Network energy saving techniques for minimizing paging transmissions

Abstract

Various aspects of the present disclosure relate to receiving (802), from a first cell associated with a first frequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer. Aspects of the present disclosure may relate to re-tuning (804) a receiver frequency to the second frequency layer based on a next paging occasion associated with the second cell and receiving (806) a paging message on the second cell. Aspects of the present disclosure may relate to re-tuning (808) the receiver frequency to the first frequency layer based on an end of the next paging occasion and initiating (810) a connection with the first cell based at least in part on the paging message.

Description

NETWORK ENERGY SAVING TECHNIQUES FOR MINIMIZINGPAGING TRANSMISSIONSTECHNICAL FIELD

[0001] The present disclosure relates to wireless communications, and more specifically to network energy saving techniques by minimizing paging transmissions.BACKGROUND

[0002] A wireless communications system may include one or multiple network communication devices, which may be known as a network equipment (NE), supporting 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, or the like). Additionally, the wireless communications system may support wireless communications across various radio access technologies (RATs) 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., 5G- Advanced (5G-A), sixth generation (6G)).SUMMARY

[0003] An article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a,” “at least one,” “one or more,” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of’ or “one or more of’ or “one or both of) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, anexample 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.

[0004] A UE for wireless communication is described. The UE may be configured to, capable of, or operable to receive, from a first cell associated with a first frequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer; re-tune a receiver frequency to the second frequency layer based on a next paging occasion associated with the second cell; receive a paging message on the second cell; re-tune the receiver frequency to the first frequency layer based on an end of the next paging occasion; and initiate a connection with the first cell based at least in part on the paging message.

[0005] A processor for wireless communication is described. The processor may be configured to, capable of, or operable to receive, from a first cell associated with a first frequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer; re-tune a receiver frequency to the second frequency layer based on a next paging occasion associated with the second cell; receive a paging message on the second cell; re-tune the receiver frequency to the first frequency layer based on an end of the next paging occasion; and initiate a connection with the first cell based at least in part on the paging message.

[0006] A method performed or performable by a UE for wireless communication is described. The method may include receiving, from a first cell associated with a first frequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer; re-tuning a receiver frequency to the second frequency layer based on a next paging occasion associated with the second cell; receiving a paging message on the second cell; re-tuning the receiver frequency to the first frequency layer based on an end of the next paging occasion; and initiating a connection with the first cell based at least in part on the paging message.

[0007] A base station for wireless communication is described. The base station may be configured to, capable of, or operable to transmit, on a first cell associated with a firstfrequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer; transmit, to a UE, a paging message via the second cell; receive, from the UE, a paging response message via the first cell; and establish a connection with the UE via the first cell.

[0008] A processor for wireless communication by a base station is described. The processor may be configured to, capable of, or operable to transmit, on a first cell associated with a first frequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer; transmit, to a UE, a paging message via the second cell; receive, from the UE, a paging response message via the first cell; and establish a connection with the UE via the first cell.

[0009] A method performed or performable by an anchor base station for wireless communication is described. The method may include transmitting, on a first cell associated with a first frequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer; transmitting, to a UE, a paging message via the second cell; receiving, from the UE, a paging response message via the first cell; and establishing a connection with the UE via the first cell.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 illustrates an example of a wireless communications system in accordance with aspects of the present disclosure.

[0011] Figure 2 illustrates an example of a protocol stack showing different protocol layers in the UE and network, in accordance with aspects of the present disclosure.

[0012] Figure 3 illustrates an example of overlaying cells on different frequency layers, in accordance with aspects of the present disclosure.

[0013] Figure 4 illustrates an example of a procedure for radio frequency (RF) retuning between cells on different frequency layers, in accordance with aspects of the present disclosure.

[0014] Figure 5 illustrates an example of a UE, in accordance with aspects of the present disclosure.

[0015] Figure 6 illustrates an example of a processor, in accordance with aspects of the present disclosure.

[0016] Figure 7 illustrates an example of a NE, in accordance with aspects of the present disclosure.

[0017] Figure 8 illustrates a flowchart of a method performed by a UE, in accordance with aspects of the present disclosure.

[0018] Figure 9 illustrates a flowchart of a method performed by an NE, in accordance with aspects of the present disclosure.DETAILED DESCRIPTION

[0019] Generally, the present disclosure describes systems, methods, and apparatuses for cell measurement of network energy saving cells. In certain embodiments, the methods may be performed using computer-executable code embedded on a computer- readable medium. In certain embodiments, an apparatus or system may include a computer-readable medium containing computer-readable code which, when executed by a processor, causes the apparatus or system to perform at least a portion of the below described solutions.

[0020] Emissions and energy consumption from different elements of a telecommunication system are adversely contributing to the climate. Synchronization signal and physical broadcast channel (SS / PBCH) transmissions are necessary for initial access of a radio access network, yet cause significant network energy consumption. Moreover, these SS / PBCH transmissions are wasted energy when no UE is attempting to access the cell.

[0021] Additionally, the operating expenses to run a telecommunication services are huge. In telecommunications, a number of industry-specific factors rooted in countering rising network costs have further shaped efficiency efforts. A continued rise in mobile data traffic, estimated at 6.4 gigabytes (GB) per user per month in 2019 and forecast to grow threefold on a per-user basis over the next five years. Combined with the rising costs of spectrum, capital investment and ongoing RAN maintenance / upgrades, energysaving measures in network operations are necessary rather than nice to have.

[0022] 5G new radio (NR) offers a significant energy-efficiency improvement per gigabyte over previous generations of mobility. However, new 5G use cases and the adoption of mm Wave will require more sites and antennas. This leads to the prospect of a more efficient network that could paradoxically result in higher emissions without active intervention.

[0023] A study on network energy saving in NR justifies the need for energy saving. 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) services and applications), networks are being denser, use more antennas, larger bandwidths, and more frequency bands. The environmental impact of 5G needs to stay under control, and novel solutions to improve network energy savings need to be developed.

[0024] Energy consumption has become a key part of the operators’ operating expenses. By some reports, the energy cost on mobile networks accounts for approximately 23% of the total operator cost. 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.

[0025] Although a UE power consumption model was already defined by the 3rd generation partnership project (3GPP), there was a need to study and develop a network energy consumption model especially for the base station, key performance indicators (KPIs), an evaluation methodology and to identify and study network energy savings techniques in targeted deployment scenarios. The study investigated how to achieve 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 / coordination over network interfaces.

[0026] The 3GPP study not only evaluated the potential network energy consumption gains, but also assessed and balanced 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 KPIs, etc.

[0027] A network expends substantial energy in transmitting synchronization signal blocks (SSBs), physical broadcast channel (PBCH) (i.e., containing the master information block (MIB) and the system information block type 1 (SIB1). In the legacy 5G network, the system information blocks (SIBs) apart from SIB1 can already be provided on demand.

[0028] However, transmission of SSB and SIB1 is useful for cell identification, idle and connected mode mobility etc. Energy consumption from constant paging transmission can be unnecessary especially if few (or none) of the UEs being paged are actually present in a cell intending to save energy.

[0029] To solve the problems with network energy consumption discussed herein, the present disclosure describes UE and network techniques enabling network energy saving by minimizing paging transmissions. One straightforward option is to not transmit SSBs, whereby the network can ensure that there are no UEs in the cell in the radio resource control (RRC) Idle or Inactive states, and therefore no paging needs to be transmitted as well.

[0030] However, this option is sub-optimal since this prohibits cell detection and camping by UEs which may otherwise not have any cellular coverage. This option is also undesirable if all UEs camp on an overlaying cell thereby increasing the load on the corresponding coverage layer.

[0031] In various embodiments, the aspects of the present disclosure optimize the energy savings in the network by preventing / avoiding paging on a frequency layer, e.g., a first frequency layer. In such embodiments, the UE monitor paging on an associatedsecond frequency layer, wherein the first and second frequency layers correspond to overlapping cells. In one embodiment, a respective UE transitions (i.e., re-tunes a RF receiver chain) to the second frequency layer only for receiving paging in the paging occasion (PO) and / or paging frame (PF) as determined from broadcasted parameters in the first cell. In another embodiment, a respective UE stays (i.e., camps) on the second frequency layer (and receives paging on the second frequency layer), but if an RRC Connection is required to be established (e.g., due to the UE being paged), then the UE quickly re-tunes to an associated cell on the first frequency layer and initiates a randomaccess procedure (referred to as “RACH procedure”).

[0032] In another technique, the RAN distributed the paging occasions between two overlapping cells. In some embodiments, a ratio-based distribution may be used, whereby the UEs in a coverage area of the overlapping cells determine on which of the two associated cell they should consider themselves camped on and / or should monitor for paging. In one embodiment, the distribution is based on a UE identity (UE_ID). In another embodiment, the distribution is based on a temporary identifier, such as the 5G serving temporary mobile subscriber identity (5G-S-TMSI).

[0033] In yet another technique, a UE in the RRC Idle state (or RRC Inactive state) may be configured to notify a cell upon its arrival to, and departure from, the cell. In some embodiments, this notification behavior may be controlled using a suitable indication in SIB 1 of the serving cell.

