Patent Description:
<INSERT New Page 2a> a.

In some aspects, a method of wireless communication, performed by a user equipment (UE), may include receiving, from a serving cell, signaling identifying a core network type cell ranking offset parameter; ranking, based at least in part on the core network type cell ranking offset parameter, a neighbor cell for reselection relative to the serving cell, wherein the neighbor cell is associated with a different core network type than the serving cell; and selectively reselecting to the neighbor cell based at least in part on ranking the neighbor cell for reselection relative to the serving cell.

Its presumably accurate English translation <CIT>, and discloses a mobility management method comprising the steps of receiving at a UE core network information about each cell from a network side device, the core network information being used to indicate a type of a core network, and when a UE is in an idle state, performing cell reselection in accordance with the type of the core network for each cell and a capability of the UE for sup-porting the core network.

3GPP TR <NUM> V6. <NUM> discloses in section <NUM>. <NUM> examples for core network steering via CN type selection rules configuration/reconfiguration. It discloses a new UE configuration parameter named "CN type selection rules", which may take the values "Prefer 5GC over EPC" and "Prefer EPC over 5GC". If the UE has a CN type selection rule indicating "Prefer 5GC over EPC" then the UE shall prioritize cells supporting 5GC when performing cell selection/reselection and shall select 5GC if available in the cell the UE is camping on. Document <NPL>, also discloses UE selection of 5GC or EPC based on Cellular IoT feature support.

Controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with inter-core network reselection control, as described in more detail elsewhere herein. For example, controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform or direct operations of, for example, process <NUM> of <FIG> and/or other processes as described herein. Memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively.

In some aspects, UE <NUM> may include means for receiving, from a serving cell, signaling identifying a core network type cell ranking offset parameter; means for ranking, based at least in part on the core network type cell ranking offset parameter, a neighbor cell for reselection relative to the serving cell, wherein the neighbor cell is associated with a different core network type than the serving cell; means for selectively reselecting to the neighbor cell based at least in part on ranking the neighbor cell for reselection relative to the serving cell, and/or the like. In some aspects, such means may include one or more components of UE <NUM> described in connection with <FIG>.

In some aspects, the base station may transmit the PSS, the SSS, and/or the PBCH in accordance with a synchronization communication hierarchy (e.g., a synchronization signal (SS) hierarchy) including multiple synchronization communications (e.g., SS blocks).

An interlace structure may be used for each of the downlink and uplink for FDD in certain telecommunications systems (e.g., NR). For example, Q interlaces with indices of <NUM> through Q - <NUM> may be defined, where Q may be equal to <NUM>, <NUM>, <NUM>, <NUM>, or some other value. Each interlace may include slots that are spaced apart by Q frames. In particular, interlace q may include slots q, q + Q, q + 2Q, etc., where q E <NUM>,. , Q-<NUM>}.

New Radio (NR) may refer to radios configured to operate according to a new air interface (e.g., other than Orthogonal Frequency Divisional Multiple Access (OFDMA)-based air interfaces) or fixed transport layer (e.g., other than Internet Protocol (IP)). In aspects, NR may utilize OFDM with a CP (herein referred to as cyclic prefix OFDM or CP-OFDM) and/or SC-FDM on the uplink, may utilize CP-OFDM on the downlink and include support for half-duplex operation using time division duplexing (TDD).

In some network deployments, available BSs may provide access to different types of core networks. For example, a UE may be within range of a first BS that uses an evolved packet core network (EPC), a second BS that uses a <NUM> core network (5GC), and/or the like. In some cases, a single BS may provide access to a plurality of different types of core networks. For example, the first BS may provide access to both an EPC and a 5GC. Some UEs, such as narrowband Internet of Things (NB-IoT) UEs, may be configured to connect to a plurality of different types of core networks, such as being configured to connect to both the EPC and the 5GC. In this case, a UE may connect to a single core network of a plurality of different types of core networks (e.g., either the EPC or the 5GC) available in connection with a single cell of a single BS.

