Derivation of the SSB index on the target cell

Abstract

Disclosed are methods, systems, and computer-readable media for performing operations including receiving, by a user equipment (UE), a message from a serving cell serving the UE, the message including (i) synchronization signal block (SSB) information associated with a target SSB burst of the target cell and (ii) a flag indicating that the UE is authorized to use timing of a reference cell to derive an index of the target SSB burst, the target SSB burst including one or more SSBs; calculating a tolerance of frame boundary alignment between the reference cell and the target cell; and determining an index of the target SSB burst based on the tolerance.

Description

Background Art

[0001] A wireless communication network provides an integrated communication platform and telecommunications services to wireless user devices. Exemplary telecommunications services include telephony, data (e.g., voice, audio, and / or video data), messaging, Internet access, and / or other services. The wireless communication network has wireless access nodes that exchange wireless signals with wireless user devices using wireless network protocols such as those described in various telecommunications standards published by the 3rd Generation Partnership Project (3GPP). Exemplary wireless communication networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal Frequency Division Multiple Access (OFDMA) networks, Long Term Evolution (LTE), and 5th Generation New Radio (5G NR). The wireless communication network facilitates mobile broadband services using technologies such as OFDM, Multiple-Input Multiple-Output (MIMO), advanced channel coding, massive MIMO, beamforming, and / or other features.

[0002] For some procedures in 5G NR, such as handover or addition of a component carrier (CC), a user equipment (UE) is configured to measure signals from the UE's serving cell and / or from neighboring cells. 5G NR has introduced cell signal measurement by using a Synchronization Signal Block (SSB) that includes a Synchronization Signal (SS) and a Physical Broadcast Channel (PBCH). The SS includes a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). The PBCH includes a PBCH Demodulation Reference Signal (DMRS) and PBCH data. The SSB is used for measurements of Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), and Signal-to-Interference-plus-Noise Ratio (SINR).

Summary of the Invention

[0003] This disclosure describes a method and system for deriving an SSB index on an adjacent cell. In one example, the disclosed method and system can be used to derive an SSB index in a scenario in which the interfrequency target cell has a different SCS than the serving cell.

[0004] This disclosure relates to a method, system, apparatus, computer program, or combination thereof for deriving an SSB index on a target cell. According to one aspect of this disclosure, a method performed by a user device (UE) serviced by a serving cell includes receiving a message from the serving cell that includes (i) synchronization signal block (SSB) information associated with a target SSB burst of a target cell, and (ii) a flag indicating that the UE is permitted to use the timing of a reference cell to derive an index of a target SSB burst, where the target SSB burst includes one or more SSBs; calculating a tolerance (Δt) of frame boundary alignment between the reference cell and the target cell; and determining the index of the target SSB burst based on the tolerance.

[0005] Other versions include corresponding systems, devices, and computer programs for performing actions in a manner defined by instructions encoded on a computer-readable storage device. These and other versions may optionally include one or more of the following features:

[0006] In some implementations, the SSB information includes the frequency of the target SSB burst and the subcarrier interval of the target SSB burst.

[0007] In some implementations, the method further includes measuring at least a portion of the target SSB burst during a measurement window based on at least one of tolerance (Δt) or SSB information.

[0008] In some implementations, measuring at least a portion of the target SSB burst based on tolerance (Δt) or at least a portion of the SSB information determines the time length of the measurement window.

number

[0009] In some implementations, determining the index of a target SSB burst includes determining a candidate position for a first SSB within the target SSB burst based on tolerances, and determining the index of the target SSB burst based on at least one of the candidate positions for the first SSB or a measured portion of the target SSB index.

[0010] In some implementations, calculating the tolerance (Δt) involves calculating the tolerance as Δt = min(two SSB symbols in the reference cell, one PDSCH symbol in the reference cell).

[0011] In some implementations, calculating the tolerance (Δt) involves calculating the tolerance as Δt = 2 SSB symbols of the target cell.

[0012] In some implementations, calculating the tolerance (Δt) involves receiving a signal indicating the formula to be used to calculate the tolerance, and then calculating the tolerance based on the signaled formula.

[0013] In some implementations, the signaled expression is one of the following: i) Δt = min(2 SSB symbols of the reference cell, 1 PDSCH symbol of the reference cell), and (ii) Δt = 2 SSB symbols of the target cell.

[0014] In some implementations, the tolerance includes a separate tolerance defined for each of several predetermined SSB pattern cases.

[0015] In some implementations, calculating the tolerance (Δt) involves determining a first SSB pattern case associated with the target cell and a second SSB pattern case associated with the reference cell, determining that the first SSB pattern has a larger subcarrier spacing than the second SSB pattern, and calculating the tolerance based on the individual tolerances associated with the first SSB pattern.

[0016] In some implementations, a set of predetermined SSB pattern cases includes the following: [Table 1]

[0017] In some implementations, the individual tolerances defined for Case B, Case D, or Case E are calculated as Δt = 2 SSB symbols.

[0018] In some implementations, the individual tolerances defined for case A or case C are calculated as Δt = 3 SSB symbols.

[0019] In some implementations, the individual tolerances defined for case F or case G are calculated as Δt = 3.5 SSB symbols.

[0020] In some implementations, separate tolerances are defined for case B or D, and if two consecutive SSBs are transmitted, Δt is calculated as 6 SSB symbols.

[0021] According to another aspect of the present disclosure, a method performed by a base station of a serving cell includes generating, for a user equipment (UE) served by the serving cell, a message including (i) synchronization signal block (SSB) information associated with a target SSB burst of a target cell and (ii) a flag indicating that the UE is permitted to use the timing of a reference cell to derive an index of the target SSB burst, where the target SSB burst is a target SSB burst that includes one or more SSBs, and preparing the message for transmission to the UE.

[0022] Other versions include corresponding systems, apparatuses, and computer programs for performing the actions of a method defined by instructions encoded on a computer-readable storage device. These and other versions may optionally include one or more of the following features.

[0023] In some implementations, the SSB information includes the frequency of the target SSB burst and the subcarrier spacing of the target SSB burst.

[0024] In some implementations, the method further includes transmitting the message to the UE.

[0025] Details of one or more embodiments of these systems and methods are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of these systems and methods will be apparent from the description and drawings, and from the claims.