[0034] Aspects of the present disclosure are described in the context of a wireless communications system.

[0035] Figure 1 illustrates an example of a wireless communications system 100 in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more NE 102, one or more UE 104, and a core network (CN) 106. 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 a Long-Term Evolution (LTE) network or an LTE- Advanced (LTE-A) network. In some other implementations, the wireless communications system100 may be a New Radio (NR) network, such as a 5G network, a 5G-Advanced (5G-A) network, or a 5G ultrawideband (5G-UWB) network.

[0036] 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, for example, 6G. 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.

[0037] The one or more NE 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the NE 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a network function, a network entity, a radio access network (RAN), a NodeB, an eNodeB (eNB), a next-generation NodeB (gNB), or other suitable terminology. An NE 102 and a UE 104 may communicate via a communication link, which may be a wireless or wired connection. For example, an NE 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

[0038] An NE 102 may provide a geographic coverage area for which the NE 102 may support services for one or more UEs 104 within the geographic coverage area. For example, an NE 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, an NE 102 may be moveable, for example, a satellite associated with a non-terrestrial network (NTN). In some implementations, different geographic coverage areas associated with the same or different radio access technologies may overlap, but the different geographic coverage areas may be associated with different NE 102.

[0039] The one or more UE 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to asa remote unit, a mobile device, a wireless device, a remote device, a subscriber device, a transmitter device, a receiver 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 machinetype communication (MTC) device, among other examples.

[0040] A UE 104 may be able to support wireless communication directly with other UEs 104 over a communication link. 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 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.

[0041] An NE 102 may support communications with the CN 106, or with another NE 102, or both. For example, an NE 102 may interface with other NE 102 or the CN 106 through one or more backhaul links (e.g., SI, N2, N3, or network interface). In some implementations, the NE 102 may communicate with each other directly. In some other implementations, the NE 102 may communicate with each other or indirectly (e.g., via the CN 106). In some implementations, one or more NE 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).

[0042] The CN 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The CN 106 may be an evolved packet core (EPC), or a 5G core (5GC), which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management functions (AMF)) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P-GW), or a user plane function (UPF)). In some implementations, the control plane entity may manage non-access stratum (NAS)functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc.) for the one or more UEs 104 served by the one or more NE 102 associated with the CN 106.

[0043] The CN 106 may communicate with a packet data network over one or more backhaul links (e.g., via an SI, N2, N3, or another network interface). The packet data network may include an application server. In some implementations, one or more UEs 104 may communicate with the application server. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or a PDN connection, or the like) with the CN 106 via an NE 102. The CN 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server 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 CN 106 (e.g., one or more network functions of the CN 106).

[0044] In the wireless communications system 100, the NEs 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers)) to perform various operations (e.g., wireless communications). In some implementations, the NEs 102 and the UEs 104 may support different resource structures. For example, the NEs 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the NEs 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 NEs 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures). The NEs 102 and the UEs 104 may support various frame structures based on one or more numerologies.

[0045] 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., jU=O) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., ^=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., != 1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., jU=2) may beassociated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., jU=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., ^=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

[0046] 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.

[0047] Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., / i=0, 11=1, ii=2, / i=3, t=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively.

[0048] Each slot may include a number (e.g., quantity) of symbols (e.g., orthogonal frequency domain 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., jU=O) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

[0049] 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 NEs 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 NEs 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 NEs 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

[0050] 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., ^=0), which includes 15 kHz subcarrier spacing; a second numerology (e.g., jU=l), which includes 30 kHz subcarrier spacing; and a third numerology (e.g., ^=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., ^=2), which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., jU=3), which includes 120 kHz subcarrier spacing.

[0051] Wireless communication in unlicensed spectrum (also referred to as “shared spectrum”) in contrast to licensed spectrum offer some obvious cost advantages allowing communication to obviate overlaying operator’s licensed spectrum and rather use license free spectrum according to local regulation in specific geographies. From the 3GPP technology perspective, the unlicensed operation can be on the Uu interface (referred to as NR-U) or also on sidelink interface (e.g., SL-U).

[0052] For initial access, a UE 104 detects a candidate cell and performs downlink (DL) synchronization. For example, the gNB (e.g., an embodiment of the NE 102) may transmit a synchronization signal and broadcast channel (SS / PBCH) transmission, referred to as a synchronization signal block (SSB). The synchronization signal is apredefined data sequence known to the UE 104 (or derivable using information already stored at the UE 104) and is in a predefined location in time relative to frame / subframe boundaries, etc. The UE 104 searches for the SSB and uses the SSB to obtain DL timing information (e.g., symbol timing) for the DL synchronization. The UE 104 may also decode system information (SI) based on the SSB. Note that with beam-based communication, each DL beam may be associated with a respective SSB.

[0053] After performing DL synchronization and acquiring essential system information, such as the master information block (MIB) and the system information block type 1 (SIB1), the UE 104 performs uplink (UL) synchronization and resource request by performing a random-access procedure, referred to as “RACH procedure” by selecting and transmitting a preamble on the physical random access channel (PRACH). The PRACH preamble is transmitted during a random access channel (RACH) occasion, i.e., a predetermined set of time-frequency resources that are available for the reception of the PRACH preamble. Note that with beam-based communication, the UE 104 may select a certain DL beam and transmit the PRACH preamble on a corresponding UL beam. In such embodiments, there may be a mapping between SSB and RACH occasion, allowing the network to determine which beam the UE 104 has selected.

[0054] Regarding random access, two types of RACH procedure are supported in a 3GPP wireless communication network: A) a 4-step random-access (RA) type initiated by the sending of a RACH message 1 (Msgl) and 2-step RA type with RACH message A (MsgA). Both types of RACH procedure support contention-based random access (CBRA) and contention-free random access (CFRA).

[0055] The UE 104 selects the RA type at the initiation of the RACH procedure, e.g., based on network configuration. In one example, when CFRA resources are not configured, a reference signal received power (RSRP) threshold is used by the UE 104 to select between 2-step RA type and 4-step RA type. In another example, when CFRA resources for 4-step RA type are configured, the UE 104 performs random access with 4- step RA type. In another example, when CFRA resources for 2-step RA type are configured, the UE 104 performs random access with 2-step RA type.

[0056] Note that the network does not configure CFRA resources for 4-step and 2- step RA types at the same time for a bandwidth part (BWP). Additionally, the CFRA with 2-step RA type is only supported for handover.

[0057] The Msgl of the 4-step RA type consists of a preamble transmitted on a physical random access channel (PRACH). After the Msgl transmission, the UE 104 monitors for a response from the network within a configured window. For CFRA, a dedicated preamble for Msgl transmission is assigned by the network and upon receiving a random access response (RAR) from the network, the UE 104 ends the random access procedure. For CBRA, upon reception of the RAR, the UE 104 sends a RACH message 3 (Msg3) using a UL grant scheduled in the RAR and monitors for contention resolution. If contention resolution is not successful after Msg3 (re)transmission(s), then the UE 104 goes back to Msgl transmission.

[0058] The MsgA of the 2-step RA type includes a preamble on the PRACH and a payload on a physical uplink shared channel (PUSCH). After the MsgA transmission, the UE 104 monitors for a response from the network within a configured window. For CFRA, a dedicated preamble and PUSCH resource are configured for MsgA transmission and upon receiving the network response, the UE 104 ends the random access procedure. For CBRA, if contention resolution is successful upon receiving the network response, then the UE 104 ends the random access procedure; however, if a fallback indication is received in a RACH message B (MsgB), the UE 104 performs Msg3 transmission using the UL grant scheduled in the fallback indication and monitors for contention resolution. If contention resolution is not successful after Msg3 (re)transmission(s), the UE 104 goes back to MsgA transmission.

[0059] If the random access procedure with 2-step RA type is not completed after a number of MsgA transmissions, the UE 104 can be configured to switch to CBRA with 4- step RA type.

[0060] In 3GPP New Radio (NR), the gNB may transmit the maximum 64 SSBs and the maximum 64 corresponding copies of physical downlink control channel (PDCCH) and / or physical downlink shared channel (PDSCH) for delivery of SIB 1 in high frequency bands (e.g., 28 GHz). This may cause significant network energy consumptioneven for a very low traffic load condition. According to 3GPP Technical Report (TR) 38.864 (vl8.1.0), for network energy savings, on-demand SSB and / or SIB1 (SSB / SIB1) transmissions and a cell without SSB / SIB 1 transmission were considered. When a cell does not transmit SSB / SIB 1, for a UE 104 to access the cell, the UE 104 should obtain SI of the cell from other associated carriers / cells and synchronize from other associated carriers / cells. When a cell is in a long period of cell inactivity, a UE 104 served by the cell can trigger SSB / SIB 1 transmissions by sending a request to the cell.

