the UE NAS layer. The UE NAS layer considers the list of PLMNs to be used during switch-off for the network selection procedure. When the UE selects a network from the list of PLMNs to be used during switch-off, the UE performs the registration procedure to register with the selected network.

[0074] Accordingly, as discussed herein, cell switch off negotiations between operators may be a fixed time based approach or a cell load based approach.

[0075] Additionally or alternatively, RRC Connected UEs of the switching off cell are informed apriori of the situation (the intent to switch off the cell). RRC Connected UEs are redirected to an overlaying cell of the second operator. RRC Connected UEs are handed over to the overlaying cell of the second operator, even blindly.

[0076] Additionally or alternatively, for RRC Idle UEs, the switching off cell broadcasts information about its impending switch-off and possibly also the time when the cell is switching on again. The broadcast information may include at least one of frequency, physical cell identity, or other information (e.g., as part of Carrier Info NR discussed above). The broadcast information may include a PLMN ID of the second operator and an indication that this PLMN ID is to be used as proxy: subscriber UEs of the first operator enabling the PLMN ID of the second operator to be treated as the Home PLMN - NAS need not trigger a PLMN selection or trigger re-registration afresh. A list of tracking areas with TAI that already includes the TAI of the overlaying cell of the second operator may be provided to the UE as part of its registration area. The broadcast information may include a PLMN ID of the second operator and an indication that this PLMN ID is to be used for registration or re-registration while the coverage from the home operator may not be available.

[0077] Additionally or alternatively, RRC Inactive UEs release SDT configuration and transition to RRC Idle state and select a cell of the second operator.

[0078] A procedure of return to a cell of the home PLMN with or without re-registration is discussed above. [0079] The techniques discussed herein enable operator sharing at a new level enabling the cells to be switched off completely from time to time, realizing a more effective power saving in the network.

[0080] Furthermore, as discussed above, in one or more implementations operators negotiate one or more time periods when each of these can take turns and switch off a radio cell and during this time the other (second) operator ensures radio coverage for subscribers of the first operator. Alternatively to or in addition to a fixed time based approach, operators may agree on a load based power saving. With the load based power saving if, for example, the total number of RRC Connected UEs, total amount of DL data, total amount of UL data, or equivalent transmission power, goes below a certain corresponding threshold in a radio cell, the radio cell can be switched off.

[0081] FIG. 7 illustrates an example of a block diagram 700 of a device 702 that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. The device 702 may be an example of a UE 104 as described herein. The device 702 may support wireless communication with one or more network entities 102, UEs 104, or any combination thereof. The device 702 may include components for bi-directional communications including components for transmitting and receiving communications, such as a processor 704, a memory 706, a transceiver 708, and an I/O controller 710. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses).

[0082] The processor 704, the memory 706, the transceiver 708, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. For example, the processor 704, the memory 706, the transceiver 708, or various combinations or components thereof may support a method for performing one or more of the operations described herein.

[0083] In some implementations, the processor 704, the memory 706, the transceiver 708, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry). The hardware may include a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some implementations, the processor 704 and the memory 706 coupled with the processor 704 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 704, instructions stored in the memory 706).

[0084] For example, the processor 704 may support wireless communication at the device 702 in accordance with examples as disclosed herein. Processor 704 may be configured as or otherwise support to: receive, from a first serving cell of a first PLMN, a first signaling indicating an intention of the first serving cell to switch off the first serving cell; select, in response to the first signaling, a second serving cell of a second PLMN; and transmit, to the second cell of the second PLMN, a second signaling.