Brief Description of the Drawings

[0026] [Figure 1] An example of deriving an SSB index according to some embodiments is shown.

[0027] [Figure 2] A wireless network according to some embodiments is shown.

[0028] [Figure 3] Here is another example of deriving an SSB index according to several embodiments.

[0029] [Figure 4A] A flowchart illustrating an exemplary method in several embodiments is shown. [Figure 4B] A flowchart illustrating an exemplary method in several embodiments is shown.

[0030] [Figure 5] The following are user equipment (UE) configurations according to several embodiments.

[0031] [Figure 6] Several embodiments of access nodes are shown. [Modes for carrying out the invention]

[0032] As mentioned above, 5GNR introduces cell signal measurement using synchronous signal blocks (SSBs). In the time domain, SSBs span four orthogonal frequency division multiplexing (OFDM) symbols and are transmitted periodically with periods of 5 milliseconds (ms), 10 ms, 20 ms, 40 ms, 80 ms, or 160 ms. To enable beamforming and beam sweeping for SSBs, the standard published by the Third Generation Partnership Project (3GPP) defines SS burst sets. An SS burst set includes one or more sets of SSBs, each of which can be transmitted on a different beam.

[0033] The 3GPP standard defines different cases of time-domain patterns for SSB transmission. In particular, the 3GPP standard defines a set of symbols designated as candidates for the start of an SSB transmission. For a half-frame with an SSB block, the first symbol index for the candidate SSB is determined according to the subcarrier spacing (SCS) of the SS / PBCH block, where index 0 corresponds to the first symbol of the first slot in the half-frame. The following cases are specified in 3GPP TS 38.213.

[0034] Case A - 15kHz SCS: The first symbol of the candidate SS / PBCH block has an index of {2,8}+14n. - For operations that do not involve shared spectral channel access: - For carrier frequencies below 3GHz, n=0,1. - For carrier frequencies within FR1 greater than 3GHz, n=0,1,2,3. - As described in [TS 37.213], for operation with shared spectral channel access, n=0, 1, 2, 3, 4.

[0035] Case B - 30kHz SCS: The first symbol of the candidate SS / PBCH block has an index {4,8,16,20} + 28·n. For carrier frequencies below 3GHz, n=0. For carrier frequencies within FR1 greater than 3GHz, n=0,1.

[0036] Case C-30kHz SCS: The first symbol of the candidate SS / PBCH block has an index {2,8}+14·n. - In the case of operation without shared spectral channel access - In the case of spectral operation - For carrier frequencies below 3GHz, n=0,1. For carrier frequencies within FR1 greater than 3GHz, n=0,1,2,3. - For non-paired spectral operation. - For carrier frequencies smaller than 1.88GHz, n=0,1. For carrier frequencies within FR1 of 1.88GHz or higher, n=0,1,2,3. - For operation with shared spectral channel access, n = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

[0037] Case D-120kHz SCS: The first symbol of the candidate SS / PBCH block has indices {4, 8, 16, 20} + 28·n. For carrier frequencies within FR2, n = 0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18.

[0038] Case E-240kHz SCS: The first symbol of the candidate SS / PBCH block has indices {8, 12, 16, 20, 32, 36, 40, 44} + 56·n. For carrier frequencies within FR2-1, n = 0, 1, 2, 3, 5, 6, 7, 8.

[0039] Case F-480kHz SCS: The first symbol in the candidate SS / PBCH block has an index {2,9}+14·n. For carrier frequencies within FR2-2, n=0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31.

[0040] Case G-960kHz SCS: The first symbol of the candidate SS / PBCH block has the index {2,9}+14·n. For carrier frequencies within FR2-2, n=0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31. Cases A-G are summarized in Table 1. [Table 2]

[0041] 3GPP also introduces an SSB-based measurement timing configuration window called the SMTC window. The SMTC window indicates the measurement period and timing of the SSB that the UE can use for measurement. The SMTC window period can be set within the same range as the SSB period (e.g., 5, 10, 20, 40, 80, or 160 ms). Furthermore, the window duration can be set to 1, 2, 3, 4, or 5 ms, depending on the number of SSBs transmitted on the cell being measured.

[0042] In 5G NR, measurement objects are defined for in-frequency and inter-frequency measurements. Information indicating the reference signal to be measured may be transmitted by the network using IEMeasObjectNR. Such information may include the frequency / time location and subcarrier spacing of the reference signal. For example, a measurement configuration for SSB is provided under measObjectToAddMod as part of MeasObjectNRIE. IE includes at least the following fields: ssbFrequency, ssbSubcarrierSpacing, smtc1, and smtc2. The field ssbFrequency provides the frequency of the SS associated with the measurement object. The field ssbSubcarrierSpacing provides the subcarrier spacing of the SSB. The fields smtc1 and smtc2 provide the primary and secondary measurement timing configurations, respectively. The primary measurement timing configuration provides the timing offset and duration for the SSB.

[0043] After receiving the MeasObjectNRIE, the UE can perform the measurements provided in the IE. In the case of an SSB set (also called an SSB burst), the UE can measure one or more SSBs contained in the burst. When the UE receives an SSB in an SSB burst, it is important for the UE to identify the index of the SSB (i.e., which SSB in the burst was received). This is particularly difficult when the UE is receiving an SSB from a target cell (i.e., a cell other than the serving cell or an adjacent cell). To address this challenge, 3GPP introduced the field `deriveSSB-IndexFromCell`, which allows the UE to derive the SSB index of the target cell(s) at the same frequency as the serving cell. This field is contained in the `SSB-ConfigMobilityIE` found in the IEMeasObjectNR of an adjacent cell. TS 38.331 defines `deriveSSB-IndexFromCell` as follows: If this field is set to true, the UE assumes SFN [System Frame Number] and frame boundary alignment across cells on the same frequency carrier, as specified in TS 38.133

[14] . Thus, if the UE is configured with a serving cell where (ServingCellConfigCommon,subcarrierSpacing) in absoluteFrequencySSB is equal to (ssbFrequency,ssbSubcarrierSpacing) in this MeasObjectNR, this field indicates whether the UE can utilize the timing of this serving cell to derive the index of the SS block transmitted by the neighboring cell. If not, this field indicates whether the UE can use the timing of any detected cell on its target frequency to derive the SSB index of all neighboring cells on that frequency.