[0061] Figure 2 illustrates an example of a NR protocol stack 200, in accordance with aspects of the present disclosure. While Figure 2 shows a UE 206, a RAN node 208, and a 5G core network (5GC) 210 (e.g., comprising at least an AMF), these are representative of a set of UEs 104 interacting with an NE 102 (e.g., base station) and a CN 106. As depicted, the NR protocol stack 200 comprises a user plane protocol stack 202 and a control plane protocol stack 204. The user plane protocol stack 202 includes a physical (PHY) layer 212, a medium access control (MAC) sublayer 214, a radio link control (RLC) sublayer 216, a packet data convergence protocol (PDCP) sublayer 218, and a service data adaptation protocol (SDAP) layer 220. The control plane protocol stack 204 includes a PHY layer 212, a MAC sublayer 214, a RLC sublayer 216, and a PDCP sublayer 218. The control plane protocol stack 204 also includes a radio resource control (RRC) layer 222 and a non-access stratum (NAS) layer 224.

[0062] The access stratum (AS) layer 226 (also referred to as “AS protocol stack”) for the user plane protocol stack 202 consists of at least SDAP, PDCP, RLC and MAC sublayers, and the physical layer. The AS layer 228 for the control plane protocol stack 204 consists of at least RRC, PDCP, RLC and MAC sublayers, and the physical layer. The layer-1 (LI) includes the PHY layer 212. The layer-2 (L2) is split into the SDAP layer 220, PDCP sublayer 218, RLC sublayer 216, and MAC sublayer 214. The layer-3 (L3) includes the RRC layer 222 and the NAS layer 224 for the control plane and includes, e.g., an internet protocol (IP) layer and / or PDU Layer (not depicted) for the user plane. LI and L2 are referred to as “lower layers,” while L3 and above (e.g., transport layer, application layer) are referred to as “higher layers” or “upper layers.”

[0063] The PHY layer 212 offers transport channels to the MAC sublayer 214. The PHY layer 212 may perform a beam failure detection procedure using energy detectionthresholds, as described herein. In certain embodiments, the PHY layer 212 may send an indication of beam failure to a MAC entity at the MAC sublayer 214. The MAC sublayer 214 offers logical channels to the RLC sublayer 216. The RLC sublayer 216 offers RLC channels to the PDCP sublayer 218. The PDCP sublayer 218 offers radio bearers to the SDAP sublayer 220 and / or RRC layer 222. The SDAP sublayer 220 offers QoS flows to the core network (e.g., 5GC). The RRC layer 222 provides for the addition, modification, and release of carrier aggregation and / or dual connectivity. The RRC layer 222 also manages the establishment, configuration, maintenance, and release of signaling radio bearers (SRBs) and data radio bearers (DRBs).

[0064] The NAS layer 224 is between the UE 206 and an AMF in the 5GC 210. NAS messages are passed transparently through the RAN. The NAS layer 224 is used to manage the establishment of communication sessions and for maintaining continuous communications with the UE 206 as it moves between different cells of the RAN. In contrast, the AS layers 226 and 228 are between the UE 206 and the RAN (i.e., RAN node 208) and carry information over the wireless portion of the network. While not depicted in Figure 2, the IP layer exists above the NAS layer 224, a transport layer exists above the IP layer, and an application layer exists above the transport layer.

[0065] The MAC sublayer 214 is the lowest sublayer in the L2 architecture of the NR protocol stack. Its connection to the PHY layer 212 below is through transport channels, and the connection to the RLC sublayer 216 above is through logical channels. The MAC sublayer 214 therefore performs multiplexing and demultiplexing between logical channels and transport channels: the MAC sublayer 214 in the transmitting side constructs MAC PDUs (also known as transport blocks (TBs)) from MAC service data units (SDUs) received through logical channels, and the MAC sublayer 214 in the receiving side recovers MAC SDUs from MAC PDUs received through transport channels.

[0066] The MAC sublayer 214 provides a data transfer service for the RLC sublayer 216 through logical channels, which are either control logical channels which carry control data (e.g., RRC signaling) or traffic logical channels which carry user plane data. On the other hand, the data from the MAC sublayer 214 is exchanged with the PHY layer 212 through transport channels, which are classified as UL or downlink (DL). Data is multiplexed into transport channels depending on how it is transmitted over the air.

[0067] The PHY layer 212 is responsible for the actual transmission of data and control information via the air interface, i.e., the PHY layer 212 carries all information from the MAC transport channels over the air interface on the transmission side. Some of the important functions performed by the PHY layer 212 include coding and modulation, link adaptation (e.g., adaptive modulation and coding (AMC)), power control, cell search and random access (for initial synchronization and handover purposes) and other measurements (inside the 3GPP system (i.e., NR and / or LTE system) and between systems) for the RRC layer 222. The PHY layer 212 performs transmissions based on transmission parameters, such as the modulation scheme, the coding rate (i.e., the modulation and coding scheme (MCS)), the number of physical resource blocks (PRBs), etc.

[0068] Note that an LTE protocol stack comprises similar structure to the NR protocol stack 200, with the differences that the LTE protocol stack lacks the SDAP sublayer 220 in the AS layer 226, that an EPC replaces the 5GC 510, and that the NAS layer 224 is between the UE 206 and an MME in the EPC. Also note that the present disclosure distinguishes between a protocol layer (such as the aforementioned PHY layer 212, MAC sublayer 214, RLC sublayer 216, PDCP sublayer 218, SDAP layer 220, RRC layer 222 and NAS layer 224) and a transmission layer in multiple-input multiple-output (MIMO) communication (also referred to as a “MIMO layer” or a “data stream”).

[0069] Regarding RRC states, 3GPP defines three different RRC states / modes for 5G NR: RRCJDLE, RRCJN ACTIVE. and RRC_CONNECTED. Initially, i.e., upon powering up, the UE is in an idle mode corresponding to the RRC_IDLE state. Before performing data transfer (including placing calls), the UE must establish a connection with the network which is done using initial access via RRC connection establishment procedure. Once RRC connection is established, the UE is in the RRC_CONNECTED state. The RRC connection may be suspended due to inactivity, wherein the UE transitions to the RRC_INACTIVE state. Via the RRC release procedure, the RRC connection is released and the UE transitions to the RRC_IDLE state.

[0070] Paging allows the network to reach UEs in the RRC_IDLE and RRC_INACTIVE states through Paging messages, and to notify UEs in RRC_IDLE, RRC_INACTIVE and RRC_CONNECTED state of system information change and earthquake and tsunami warning system (ETWS) and / or commercial mobile alert system(CMAS) indications through Short Messages. Both Paging messages and Short Messages are addressed with paging radio network temporary identifier (P-RNTI) on PDCCH, but while the former is sent on the Paging Control Channel (PCCH) (e.g., a (DL) logical channel), the latter is sent over PDCCH directly.

[0071] While in RRC_IDLE the UE monitors the paging channels for CN-initiated paging. While in RRC_INACTIVE with no ongoing small-data transmission (SDT) procedure the UE monitors paging channels for RAN-initiated paging and CN-initiated paging. A UE need not monitor paging channels continuously though. Paging discontinuous reception (DRX) is defined where the UE in RRC_IDLE or RRC_INACTIVE is only required to monitor paging channels during one Paging Occasion (PO) per DRX cycle. The Paging DRX cycles are configured by the network.

[0072] For CN-initiated paging, a default cycle is broadcast in system information. For CN-initiated paging, a UE-specific cycle can be configured via NAS signaling. For RAN-initiated paging, a UE-specific cycle is configured via RRC signaling. The UE uses the shortest of the DRX cycles applicable, i.e., a UE in RRC_IDLE uses the shortest of the first two cycles above, while a UE in RRC_INACTIVE uses the shortest of the three cycles.

[0073] The POs of a UE for CN-initiated and RAN-initiated paging are based on the same UE ID, resulting in overlapping POs for both. The number of different POs in a DRX cycle is configurable via system information and a network may distribute UEs to those POs based on their IDs.

[0074] While in RRC_CONNECTED and while in RRC_IN ACTI VE with ongoing SDT procedure, the UE monitors the paging channels in any PO signaled in system information for SI change indication and public warning system (PWS) notification. In the case of Bandwidth Adaptation, a UE in RRC_CONNECTED only monitors paging channels on the active BWP with common search space configured.

[0075] For operation with shared spectrum channel access, a UE can be configured for an additional number of PDCCH monitoring occasions in its PO to monitor for paging. However, when the UE detects a PDCCH transmission within the UE's POaddressed with P-RNTI, the UE is not required to monitor the subsequent PDCCH monitoring occasions within this PO.

[0076] Regarding the determination of paging occasions in the UE, the UE may useDRX in RRC_IDLE and RRC_INACTIVE state in order to reduce power consumption. The UE monitors one PO per DRX cycle. A PO is a set of PDCCH monitoring occasions and can consist of multiple time slots (e.g., subframe or OFDM symbol) where paging downlink control information (DCI) can be sent. One paging frame (PF) is one radio frame and may contain one or multiple PO(s) or starting point of a PO.

[0077] In multi-beam operations, the UE assumes that the same paging message and the same short message are repeated in all transmitted beams and thus the selection of the beam(s) for the reception of the paging message and short message is up to UE implementation. The paging message is the same for both RAN-initiated paging and CN- initiated paging.

[0078] The UE initiates RRC connection resume procedure upon receiving RAN- initiated paging. If the UE receives a CN-initiated paging in RRC_INACTIVE state, the UE moves to RRC_IDLE and informs NAS.