[0085] Additionally or alternatively, the processor 704 may be configured to or otherwise support: where the first signaling comprises a broadcast signaling; where the first signaling includes a radio resource control message; where the first signaling is at an access stratum layer and where the processor is further configured to: forward cell switch off information to a non access stratum layer; where the processor is further configured to: select the second PLMN based at least in part on information received from the non access stratum layer; where the processor is further configured to: determine that a registration procedure is to be performed for the second cell; and perform the registration procedure for the second cell; where the processor is further configured to: determine that the registration procedure is to be performed based on an indication in the first signaling; where the first signaling indicates at least one of an identification of the second PLMN, frequency information, or an identifier of the second cell; where the processor is further configured to cause the apparatus to select the second serving cell without having performed a reference signal measurement on the second serving cell; where the first signaling includes an indication of a time when the first serving cell will switch on; where the processor is further configured to cause the apparatus to release, in response to the first signaling, a SDT configuration for the first serving cell; where the apparatus comprises a user equipment.

[0086] For example, the processor 704 may support wireless communication at the device 702 in accordance with examples as disclosed herein. Processor 704 may be configured as or otherwise support a means for receiving, from a first serving cell of a first PLMN, a first signaling indicating an intention of the first serving cell to switch off the first serving cell; selecting, in response to the first signaling, a second serving cell of a second PLMN; and transmitting, to the second cell of the second PLMN, a second signaling.

[0087] Additionally or alternatively, the processor 704 may be configured to or otherwise support: where the first signaling comprises a broadcast signaling; where the first signaling includes a radio resource control message; where the first signaling is at an access stratum layer and the method further comprises: forwarding cell switch off information to a non access stratum layer; selecting the second PLMN based at least in part on information received from the non access stratum layer; determining that a registration procedure is to be performed for the second cell; and performing the registration procedure for the second cell; determining that the registration procedure is to be performed based on an indication in the first signaling; where the first signaling indicates at least one of an identification of the second PLMN, frequency information, or an identifier of the second cell; selecting the second serving cell without having performed a reference signal measurement on the second serving cell; where the first signaling includes an indication of a time when the first serving cell will switch on; releasing, in response to the first signaling, a SDT configuration for the first serving cell; where the method is implemented by a user equipment.

[0088] The processor 704 of the device 702, such as a UE 104, may support wireless communication in accordance with examples as disclosed herein. The processor 704 includes at least one controller coupled with at least one memory, and is configured to or operable to cause the processor to receive, from a first serving cell of a first PLMN, a first signaling indicating an intention of the first serving cell to switch off the first serving cell; select, in response to the first signaling, a second serving cell of a second PLMN; and transmit, to the second cell of the second PLMN, a second signaling.

[0089] The processor 704 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some implementations, the processor 704 may be configured to operate a memory array using a memory controller. In some other implementations, a memory controller may be integrated into the processor 704. The processor 704 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 706) to cause the device 702 to perform various functions of the present disclosure.

[0090] The memory 706 may include random access memory (RAM) and read-only memory (ROM). The memory 706 may store computer-readable, computer-executable code including instructions that, when executed by the processor 704 cause the device 702 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some implementations, the code may not be directly executable by the processor 704 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 706 may include, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

[0091] The I/O controller 710 may manage input and output signals for the device 702. The I/O controller 710 may also manage peripherals not integrated into the device 702. In some implementations, the I/O controller 710 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 710 may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. In some implementations, the I/O controller 710 may be implemented as part of a processor, such as the processor 704. In some implementations, a user may interact with the device 702 via the I/O controller 710 or via hardware components controlled by the I/O controller 710.

[0092] In some implementations, the device 702 may include a single antenna 712. However, in some other implementations, the device 702 may have more than one antenna 712 (i.e., multiple antennas), including multiple antenna panels or antenna arrays, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 708 may communicate bi-directionally, via the one or more antennas 712, wired, or wireless links as described herein. For example, the transceiver 708 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 708 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 712 for transmission, and to demodulate packets received from the one or more antennas 712. [0093] FIG. 8 illustrates an example of a block diagram 800 of a device 802 that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. The device 802 may be an example of a network entity 102 as described herein. The device 802 may support wireless communication with one or more network entities 102, UEs 104, or any combination thereof. The device 802 may include components for bidirectional communications including components for transmitting and receiving communications, such as a processor 804, a memory 806, a transceiver 808, and an I/O controller 810. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses).