[0044] Furthermore, when deriveSSB-IndexFromCell is enabled, the UE assumes that the frame boundary alignment (including half-frame, subframe, and slot boundary alignment) across cells on the same frequency carrier is within a tolerance (Δt) not worse than min(2 SSB symbols, 1 PDSCH symbol). The UE also assumes that the SFNs of all cells on the same frequency carrier are the same. Thus, the UE can determine the candidate position of the first SSB in the burst (also called SSB index #0 or SSB#0). If the UE measures an SSB within that candidate position, the UE can determine that the measured SSB is SSB#0. The UE can also derive candidate positions for SSBs in the SSB burst (if any). For example, using Table 1, the UE can derive candidate positions for each of the remaining SSB positions (if any) in the burst from the position of SSB#0.

[0045] The flag `deriveSSB-IndexFromCell` achieves many advantages. For example, the flag reduces the time required for SSB index discovery (T SSB_time_index (=0). As another example, the flag allows more symbols to be scheduled when scheduling restrictions are applied. If the flag is not available, the UE must restrict the entire SMTC window for SSB detection because, without the flag, the UE would not know when an SSB occurs within the window.

[0046] Figure 1 shows an example 100 of deriving an SSB index according to several embodiments. In Example 100, a UE (not shown in Figure 1) receives the flag `deriveSSB-IndexFromCell`. Thus, the UE assumes that the frame boundary alignment (including half-frame, subframe, and slot boundary alignment) across cells on the same frequency carrier is within tolerance Δt. Thus, the UE can derive the SSB index of a target SSB burst broadcast by an adjacent cell. In particular, the UE knows that SSB index #0 is received within the frame boundary tolerance Δt of the SSB scheduled by the source cell. Thus, if the UE measures an SSB within tolerance, the UE can determine that the measured SSB is SSBindex #0.

[0047] In Example 100, the UE measures the target SSB burst on adjacent cell 1, which is operating on carrier 1 as well as the UE's serving cell. Therefore, the UE assumes that the frame boundary alignment across the serving cell and the adjacent cell is within tolerance Δt. Thus, the UE knows the candidate position for SSB#0 (i.e., the first SSB in the target SSB burst). When the UE detects an SSB within tolerance, the UE knows that the detected SSB is SSB#0.

[0048] However, in the inter-frequency case, the meaning of the `deriveSSB-IndexFromCell` flag is different. The timing of the serving cell cannot be used for the inter-frequency target cell. Rather, the UE must first read the SSB index of at least one of the neighboring cells, and then derive the SSB index of the other neighboring cells on the same inter-frequency carrier. It has been proposed to enhance the IE for inter-frequency cells having the same SCS. In particular, RAN4 agreed to introduce a new network signaling [deriveSSB-indexFromCell-inter] that informs the UE that the SSB index of a target cell(s) on a different frequency than the serving cell's frequency may be derived from the serving cell. Furthermore, the IE would inform the UE which serving cell to use for the target SSB index derive. RAN4 also agreed that the IE can only be configured if the SCS of the SSB is the same between the target cell and the serving cell used for SSB index derive. However, this IE is not applicable to inter-frequency target cells that have a different SCS than the serving cell.

[0049] This disclosure describes a method and system for deriving an SSB index on an inter-frequency adjacent cell. In one example, the disclosed method and system can be used to derive an SSB index in a scenario in which the inter-frequency target cell has a different SCS than the serving cell.

[0050] Figure 2 shows a wireless network 200 according to several embodiments. The wireless network 200 includes UEs 202 and base stations 204 connected via one or more channels 206A, 206B across an air interface 208. The UEs 202 and base stations 204 communicate using a system that supports control for managing the UEs 202's access to the network via base stations 204.

[0051] For convenience, and without limitation, wireless network 200 is described in the context of Long-Term Evolution (LTE) and Fifth Generation (5G) New Radio (NR) communication standards as defined by the Third Generation Partnership Project (3GPP) technical standards. More specifically, wireless network 200 is described in the context of non-standalone (NSA) networks incorporating both LTE and NR, such as E-UTRA (Evolutionary Universal Terrestrial Radio Access)-NR dual connectivity (EN-DC) networks and NE-DC networks. However, wireless network 200 can also be a standalone (SA) network incorporating only NR. Furthermore, other types of communication standards are possible, including future 3GPP systems (e.g., Sixth Generation (6G)) systems, IEEE 802.16 protocols (e.g., WMAN, WiMAX, etc.). While embodiments may be described herein using terms generally associated with 5G NR, embodiments of this disclosure may also apply to other systems, such as systems following 3G, 4G, and / or 5G (e.g., 6G).

[0052] In the wireless network 200, UE 202 and any other UEs in the system may be, for example, machine-type devices such as laptop computers, smartphones, tablet computers, printers, smart meters, or dedicated devices for healthcare monitoring, remote security monitoring systems, intelligent transport systems, or any other wireless devices with or without a user interface. In the network 200, base station 204 provides network connectivity to a wider network (not shown) for UE 202. This UE 202 connectivity is provided via an air interface 208 within the base station service area provided by base station 204. In some embodiments, such a wider network may be a wide-area network operated by a cellular network provider, or it may be the Internet. Each base station service area associated with base station 204 is supported by an antenna integrated with base station 204. The service area is divided into several sectors associated with a particular antenna. Such sectors may be physically associated with a fixed antenna, or they may be assigned to physical areas using a tunable antenna or antenna configuration that can be adjusted in a beamforming process used to direct signals to a particular sector.

[0053] The UE202 includes a control circuit 210 coupled to a transmit circuit 212 and a receive circuit 214. Each of the transmit circuit 212 and the receive circuit 214 may be coupled to one or more antennas. The control circuit 210 may be adapted to perform operations associated with codec selection for communication and codec adaptation for wireless communication as part of system congestion control. The control circuit 210 may include various combinations of application-specific circuits and baseband circuits. The transmit circuit 212 and the receive circuit 214 may be adapted to transmit and receive data, respectively, and may include radio frequency (RF) circuits or front-end module (FEM) circuits, including communication using the codecs described herein.