[0079] The PF and PO for paging are determined by the following formulae:

[0080] The system frame number (SFN) for the PF is determined by:(SFN + PF_offset) mod T = (T div N)*(UE_ID mod N)

[0081] The index (i_s), indicating the index of the PO is determined by: i_s = floor (UE_ID / N) mod Ns

[0082] The PDCCH monitoring occasions for paging are determined according to pagingSearchSpace w firstPDCCH-MomtoringOccasionOfPO and nrofPDCCH- MonitoringOccasionPerSSB-InPO if configured (e.g., as specified in 3GPP technical specification (TS) 38.331). When SearchSpaceld = 0 is configured for pagingSearchSpace, the PDCCH monitoring occasions for paging are same as for remaining minimum system information (RMSI).

[0083] When SearchSpaceld = 0 is configured for pagingSearchSpace, Ns is either 1 or 2. For Ns = 1, there is only one PO which starts from the first PDCCH monitoring occasion for paging in the PF. For Ns = 2, PO is either in the first half frame (i_s = 0) or the second half frame (i_s = 1) of the PF.

[0084] When SearchSpaceld other than 0 is configured for pagingSearchSpace, the UE monitors the (i_s + l)thPO. A PO is a set of 'S*X ' consecutive PDCCH monitoring occasions where 'S' is the number of actual transmitted SSBs determined according to ssb-PositionsInBurst in SIB1 and X is the nrojPDCCH-MonitoringOccasionPerSSB- InPO if configured or is equal to 1 otherwise. The [x*S+K]thPDCCH monitoring occasion for paging in the PO corresponds to the K111transmitted SSB, where x=0,l,...,X- 1, K=1,2,...,S.

[0085] The PDCCH monitoring occasions for paging which do not overlap with UL symbols (determined according to tdd-UL-DL-ConfigurationCommori) are sequentially numbered from zero starting from the first PDCCH monitoring occasion for paging in the PF. W'hcn firstPDCCH-MonitoringOccasionOfPO is present, the starting PDCCH monitoring occasion number of (i_s + l)thPO is the (i_s + l)thvalue of the firstPDCCH- MonitoringOccasionOfPO parameter; otherwise, it is equal to i_s * S*X. If X > 1, when the UE detects a PDCCH transmission addressed to P-RNTI within its PO, the UE is not required to monitor the subsequent PDCCH monitoring occasions for this PO.

[0086] Note that a PO associated with a PF may start in the PF or after the PF. Additionally, the PDCCH monitoring occasions for a PO can span multiple radio frames. When SearchSpaceld other than 0 is configured for pagingSearchSpace the PDCCH monitoring occasions for a PO can span multiple periods of the paging search space.

[0087] The parameter T represents the DRX cycle of the UE and is used for the calculation of PF and i_s above.

[0088] If the UE does not operate in eDRX, then T is determined by the shortest of the UE-specific DRX value(s), if configured by RRC and / or upper layers or provided in PC5-RRC signaling in case of a L2 UE-to-network (U2N) Relay UE, and a default DRX value broadcast in system information. In RRC_IDLE state, if UE-specific DRX is not configured by upper layers, the default value is applied.

[0089] In RRC_IDLE state, if the UE operates in eDRX and eDRX is configured by upper layers, i.e., TSDRX, CN- If TSDRX, CN is no longer than 1024 radio frames, then T = TeDRx, CN; else, during CN-configured paging time window (PTW), T is determined by the shortest of the UE-specific DRX value, if configured by upper layers, and the default DRX value broadcast in system information.

[0090] In RRC_INACTIVE state, if the UE operates in eDRX and eDRX is configured by RRC, i.e., TeDRx, RAN , and / or upper layers, i.e., TeDRx, CN, then if both TeDRx, CN and used TSDRX, RAN are no longer than 1024 radio frames, then T = min{TeDRx, RAN, TeDRx, CN}. However, if TeDRx, CN is no longer than 1024 radio frames and no TeDRx, RAN is configured or used, then T is determined by the shortest of UE-specific DRX value configured by RRC and TeDRx, CN.

[0091] If TeDRx, CN is longer than 1024 radio frames, and if TeDRx, RAN is not configured or used, then during CN configured PTW, the value of T is determined by the shortest of the UE-specific DRX value (s), if configured by RRC and / or upper layers, and a default DRX value broadcast in system information. Outside the CN configured PTW, the value of T is determined by the UE-specific DRX value configured by RRC. Else, if used TeDRx, RAN is no longer than 1024 radio frames, then during CN configured PTW, T is determined by the shortest of the UE-specific DRX value, if configured by upper layers and TeDRx, RAN, and a default DRX value broadcast in system information. Outside the CN configured PTW, T is determined by TSDRX, RAN-

[0092] The parameter N represents the number of total paging frames in T and is used for the calculation of PF and i_s above. The parameter Ns represents the number of paging occasions for a PF and is used for the calculation of PF and i_s above.

[0093] The parameter PF_offset represents the offset used for PF determination and is used for the calculation of PF and i_s above. The parameter UE_ID is used for the calculation of PF and i_s above. If the UE operates in eDRX, then UE_ID = 5G-S-TMSI mod 4096. Else, UE_ID = 5G-S-TMSI mod 1024.

[0094] The parameters Ns, nAndPagingFrameOffset, nrofPDCCH- MonitoringOccasionPerSSB-InPO , and the length of default DRX Cycle are signaled in SIB I. The values of N and PF_offset are derived from the parameternAndPagingFrameOffset as defined in TS 38.331. The parameter firstPDCCH- MonitoringOccasionOfPO is signaled in SIB I for paging in the BWP configured by mitialDownlmkBWP . For paging in a DL BWP other than the BWP configured by mitialDownlmkBWP , the parameter first-PDCCH-MonitoringOccasionOfPO is signaled in the corresponding BWP configuration.

[0095] If the UE has no 5G-S-TMSI, for instance when the UE has not yet registered onto the network, the UE shall use as default identity UE_ID = 0 in the PF and i_s formulas above.

[0096] 5G-S-TMSI is a 48 bit long bit string (e.g., as defined in 3GPP TS 23.501). 5G-S-TMSI shall in the formulae above be interpreted as a binary number where the left most bit represents the most significant bit.

[0097] In RRC_INACTIVE state, if the UE supports inactiveStatePO-Determination and the network broadcasts ranPaginglnldlePO with value "true", the UE shall use the same i_s as for RRC_IDLE state. Otherwise, the UE determines the i_s based on the parameters and formula above.

[0098] In RRC_INACTIVE state, if used eDRX value configured by upper layers is no longer than 1024 radio frames, the UE shall use the same i_s as for RRC_IDLE state.

[0099] In RRC_INACTIVE state, if used eDRX value configured by upper layers is longer than 1024 radio frames, during CN PTW, the UE shall use the same i_s as for RRC_IDLE state. Outside CN PTW, the UE shall use the i_s for RRC_INACTIVE state.

[0100] Regarding paging optimization for UEs in CM_IDLE, at UE context release, the next generation RAN (NG-RAN) node may provide the AMF with a list of recommended cells and NG-RAN nodes as assistance info for subsequent paging. The AMF may also provide Paging Attempt Information consisting of a Paging Attempt Count and the Intended Number of Paging Attempts and may include the Next Paging Area Scope. If Paging Attempt Information is included in the Paging message, each paged NG-RAN node receives the same information during a paging attempt. The Paging Attempt Count shall be increased by one at each new paging attempt. The Next Paging Area Scope, when present, indicates whether the AMF plans to modify the paging areacurrently selected at the next paging attempt. If the UE has changed its state to CM_CONNECTED, then the Paging Attempt Count is reset.

[0101] Regarding paging optimization for UEs in RRC_INACTIVE, at RAN Paging, the serving NG-RAN node provides RAN Paging area information. The serving NG- RAN node may also provide RAN Paging attempt information. Each paged NG-RAN node receives the same RAN Paging attempt information during a paging attempt with the following content: Paging Attempt Count, the intended number of paging attempts and the Next Paging Area Scope. The Paging Attempt Count shall be increased by one at each new paging attempt. The Next Paging Area Scope, when present, indicates whether the serving NG_RAN node plans to modify the RAN Paging Area currently selected at next paging attempt. If the UE leaves RRC_INACTIVE state, the Paging Attempt Count is reset.

[0102] Regarding UE power saving for paging monitoring, in order to reduce UE power consumption due to false paging alarms, the group of UEs monitoring the same PO can be further divided into multiple subgroups. With subgrouping, a UE shall monitor PDCCH in its PO for paging if the subgroup to which the UE belongs is paged as indicated via associated paging early indication (PEI). If a UE cannot find its subgroup ID with the PEI configurations in a cell or if the UE is unable to monitor the associated PEI occasion corresponding to its PO, it shall monitor the paging in its PO.