[0094] The processor 804, the memory 806, the transceiver 808, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. For example, the processor 804, the memory 806, the transceiver 808, or various combinations or components thereof may support a method for performing one or more of the operations described herein.

[0095] In some implementations, the processor 804, the memory 806, the transceiver 808, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry). The hardware may include a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some implementations, the processor 804 and the memory 806 coupled with the processor 804 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 804, instructions stored in the memory 806).

[0096] For example, the processor 804 may support wireless communication at the device 802 in accordance with examples as disclosed herein. Processor 804 may be configured as or otherwise support to: transmit, to a UE, a first signaling indicating an intention of a first serving cell of a first PLMN to switch off the first serving cell; and switch off cell transmission and reception at the first serving cell. [0097] Additionally or alternatively, the processor 804 may be configured to or otherwise support: to: determine to switch off the first cell based on load information at the first serving cell; where the load information comprises at least one of a total number of a number of radio resource control connected UEs of the first serving cell, an amount of downlink data at the first serving cell, an amount of uplink data at the first serving cell, or a transmission power of the first serving cell; to: determine to switch off the first cell based on whether a current time at the first serving cell is within a particular time range; where the apparatus comprises a base station of the first serving cell; where the first signaling comprises a broadcast signaling; where the first signaling includes a radio resource control message; where the processor is further configured to: perform a registration procedure with the UE; where the first signaling includes an indication that the registration procedure is to be performed; where the first signaling indicates at least one of an identification of a second PLMN for the UE to switch to, frequency information, or an identifier of a second cell for the UE to switch to; where the first signaling includes an indication of a time when the first serving cell will switch on.

[0098] For example, the processor 804 may support wireless communication at the device 802 in accordance with examples as disclosed herein. Processor 804 may be configured as or otherwise support a means for transmitting, to a UE, a first signaling indicating an intention of a first serving cell of a first PLMN to switch off the first serving cell; and switching off cell transmission and reception at the first serving cell.

[0099] Additionally or alternatively, the processor 804 may be configured to or otherwise support: determining to switch off the first cell based on load information at the first serving cell; where the load information comprises at least one of a total number of a number of radio resource control connected UEs of the first serving cell, an amount of downlink data at the first serving cell, an amount of uplink data at the first serving cell, or a transmission power of the first serving cell; determining to switch off the first cell based on whether a current time at the first serving cell is within a particular time range; where the method is implemented by a base station of the first serving cell; where the first signaling comprises a broadcast signaling; where the first signaling includes a radio resource control message; performing a registration procedure with the UE; where the first signaling includes an indication that the registration procedure is to be performed; where the first signaling indicates at least one of an identification of a second PLMN for the UE to switch to, frequency information, or an identifier of a second cell for the UE to switch to; where the first signaling includes an indication of a time when the first serving cell will switch on.

[0100] The processor 804 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some implementations, the processor 804 may be configured to operate a memory array using a memory controller. In some other implementations, a memory controller may be integrated into the processor 804. The processor 804 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 806) to cause the device 802 to perform various functions of the present disclosure.

[0101] The memory 806 may include random access memory (RAM) and read-only memory (ROM). The memory 806 may store computer-readable, computer-executable code including instructions that, when executed by the processor 804 cause the device 802 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some implementations, the code may not be directly executable by the processor 804 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 806 may include, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

[0102] The I/O controller 810 may manage input and output signals for the device 802. The I/O controller 810 may also manage peripherals not integrated into the device 802. In some implementations, the I/O controller 810 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 810 may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. In some implementations, the I/O controller 810 may be implemented as part of a processor, such as the processor 804. In some implementations, a user may interact with the device 802 via the I/O controller 810 or via hardware components controlled by the I/O controller 810. [0103] In some implementations, the device 802 may include a single antenna 812. However, in some other implementations, the device 802 may have more than one antenna 812 (i.e., multiple antennas), including multiple antenna panels or antenna arrays, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 808 may communicate bi-directionally, via the one or more antennas 812, wired, or wireless links as described herein. For example, the transceiver 808 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 808 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 812 for transmission, and to demodulate packets received from the one or more antennas 812.