[0054] In various embodiments, the transmitter circuit 212, the receiver circuit 214, and the control circuit 210 may be integrated in various ways to implement the circuits described herein. The control circuit 210 may be adapted or configured to perform various operations, such as those described elsewhere in this disclosure relating to the UE. The transmitter circuit 212 may transmit multiple multiplexed uplink physical channels. The multiple uplink physical channels may be multiplexed by time division multiplexing (TDM) or frequency division multiplexing (FDM) together with carrier aggregation. The transmitter circuit 212 may be configured to receive block data from the control circuit 210 for transmission over the air interface 208. Similarly, the receiver circuit 214 may receive multiple multiplexed downlink physical channels from the air interface 208 and relay the physical channels to the control circuit 210. The multiple downlink physical channels may be multiplexed by TDM or FDM together with carrier aggregation. The transmitting circuit 212 and the receiving circuit 214 can transmit and receive both control data and content data (e.g., messages, images, videos, etc.) structured within data blocks carried by the physical channel.

[0055] Figure 2 also shows a base station 204. In this embodiment, the base station 204 may be an NG radio access network (RAN), a 5G RAN, an E-UTRAN, a non-terrestrial cell, or a legacy RAN such as UTRAN or GERAN. As used herein, terms such as "NG RAN" may refer to a base station 204 operating on an NR or 5G radio network 200, and terms such as "E-UTRAN" may refer to a base station 204 operating on an LTE or 4G radio network 200. The UE 202 utilizes connections (or channels) 206A, 206B, each including a physical communication interface or layer.

[0056] The base station 204 circuit may include a control circuit 216 coupled to a transmitting circuit 218 and a receiving circuit 220. Each of the transmitting circuit 218 and the receiving circuit 220 may be coupled to one or more antennas that can be used to enable communication via the air interface 208.

[0057] The control circuit 216 may be adapted to perform operations to analyze and select a codec, manage congestion control and bandwidth limiting communications from the base station, determine whether the base station is codec-aware, and communicate with a codec-aware base station to manage codec selection for the various communication operations described herein. The transmit circuit 218 and the receive circuit 220 may be adapted to transmit and receive data to and from any UE connected to the base station 204 using data generated with the various codecs described herein. The transmit circuit 218 may transmit a downlink physical channel consisting of multiple downlink subframes. The receive circuit 220 may receive multiple uplink physical channels from various UEs, including UE 202.

[0058] In this example, one or more channels 206A, 206B are shown as air interfaces enabling a communicable coupling and can comply with cellular communication protocols such as GSM protocol, CDMA network protocol, PTT protocol, POC protocol, UMTS protocol, 3GPPLTE protocol, Advanced Long-Term Evolution (LTE-A) protocol, LTE-Based Access to Unlicensed Spectrum (LTE-U), 5G protocol, NR protocol, NR-Based Access to Unlicensed Spectrum (NR-U) protocol, and / or any other communication protocols described herein. In embodiments, UE202 may directly exchange communication data via a ProSe interface. The ProSe interface may alternatively be referred to as an SL interface and may include one or more logical channels, including but not limited to PSCCH, PSSCH, PSDCH, and PSBCH.

[0059] In some embodiments, the wireless network 200 is configured to use a new field called `deriveSSB-IndexFromCell-inter` in a measurement object associated with an adjacent cell (also called a target cell). In particular, this field can be used when the measurement object is for an SSB burst of the target cell, and the SSB burst or set contains one or more SSBs. Details of the SSB burst for measurement can be provided in `ssb-ToMeasure`. The `deriveSSB-IndexFromCell-inter` field indicates whether the UE 202 can derive the SSB indices of all adjacent cells on the frequency provided in the measurement object using the timing of the reference cell. In some examples, the reference cell is the serving cell of the UE 202 if the UE has only a serving cell. However, if the UE 202 has multiple serving cells, `deriveSSB-IndexFromCell-inter` (or another field in `ssb-ToMeasure`) indicates which of the serving cells should be used as the reference cell.

[0060] In some embodiments, the `deriveSSB-IndexFromCell-inter` field is a single bit that can be set to 0 or 1. In another example, the field is a Boolean data type that can be set to false or true. When the field is set to 1 or true, the UE202 assumes SFN and frame boundary alignment across cells on adjacent frequencies (as specified, for example, in TS 38.133).

[0061] In some embodiments, when the wireless network 200 enables deriveSSB-IndexFromCell-inter for UE 202, the UE assumes that the frame boundary alignment across cells on the same carrier (e.g., half-frame, subframe, and / or slot boundary alignment) is not worse than a tolerance Δt (i.e., within tolerance). Furthermore, the UE assumes that the SFNs of all cells on the same frequency carrier are the same.

[0062] In some embodiments, receiving `deriveSSB-IndexFromCell-inter` set to true in a measurement object for a target cell allows UE202 to derive the SSB index for the SSB burst broadcast of that target cell. In one example, if `deriveSSB-IndexFromCell-inter` is set to true, UE202 can determine a candidate location for SSB#0 in the target cell (even if no SSB is transmitted). More specifically, if `deriveSSB-IndexFromCell-inter` is set to true, UE202 can determine that the symbol boundary of SSB#0 in the target cell lies (Δt~Δt) within the frame boundary of SSB#0 in the reference cell. Once UE202 has determined a candidate location for SSB#0, UE can determine candidate locations for the remaining SSBs (if any) in the burst. UE202 can do this even if SSB#0 itself is not transmitted. In particular, the UE202 can use an SSB pattern (such as the one defined in Table 1) to determine candidate locations for any remaining SSBs during a burst.

[0063] In some embodiments, UE202 may determine the window for measuring the target SSB burst. The target SSB is comprised of the radio network 100 via the RRC "SSB-ToMeasure". SSB-ToMeasure indicates the set of SS blocks to be measured within the SMTC measurement duration (as described, for example, in TS 38.215). If no field exists, the UE measures on all SSBs. In one example, the window length for measuring each SSB is equal to the four SSB symbols of the target cell + 2*Δt. The total measurement window is the combination of all measurement windows for each SSB to be measured (as specified, for example, in SSB-ToMeasure).