To connect to a core network, the UE may select to a serving cell associated with the core network on a first frequency. The UE may subsequently reselect to a second frequency, which may be associated with the same type of core network or a different type of core network. However, reselection between different types of core networks may result in excessive signaling overhead to perform registration procedures, tracking area update procedures, UE context transfer procedures, and/or the like. Such signaling overhead may be particularly detrimental to operation of networks with deployments of thousands, millions, or billions of UEs, such as in massive NB-IoT types of deployments. Moreover, a transfer between types of core networks may result in a UE using excessive power resources, which may reduce performance for low-power UEs, such as NB-IoT UEs.

Some aspects described herein provide for inter-core network reselection control. For example, a UE may account for whether a reselection to a neighbor cell is an inter-core network reselection when ranking neighbor cells for reselection. In this case, the UE may selectively reselect to the neighbor cell based at least in part on the ranking of neighbor cells. In this way, by accounting for whether the reselection is an inter-core network reselection, the UE reduces a likelihood of performing an inter-core network reselection to a neighbor cell associated with a different type of core network than a serving cell of the UE. In this way, the UE may reduce signaling overhead, utilization of power resources, and/or the like.

Moreover, the UE may, in some cases, still allow inter-core network reselection. For example, the UE may reselect to a particular neighbor cell associated with a different type of core network that is associated with other factors that are significantly better than those of other available neighbor cells with a same type of core network as a serving cell. In other words, the UE may perform an inter-core network reselection when a neighbor cell is associated with, for example, significantly better cell quality than other neighbor cells to compensate for the reselection being an inter-core network reselection. In this way, the UE ensures that the UE does not remain on or reselect to a cell with poor quality, thereby improving performance relative to disabling all inter-core network reselections.

<FIG> is a diagram illustrating an example <NUM> of inter-core network reselection control, in accordance with various aspects of the present disclosure. As shown in <FIG>, example <NUM> includes a UE <NUM>, a BS <NUM>-<NUM> associated with a first type of core network (CN), a BS <NUM>-<NUM> associated with the first type of core network, and a BS <NUM>-<NUM> associated with a second type of core network. Although some aspects are described herein in terms of a particular set of core network capabilities, other core network capabilities are contemplated, such as other types of core networks, other quantities of types of core networks provided by each BS <NUM>, and/or the like.

As further shown in <FIG>, and by reference number <NUM>, UE <NUM> may be camping on BS <NUM>-<NUM>. For example, UE <NUM> may be connected to the first type of core network, such as an EPC or 5GC, via a serving cell on BS <NUM>-<NUM>. In some aspects, BS <NUM>-<NUM> may provide a plurality of types of core networks. For example, BS <NUM>-<NUM> may provide connection to both the EPC and the 5GC. In this case, UE <NUM> may be connected to a single core network of the plurality of types of core networks. For example, UE <NUM> may connect to the EPC via a particular frequency of BS <NUM>-<NUM>.

As further shown in <FIG>, and by reference number <NUM>, UE <NUM> may receive signaling identifying a core network type cell ranking offset parameter (QOffsetfteq_cn_type). For example, BS <NUM>-<NUM> may provide the signaling to indicate a factor accounting for whether a cell reselection is an inter-core network reselection for determining a ranking of cells for reselection.

In some aspects, BS <NUM>-<NUM> may transmit a system information block (SIB) type of message to convey the core network type cell ranking offset parameter. Additionally, or alternatively, UE <NUM> may receive an indication of whether to use the core network type cell ranking offset parameter (e.g., that is already configured, such as a stored core network type cell ranking offset parameter) via a SIB. For example, BS <NUM>-<NUM> may provide a SIB to indicate that UE <NUM> is to account for core network type when ranking cells for reselection. In some aspects, accounting for core network type may be configured on a per public land mobile network (PLMN) basis. For example, BS <NUM>-<NUM> may provide the SIB to each UE <NUM> on a single PLMN. Additionally, or alternatively, accounting for core network type may be configured for all PLMNs and a group of BSs <NUM> may provide respective SIBs to each UE <NUM> on each PLMN. In this case, a network device may provide an indication to the group of BSs <NUM> indicating that the group of BSs <NUM> are to provide the respective SIBs.