[0104] FIG. 9 illustrates a flowchart of a method 900 that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. The operations of the method 900 may be implemented by a device or its components as described herein. For example, the operations of the method 900 may be performed by a UE 104 as described with reference to FIGs. 1 through 8. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

[0105] At 905, the method may include receiving, from a first serving cell of a first PLMN, a first signaling indicating an intention of the first serving cell to switch off the first serving cell. The operations of 905 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 905 may be performed by a device as described with reference to FIG. 1.

[0106] At 910, the method may include selecting, in response to the first signaling, a second serving cell of a second PLMN. The operations of 910 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 910 may be performed by a device as described with reference to FIG. 1.

[0107] At 915, the method may include transmitting, to the second cell of the second PLMN, a second signaling. The operations of 915 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 915 may be performed by a device as described with reference to FIG. 1.

[0108] FIG. 10 illustrates a flowchart of a method 1000 that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. The operations of the method 1000 may be implemented by a device or its components as described herein. For example, the operations of the method 1000 may be performed by a UE 104 as described with reference to FIGs. 1 through 8. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

[0109] At 1005, the method may include determining that a registration procedure is to be performed for the second cell. The operations of 1005 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1005 may be performed by a device as described with reference to FIG. 1.

[0110] At 1010, the method may include performing the registration procedure for the second cell. The operations of 1010 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1010 may be performed by a device as described with reference to FIG. 1.

[0111] FIG. 11 illustrates a flowchart of a method 1100 that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. The operations of the method 1100 may be implemented by a device or its components as described herein. For example, the operations of the method 1100 may be performed by a UE 104 as described with reference to FIGs. 1 through 8. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

[0112] At 1105, the method may include the first signaling indicates at least one of an identification of the second PLMN, frequency information, or an identifier of the second cell. The operations of 1105 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1105 may be performed by a device as described with reference to FIG. 1.

[0113] FIG. 12 illustrates a flowchart of a method 1200 that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. The operations of the method 1200 may be implemented by a device or its components as described herein. For example, the operations of the method 1200 may be performed by a network entity 102 as described with reference to FIGs. 1 through 8. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

[0114] At 1205, the method may include transmitting, to a UE, a first signaling indicating an intention of a first serving cell of a first PLMN to switch off the first serving cell. The operations of 1205 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1205 may be performed by a device as described with reference to FIG. 1.

[0115] At 1210, the method may include switching off cell transmission and reception at the first serving cell. The operations of 1210 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1210 may be performed by a device as described with reference to FIG. 1.

[0116] FIG. 13 illustrates a flowchart of a method 1300 that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. The operations of the method 1300 may be implemented by a device or its components as described herein. For example, the operations of the method 1300 may be performed by a network entity 102 as described with reference to FIGs. 1 through 8. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

[0117] At 1305, the method may include determining to switch off the first cell based on load information at the first serving cell, wherein the load information comprises at least one of a total number of a number of radio resource control connected UEs of the first serving cell, an amount of downlink data at the first serving cell, an amount of uplink data at the first serving cell, or a transmission power of the first serving cell. The operations of 1305 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1305 may be performed by a device as described with reference to FIG. 1.

[0118] FIG. 14 illustrates a flowchart of a method 1400 that supports switching off cells for energy saving in a wireless communications system in accordance with aspects of the present disclosure. The operations of the method 1400 may be implemented by a device or its components as described herein. For example, the operations of the method 1400 may be performed by a network entity 102 as described with reference to FIGs. 1 through 8. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

[0119] At 1405, the method may include determining to switch off the first cell based on whether a current time at the first serving cell is within a particular time range. The operations of 1405 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1405 may be performed by a device as described with reference to FIG. 1.

[0120] It should be noted that the methods described herein describes possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

[0121] The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0122] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

[0123] Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor.