[0064] In some embodiments, the UE202 may be configured using one or more methods for calculating the tolerance Δt. In one method, the tolerance is calculated using a predetermined formula. In one example, the tolerance is defined according to the following formula [1]: [1] Δt = min(2 SSB symbols in the reference cell, 1 PDSCH symbol in the reference cell) In this example, UE calculates Δt for all SSB pattern cases according to equation [1] (see, for example, Table 1). In another example, the tolerance is defined according to the following equation [2]. [2] Δt = 2 SSB symbols of the target cell.

[0065] Alternatively, UE202 receives network signaling that indicates to the UE an equation for calculating tolerances. In this method, UE202 receives signaling from wireless network 200 that indicates an equation (e.g., equation [1] or equation [2]) to be used to calculate Δt associated with a particular measurement object. Thus, wireless network 200 can specify different equations for different measurement objects. For example, wireless network 200 can specify that UE202 use equation [1] for measurement objects associated with a first adjacent cell and equation [2] for measurement objects associated with a second adjacent cell.

[0066] In yet another method, tolerances are determined based on the SSB pattern cases of the target cell and / or reference cell. The SSB pattern cases are shown in Table 1. In this method, a separate tolerance is defined for each SSB pattern case. However, there are SSB pattern cases associated with the reference cell and SSB pattern cases associated with the target cell. Therefore, to determine the tolerance of selection, UE202 selects one of the SSB pattern cases associated with the reference cell and one associated with the target cell. In one example, UE202 selects the SSB pattern case with the larger SCS of the two. Once UE202 has selected the SSB pattern case to use, UE202 selects the tolerance based on the selected pattern.

[0067] In some embodiments, SSB pattern cases containing consecutive candidate SSB locations are assigned the same individual tolerance. Such pattern cases include cases B, D, and E from Table 1. In one example, the tolerance is calculated using formula [3]. [3] Δt = 2 SSB symbols. In these embodiments, SSB pattern cases A and C from Table 1 are assigned the same individual tolerances. In one example, the tolerances are calculated using formula [4]. [4] Δt = 3 SSB symbols. In these embodiments, SSB pattern cases F and G from Table 1 are assigned the same individual tolerances. In one example, the tolerances are calculated using formula [5]. [5] Δt = 3.5 SSB symbols. In equations [3], [4], and [5], the symbol duration of the SSB symbol is determined by the larger SCS of the reference cell and the target cell.

[0068] In some embodiments, if the selected SSB pattern is case B or D from Table 1 and two consecutive SSBs are transmitted, the tolerance is calculated using formula [6]. [6] Δt = 6 SSB symbols. For example, a measurement object could include an instruction that the target cell is transmitting two consecutive SSBs.

[0069] Figure 3 shows an example 300 of deriving an SSB index according to several embodiments. In Example 300, a UE (not shown in Figure 3) is served by a serving cell 1 operating on carrier 2. The UE receives a measurement object that instructs the UE to measure an SSB burst of an adjacent cell 1 operating on carrier 1. The measurement object also contains a field, deriveSSB-IndexFromCell-inter, which is set to true. Thus, the UE assumes that the frame boundary alignment (including half-frame, subframe, and slot boundary alignment) across all adjacent cells on carrier 2 is within tolerance Δt. Thus, the UE can derive the SSB index of the target SSB burst broadcast by adjacent cell 1. In particular, the UE knows that SSB#0 is received within frame boundary tolerance Δt of the SSB scheduled by serving cell 1. Thus, if the UE measures an SSB within tolerance, the UE can determine that the measured SSB is SSB#0. In Example 300, the UE knows the candidate position of SSB#0. When the UE detects an SSB within the tolerance, as shown in Figure 3, the UE knows that the detected SSB is SSB#0. Furthermore, by knowing the location of SSB#0, the UE can derive the locations of the remaining SSBs (e.g., SSB#1, SSB#2, SSB#3).

[0070] Figure 4A shows a flowchart of exemplary Method 400 in several implementation forms. For clarity of presentation, the following description generally explains Method 400 in the context of other figures in this description. For example, Method 400 may be implemented by UE500 in Figure 5. It will be understood that Method 400 may be implemented as appropriate by any suitable system, environment, software, hardware, or combination of system, environment, software, and hardware, for example. In some implementation forms, the various steps of Method 400 may be performed in parallel, in combination, in a loop, or in any order.

[0071] In step 402, method 400 includes receiving a message from a serving cell serving the UE, which includes (i) synchronization signal block (SSB) information associated with a target SSB burst of the target cell, and (ii) a flag indicating that the UE is permitted to use the timing of a reference cell to derive an index of a target SSB burst, where the target SSB burst contains one or more SSBs.

[0072] In step 404, method 400 includes calculating the tolerance (Δt) of the frame boundary alignment between the reference cell and the target cell.

[0073] In 406, method 400 includes determining the index of the target SSB burst based on tolerances.

[0074] In some implementations, the SSB information includes the frequency of the target SSB burst and the subcarrier interval of the target SSB burst.

[0075] In some implementations, the method further includes measuring at least a portion of the target SSB burst during a measurement window based on at least one of tolerance (Δt) or SSB information.

[0076] In some implementations, measuring at least a portion of the target SSB burst based on tolerance (Δt) or at least a portion of the SSB information determines the time length of the measurement window.

number

[0077] In some implementations, determining the index of a target SSB burst includes determining a candidate position for a first SSB within the target SSB burst based on tolerances, and determining the index of the target SSB burst based on at least one of the candidate positions for the first SSB or a measured portion of the target SSB index.

[0078] In some implementations, calculating the tolerance (Δt) involves calculating the tolerance as Δt = min(two SSB symbols in the reference cell, one PDSCH symbol in the reference cell).

[0079] In some implementations, calculating the tolerance (Δt) involves calculating the tolerance as Δt = 2 SSB symbols of the target cell.

[0080] In some implementations, calculating the tolerance (Δt) involves receiving a signal indicating the formula to be used to calculate the tolerance, and then calculating the tolerance based on the signaled formula.

[0081] In some implementations, the signaled expression is one of the following: i) Δt = min(2 SSB symbols of the reference cell, 1 PDSCH symbol of the reference cell), and (ii) Δt = 2 SSB symbols of the target cell.

[0082] In some implementations, the tolerance includes a separate tolerance defined for each of several predetermined SSB pattern cases.