[0103] These subgroups have the following characteristics: A) They are formed based on either CN controlled subgrouping or UE ID based subgrouping; B) If CN controlled subgroup ID is not provided from AMF, UE ID based subgrouping is used if supported by the UE and network; C) The RRC state (RRC_IDLE or RRC_INACTIVE state) does not impact which subgroup the UE belongs to; D) Subgrouping support for a cell is broadcast in the system information as one of the following: Only CN controlled subgrouping supported, only UE ID based subgrouping supported, or both CN controlled subgrouping and UE ID based subgrouping supported; E) Total number of subgroups allowed in a cell is up to 8 and represents the sum of CN controlled and UE ID based subgrouping configured by the network; F) A UE configured with CN controlled subgroup ID applies CN controlled subgroup ID if the cell supports CN controlled subgrouping; otherwise, it derives UE ID based subgroup ID if the cell supports only UE ID based subgrouping.

[0104] Regarding the PEI, this indication PEI incorporates special wake up signal that UE monitors before the PO. The PEI indicates UE the presence or absence of paging message in the PO. If the PEI is present, then the UE proceeds with relevant SSB measurements and paging message reception in the PO.

[0105] The PEI associated with subgroups has the following characteristics: A) If the PEI is supported by the UE, it shall at least support UE ID based subgrouping method; B) PEI monitoring can be limited via system information to the last used cell (i.e., the cell in which the UE most recently received RRCRelease without indicating that the last used cell for PEI shall not be updated); C) A PEI-capable UE shall store its last used cell information; D) gNBs supporting the PEI monitoring to the last used cell function provide the UE's last used cell information to the AMF in the next generation application protocol (NG-AP) UE Context Release Complete message for PEI capable UEs; E) UE that expects multicast-broadcast system (MBS) group notification shall ignore the PEI and shall monitor paging in its PO.

[0106] Regarding CN controlled subgrouping, the AMF is responsible for assigning subgroup ID to the UE. The total number of subgroups for CN controlled subgrouping which can be configured, e.g., by the operation, administration, and maintenance (0AM), is up to 8. It is assumed that CN controlled subgrouping support is homogeneous within an RAN-based notification area.

[0107] In an exemplary procedure for CN controlled subgrouping, the UE indicates its support of CN controlled subgrouping via NAS signaling. If the UE supports CN controlled subgrouping, the AMF determines the subgroup ID assignment for the UE. The AMF sends subgroup ID to the UE via NAS signaling.

[0108] Additionally, the AMF informs the gNB about the CN assigned subgroup ID for paging the UE in RRC_IDLE / RRC_INACTIVE state. When the paging message for the UE is received from the CN or is generated by the gNB, the gNB determines the PO and the associated PEI occasion for the UE. Before the UE is paged in the PO, the gNB transmits the associated PEI and indicates the corresponding CN controlled subgroup of the UE that is to be paged in the PEI.

[0109] Regarding UE ID based subgrouping, the gNB and UE can determine the subgroup ID based on the UE ID and the total number of subgroups for UE ID based subgrouping in the cell. The total number of subgroups for UE ID based subgrouping is decided by the gNB for each cell and can be different in different cells.

[0110] In an exemplary procedure for UE ID based subgrouping, the gNB determines the total number of subgroups for UE ID based subgrouping in a cell. The gNB broadcasts the total number of subgroups for UE ID based subgrouping in a cell and the UE determines its subgroup in a cell.

[0111] When paging message for the PEI capable UE is received from the CN at the gNB or is generated by the gNB, the gNB determines the PO and the associated PEI occasion for the UE. Before the UE is paged in the PO, the gNB transmits the associated PEI and indicates the corresponding subgroup derived based on UE ID of the UE that is paged in the PEI.

[0112] Figure 3 depicts an exemplary RAN deployment 300 of two overlapping cells operating on different frequency layers, in accordance with aspects of the disclosure. The RAN deployment 300 comprises a first cell 302 which operates on a first frequency layer (e.g., corresponding to frequency fo) and a second cell 304 which operates on a second frequency layer (e.g., corresponding to frequency fi). A frequency layer, also referred to as an RF channel, refers to the carrier frequency where a cell transmitting synchronization signal can be expected. The cell may also be transmitting system information.

[0113] Ideally one frequency layer (fo) may only be used for traffic offloading and therefore no RRC Idle UE may camp there - this is already possible today e.g., using SSB-less transmission in a cell (which is only visible to RRC Connected UEs as a secondary cell (SCell)). This would ensure that the cell is not visible (i.e., detectable) to the RRC Idle / Inactive UEs. However, this is sub-optimal since this prohibits cell detection and camping by UEs which may otherwise not have any cellular coverage. This is also unwanted if all UEs camp on an overlaying cell, thereby incresing the load on the corresponding coverage layer.

[0114] Techniques are disclosed herein to enable network energy saving by minimization of paging tranmission without having to stop SSB / MIB / SI transmission,thereby without adversely affecting user experience due to longer call setup time, or without delaying system information change notification.

[0115] According to aspects of a first solution, a first cell on a first frequency layer fo may allow camping and therefore transmit SSB and System Information but still some power can be saved by not requiring Paging transmission. Paging is transmitted in an associated second cell on a different frequency layer (fi). In another example, both cells may be on the same frequency without affecting the paging related optimizations revealed here.

[0116] Figure 4 depicts a procedure 400 for RF re-tuning between two cells on two different frequencies, in accordance with aspects of the present disclosure. The procedure 400 may be performed by the RF receiver 402 of a UE (such as the UE 104 and / or UE 206), wherein the UE RF receiver 402 tunes to the second cell 304 only to receive paging.

[0117] The UE calculates its paging occasion (PO) based on the paging parameters broadcasted in the first cell but monitors paging on the second cell. To accomplish this, just before a PO of the second cell 304 (e.g., POx 406 or POx+1 408) the UE RF receiver 402 tunes (from the first cell 302) to the second cell 304. If a paging is received for the UE, then the UE RF receiver 402 tunes back to the first cell 302 and transmits a Paging Response message.

[0118] In some embodiments, the paging parameters broadcasted in the first cell 302 for receiving paging on the second cell 304 may be specific to the second cell 304, in which case broadcasted separately by the first cell 302 (e.g., in SIB1 or another SIB) or can be cell parameter values as used by the first cell 302. An explicit indication for the paging parameters may be used to direct the UE to acquire the paging parameters for the second cell 304 broadcasted in the first cell 302 itself.

[0119] The above implementation may need too many and frequent RF re-tuning for the UE. Therefore, in an alternative implementation, the UE camps on the second cell 304 and receives paging there but for establishing RRC Connection it will reselect to the associated first cell 302 on fo. This keeps the RF re-tuning to a minimum. To accomplish this, the network advertises (broadcasts e.g., SIB1, system information block type 4 (SIB4), or a new System Information Block (SIB) of the first cell 302) that first cell 302(e.g., on frequency layer fo) is only for RRC connection establishment purpose and second cell 304 (e.g., on frequency layer fi) should be used for camping.

[0120] In some embodiments, the absolute radio quality value (e.g., RSRP and / or reference signal received quality (RSRQ)) and / or Cell Reselection Priorities or Frequency Priorities can be ignored for comparison between the first cell 302 and the second cell 304. In such embodiments, for establishing an RRC Connection, the UE need not perform a reselection first to the first cell 302. For camping on the second cell 304, in certain implementations, the UE camps on the second cell 304 only if the second cell 304 is the best radio cell on its associated frequency layer (e.g., corresponding to frequency fi), or the first cell 302 is the best radio cell on its associated frequency layer (e.g., corresponding to frequency fo), or both, such that radio quality of first cell 302 may (or may) be better than the second cell 304, but the UE does not compare the radio quality of the first cell 302 to that of the second cell 304. In addition, the Cell Reselection Priorities or Frequency Priorities received in the broadcasted or dedicated (e.g., in RRC Connection Release message) may be not used when a camping (cell selection or cell reselection) decision has to be made between two associated cells i.e., both frequencies are considered of the same priority, irrespective of their actual priority levels.

[0121] According to aspects of a second solution, the paging occasions may be distributed between two or more overlapping cells. In some embodiments, the distribution of the paging occasions may be based on a UE identity, such as the UE_ID calculated from the 5G-S-TMSI (e.g., 5G-S-TMSI modulo 4096 or 1024, as described above). In such embodiments, after calculating their UE_IDs, the UEs in the coverage area of the overlapping cells will determine which cell to monitor paging occasions.

[0122] For example, for an even distribution, those UEs having an ‘odd’ UE_ID (i.e., a UE_ID ending in 1, 3, 5, 7 or 9) will camp on to the first cell and the ‘even’ UE_ID will camp on the second cell. Put in other terms, a UE with UE_ID modulo 2 = 1 will camp on the first cell, while a different UE with UE_ID modulo 2 = 0 will camp on the second cell.

[0123] In a different example instead of a 50% distribution, another ratio can be used. Accordingly, for a 20% distribution, every fifth UE_ID (e.g., a UE_ID ending in 0 or 6) will camp on to the first cell, and the remaining UE_IDs will camp on the second cell.

[0124] In one implementation of the above examples, a respective UE camping on the first cell may monitor the first cell for paging. In another embodiment of the above examples, the respective UE camping on the first cell may re-tune to the second cell to monitor a paging occasion, as described in the first solution. Similarly, a respective UE camping on the second cell may monitor the second cell for paging.