As further shown in <FIG>, and by reference number <NUM>, UE <NUM> may rank neighbor cells for reselection. For example, for a first neighbor cell (e.g., BS <NUM>-<NUM>) that is associated with a different type of core network than a type of core network to which UE <NUM> is connected, UE <NUM> may rank the first neighbor cell based at least in part on the core network type cell ranking offset parameter. Additionally, or alternatively, UE <NUM> may rank the first neighbor cell based at least in part on another parameter. For example, UE <NUM> may rank the first neighbor cell based at least in part on a cell quality parameter, a cell hysteresis parameter, a temporary offset parameter, a cell ranking offset parameter, a single cell point-to-multipoint parameter, a combination thereof, and/or the like. In some aspects, UE <NUM> may rank BS <NUM>-<NUM> based at least in part on an equation of the form: <MAT> where Rn represents a ranking for a neighbor cell for which an inter-core network reselection is to occur, Qmeas,n represents the cell quality parameter for a different core network type than a current core network type, Qhyst represents the cell hysteresis parameter, Qoffsettemp represents the temporary offset parameter, QoffsetSCPTM represents the single cell point-to-multipoint parameter, and Qoffsetfreq_cn_type represents the core network type cell ranking offset parameter.

In contrast, UE <NUM> may rank a second neighbor cell (e.g., BS <NUM>-<NUM>) without using the core network type cell ranking offset parameter based at least in part on the second neighbor cell being associated with a same core network type as a serving cell (e.g., BS <NUM>-<NUM>). Additionally, or alternatively, the second neighbor cell may be associated with a plurality of types of core networks, which includes the same core network type as the serving cell. In this case, UE <NUM> may omit the core network type cell ranking offset parameter from determining a ranking for the second neighbor cell based at least in part on determining that UE <NUM> can reselect to the second neighbor cell and remain on the same type of core network. For example, BS <NUM>-<NUM> may be associated with an EPC connection and BS <NUM>-<NUM> may be associated with both an EPC connection and a 5GC connection, thereby enabling UE <NUM> to reselect to BS <NUM>-<NUM> and remain on the EPC connection. In some aspects, UE <NUM> may rank BS <NUM>-<NUM> based at least in part on an equation of the form: <MAT> where Rs represents a ranking for a neighbor cell with a same core network type as a serving cell and Qmeas,s represents the cell quality parameter for a same core network type as a current core network type.

As further shown in <FIG>, and by reference number <NUM>, in some aspects, UE <NUM> may selectively reselect to a neighbor cell with a different core network type than a current core network type. For example, when BS <NUM>-<NUM> is ranked higher than, for example, BS <NUM>-<NUM>, UE <NUM> may reselect to BS <NUM>-<NUM> despite reselecting to BS <NUM>-<NUM> being an inter-core network reselection. In this way, UE <NUM> ensures that UE <NUM> camps onto a cell with a superior connection (e.g., a highest cell quality, a best hysteresis, and/or the like).

In contrast, as shown by reference number <NUM>, in some aspects, when BS <NUM>-<NUM> ranks higher than BS <NUM>-<NUM>, UE <NUM> may reselect to BS <NUM>-<NUM> to remain on a same core network type. In this case, BS <NUM>-<NUM> may still be associated with a better connection than BS <NUM>-<NUM> (or may be associated with a worse connection), but the connection may not be better by a sufficient difference to justify performing an inter-core network reselection. In this way, UE <NUM> reduces a signaling overhead and a utilization of power resources relative to reselecting to a different core network type.