[0083] In some implementations, calculating the tolerance (Δt) involves determining a first SSB pattern case associated with the target cell and a second SSB pattern case associated with the reference cell, determining that the first SSB pattern has a larger subcarrier spacing than the second SSB pattern, and calculating the tolerance based on the individual tolerances associated with the first SSB pattern.

[0084] In some implementations, a set of predetermined SSB pattern cases includes the following: [Table 3]

[0085] In some implementations, the individual tolerances defined for Case B, Case D, or Case E are calculated as Δt = 2 SSB symbols.

[0086] In some implementations, the individual tolerances defined for case A or case C are calculated as Δt = 3 SSB symbols.

[0087] In some implementations, the individual tolerances defined for case F or case G are calculated as Δt = 3.5 SSB symbols.

[0088] In some implementations, separate tolerances are defined for case B or D, and if two consecutive SSBs are transmitted, Δt is calculated as 6 SSB symbols.

[0089] Figure 4B shows flowcharts of exemplary Method 420 in several implementation forms. For clarity of presentation, the following description generally explains Method 420 in the context of other figures in this description. For example, Method 420 may be implemented by the access node 600 in Figure 6. It will be understood that Method 420 may be implemented as appropriate by any suitable system, environment, software, hardware, or combination of system, environment, software, and hardware, for example. In some implementation forms, the various steps of Method 420 may be performed in parallel, in combination, in a loop, or in any order.

[0090] In step 422, method 420 includes generating a message for a user device (UE) served by a serving cell, which includes (i) synchronization signal block (SSB) information associated with a target SSB burst of a target cell, and (ii) a flag indicating that the UE is permitted to use the timing of a reference cell to derive an index of a target SSB burst, where the target SSB burst contains one or more SSBs.

[0091] In step 424, method 420 includes preparing a message for transmission to the UE.

[0092] In some implementations, the SSB information includes the frequency of the target SSB burst and the subcarrier interval of the target SSB burst.

[0093] In some implementations, this method further includes sending a message to the UE.

[0094] In some embodiments, a system, such as a base station or a device including one or more baseband processors, can be configured to perform a specific operation or action by installing software, firmware, hardware, or a combination thereof on the operating system and causing the system to perform that operation. The operation or action performed by the system may include methods 400, 420.

[0095] Figure 5 shows the UE500 in several embodiments. The UE500 is similar to the UE202 in Figure 2 and may be substantially interchangeable.

[0096] The UE500 may be any mobile or non-mobile computing device, such as mobile phones, computers, tablets, industrial wireless sensors (e.g., microphones, carbon dioxide sensors, barometric pressure sensors, moisture sensors, thermometers, motion sensors, accelerometers, laser scanners, fluid level sensors, inventory sensors, voltmeters / current meters, actuators, etc.), video surveillance / monitoring devices (e.g., cameras, video cameras, etc.), wearable devices (e.g., smartwatches), and relaxation-type IoT devices.

[0097] The UE500 may include a processor 502, an RF interface circuit 504, memory / storage 506, a user interface 508, a sensor 510, a driver circuit 512, a power management integrated circuit (PMIC) 514, an antenna structure 516, and a battery 518. The components of the UE500 may be implemented as an integrated circuit (IC), a part thereof, individual electronic devices, or other modules, logic, hardware, software, firmware, or a combination thereof. The block diagram in Figure 5 is intended to show a high-level diagram of some of the components of the UE500. However, some of the components shown may be omitted, additional components may be present, and different arrangements of the components shown may occur in other embodiments.

[0098] The components of the UE500 may be coupled to various other components via one or more interconnectors 520, and one or more interconnectors may represent any type of interface, input / output section, (local, system, or expansion) bus, transmission line, trace, optical connection, etc., that can cause various circuit components (on common or different chips or chipsets) to interact with each other.

[0099] The processor 502 may include, for example, a baseband processor circuit (BB) 522A, a central processing unit circuit (CPU) 522B, and a graphics processing unit circuit (GPU) 522C. The processor 502 may include any type of circuit or processor circuit that causes the UE 500 to perform the operations described herein by executing or otherwise operating computer executable instructions, such as program code, software modules, or functional processes, from the memory / storage 506.

[0100] In some embodiments, the baseband processor circuit 522A may access the communication protocol stack 524 in memory / storage 506 for communication over a 3GPP-compliant network. Generally, the baseband processor circuit 522A may access the communication protocol stack to perform user plane functions in the PHY layer, MAC layer, RLC layer, PDCP layer, SDAP layer, and PDU layer, and control plane functions in the PHY layer, MAC layer, RLC layer, PDCP layer, RRC layer, and non-access layer. In some embodiments, PHY layer operation may be additionally / alternatively performed by components of the RF interface circuit 504. The baseband processor circuit 522A may generate or process baseband signals or waveforms that carry information within a 3GPP-compliant network. In some embodiments, waveforms for NR may be based on cyclic prefix OFDM "CP-OFDM" in the uplink or downlink, and discrete Fourier transform spread OFDM "DFT-S-OFDM" in the uplink.

[0101] The memory / storage 506 may include one or more non-temporary computer-readable media (e.g., a communication protocol stack 524) containing instructions that can be executed by one or more processors 502 to cause the UE 500 to perform the various operations described herein. The memory / storage 506 includes any type of volatile or non-volatile memory that can be distributed throughout the UE 500. In some embodiments, some of the memory / storage 506 may be located within the processor 502 itself (e.g., L1 and L2 caches), while other memory / storage 506 may be outside the processor 502 but accessible via a memory interface. The memory / storage 506 may include, but is not limited to, volatile or non-volatile memory, such as dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory, or any other type of memory device technology.

[0102] The RF interface circuit 504 may include a transceiver circuit and a radio frequency front module (RFEM) that enable the UE500 to communicate with other devices via a wireless access network. The RF interface circuit 504 may include various elements located in the transmit or receive path. These elements may include, for example, switches, mixers, amplifiers, filters, combiner circuits, control circuits, and the like.

[0103] In the receiving path, the RFEM may receive the radiated signal from the air interface via the antenna structure 516 and proceed to filter and amplify the signal (using a low-noise amplifier). The signal may be supplied to the receiver of the transceiver, which downconverts the RF signal into a baseband signal provided to the baseband processor of the processor 502.