[0125] In certain implementations, the distribution of the paging occasions may be directly based on the 5G-S-TMSI (i.e., not dependent on the outcome of the above UE_ID calculated from the 5G-S-TMSI). In such implementations, the cell where the camping is done and / or where the POs / PFs will be received at, is decided first and then the UE continues with the calculation of POs / PFs for the resulting cell.

[0126] Alternatively, the camping (cell selection or reselection) is not affected by the distribution of paging occasion (e.g., the UE camping behavior still depends purely on the radio quality, as in legacy), but rather the above UE_ID calculation is used only to determine distribution for the reception of paging. Accordingly, a UE camping on the first cell may need to receive paging on the second cell, e.g., if its 5G-S-TMSI modulo 5 = 0 for the above 20% distribution example.

[0127] To implement this second solution, the UE may be preconfigured with the identities of energy-saving cells, with rules for determining where the camping is done and / or where the POs / PFs will be received at. In an alternative implementation, the network may configure the UE with rules for determining where the camping is done and / or where the POs / PFs will be received at. For example, a particular cell may indicate where the camping is done and / or where the POs / PFs will be received at, e.g., broadcast in system information, such as SIB1, SIB4, or a new SIB. In this later example, the particular cell may indicate the rules for determining where the camping is done and / or POs / PFs reception for both the particular cell and for a neighboring and / or overlapping cell.

[0128] In a different implementation, the paging load distribution is done based on subgroup ID, described earlier. In one example, the first four subgroups (0 to 3) will monitor paging in the first cell and the last four subgroups (4 to 7) will monitor paging in the second cell. This may also affect the cell camping / reselection decision of the UE.

[0129] According to aspects of a third solution, a UE in the RRC Idle state (or RRC Inactive state) may be configured to announce its arrival to a serving cell and to announce its departure from the serving cell. Here, the arrival to a cell may be due to a cell selection (or cell re-selection) procedure performed by the UE in the RRC Idle / Inactive state. Similarly, the departure from the serving cell may be due to the UE re-selecting to a different cell. Accordingly, the arrival and departure of the UE in the RRC Idle / Inactive state may be based on UE mobility, changing radio conditions, or a combination thereof.

[0130] Based on this arrival and departure information, the informed cell is able to track (i.e., keep a count) of the Idle UEs within its radio coverage area. In some embodiments, when number of Idle UEs is below a threshold number (e.g., when no Idle UEs are present within the cell), then the serving cell may temporarily stop paging, thereby saving power.

[0131] In certain implementations, the UE includes a UE_ID / 5G-S-TMSI or similar identifier (e.g., inactive radio network temporary identifier (I-RNTI)) in the arrival announcement. In such implementations, the serving cell stores the identities of the UEs in the RRC Idle state (or RRC Inactive state) present in the cell. Upon receiving a paging request, e.g., from an AMF, the serving cell pages only those Idle / Inactive UEs known to be present in the cell and ignores any paging request for other UEs.

[0132] In some embodiments, the arrival and departure notifications may be controlled using a suitable indication, e.g., in SIB1 of the serving cell. However, transmitting arrival and departure notifications causes battery consumption in the UE. Therefore, the SIB 1 configuration for arrival and departure notifications should only be used sporadically, such that the UE(s) indicate arrival / departure only when the configuration is activated.

[0133] Figure 5 illustrates an example of a UE 500 in accordance with aspects of the present disclosure. The UE 500 may include a processor 502, a memory 504, a controller 506, and a transceiver 508. The processor 502, the memory 504, the controller 506, or the transceiver 508, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as describedherein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

[0134] The processor 502, the memory 504, the controller 506, or the transceiver 508, or various combinations or components thereof may be implemented in hardware (e.g., circuitry). The hardware may include a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

[0135] The processor 502 may include an intelligent hardware device (e.g., a general- purpose processor, a DSP, a central processing unit (CPU), an ASIC, a field programmable gate array (FPGA), or any combination thereof). In some implementations, the processor 502 may be configured to operate the memory 504. In some other implementations, the memory 504 may be integrated into the processor 502. The processor 502 may be configured to execute computer-readable instructions stored in the memory 504 to cause the UE 500 to perform various functions of the present disclosure.

[0136] The memory 504 may include volatile or non-volatile memory. The memory 504 may store computer-readable, computer-executable code including instructions that, when executed by the processor 502, cause the UE 500 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such the memory 504 or another type of memory. 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.

[0137] In some implementations, the processor 502 and the memory 504 coupled with the processor 502 may be configured to cause the UE 500 to perform various functions (e.g., operations, signaling) described herein (e.g., executing, by the processor 502, instructions stored in the memory 504). In some implementations, the processor 502 may include multiple processors and the memory 504 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiplememories, which may be individually or collectively, configured to perform various functions (e.g., operations, signaling) of the UE 500 as disclosed herein.

[0138] The processor 502 coupled with the memory 504 may be configured to, capable of, or operable to cause the UE 500 to receive, from a first cell associated with a first frequency layer, broadcast signaling including an indication of a second cell associated with a second frequency layer; re-tune a receiver frequency to the second frequency layer based on a next paging occasion associated with the second cell; receive a paging message on the second cell; re-tune the receiver frequency to the first frequency layer based on an end of the next paging occasion; and initiate a connection with the first cell based at least in part on the paging message.

[0139] In some implementations, to receive the broadcast signaling, the UE 500 is configured to receive a SIB1, a SIB4, or another (e.g., new) SIB including the broadcast signaling. In some implementations, the broadcast signaling further includes a set of paging parameters. In such implementations, the processor 502 coupled with the memory 504 may be configured to, capable of, or operable to cause the UE 500 to determine, based on the set of paging parameters, the next paging occasion and the paging frame associated with the second cell.

[0140] In certain implementations, the broadcast signaling further includes a second indication that a set of paging parameters associated with the first cell is usable for receiving paging on the second cell. In other implementations, the set of paging parameters includes separate sets of parameters associated with the first cell and the second cell. In such implementations, the broadcast signaling may further include a second indication for acquisition of the set of parameters associated with the second cell.

[0141] In some implementations, the broadcast signaling further indicates that the first cell is dedicated for RRC connection establishment. In such implementations, the processor 502 coupled with the memory 504 may be configured to, capable of, or operable to cause the UE 500 to camp on the second cell in response to determining that the first cell is dedicated for RRC connection establishment.

[0142] In certain implementations, the processor 502 coupled with the memory 504 may be configured to, capable of, or operable to cause the UE 500 to avoid performingcell reselection to the first cell in response to determining that the first cell is dedicated for RRC connection establishment.

[0143] In certain implementations, the processor 502 coupled with the memory 504 may be configured to, capable of, or operable to cause the UE 500 to camp on the second cell further in response to determining that the first cell has a best radio quality associated with the first frequency layer, that the second cell has a best radio quality associated with the second frequency layer, or both. In addition, the Cell Reselection Priorities or Frequency Priorities received in the broadcasted or dedicated (e.g., in RRC Connection Release message) may be not used when a camping (cell selection or cell reselection) decision has to be made between two associated cells i.e., both frequencies are considered of the same priority, irrespective of their actual priority levels.

[0144] In some implementations, the processor 502 coupled with the memory 504 may be configured to, capable of, or operable to cause the UE 500 to A) determine a UE identity (ID) for paging, and to B) determine to re-tune the receiver frequency to the second frequency layer based on the UE ID. In certain implementations, the processor 502 coupled with the memory 504 may be configured to, capable of, or operable to cause the UE 500 to receive a condition for camping on the first cell based on the UE ID. In certain implementations, the processor 502 coupled with the memory 504 may be configured to, capable of, or operable to cause the UE 500 to receive a condition for paging reception on the second cell based on the UE ID.

[0145] In some implementations, the processor 502 coupled with the memory 504 may be configured to, capable of, or operable to cause the UE 500 to A) detect an arrival in the first cell while the UE is in an idle state, and to B) transmit a notification to the first cell in response to the arrival. In certain implementations, the notification includes a UE identity for paging (e.g., UE_ID, 5G-S-TMSI, I-RNTI, or similar identity).

[0146] In certain implementations, the processor 502 coupled with the memory 504 may be configured to, capable of, or operable to cause the UE 500 to detect the arrival based on a cell selection procedure or cell reselection procedure. In certain implementations, the processor 502 coupled with the memory 504 may be configured to,capable of, or operable to cause the UE 500 to transmit a second notification in response to a departure from the first cell.

[0147] In certain implementations, the processor 502 coupled with the memory 504 may be configured to, capable of, or operable to cause the UE 500 to receive a second indication for notifications of arrivals or departures, and transmit the notification based at least in part on the second indication. In such implementations, the broadcast signaling may include the second indication. In certain implementations, the second indication may be one or more bits in a SIB 1 transmission.

[0148] The controller 506 may manage input and output signals for the UE 500. The controller 506 may also manage peripherals not integrated into the UE 500. In some implementations, the controller 506 may utilize an operating system (OS) such as iOS®, ANDROID®, WINDOWS®, or other operating systems. In some implementations, the controller 506 may be implemented as part of the processor 502.