In contrast, as shown by reference number <NUM>, in some aspects, based at least in part on ranking the neighbor cells, UE <NUM> may determine to forgo an inter-frequency cell reselection. For example, based at least in part on ranking the neighbor cells, UE <NUM> may determine that no neighbor cell satisfies a threshold ranking for reselection and may remain on the serving cell. In this way, UE <NUM> reduces signaling overhead and a utilization of power resources relative to reselecting to a different core network type. In this way, UE <NUM> reduces inter-core network mobility, thereby improving network performance, UE performance, and/or the like.

<FIG> and <FIG> are diagrams illustrating an examples <NUM>/<NUM>' of inter-core network reselection control, in accordance with various aspects of the present disclosure. As shown in <FIG>, different tracking areas (TAs) may be associated with different core network types (e.g., a <NUM> core (5GC) and an evolved packet core (EPC). The different core network types may be connected to BSs <NUM> in different geographical areas providing different frequencies. For example, As shown in <FIG> and by example <NUM>, a first geographical area may include BSs <NUM> providing a first frequency with access to the EPC and the 5GC. In contrast, a second geographical area may include BSs <NUM> providing a second frequency, which has access to the EPC and the 5GC, and a third frequency, which has access to only the 5GC.

As shown in <FIG>, and by example <NUM>' a UE <NUM> may be operating in a first region with a first frequency. In this case, UE <NUM> may be operating in a coverage enhancement mode connected to the evolved packet core (EPC) on cell A using a frequency F1. When UE <NUM> moves to a second region, a border cell B may support a frequency F2 and a frequency F3. Frequency F2 may be associated with a <NUM> core (5GC) and the EPC, whereas frequency F3 may be associated with only the 5GC. In some aspects, UE <NUM> may prioritize F2 with the EPC connection over F3 with the 5GC connection to avoid changing core network type. Moreover, by prioritizing the EPC on F2, when UE <NUM> moves back to region <NUM>, UE <NUM> is able to stay on an EPC connection rather than switching core networks as may have happened had UE <NUM> selected the 5GC of F3.

In some aspects, UE <NUM> may receive a system information block (SIB) configured frequency priority indicator and may perform inter-frequency idle cell reselection based at least in part on the frequency priority indicator. For example, UE <NUM> may prioritize reselection to an inter-frequency neighbor cell with the same core network type and with a higher frequency priority than another neighbor cell with the same core network type and a lower frequency priority. For example, when UE <NUM> is camped on F1, which has a lower priority than F2 and F3, UE <NUM> may determine that F2 has a higher priority and the same core network type, which may trigger UE <NUM> to reselect to F2. In some aspects, UE <NUM> may set a threshold for determining whether to select to F3 based at least in part on whether a target cell frequency meets one or more criteria: <MAT> or <MAT> where Squal represents a cell selection quality threshold (in decibels (dB)), ThreshX, HighQ specifies an Squal threshold (in dB) used by a UE when reselecting towards a higher priority frequency than a current serving frequency, and Srxlev specifies a cell selection receive (RX) level value (in dB). In some aspects, threshX, HighP specifies the Srxlev threshold (in dB) used by a UE when reselecting towards a higher priority frequency than the current serving frequency and Qoffsetfreq_cn_type is a factor associated with F3 having a different core network type from F1. Similarly, when UE <NUM> is reselecting to a lower priority frequency, UE <NUM> may determine whether to select to a target cell or serving cell lower priority frequency based at least in part on one or more criteria: <MAT> <MAT> <MAT> <MAT> where ThreshX,LowQ specifies an Squal threshold (in dB) used by a UE when reselecting towards a lower priority frequency than a current serving frequency; ThreshServing,LowQ specifies an Squal threshold (in dB) used by the UE on the serving cell when reselecting towards a lower priority frequency; Threshx, LowP specifies the Srxlev threshold (in dB) used by the UE when reselecting towards a lower priority frequency than the current serving frequency; and ThreshServing,LowP specifies the Srxlev threshold (in dB) used by the UE on the serving cell when reselecting towards a lower priority frequency. In some aspects, TreselectionEUTRAN specifies the cell reselection timer value TreselectionRAT for E-UTRAN.