[0104] In the transmission path, the transmitter of the transceiver upconverts the baseband signal received from the baseband processor and provides the RF signal to the RFEM. The RFEM may amplify the RF signal through a power amplifier before the signal is radiated across the air interface via antenna 516.

[0105] In various embodiments, the RF interface circuit 504 may be configured to transmit and receive signals in accordance with NR access technology.

[0106] Antenna 516 may include antenna elements that convert electrical signals into radio waves and propagate them through the air, as well as antenna elements that convert received radio waves into electrical signals. Antenna elements may be arranged on one or more antenna panels. Antenna 516 may have antenna panels that are omnidirectional, directional, or a combination thereof to enable beamforming and multi-input multi-output communication. Antenna 516 may include microstrip antennas, printed antennas fabricated on the surface of one or more printed circuit boards, patch antennas, phased array antennas, and the like. Antenna 516 may have one or more panels designed for a specific frequency band, including the band in FR1 or FR2.

[0107] The user interface circuit 508 includes various input / output (I / O) devices designed to enable user interaction with the UE500. The user interface 508 includes input device circuits and output device circuits. The input device circuit configuration includes, among other things, any physical or virtual means for receiving input, including one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, a keypad, a mouse, a touchpad, a touchscreen, a microphone, a scanner, a headset, and so on. The output device circuit includes any physical or virtual means for displaying or otherwise transmitting information, such as sensor readings, actuator positions (one or more), or other similar information. The output device circuit may include any number or combination of audio or visual displays, including, in particular, one or more simple visual outputs / indicators (e.g., binary state indicators such as light-emitting diodes "LEDs" and multi-character visual outputs), or more complex outputs such as display devices or touchscreens (e.g., liquid crystal displays "LCDs", LED displays, quantum dot displays, projectors, etc.), and outputs such as characters, graphics, and multimedia objects are generated or created from the operation of the UE500.

[0108] Sensor 510 may include devices, modules, or subsystems intended to detect events or changes in the environment and transmit information about the detected events (sensor data) to some other device, module, subsystem, etc. Examples of such sensors include, in particular, inertial measurement units including accelerometers, gyroscopes, or magnetometers; micro-electromechanical systems or nano-electromechanical systems including 3-axis accelerometers, 3-axis gyroscopes, or magnetometers; level sensors; flow sensors; temperature sensors (e.g., thermistors); pressure sensors; barometric pressure sensors; gravimeters; altimeters; image capture devices (e.g., cameras or lensless apertures); light detection and distance measuring sensors, proximity sensors (e.g., infrared detectors, etc.), depth sensors, ambient light sensors, ultrasonic transceivers, microphones, or other similar audio capture devices.

[0109] The driver circuit configuration 512 may include software and hardware elements that operate to control specific devices that are built into, attached to, or otherwise communicatively coupled to the UE500. The driver circuit 512 may include individual drivers that enable other components to interact with or control various input / output (I / O) devices that may be present in or connected to the UE500. For example, the driver circuit 512 may include a display driver that controls and enables access to a display device, a touchscreen driver that controls and enables access to a touchscreen interface, a sensor driver that acquires sensor readings from the sensor circuit 528 and controls and enables access to the sensor circuit 528, a driver that acquires the actuator position of an electromechanical component or controls and enables access to an electromechanical component, a camera driver that controls and enables access to an embedded image capture device, and an audio driver that controls and enables access to one or more audio devices.

[0110] The PMIC514 can manage the power supplied to various components of the UE500. In particular, with respect to the processor 502, the PMIC514 can control power supply selection, voltage scaling, battery charging, or DC-DC conversion.

[0111] In some embodiments, the PMIC 514 may control, or otherwise be part of, various power-saving mechanisms of the UE 500, including the DRX discussed herein. The battery 518 may supply power to the UE 500, but in some examples, the UE 500 may be mounted and deployed in a fixed location or have a power source coupled to a power grid. The battery 518 may be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, etc. In some implementations, such as vehicle-based applications, the battery 518 may be a typical automotive lead-acid battery.

[0112] In some embodiments, one or more elements of the UE500 are configured to perform operations including receiving a message from a serving cell serving the UE that includes (i) synchronization signal block (SSB) information associated with a target SSB burst of a target cell, and (ii) a flag indicating that the UE is permitted to use the timing of a reference cell to derive an index of a target SSB burst, where the target SSB burst includes one or more SSBs; calculating a tolerance for frame boundary alignment between the reference cell and the target cell; and determining the index of the target SSB burst based on the tolerance.

[0113] Figure 6 shows an access node 600 (e.g., a base station or gNB) according to several embodiments. The access node 600 is similar to the base station 204 and may be substantially interchangeable. The access node 600 may include a processor 602, an RF interface circuit 604, a core network (CN) interface circuit 606, a memory / storage circuit 608, and an antenna structure 610.

[0114] The components of the access node 600 may be coupled with various other components via one or more interconnects 612. The processor 602, RF interface circuit 604, memory / storage circuit 608 (including the communication protocol stack 614), antenna structure 610, and interconnects 612 may be similar to elements of similar names illustrated and described with respect to Figure 5. For example, the processor 602 may include processor circuits such as a baseband processor circuit (BB) 616A, a central processing unit circuit (CPU) 616B, and a graphics processing unit (GPU) 616C.

[0115] The CN interface circuit 606 may provide connectivity to a core network, such as a fifth-generation core network (5GC), using a 5GC-compliant network interface protocol, such as the Carrier Ethernet protocol or some other suitable protocol. Network connectivity may be provided to and from the access node 600 via optical fiber or wireless backhaul. The CN interface circuit 606 may include one or more dedicated processors or FPGAs for communication using one or more of the protocols described above. In some implementations, the CN interface circuit 606 may include multiple controllers to provide connectivity to other networks using the same or different protocols.