[0149] In some implementations, the UE 500 may include at least one transceiver 508. In some other implementations, the UE 500 may have more than one transceiver 508. The transceiver 508 may represent a wireless transceiver. The transceiver 508 may include one or more receiver chains 510, one or more transmitter chains 512, or a combination thereof.

[0150] A receiver chain 510 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 510 may include one or more antennas for receiving the signal over the air or wireless medium. The receiver chain 510 may include at least one amplifier (e.g., a low-noise amplifier (LN A)) configured to amplify the received signal. The receiver chain 510 may include at least one demodulator configured to demodulate the received signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 510 may include at least one decoder for decoding / processing the demodulated signal to receive the transmitted data.

[0151] A transmitter chain 512 may be configured to generate and transmit signals (e.g., control information, data, packets). The transmitter chain 512 may include at least one modulator for modulating data onto a carrier signal, preparing the signal fortransmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM). The transmitter chain 512 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 512 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

[0152] Figure 6 illustrates an example of a processor 600 in accordance with aspects of the present disclosure. The processor 600 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 600 may include a controller 602 configured to perform various operations in accordance with examples as described herein. The processor 600 may optionally include at least one memory 604, which may be, for example, an L1 / L2 / L3 cache. Additionally, or alternatively, the processor 600 may optionally include one or more arithmetic-logic units (ALUs) 606. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses).

[0153] The processor 600 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 600) or other memory (e.g., random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), static RAM (SRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, phase change memory (PCM), and others).

[0154] The controller 602 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of theprocessor 600 to cause the processor 600 to support various operations in accordance with examples as described herein. For example, the controller 602 may operate as a control unit of the processor 600, generating control signals that manage the operation of various components of the processor 600. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

[0155] The controller 602 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 604 and determine subsequent instruction(s) to be executed to cause the processor 600 to support various operations in accordance with examples as described herein. The controller 602 may be configured to track memory address of instructions associated with the memory 604. The controller 602 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 602 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 600 to cause the processor 600 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 602 may be configured to manage flow of data within the processor 600. The controller 602 may be configured to control transfer of data between registers, arithmetic logic units (ALUs), and other functional units of the processor 600.

[0156] The memory 604 may include one or more caches (e.g., memory local to or included in the processor 600 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, the memory 604 may reside within or on a processor chipset (e.g., local to the processor 600). In some other implementations, the memory 604 may reside external to the processor chipset (e.g., remote to the processor 600).

[0157] The memory 604 may store computer-readable, computer-executable code including instructions that, when executed by the processor 600, cause the processor 600 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 602 and / or the processor 600 may be configured to execute computer-readable instructions stored in the memory 604 to cause the processor 600 to perform variousfunctions. For example, the processor 600 and / or the controller 602 may be coupled with or to the memory 604, the processor 600, the controller 602, and the memory 604 may be configured to perform various functions described herein. In some examples, the processor 600 may include multiple processors and the memory 604 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

[0158] The one or more ALUs 606 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 606 may reside within or on a processor chipset (e.g., the processor 600). In some other implementations, the one or more ALUs 606 may reside external to the processor chipset (e.g., the processor 600). One or more ALUs 606 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 606 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 606 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation.Additionally, or alternatively, the one or more ALUs 606 may support logical operations such as AND, OR, exclusive-OR (XOR), not-OR (NOR), and not-AND (NAND), enabling the one or more ALUs 606 to handle conditional operations, comparisons, and bitwise operations.

[0159] In various implementations, the processor 600 may support various functions (e.g., operations, signaling) of a UE, in accordance with examples as disclosed herein. For example, the controller 602 coupled with the memory 604 may be configured to, capable of, or operable to cause the processor 600 to receive, from a first cell associated with a first frequency layer, broadcast signaling including an indication of a second cell associated with a second frequency layer; re-tune a receiver frequency to the second frequency layer based on a next paging occasion associated with the second cell; receive a paging message on the second cell; re-tune the receiver frequency to the first frequency layer based on the end of the next paging occasion; and initiate a connection with the first cell based at least in part on the paging message. Additionally, the controller 602 coupledwith the memory 604 may be configured to, capable of, or operable to cause the processor 600 to perform one or more functions (e.g., operations, signaling) of the UE as described herein.

[0160] Additionally, or alternatively, in some other implementations, the processor 600 may support various functions (e.g., operations, signaling) of a NE (e.g., base station), in accordance with examples as disclosed herein. For example, the controller 602 coupled with the memory 604 may be configured to, capable of, or operable to cause the processor 600 to transmit, in a first cell associated with a first frequency layer, broadcast signaling including an indication of a second cell associated with a second frequency layer; transmit, to a UE, a paging message via the second cell; receive, from the UE, a paging response message via the first cell; and establish a connection with the UE via the first cell. Additionally, the controller 602 coupled with the memory 604 may be configured to, capable of, or operable to cause the processor 600 to perform one or more functions (e.g., operations, signaling) of the NE as described herein.

[0161] Figure 7 illustrates an example of a NE 700 in accordance with aspects of the present disclosure. The NE 700 may include a processor 702, a memory 704, a controller 706, and a transceiver 708. The processor 702, the memory 704, the controller 706, or 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. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

[0162] The processor 702, the memory 704, the controller 706, or the transceiver 708, or various combinations or components thereof may be implemented in hardware (e.g., circuitry). The hardware may include a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

[0163] The processor 702 may include an intelligent hardware device (e.g., a general- purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof). In some implementations, the processor 702 may be configured to operate the memory 704.In some other implementations, the memory 704 may be integrated into the processor 702. The processor 702 may be configured to execute computer-readable instructions stored in the memory 704 to cause the NE 700 to perform various functions of the present disclosure.

[0164] The memory 704 may include volatile or non-volatile memory. The memory 704 may store computer-readable, computer-executable code including instructions when executed by the processor 702 cause the NE 700 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such the memory 704 or another type of memory. 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.

[0165] In some implementations, the processor 702 and the memory 704 coupled with the processor 702 may be configured to cause the NE 700 to perform one or more RAN functions of an anchor cell as described herein (e.g., executing, by the processor 702, instructions stored in the memory 704). For example, the processor 702 may support the wireless communication anchor cell at the NE 700 in accordance with examples as disclosed herein.

[0166] The processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to support a means for transmitting, in a first cell associated with a first frequency layer, broadcast signaling including an indication of a second cell associated with a second frequency layer. In some implementations, to transmit the broadcast signaling, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to transmit a SIB1, a SIB4, or another (new) SIB including the broadcast signaling.

[0167] The processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to support a means for transmitting, to a UE, a paging message via the second cell. The processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to support a means forreceiving, from the UE, a paging response message via the first cell. The processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to support a means for establishing a connection with the UE via the first cell.

[0168] In some implementations, the broadcast signaling further includes a set of paging parameters for determining a next paging occasion and a paging frame associated with the second cell. In such implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to transmit the paging message via the second cell based on the set of paging parameters.

[0169] In certain implementations, the broadcast signaling further includes a second indication that a set of paging parameters associated with the first cell is usable for receiving paging on the second cell. In other implementations, the set of paging parameters includes separate sets of parameters associated with the first cell and the second cell. In such implementations, the broadcast signaling may further include a second indication for acquisition of the set of parameters associated with the second cell.

[0170] In some implementations, the broadcast signaling further indicates that the first cell is dedicated for RRC connection establishment. In some implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to transmit a condition for camping on the first cell based on the UE identity for paging (e.g., UE_ID, 5G-S-TMSI, I-RNTI, or similar). In certain implementations, to transmit the condition for camping on the first cell, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to transmit a SIB1, a SIB4, or a (new) SIB including the condition.

[0171] In some implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to transmit a condition for camping on the second cell based on a UE identity for paging (e.g., UE_ID, 5G-S- TMSI, I-RNTI, or similar). In certain implementations, to transmit the condition for camping on the second cell, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to transmit a SIB1, a SIB4, or a (new) SIB including the condition.

[0172] In some implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to transmit a condition for paging reception on the first cell based on the UE identity for paging (e.g., UE_ID, 5G-S-TMSI, I-RNTI, or similar). In certain implementations, to transmit the condition for paging reception on the first cell, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to transmit a SIB1, a SIB4, or a (new) SIB including the condition.

[0173] In some implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to transmit a condition for paging reception on the second cell based on the UE identity for paging (e.g., UE_ID, 5G-S-TMSI, I-RNTI, or similar). In certain implementations, to transmit the condition for paging reception on the second cell, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to transmit a SIB 1 , a SIB4, or a (new) SIB including the condition.

[0174] In some implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to receive, from the UE, a notification of an arrival in the first cell and to determine a number of idle-state UEs in the first cell based at least in part on the notification. In certain implementations, the notification is based at least in part on a cell selection procedure or cell reselection procedure.

[0175] In certain implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to stop paging in the first cell based at least in part on the number of idle-state UEs satisfying a threshold (e.g., where the number of UEs is low). In certain implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to offload paging from the first cell to the second cell based at least in part on the number of idle-state UEs satisfying a threshold (e.g., where the number of UEs is low).