As indicated above, <FIG> and <FIG> are provided as an example. Other examples may differ from what is described with respect to <FIG> and <FIG>.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where a UE (e.g., UE <NUM> and/or the like) performs operations associated with inter-core network reselection control.

As shown in <FIG>, in some aspects, process <NUM> may include receiving, from a serving cell, signaling identifying a core network type cell ranking offset parameter (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may receive, from a serving cell, signaling identifying a core network type cell ranking offset parameter, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include ranking, based at least in part on the core network type cell ranking offset parameter, a neighbor cell for reselection relative to the serving cell, wherein the neighbor cell is associated with a different core network type than the serving cell (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may rank, based at least in part on the core network type cell ranking offset parameter, a neighbor cell for reselection relative to the serving cell, as described above. In some aspects, the neighbor cell is associated with a different core network type than the serving cell.

As further shown in <FIG>, in some aspects, process <NUM> may include selectively reselecting to the neighbor cell based at least in part on ranking the neighbor cell for reselection relative to the serving cell (block <NUM>). For example, the UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or the like) may selectively reselect to the neighbor cell based at least in part on ranking the neighbor cell for reselection relative to the serving cell, as described above.

In a first aspect, selectively reselecting to the neighbor cell includes selectively performing an inter-frequency reselection.

In a second aspect, selectively reselecting to the neighbor cell includes reselecting to another cell that is associated with a same core network type as the serving cell based at least in part on ranking the neighbor cell for reselection relative to the serving cell.

In a third aspect, alone or in combination with one or more of the first and second aspects, process <NUM> may include ranking another cell for reselection relative to the serving cell without using the core network type cell ranking offset parameter, the other cell being associated with a same core network type as the serving cell.

In a fourth aspect, alone or in combination with the third aspect, ranking, without using the core network type cell ranking offset parameter, the other cell for reselection relative to the serving cell is based at least in part on the other cell being associated with the same core network type as the serving cell.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, ranking the neighbor cell for reselection relative to the serving cell includes ranking the neighbor cell for reselection relative to the serving cell based at least in part on at least one of a cell quality parameter, a cell hysteresis parameter, a temporary offset parameter, a cell ranking offset parameter, a single cell point-to-multipoint parameter, or a combination thereof.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, receiving the core network type cell ranking offset parameter includes receiving a system information block message identifying the core network type cell ranking offset parameter.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the core network type cell ranking offset parameter is configured on a per public land mobile network basis.

In an eighth aspect, alone or in combination with one or more of the first through sixth aspects, the core network type cell ranking offset parameter is associated with a common configuration across a plurality of public land mobile networks.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, a core network type of one of the serving cell or the neighbor cell is at least one of an evolved packet core network or a <NUM> core network.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the serving cell is associated with a single core network type and the neighbor cell is associated with a different, single core network type.

In an eleventh aspect, alone or in combination with one or more of the first through ninth aspects, the serving cell is associated with a plurality of core network types, and the plurality of core network types include a first core network type that is the same as the neighbor cell and a second core network type that is different from the neighbor cell. In some aspects, the UE is connected to the serving cell using the second core network type.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, ranking, based at least in part on the core network type cell ranking offset parameter, the neighbor cell for reselection relative to the serving cell is based at least in part on the neighbor cell being associated with the different core network type than the serving cell.

Claim 1:
A method (<NUM>) of wireless communication performed by a user equipment, UE, comprising:
receiving (<NUM>), from a serving cell, signaling identifying a core network type cell ranking offset parameter;
ranking (<NUM>), based at least in part on the core network type cell ranking offset parameter, a neighbor cell for reselection relative to the serving cell, wherein the neighbor cell is associated with a different core network type than the serving cell, wherein the ranking is further based on a combination of a cell quality parameter, a cell hysteresis parameter, a temporary offset parameter, a cell ranking offset parameter, and a single cell point-to-multipoint parameter; and
selectively reselecting (<NUM>) to the neighbor cell based at least in part on ranking the neighbor cell for reselection relative to the serving cell.