[0124] Any connection may be properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0125] As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of’ or “one or more of’ or “one or both of’) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Similarly, a list of at least one of A; B; or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. Further, as used herein, including in the claims, a “set” may include one or more elements.

[0126] The terms “transmitting,” “receiving,” or “communicating,” when referring to a network entity, may refer to any portion of a network entity (e.g., a base station, a CU, a DU, a RU) of a RAN communicating with another device (e.g., directly or via one or more other network entities).

[0127] The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described example.

[0128] The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

CLAIMS What is claimed is:

1. A user equipment (UE) for wireless communication, comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: receive, from a first serving cell of a first public land mobile network (PLMN), a first signaling indicating an intention of the first serving cell to switch off the first serving cell; select, in response to the first signaling, a second serving cell of a second PLMN; and transmit, to the second cell of the second PLMN, a second signaling.

2. The UE of claim 1, wherein the first signaling comprises a broadcast signaling.

3. The UE of claim 2, wherein the first signaling includes a radio resource control message.

4. The UE of claim 1, wherein the first signaling is at an access stratum layer and wherein the at least one processor is further configured to: forward cell switch off information to a non access stratum layer.

5. The UE of claim 4, wherein the at least one processor is further configured to: select the second PLMN based at least in part on information received from the non access stratum layer.

6. The UE of claim 1, wherein the at least one processor is further configured to: determine that a registration procedure is to be performed for the second cell; and perform the registration procedure for the second cell.

7. The UE of claim 6, wherein the at least one processor is further configured to: determine that the registration procedure is to be performed based on an indication in the first signaling.

8. The UE of claim 1, wherein the first signaling indicates at least one of an identification of the second PLMN, frequency information, or an identifier of the second cell.

9. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to select the second serving cell without having performed a reference signal measurement on the second serving cell.

10. The UE of claim 1, wherein the first signaling includes an indication of a time when the first serving cell will switch on.

11. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to release, in response to the first signaling, a small data transmission (SDT) configuration for the first serving cell.

12. A base station for wireless communication, comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the base station to: transmit, to a user equipment (UE), a first signaling indicating an intention of a first serving cell of a first public land mobile network (PLMN) to switch off the first serving cell; and switch off cell transmission and reception at the first serving cell.

13. The base station of claim 12, wherein the at least one processor is further configured to cause the base station to: determine to switch off the first cell based on load information at the first serving cell.

14. The base station of claim 13, wherein the load information comprises at least one of a total number of a number of radio resource control connected UEs of the first serving cell, an amount of downlink data at the first serving cell, an amount of uplink data at the first serving cell, or a transmission power of the first serving cell.

15. The base station of claim 12, wherein the at least one processor is further configured to cause the base station to: determine to switch off the first cell based on whether a current time at the first serving cell is within a particular time range.

16. A method performed by a user equipment (UE), the method comprising: receiving, from a first serving cell of a first public land mobile network (PLMN), a first signaling indicating an intention of the first serving cell to switch off the first serving cell; selecting, in response to the first signaling, a second serving cell of a second PLMN; and transmitting, to the second cell of the second PLMN, a second signaling.

17. A processor for wireless communication, comprising: at least one controller coupled with at least one memory and configured to cause the processor to: receive, from a first serving cell of a first public land mobile network (PLMN), a first signaling indicating an intention of the first serving cell to switch off the first serving cell; select, in response to the first signaling, a second serving cell of a second PLMN; and transmit, to the second cell of the second PLMN, a second signaling.

18. The processor of claim 17, wherein the at least one controller is further configured to cause the processor to: determine that a registration procedure is to be performed for the second cell; and perform the registration procedure for the second cell.

19. The processor of claim 17, wherein the first signaling indicates at least one of an identification of the second PLMN, frequency information, or an identifier of the second cell.

20. The processor of claim 17, wherein the at least one controller is further configured to cause the processor to select the second serving cell without having performed a reference signal measurement on the second serving cell.