[0176] In certain implementations, the notification includes a UE identity for paging (e.g., UE_ID, 5G-S-TMSI, I-RNTI, or similar). In such implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to causethe NE 700 to: A) store the UE ID in a database associated with the first cell; B) receive (e.g., from an AMF) a paging signal for a respective UE having a respective UE ID; and C) ignore the paging signal in response to the respective UE ID being absent from the database.

[0177] In certain implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to receive, from the UE, a second notification in response to a departure from the first cell. In further implementations, the second notification includes a UE identity for paging (e.g., UE_ID, 5G-S-TMSI, I-RNTI, or similar). In such implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to remove the UE ID from a database associated with the first cell.

[0178] In certain implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to transmit a second indication for notifications of arrivals or departures. In one implementation, the broadcast signaling includes the second indication. In another implementation, the second indication includes at least one bit in a SIB 1 transmission.

[0179] In some implementations, the processor 702 coupled with the memory 704 may be configured to, capable of, or operable to cause the NE 700 to transmit, in the first cell, a SIB including one or more parameters for monitoring a PDCCH that carries the paging message. In one implementation, the SIB including the one or more parameters is a SIB 1 of the first cell.

[0180] The controller 706 may manage input and output signals for the NE 700. The controller 706 may also manage peripherals not integrated into the NE 700. In some implementations, the controller 706 may utilize an operating system such as iOS®, ANDROID®, WINDOWS®, or other operating systems. In some implementations, the controller 706 may be implemented as part of the processor 702.

[0181] In some implementations, the NE 700 may include at least one transceiver 708. In some other implementations, the NE 700 may have more than one transceiver 708. The transceiver 708 may represent a wireless transceiver. The transceiver 708 mayinclude one or more receiver chains 710, one or more transmitter chains 712, or a combination thereof.

[0182] A receiver chain 710 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 710 may include one or more antennas for receiving the signal over the air or wireless medium. The receiver chain 710 may include at least one amplifier (e.g., a low-noise amplifier (LN A)) configured to amplify the received signal. The receiver chain 710 may include at least one demodulator configured to demodulate the received signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 710 may include at least one decoder for decoding / processing the demodulated signal to receive the transmitted data.

[0183] A transmitter chain 712 may be configured to generate and transmit signals (e.g., control information, data, packets). The transmitter chain 712 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM). The transmitter chain 712 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 712 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

[0184] Figure 8 depicts one embodiment of a method 800 in accordance with aspects of the present disclosure. In various embodiments, the operations of the method 800 may be implemented by a UE as described herein. In some implementations, the UE may execute a set of instructions to control the function elements of the UE to perform the described functions.

[0185] At step 802, the method 800 may include receiving, from a first cell associated with a first frequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer. The operations of step 802 may be performedin accordance with examples as described herein. In some implementations, aspects of the operation of step 802 may be performed by a UE, as described with reference to Figure 5.

[0186] At step 804, the method 800 may include re-tuning a receiver frequency to the second frequency layer based on a next paging occasion associated with the second cell. The operations of step 804 may be performed in accordance with examples as described herein. In some implementations, aspects of the operation of step 804 may be performed by a UE, as described with reference to Figure 5.

[0187] At step 806, the method 800 may include receiving a paging message on the second cell. The operations of step 806 may be performed in accordance with examples as described herein. In some implementations, aspects of the operation of step 806 may be performed by a UE, as described with reference to Figure 5.

[0188] At step 808, the method 800 may include re-tuning the receiver frequency to the first frequency layer based on the end of the next paging occasion. The operations of step 808 may be performed in accordance with examples as described herein. In some implementations, aspects of the operation of step 808 may be performed by a UE, as described with reference to Figure 5.

[0189] At step 810, the method 800 may include initiating a connection with the first cell based at least in part on the paging message. The operations of step 810 may be performed in accordance with examples as described herein. In some implementations, aspects of the operation of step 810 may be performed by a UE, as described with reference to Figure 5.

[0190] It should be noted that the method 800 described herein describes one possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0191] It should be noted that the method 800 described herein describes one possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0192] Figure 9 depicts one embodiment of a method 900 in accordance with aspects of the present disclosure. The operations of the method 900 may be implemented by aRAN as described herein. In some implementations, the RAN may execute a set of instructions to control the function elements of the RAN to perform the described functions.

[0193] At step 902, the method 900 may include transmitting, on a first cell associated with a first frequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer. The operations of step 902 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of step 902 may be performed by a NE, as described with reference to Figure 7.

[0194] At step 904, the method 900 may include transmitting, to a UE, a paging message via the second cell. The operations of step 904 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of step 904 may be performed by a NE, as described with reference to Figure 7.

[0195] At step 906, the method 900 may include receiving, from the UE, a paging response message via the first cell. The operations of step 906 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of step 906 may be performed by a NE, as described with reference to Figure 7.

[0196] At step 908, the method 900 may include establishing a connection with the UE via the first cell. The operations of step 908 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of step 908 may be performed by a NE, as described with reference to Figure 7.

[0197] It should be noted that the method 900 described herein describes one possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0198] 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 describedherein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

CLAIMSWhat 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 cell associated with a first frequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer; re-tune a receiver frequency to the second frequency layer based on a next paging occasion associated with the second cell; receive a paging message on the second cell; re-tune the receiver frequency to the first frequency layer based on an end of the next paging occasion; and initiate a connection with the first cell based at least in part on the paging message.

2. The UE of claim 1, wherein the broadcast signaling further comprises a set of paging parameters, and wherein the at least one processor is configured to cause the UE to determine, based on the set of paging parameters, the next paging occasion and a paging frame associated with the second cell.

3. The UE of claim 1, wherein to receive the broadcast signaling, the at least one processor is configured to cause the UE to receive a system information block type 1 (SIB1), a system information block type 4 (SIB4), or a system information block (SIB) comprising the broadcast signaling.

4. The UE of claim 1 , wherein the broadcast signaling further indicates that the first cell is dedicated for radio resource control (RRC) connection establishment, and wherein the at least one processor is configured to cause the UE to camp on the second cell in response to determining that the first cell is dedicated for RRC connection establishment.

5. The UE of claim 1, wherein the at least one processor is configured to cause the UE to: determine a UE identity (ID) for paging, and determine to re-tune the receiver frequency to the second frequency layer based on the UE ID.

6. The UE of claim 1, wherein the at least one processor is configured to cause the UE to detect an arrival in the first cell while the UE is in an idle state; and transmit a notification to the first cell in response to the arrival.

7. The UE of claim 6, wherein the notification comprises a UE identity (ID) for paging.

8. The UE of claim 6, wherein the at least one processor is configured to cause the UE to detect the arrival based on a cell selection procedure or cell reselection procedure.

9. The UE of claim 6, wherein the at least one processor is configured to cause the UE to transmit a second notification in response to a departure from the first cell.

10. The UE of claim 6, wherein the at least one processor is configured to cause the UE to: receive a second indication for notifications of arrivals or departures, and transmit the notification based at least in part on the second indication.

11. A method performed by a user equipment (UE), the method comprising: receiving, from a first cell associated with a first frequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer; re-tuning a receiver frequency to the second frequency layer based on a next paging occasion associated with the second cell; receiving a paging message on the second cell; re-tuning the receiver frequency to the first frequency layer based on an end of the next paging occasion; andinitiating a connection with the first cell based at least in part on the paging message.

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, on a first cell associated with a first frequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer; transmit, to a user equipment (UE), a paging message via the second cell; receive, from the UE, a paging response message via the first cell; and establish a connection with the UE via the first cell.

13. The base station of claim 12, wherein the broadcast signaling further comprises a set of paging parameters for determining a next paging occasion and a paging frame associated with the second cell, and wherein the at least one processor is configured to cause the base station to transmit the paging message via the second cell based on the set of paging parameters.

14. The base station of claim 12, wherein the at least one processor is configured to cause the base station to transmit a condition for camping on the first cell based on a UE identity (ID) for paging, or transmit a condition for camping on the second cell based on a UE ID for paging, or both.

15. The base station of claim 12, wherein the at least one processor is configured to cause the base station to transmit a condition for paging reception on the first cell based on a UE identity (ID) for paging, or transmit a condition for paging reception on the second cell based on a UE ID for paging, or both.

16. The base station of claim 12, wherein the at least one processor is configured to cause the base station to receive, from the UE, a notification of an arrival in the first cell; anddetermine a number of idle-state UEs in the first cell based at least in part on the notification.

17. The base station of claim 16, wherein the at least one processor is configured to cause the base station to stop paging in the first cell based at least in part on the number of idle-state UEs satisfying a threshold.

18. The base station of claim 16, wherein the at least one processor is configured to cause the base station to offload paging from the first cell to the second cell based at least in part on the number of idle-state UEs satisfying a threshold.

19. The base station of claim 16, wherein the notification comprises a UE identity (ID) for paging.

20. A method performed by a base station, the method comprising: transmitting, on a first cell associated with a first frequency layer, broadcast signaling comprising an indication of a second cell associated with a second frequency layer; transmitting, to a user equipment (UE), a paging message via the second cell; receiving, from the UE, a paging response message via the first cell; and establishing a connection with the UE via the first cell.

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