[0116] As used herein, the terms “access node,” “access point,” etc., may refer to equipment that provides wireless baseband functionality for data connectivity and / or voice connectivity between a network and one or more users. These access nodes may be referred to as BS, gNB, RAN node, eNB, NodeBs, RSUs, TRxP, or TRP, and may include ground stations (e.g., ground access points) or satellite stations that provide coverage within a geographical area (e.g., a cell). As used herein, the terms “NG RAN node,” etc., may refer to an access node 600 operating on an NR or 5G system (e.g., a gNB), and the terms “E-UTRAN node,” etc., may refer to an access node 600 operating on an LTE or 4G system (e.g., an eNB). According to various embodiments, the access node 600 may be implemented as one or more dedicated physical devices, such as macrocell base stations and / or low-power (LP) base stations, for providing femtocells, picocells, or other similar cells that have a smaller coverage area, smaller user capacity, or higher bandwidth compared to macrocells.

[0117] In some embodiments, all or part of the access node 600 may be implemented as one or more software entities running on a server computer as part of a virtual network, which may be called CRAN and / or virtual baseband unit pool (vBBUP). In these embodiments, CRAN or vBBUP may implement RAN functional partitioning such as PDCP partitioning, where the RRC and PDCP layers are operated by CRAN / vBBUP and other L2 protocol entities are operated by the access node 600; MAC / PHY partitioning, where the RRC, PDCP, RLC, and MAC layers are operated by CRAN / vBBUP and the PHY layer is operated by the access node 600; or "lower PHY" partitioning, where the upper part of the RRC, PDCP, RLC, MAC, and PHY layers is operated by CRAN / vBBUP and the lower part of the PHY layer is operated by the access node 600.

[0118] In a V2X scenario, access node 600 may be or may operate as an RSU. The term “Road Side Unit” or “RSU” may refer to any traffic infrastructure entity used for V2X communication. An RSU may be implemented in or by a suitable RAN node or a stationary (or relatively stationary) UE, and an RSU implemented in or by a UE may be called a “UE-type RSU,” an RSU implemented in or by an eNB may be called an “eNB-type RSU,” an RSU implemented in or by a gNB may be called a “gNB-type RSU,” and so on.

[0119] In some embodiments, one or more elements of the access node 600 may be configured to perform operations including generating a message for a user equipment (UE) served by a serving cell, which includes (i) synchronous signal block (SSB) information related to a target SSB burst of a target cell, and (ii) a flag indicating that the UE is permitted to use the timing of a reference cell to derive an index of the target SSB burst, which is a target SSB burst and which includes one or more SSBs, and preparing the message for transmission to the UE.

[0120] For convenience, various components may be described in this specification as performing one or more tasks. Such descriptions should be interpreted as including the phrase “configured to perform.” Descriptions of components configured to perform one or more tasks are expressly intended not to be subject to the interpretation of § 112(f) of the U.S. Patent Act.

[0121] For one or more embodiments, at least one of the components shown in one or more of the aforementioned figures may be configured to perform one or more operations, techniques, processes, or methods as described in the following exemplary section. For example, the baseband circuit described above in relation to one or more of the aforementioned figures may be configured to operate according to one or more of the examples described below. As another example, a circuit associated with a UE, base station, network element, etc., as described above in relation to one or more of the aforementioned figures may be configured to operate according to one or more of the examples described below in the examples section.

[0122] Although the embodiments described above are described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art if the above disclosure is fully understood. The following claims are intended to be construed as encompassing all such variations and modifications.

[0123] It should be fully understood that the use of personally identifiable information should adhere to privacy policies and practices that are generally recognized as meeting or exceeding industry or government requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and handled in a manner that minimizes the risk of unintended or unauthorized access or use, and the nature of authorized use should be clearly indicated to the user.

Claims

1. User equipment (UE), The UE receives a message containing a flag indicating that it is permitted to use the timing of a reference cell to derive an SSB index for a target synchronization signal block (SSB) burst of the target cell, The aforementioned target SSB burst includes one or more SSBs, The aforementioned target cell is an inter-frequency target cell having a different frequency from the aforementioned reference cell, and it receives, In response to receiving the aforementioned message, The SSB index of the target SSB burst is determined based on the tolerance (Δt) of the frame boundary alignment between the reference cell and the target cell, Measuring at least a portion of the target SSB burst within a measurement window determined based on the tolerance (Δt), A UE configured to perform an action, including the following.

2. The aforementioned operation, The UE according to claim 1, further comprising determining the index of the target SSB burst based on the tolerance (Δt).

3. Calculating the aforementioned tolerance (Δt) is [Math 1] The UE according to claim 1, which includes calculating as follows.

4. The UE according to claim 1, wherein calculating the tolerance (Δt) includes calculating the tolerance (Δt) based on two SSB symbols of the target cell.

5. The aforementioned operation, The UE according to claim 1, further comprising determining that, in response to receiving the aforementioned message, the system frame number (SFN) is aligned across cells on the target carrier of the target cell.

6. The aforementioned operation, The UE according to claim 1, further comprising receiving an information element (IE) containing SSB information associated with the target SSB burst of the target cell.

7. The UE according to claim 6, wherein the SSB information includes at least one of the frequency of the target SSB burst and the subcarrier interval of the target SSB burst.

8. The UE according to claim 6, wherein the IE further includes the message.

9. Based on the tolerance (Δt), measuring at least a portion of the target SSB burst is possible. The time length of the measurement window [Math 2] The UE according to claim 1, which includes calculating as follows.

10. One or more processors of a user device (UE), wherein the one or more processors Receiving a message containing a flag indicating that the UE is permitted to use the timing of a reference cell to derive the synchronization signal block (SSB) index of an inter-frequency adjacent cell on the target carrier, wherein the target carrier is an inter-frequency target carrier having a different frequency from the reference cell, In response to receiving the aforementioned message, To determine that the frame boundary alignment across the reference cell and the inter-frequency adjacent cells on the target carrier is within a tolerance no worse than the calculated tolerance, Measuring at least a portion of the target SSB burst within a measurement window determined based on the calculated tolerance, One or more processors configured to perform an operation, including [the specified operation].

11. Based on the calculated tolerance, determine the index of the target SSB burst on the target carrier. One or more processors according to claim 10, further comprising:

12. The calculated tolerance is, [Math 3] One or more processors according to claim 10, which are calculated as follows:

13. The one or more processors according to claim 10, wherein the calculated tolerance is calculated based on two SSB symbols of the target carrier.

14. The aforementioned operation, One or more processors according to claim 10, further comprising determining that the system frame numbers (SFNs) of the inter-frequency adjacent cells on the target carrier are the same in response to receiving the message.

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